diff --git a/sys/kern/subr_module.c b/sys/kern/subr_module.c index 92f22206f8cf..b2d723fef038 100644 --- a/sys/kern/subr_module.c +++ b/sys/kern/subr_module.c @@ -1,609 +1,629 @@ /*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 1998 Michael Smith * All rights reserved. * Copyright (c) 2020 NetApp Inc. * Copyright (c) 2020 Klara Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ +#include +#include "opt_ddb.h" + #include #include #include #include #include #include #include #include +#ifdef DDB +#include +#endif + /* * Preloaded module support */ vm_offset_t preload_addr_relocate = 0; caddr_t preload_metadata, preload_kmdp; const char preload_modtype[] = MODTYPE; const char preload_kerntype[] = KERNTYPE; const char preload_modtype_obj[] = MODTYPE_OBJ; void preload_initkmdp(bool fatal) { preload_kmdp = preload_search_by_type(preload_kerntype); if (preload_kmdp == NULL && fatal) panic("unable to find kernel metadata"); } /* * Search for the preloaded module (name) */ caddr_t preload_search_by_name(const char *name) { caddr_t curp; uint32_t *hdr; int next; if (preload_metadata != NULL) { curp = preload_metadata; for (;;) { hdr = (uint32_t *)curp; if (hdr[0] == 0 && hdr[1] == 0) break; /* Search for a MODINFO_NAME field */ if ((hdr[0] == MODINFO_NAME) && !strcmp(name, curp + sizeof(uint32_t) * 2)) return(curp); /* skip to next field */ next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } } return(NULL); } /* * Search for the first preloaded module of (type) */ caddr_t preload_search_by_type(const char *type) { caddr_t curp, lname; uint32_t *hdr; int next; if (preload_metadata != NULL) { curp = preload_metadata; lname = NULL; for (;;) { hdr = (uint32_t *)curp; if (hdr[0] == 0 && hdr[1] == 0) break; /* remember the start of each record */ if (hdr[0] == MODINFO_NAME) lname = curp; /* Search for a MODINFO_TYPE field */ if ((hdr[0] == MODINFO_TYPE) && !strcmp(type, curp + sizeof(uint32_t) * 2)) return(lname); /* skip to next field */ next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } } return(NULL); } /* * Walk through the preloaded module list */ caddr_t preload_search_next_name(caddr_t base) { caddr_t curp; uint32_t *hdr; int next; if (preload_metadata != NULL) { /* Pick up where we left off last time */ if (base) { /* skip to next field */ curp = base; hdr = (uint32_t *)curp; next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } else curp = preload_metadata; for (;;) { hdr = (uint32_t *)curp; if (hdr[0] == 0 && hdr[1] == 0) break; /* Found a new record? */ if (hdr[0] == MODINFO_NAME) return curp; /* skip to next field */ next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } } return(NULL); } /* * Given a preloaded module handle (mod), return a pointer * to the data for the attribute (inf). */ caddr_t preload_search_info(caddr_t mod, int inf) { caddr_t curp; uint32_t *hdr; uint32_t type = 0; int next; if (mod == NULL) return (NULL); curp = mod; for (;;) { hdr = (uint32_t *)curp; /* end of module data? */ if (hdr[0] == 0 && hdr[1] == 0) break; /* * We give up once we've looped back to what we were looking at * first - this should normally be a MODINFO_NAME field. */ if (type == 0) { type = hdr[0]; } else { if (hdr[0] == type) break; } /* * Attribute match? Return pointer to data. * Consumer may safely assume that size value precedes * data. */ if (hdr[0] == inf) return(curp + (sizeof(uint32_t) * 2)); /* skip to next field */ next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } return(NULL); } /* * Delete a preload record by name. */ void preload_delete_name(const char *name) { caddr_t addr, curp; uint32_t *hdr, sz; int next; int clearing; addr = 0; sz = 0; if (preload_metadata != NULL) { clearing = 0; curp = preload_metadata; for (;;) { hdr = (uint32_t *)curp; if (hdr[0] == MODINFO_NAME || (hdr[0] == 0 && hdr[1] == 0)) { /* Free memory used to store the file. */ if (addr != 0 && sz != 0) kmem_bootstrap_free((vm_offset_t)addr, sz); addr = 0; sz = 0; if (hdr[0] == 0) break; if (!strcmp(name, curp + sizeof(uint32_t) * 2)) clearing = 1; /* got it, start clearing */ else if (clearing) { clearing = 0; /* at next one now.. better stop */ } } if (clearing) { if (hdr[0] == MODINFO_ADDR) addr = *(caddr_t *)(curp + sizeof(uint32_t) * 2); else if (hdr[0] == MODINFO_SIZE) sz = *(uint32_t *)(curp + sizeof(uint32_t) * 2); hdr[0] = MODINFO_EMPTY; } /* skip to next field */ next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } } } void * preload_fetch_addr(caddr_t mod) { caddr_t *mdp; mdp = (caddr_t *)preload_search_info(mod, MODINFO_ADDR); if (mdp == NULL) return (NULL); return (*mdp + preload_addr_relocate); } size_t preload_fetch_size(caddr_t mod) { size_t *mdp; mdp = (size_t *)preload_search_info(mod, MODINFO_SIZE); if (mdp == NULL) return (0); return (*mdp); } /* Called from locore. Convert physical pointers to kvm. Sigh. */ void preload_bootstrap_relocate(vm_offset_t offset) { caddr_t curp; uint32_t *hdr; vm_offset_t *ptr; int next; if (preload_metadata != NULL) { curp = preload_metadata; for (;;) { hdr = (uint32_t *)curp; if (hdr[0] == 0 && hdr[1] == 0) break; /* Deal with the ones that we know we have to fix */ switch (hdr[0]) { case MODINFO_ADDR: case MODINFO_METADATA|MODINFOMD_FONT: case MODINFO_METADATA|MODINFOMD_SPLASH: case MODINFO_METADATA|MODINFOMD_SHTDWNSPLASH: case MODINFO_METADATA|MODINFOMD_SSYM: case MODINFO_METADATA|MODINFOMD_ESYM: ptr = (vm_offset_t *)(curp + (sizeof(uint32_t) * 2)); *ptr += offset; break; } /* The rest is beyond us for now */ /* skip to next field */ next = sizeof(uint32_t) * 2 + hdr[1]; next = roundup(next, sizeof(u_long)); curp += next; } } } /* * Parse the modinfo type and append to the provided sbuf. */ static void preload_modinfo_type(struct sbuf *sbp, int type) { if ((type & MODINFO_METADATA) == 0) { switch (type) { case MODINFO_END: sbuf_cat(sbp, "MODINFO_END"); break; case MODINFO_NAME: sbuf_cat(sbp, "MODINFO_NAME"); break; case MODINFO_TYPE: sbuf_cat(sbp, "MODINFO_TYPE"); break; case MODINFO_ADDR: sbuf_cat(sbp, "MODINFO_ADDR"); break; case MODINFO_SIZE: sbuf_cat(sbp, "MODINFO_SIZE"); break; case MODINFO_EMPTY: sbuf_cat(sbp, "MODINFO_EMPTY"); break; case MODINFO_ARGS: sbuf_cat(sbp, "MODINFO_ARGS"); break; default: sbuf_cat(sbp, "unrecognized modinfo attribute"); } return; } sbuf_cat(sbp, "MODINFO_METADATA | "); switch (type & ~MODINFO_METADATA) { case MODINFOMD_ELFHDR: sbuf_cat(sbp, "MODINFOMD_ELFHDR"); break; case MODINFOMD_SSYM: sbuf_cat(sbp, "MODINFOMD_SSYM"); break; case MODINFOMD_ESYM: sbuf_cat(sbp, "MODINFOMD_ESYM"); break; case MODINFOMD_DYNAMIC: sbuf_cat(sbp, "MODINFOMD_DYNAMIC"); break; case MODINFOMD_ENVP: sbuf_cat(sbp, "MODINFOMD_ENVP"); break; case MODINFOMD_HOWTO: sbuf_cat(sbp, "MODINFOMD_HOWTO"); break; case MODINFOMD_KERNEND: sbuf_cat(sbp, "MODINFOMD_KERNEND"); break; case MODINFOMD_SHDR: sbuf_cat(sbp, "MODINFOMD_SHDR"); break; case MODINFOMD_CTORS_ADDR: sbuf_cat(sbp, "MODINFOMD_CTORS_ADDR"); break; case MODINFOMD_CTORS_SIZE: sbuf_cat(sbp, "MODINFOMD_CTORS_SIZE"); break; case MODINFOMD_FW_HANDLE: sbuf_cat(sbp, "MODINFOMD_FW_HANDLE"); break; case MODINFOMD_KEYBUF: sbuf_cat(sbp, "MODINFOMD_KEYBUF"); break; #ifdef MODINFOMD_SMAP case MODINFOMD_SMAP: sbuf_cat(sbp, "MODINFOMD_SMAP"); break; #endif #ifdef MODINFOMD_SMAP_XATTR case MODINFOMD_SMAP_XATTR: sbuf_cat(sbp, "MODINFOMD_SMAP_XATTR"); break; #endif #ifdef MODINFOMD_DTBP case MODINFOMD_DTBP: sbuf_cat(sbp, "MODINFOMD_DTBP"); break; #endif #ifdef MODINFOMD_EFI_MAP case MODINFOMD_EFI_MAP: sbuf_cat(sbp, "MODINFOMD_EFI_MAP"); break; #endif #ifdef MODINFOMD_EFI_FB case MODINFOMD_EFI_FB: sbuf_cat(sbp, "MODINFOMD_EFI_FB"); break; #endif #ifdef MODINFOMD_MODULEP case MODINFOMD_MODULEP: sbuf_cat(sbp, "MODINFOMD_MODULEP"); break; #endif #ifdef MODINFOMD_VBE_FB case MODINFOMD_VBE_FB: sbuf_cat(sbp, "MODINFOMD_VBE_FB"); break; #endif case MODINFOMD_FONT: sbuf_cat(sbp, "MODINFOMD_FONT"); break; case MODINFOMD_SPLASH: sbuf_cat(sbp, "MODINFOMD_SPLASH"); break; case MODINFOMD_SHTDWNSPLASH: sbuf_cat(sbp, "MODINFOMD_SHTDWNSPLASH"); break; #ifdef MODINFOMD_BOOT_HARTID case MODINFOMD_BOOT_HARTID: sbuf_cat(sbp, "MODINFOMD_BOOT_HARTID"); break; #endif #ifdef MODINFOMD_EFI_ARCH case MODINFOMD_EFI_ARCH: sbuf_cat(sbp, "MODINFOMD_EFI_ARCH"); break; #endif default: sbuf_cat(sbp, "unrecognized metadata type"); } } /* * Print the modinfo value, depending on type. */ static void preload_modinfo_value(struct sbuf *sbp, uint32_t *bptr, int type, int len) { #ifdef __LP64__ #define sbuf_print_vmoffset(sb, o) sbuf_printf(sb, "0x%016lx", o); #else #define sbuf_print_vmoffset(sb, o) sbuf_printf(sb, "0x%08x", o); #endif switch (type) { case MODINFO_NAME: case MODINFO_TYPE: case MODINFO_ARGS: #ifdef MODINFOMD_EFI_ARCH case MODINFO_METADATA | MODINFOMD_EFI_ARCH: #endif sbuf_printf(sbp, "%s", (char *)bptr); break; case MODINFO_SIZE: case MODINFO_METADATA | MODINFOMD_CTORS_SIZE: sbuf_printf(sbp, "%lu", *(u_long *)bptr); break; case MODINFO_ADDR: case MODINFO_METADATA | MODINFOMD_SSYM: case MODINFO_METADATA | MODINFOMD_ESYM: case MODINFO_METADATA | MODINFOMD_DYNAMIC: case MODINFO_METADATA | MODINFOMD_KERNEND: case MODINFO_METADATA | MODINFOMD_ENVP: case MODINFO_METADATA | MODINFOMD_CTORS_ADDR: #ifdef MODINFOMD_SMAP case MODINFO_METADATA | MODINFOMD_SMAP: #endif #ifdef MODINFOMD_SMAP_XATTR case MODINFO_METADATA | MODINFOMD_SMAP_XATTR: #endif #ifdef MODINFOMD_DTBP case MODINFO_METADATA | MODINFOMD_DTBP: #endif #ifdef MODINFOMD_EFI_FB case MODINFO_METADATA | MODINFOMD_EFI_FB: #endif #ifdef MODINFOMD_VBE_FB case MODINFO_METADATA | MODINFOMD_VBE_FB: #endif case MODINFO_METADATA | MODINFOMD_FONT: case MODINFO_METADATA | MODINFOMD_SPLASH: case MODINFO_METADATA | MODINFOMD_SHTDWNSPLASH: sbuf_print_vmoffset(sbp, *(vm_offset_t *)bptr); break; case MODINFO_METADATA | MODINFOMD_HOWTO: sbuf_printf(sbp, "0x%08x", *bptr); break; #ifdef MODINFOMD_BOOT_HARTID case MODINFO_METADATA | MODINFOMD_BOOT_HARTID: sbuf_printf(sbp, "0x%lu", *(uint64_t *)bptr); break; #endif case MODINFO_METADATA | MODINFOMD_SHDR: case MODINFO_METADATA | MODINFOMD_ELFHDR: case MODINFO_METADATA | MODINFOMD_FW_HANDLE: case MODINFO_METADATA | MODINFOMD_KEYBUF: #ifdef MODINFOMD_EFI_MAP case MODINFO_METADATA | MODINFOMD_EFI_MAP: #endif /* Don't print data buffers. */ sbuf_cat(sbp, "buffer contents omitted"); break; default: break; } #undef sbuf_print_vmoffset } static void preload_dump_internal(struct sbuf *sbp) { uint32_t *bptr, type, len; KASSERT(preload_metadata != NULL, ("%s called without setting up preload_metadata", __func__)); /* * Iterate through the TLV-encoded sections. */ bptr = (uint32_t *)preload_metadata; sbuf_putc(sbp, '\n'); while (bptr[0] != MODINFO_END || bptr[1] != MODINFO_END) { sbuf_printf(sbp, " %p:\n", bptr); type = *bptr++; len = *bptr++; sbuf_printf(sbp, "\ttype:\t(%#04x) ", type); preload_modinfo_type(sbp, type); sbuf_putc(sbp, '\n'); sbuf_printf(sbp, "\tlen:\t%u\n", len); sbuf_cat(sbp, "\tvalue:\t"); preload_modinfo_value(sbp, bptr, type, len); sbuf_putc(sbp, '\n'); bptr += roundup(len, sizeof(u_long)) / sizeof(uint32_t); } } /* * Print the preloaded data to the console. Called from the machine-dependent * initialization routines, e.g. hammer_time(). */ void preload_dump(void) { char buf[512]; struct sbuf sb; /* * This function is expected to be called before malloc is available, * so use a static buffer and struct sbuf. */ sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN); sbuf_set_drain(&sb, sbuf_printf_drain, NULL); preload_dump_internal(&sb); sbuf_finish(&sb); sbuf_delete(&sb); } static int sysctl_preload_dump(SYSCTL_HANDLER_ARGS) { struct sbuf sb; int error; if (preload_metadata == NULL) return (EINVAL); sbuf_new_for_sysctl(&sb, NULL, 512, req); preload_dump_internal(&sb); error = sbuf_finish(&sb); sbuf_delete(&sb); return (error); } SYSCTL_PROC(_debug, OID_AUTO, dump_modinfo, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_preload_dump, "A", "pretty-print the bootloader metadata"); + +#ifdef DDB +DB_SHOW_COMMAND_FLAGS(preload, db_show_preload, DB_CMD_MEMSAFE) +{ + struct sbuf sb; + char buffer[128]; + + sbuf_new(&sb, buffer, sizeof(buffer), SBUF_FIXEDLEN); + sbuf_set_drain(&sb, sbuf_db_printf_drain, NULL); + preload_dump_internal(&sb); + sbuf_finish(&sb); +} +#endif diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c index bbf81b7a4ffe..35b5ee8ccdc8 100644 --- a/sys/kern/subr_prf.c +++ b/sys/kern/subr_prf.c @@ -1,1360 +1,1369 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1986, 1988, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #ifdef _KERNEL #include "opt_ddb.h" #include "opt_printf.h" #endif /* _KERNEL */ #include #ifdef _KERNEL #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #else /* !_KERNEL */ #include #endif #include #include #ifdef DDB #include #endif #ifdef _KERNEL #include #else #include #endif /* * This is needed for sbuf_putbuf() when compiled into userland. Due to the * shared nature of this file, it's the only place to put it. */ #ifndef _KERNEL #include #endif #ifdef _KERNEL #define TOCONS 0x01 #define TOTTY 0x02 #define TOLOG 0x04 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */ #define MAXNBUF (sizeof(intmax_t) * NBBY + 1) struct putchar_arg { int flags; int pri; struct tty *tty; char *p_bufr; size_t n_bufr; char *p_next; size_t remain; }; struct snprintf_arg { char *str; size_t remain; }; extern int log_open; extern int cn_mute; static void msglogchar(int c, int pri); static void msglogstr(char *str, int pri, int filter_cr); static void prf_putbuf(char *bufr, int flags, int pri); static void putchar(int ch, void *arg); static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len, int upper); static void snprintf_func(int ch, void *arg); static bool msgbufmapped; /* Set when safe to use msgbuf */ int msgbuftrigger; struct msgbuf *msgbufp; #ifndef BOOT_TAG_SZ #define BOOT_TAG_SZ 32 #endif #ifndef BOOT_TAG /* Tag used to mark the start of a boot in dmesg */ #define BOOT_TAG "---<>---" #endif static char current_boot_tag[BOOT_TAG_SZ + 1] = BOOT_TAG; SYSCTL_STRING(_kern, OID_AUTO, boot_tag, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, current_boot_tag, 0, "Tag added to dmesg at start of boot"); static int log_console_output = 1; SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RWTUN, &log_console_output, 0, "Duplicate console output to the syslog"); /* * See the comment in log_console() below for more explanation of this. */ static int log_console_add_linefeed; SYSCTL_INT(_kern, OID_AUTO, log_console_add_linefeed, CTLFLAG_RWTUN, &log_console_add_linefeed, 0, "log_console() adds extra newlines"); static int always_console_output; SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RWTUN, &always_console_output, 0, "Always output to console despite TIOCCONS"); /* * Warn that a system table is full. */ void tablefull(const char *tab) { log(LOG_ERR, "%s: table is full\n", tab); } /* * Uprintf prints to the controlling terminal for the current process. */ int uprintf(const char *fmt, ...) { va_list ap; struct putchar_arg pca; struct proc *p; struct thread *td; int retval; td = curthread; if (TD_IS_IDLETHREAD(td)) return (0); if (td->td_proc == initproc) { /* Produce output when we fail to load /sbin/init: */ va_start(ap, fmt); retval = vprintf(fmt, ap); va_end(ap); return (retval); } sx_slock(&proctree_lock); p = td->td_proc; PROC_LOCK(p); if ((p->p_flag & P_CONTROLT) == 0) { PROC_UNLOCK(p); sx_sunlock(&proctree_lock); return (0); } SESS_LOCK(p->p_session); pca.tty = p->p_session->s_ttyp; SESS_UNLOCK(p->p_session); PROC_UNLOCK(p); if (pca.tty == NULL) { sx_sunlock(&proctree_lock); return (0); } pca.flags = TOTTY; pca.p_bufr = NULL; va_start(ap, fmt); tty_lock(pca.tty); sx_sunlock(&proctree_lock); retval = kvprintf(fmt, putchar, &pca, 10, ap); tty_unlock(pca.tty); va_end(ap); return (retval); } /* * tprintf and vtprintf print on the controlling terminal associated with the * given session, possibly to the log as well. */ void tprintf(struct proc *p, int pri, const char *fmt, ...) { va_list ap; va_start(ap, fmt); vtprintf(p, pri, fmt, ap); va_end(ap); } void vtprintf(struct proc *p, int pri, const char *fmt, va_list ap) { struct tty *tp = NULL; int flags = 0; struct putchar_arg pca; struct session *sess = NULL; sx_slock(&proctree_lock); if (pri != -1) flags |= TOLOG; if (p != NULL) { PROC_LOCK(p); if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) { sess = p->p_session; sess_hold(sess); PROC_UNLOCK(p); tp = sess->s_ttyp; if (tp != NULL && tty_checkoutq(tp)) flags |= TOTTY; else tp = NULL; } else PROC_UNLOCK(p); } pca.pri = pri; pca.tty = tp; pca.flags = flags; pca.p_bufr = NULL; if (pca.tty != NULL) tty_lock(pca.tty); sx_sunlock(&proctree_lock); kvprintf(fmt, putchar, &pca, 10, ap); if (pca.tty != NULL) tty_unlock(pca.tty); if (sess != NULL) sess_release(sess); msgbuftrigger = 1; } static int _vprintf(int level, int flags, const char *fmt, va_list ap) { struct putchar_arg pca; int retval; #ifdef PRINTF_BUFR_SIZE char bufr[PRINTF_BUFR_SIZE]; #endif TSENTER(); pca.tty = NULL; pca.pri = level; pca.flags = flags; #ifdef PRINTF_BUFR_SIZE pca.p_bufr = bufr; pca.p_next = pca.p_bufr; pca.n_bufr = sizeof(bufr); pca.remain = sizeof(bufr); *pca.p_next = '\0'; #else /* Don't buffer console output. */ pca.p_bufr = NULL; #endif retval = kvprintf(fmt, putchar, &pca, 10, ap); #ifdef PRINTF_BUFR_SIZE /* Write any buffered console/log output: */ if (*pca.p_bufr != '\0') prf_putbuf(pca.p_bufr, flags, level); #endif TSEXIT(); return (retval); } /* * Log writes to the log buffer, and guarantees not to sleep (so can be * called by interrupt routines). If there is no process reading the * log yet, it writes to the console also. */ void log(int level, const char *fmt, ...) { va_list ap; va_start(ap, fmt); vlog(level, fmt, ap); va_end(ap); } void vlog(int level, const char *fmt, va_list ap) { (void)_vprintf(level, log_open ? TOLOG : TOCONS | TOLOG, fmt, ap); msgbuftrigger = 1; } #define CONSCHUNK 128 void log_console(struct uio *uio) { int c, error, nl; char *consbuffer; int pri; if (!log_console_output) return; pri = LOG_INFO | LOG_CONSOLE; uio = cloneuio(uio); consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK); nl = 0; while (uio->uio_resid > 0) { c = imin(uio->uio_resid, CONSCHUNK - 1); error = uiomove(consbuffer, c, uio); if (error != 0) break; /* Make sure we're NUL-terminated */ consbuffer[c] = '\0'; if (consbuffer[c - 1] == '\n') nl = 1; else nl = 0; msglogstr(consbuffer, pri, /*filter_cr*/ 1); } /* * The previous behavior in log_console() is preserved when * log_console_add_linefeed is non-zero. For that behavior, if an * individual console write came in that was not terminated with a * line feed, it would add a line feed. * * This results in different data in the message buffer than * appears on the system console (which doesn't add extra line feed * characters). * * A number of programs and rc scripts write a line feed, or a period * and a line feed when they have completed their operation. On * the console, this looks seamless, but when displayed with * 'dmesg -a', you wind up with output that looks like this: * * Updating motd: * . * * On the console, it looks like this: * Updating motd:. * * We could add logic to detect that situation, or just not insert * the extra newlines. Set the kern.log_console_add_linefeed * sysctl/tunable variable to get the old behavior. */ if (!nl && log_console_add_linefeed) { consbuffer[0] = '\n'; consbuffer[1] = '\0'; msglogstr(consbuffer, pri, /*filter_cr*/ 1); } msgbuftrigger = 1; freeuio(uio); free(consbuffer, M_TEMP); } int printf(const char *fmt, ...) { va_list ap; int retval; va_start(ap, fmt); retval = vprintf(fmt, ap); va_end(ap); return (retval); } int vprintf(const char *fmt, va_list ap) { int retval; retval = _vprintf(-1, TOCONS | TOLOG, fmt, ap); if (!KERNEL_PANICKED()) msgbuftrigger = 1; return (retval); } static void prf_putchar(int c, int flags, int pri) { if (flags & TOLOG) { msglogchar(c, pri); msgbuftrigger = 1; } if ((flags & TOCONS) && !cn_mute) { if ((!KERNEL_PANICKED()) && (constty != NULL)) msgbuf_addchar(&consmsgbuf, c); if ((constty == NULL) || always_console_output) cnputc(c); } } static void prf_putbuf(char *bufr, int flags, int pri) { if (flags & TOLOG) { msglogstr(bufr, pri, /*filter_cr*/1); msgbuftrigger = 1; } if ((flags & TOCONS) && !cn_mute) { if ((!KERNEL_PANICKED()) && (constty != NULL)) msgbuf_addstr(&consmsgbuf, -1, bufr, /*filter_cr*/ 0); if ((constty == NULL) || always_console_output) cnputs(bufr); } } static void putbuf(int c, struct putchar_arg *ap) { /* Check if no console output buffer was provided. */ if (ap->p_bufr == NULL) { prf_putchar(c, ap->flags, ap->pri); } else { /* Buffer the character: */ *ap->p_next++ = c; ap->remain--; /* Always leave the buffer zero terminated. */ *ap->p_next = '\0'; /* Check if the buffer needs to be flushed. */ if (ap->remain == 2 || c == '\n') { prf_putbuf(ap->p_bufr, ap->flags, ap->pri); ap->p_next = ap->p_bufr; ap->remain = ap->n_bufr; *ap->p_next = '\0'; } /* * Since we fill the buffer up one character at a time, * this should not happen. We should always catch it when * ap->remain == 2 (if not sooner due to a newline), flush * the buffer and move on. One way this could happen is * if someone sets PRINTF_BUFR_SIZE to 1 or something * similarly silly. */ KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd", ap->remain)); } } /* * Print a character on console or users terminal. If destination is * the console then the last bunch of characters are saved in msgbuf for * inspection later. */ static void putchar(int c, void *arg) { struct putchar_arg *ap = (struct putchar_arg*) arg; struct tty *tp = ap->tty; int flags = ap->flags; /* Don't use the tty code after a panic or while in ddb. */ if (kdb_active) { if (c != '\0') cnputc(c); return; } if ((flags & TOTTY) && tp != NULL && !KERNEL_PANICKED()) tty_putchar(tp, c); if ((flags & TOCONS) && cn_mute) { flags &= ~TOCONS; ap->flags = flags; } if ((flags & (TOCONS | TOLOG)) && c != '\0') putbuf(c, ap); } /* * Scaled down version of sprintf(3). */ int sprintf(char *buf, const char *cfmt, ...) { int retval; va_list ap; va_start(ap, cfmt); retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); buf[retval] = '\0'; va_end(ap); return (retval); } /* * Scaled down version of vsprintf(3). */ int vsprintf(char *buf, const char *cfmt, va_list ap) { int retval; retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); buf[retval] = '\0'; return (retval); } /* * Scaled down version of snprintf(3). */ int snprintf(char *str, size_t size, const char *format, ...) { int retval; va_list ap; va_start(ap, format); retval = vsnprintf(str, size, format, ap); va_end(ap); return(retval); } /* * Scaled down version of vsnprintf(3). */ int vsnprintf(char *str, size_t size, const char *format, va_list ap) { struct snprintf_arg info; int retval; info.str = str; info.remain = size; retval = kvprintf(format, snprintf_func, &info, 10, ap); if (info.remain >= 1) *info.str++ = '\0'; return (retval); } /* * Kernel version which takes radix argument vsnprintf(3). */ int vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap) { struct snprintf_arg info; int retval; info.str = str; info.remain = size; retval = kvprintf(format, snprintf_func, &info, radix, ap); if (info.remain >= 1) *info.str++ = '\0'; return (retval); } static void snprintf_func(int ch, void *arg) { struct snprintf_arg *const info = arg; if (info->remain >= 2) { *info->str++ = ch; info->remain--; } } /* * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse * order; return an optional length and a pointer to the last character * written in the buffer (i.e., the first character of the string). * The buffer pointed to by `nbuf' must have length >= MAXNBUF. */ static char * ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper) { char *p, c; p = nbuf; *p = '\0'; do { c = hex2ascii(num % base); *++p = upper ? toupper(c) : c; } while (num /= base); if (lenp) *lenp = p - nbuf; return (p); } static inline bool isbitpos(char c) { return (c != '\0' && (c <= ' ' || (c & 0x80) != 0)); } static inline bool isprintnospace(char c) { return (isprint(c) && c != ' '); } /* * Scaled down version of printf(3). * * Two additional formats: * * The format %b is supported to decode error registers. * Its usage is: * * printf("reg=%b\n", regval, "*"); * * where is the output base expressed as a control character, e.g. * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, * the first of which gives the bit number to be inspected and the next * characters (up to the bit number of the next argument or a final NUL * character), give the name of the register. * The bit number can be encoded as a character between 1 and 32 or as a * character between 128 and 255. * Thus: * * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE"); * * would produce output: * * reg=3 * * The same output would be generated by using: * * kvprintf("reg=%b\n", 3, "\10\201BITTWO\200BITONE"); * * XXX: %D -- Hexdump, takes pointer and separator string: * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX * ("%*D", len, ptr, " " -> XX XX XX XX ... */ int kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap) { #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } char nbuf[MAXNBUF]; char *d; const char *p, *percent, *q; u_char *up; int ch, n, sign; uintmax_t num; int base, lflag, qflag, tmp, width, ladjust, sharpflag, dot; int cflag, hflag, jflag, tflag, zflag; int bconv, dwidth, upper; char padc; int stop = 0, retval = 0; num = 0; q = NULL; if (!func) d = (char *) arg; else d = NULL; if (fmt == NULL) fmt = "(fmt null)\n"; if (radix < 2 || radix > 36) radix = 10; for (;;) { padc = ' '; width = 0; while ((ch = (u_char)*fmt++) != '%' || stop) { if (ch == '\0') return (retval); PCHAR(ch); } percent = fmt - 1; qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; sign = 0; dot = 0; bconv = 0; dwidth = 0; upper = 0; cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0; reswitch: switch (ch = (u_char)*fmt++) { case '.': dot = 1; goto reswitch; case '#': sharpflag = 1; goto reswitch; case '+': sign = '+'; goto reswitch; case '-': ladjust = 1; goto reswitch; case '%': PCHAR(ch); break; case '*': if (!dot) { width = va_arg(ap, int); if (width < 0) { ladjust = !ladjust; width = -width; } } else { dwidth = va_arg(ap, int); } goto reswitch; case '0': if (!dot) { padc = '0'; goto reswitch; } /* FALLTHROUGH */ case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': for (n = 0;; ++fmt) { n = n * 10 + ch - '0'; ch = *fmt; if (ch < '0' || ch > '9') break; } if (dot) dwidth = n; else width = n; goto reswitch; case 'b': ladjust = 1; bconv = 1; goto handle_nosign; case 'c': width -= 1; if (!ladjust && width > 0) while (width--) PCHAR(padc); PCHAR(va_arg(ap, int)); if (ladjust && width > 0) while (width--) PCHAR(padc); break; case 'D': up = va_arg(ap, u_char *); p = va_arg(ap, char *); if (!width) width = 16; while(width--) { PCHAR(hex2ascii(*up >> 4)); PCHAR(hex2ascii(*up & 0x0f)); up++; if (width) for (q = p; *q; q++) PCHAR(*q); } break; case 'd': case 'i': base = 10; goto handle_sign; case 'h': if (hflag) { hflag = 0; cflag = 1; } else hflag = 1; goto reswitch; case 'j': jflag = 1; goto reswitch; case 'l': if (lflag) { lflag = 0; qflag = 1; } else lflag = 1; goto reswitch; case 'n': /* * We do not support %n in kernel, but consume the * argument. */ if (jflag) (void)va_arg(ap, intmax_t *); else if (qflag) (void)va_arg(ap, quad_t *); else if (lflag) (void)va_arg(ap, long *); else if (zflag) (void)va_arg(ap, size_t *); else if (hflag) (void)va_arg(ap, short *); else if (cflag) (void)va_arg(ap, char *); else (void)va_arg(ap, int *); break; case 'o': base = 8; goto handle_nosign; case 'p': base = 16; sharpflag = (width == 0); sign = 0; num = (uintptr_t)va_arg(ap, void *); goto number; case 'q': qflag = 1; goto reswitch; case 'r': base = radix; if (sign) { sign = 0; goto handle_sign; } goto handle_nosign; case 's': p = va_arg(ap, char *); if (p == NULL) p = "(null)"; if (!dot) n = strlen (p); else for (n = 0; n < dwidth && p[n]; n++) continue; width -= n; if (!ladjust && width > 0) while (width--) PCHAR(padc); while (n--) PCHAR(*p++); if (ladjust && width > 0) while (width--) PCHAR(padc); break; case 't': tflag = 1; goto reswitch; case 'u': base = 10; goto handle_nosign; case 'X': upper = 1; /* FALLTHROUGH */ case 'x': base = 16; goto handle_nosign; case 'y': base = 16; goto handle_sign; case 'z': zflag = 1; goto reswitch; handle_nosign: if (jflag) num = va_arg(ap, uintmax_t); else if (qflag) num = va_arg(ap, u_quad_t); else if (tflag) num = va_arg(ap, ptrdiff_t); else if (lflag) num = va_arg(ap, u_long); else if (zflag) num = va_arg(ap, size_t); else if (hflag) num = (u_short)va_arg(ap, int); else if (cflag) num = (u_char)va_arg(ap, int); else num = va_arg(ap, u_int); if (bconv) { q = va_arg(ap, char *); base = *q++; } goto number; handle_sign: if (jflag) num = va_arg(ap, intmax_t); else if (qflag) num = va_arg(ap, quad_t); else if (tflag) num = va_arg(ap, ptrdiff_t); else if (lflag) num = va_arg(ap, long); else if (zflag) num = va_arg(ap, ssize_t); else if (hflag) num = (short)va_arg(ap, int); else if (cflag) num = (signed char)va_arg(ap, int); else num = va_arg(ap, int); if ((intmax_t)num < 0) { sign = '-'; num = -(intmax_t)num; } number: p = ksprintn(nbuf, num, base, &n, upper); tmp = 0; if (sharpflag && num != 0) { if (base == 8) tmp++; else if (base == 16) tmp += 2; } if (sign) tmp++; if (!ladjust && padc == '0') dwidth = width - tmp; width -= tmp + imax(dwidth, n); dwidth -= n; if (!ladjust) while (width-- > 0) PCHAR(' '); if (sign) PCHAR(sign); if (sharpflag && num != 0) { if (base == 8) { PCHAR('0'); } else if (base == 16) { PCHAR('0'); PCHAR('x'); } } while (dwidth-- > 0) PCHAR('0'); while (*p) PCHAR(*p--); if (bconv && num != 0) { /* %b conversion flag format. */ tmp = retval; while (isbitpos(*q)) { if ((*q & 0x80) != 0) n = *q++ & 0x7f; else n = *q++ - 1; if (num & (1ULL << n)) { PCHAR(retval != tmp ? ',' : '<'); for (; isprintnospace(*q); ++q) PCHAR(*q); } else for (; isprintnospace(*q); ++q) continue; } if (retval != tmp) { PCHAR('>'); width -= retval - tmp; } } if (ladjust) while (width-- > 0) PCHAR(' '); break; default: while (percent < fmt) PCHAR(*percent++); /* * Since we ignore a formatting argument it is no * longer safe to obey the remaining formatting * arguments as the arguments will no longer match * the format specs. */ stop = 1; break; } } #undef PCHAR } /* * Put character in log buffer with a particular priority. */ static void msglogchar(int c, int pri) { static int lastpri = -1; static int dangling; char nbuf[MAXNBUF]; char *p; if (!msgbufmapped) return; if (c == '\0' || c == '\r') return; if (pri != -1 && pri != lastpri) { if (dangling) { msgbuf_addchar(msgbufp, '\n'); dangling = 0; } msgbuf_addchar(msgbufp, '<'); for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;) msgbuf_addchar(msgbufp, *p--); msgbuf_addchar(msgbufp, '>'); lastpri = pri; } msgbuf_addchar(msgbufp, c); if (c == '\n') { dangling = 0; lastpri = -1; } else { dangling = 1; } } static void msglogstr(char *str, int pri, int filter_cr) { if (!msgbufmapped) return; msgbuf_addstr(msgbufp, pri, str, filter_cr); } void msgbufinit(void *ptr, int size) { char *cp; static struct msgbuf *oldp = NULL; bool print_boot_tag; TSENTER(); size -= sizeof(*msgbufp); cp = (char *)ptr; print_boot_tag = !msgbufmapped; /* Attempt to fetch kern.boot_tag tunable on first mapping */ if (!msgbufmapped) TUNABLE_STR_FETCH("kern.boot_tag", current_boot_tag, sizeof(current_boot_tag)); msgbufp = (struct msgbuf *)(cp + size); msgbuf_reinit(msgbufp, cp, size); if (msgbufmapped && oldp != msgbufp) msgbuf_copy(oldp, msgbufp); msgbufmapped = true; if (print_boot_tag && *current_boot_tag != '\0') printf("%s\n", current_boot_tag); oldp = msgbufp; TSEXIT(); } /* Sysctls for accessing/clearing the msgbuf */ static int sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) { char buf[128], *bp; u_int seq; int error, len; bool wrap; error = priv_check(req->td, PRIV_MSGBUF); if (error) return (error); /* Read the whole buffer, one chunk at a time. */ mtx_lock(&msgbuf_lock); msgbuf_peekbytes(msgbufp, NULL, 0, &seq); wrap = (seq != 0); for (;;) { len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq); mtx_unlock(&msgbuf_lock); if (len == 0) return (SYSCTL_OUT(req, "", 1)); /* add nulterm */ if (wrap) { /* Skip the first line, as it is probably incomplete. */ bp = memchr(buf, '\n', len); if (bp == NULL) { mtx_lock(&msgbuf_lock); continue; } wrap = false; bp++; len -= bp - buf; if (len == 0) { mtx_lock(&msgbuf_lock); continue; } } else bp = buf; error = sysctl_handle_opaque(oidp, bp, len, req); if (error) return (error); mtx_lock(&msgbuf_lock); } } SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); static int msgbuf_clearflag; static int sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) { int error; error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); if (!error && req->newptr) { mtx_lock(&msgbuf_lock); msgbuf_clear(msgbufp); mtx_unlock(&msgbuf_lock); msgbuf_clearflag = 0; } return (error); } SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE, &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); #ifdef DDB DB_SHOW_COMMAND_FLAGS(msgbuf, db_show_msgbuf, DB_CMD_MEMSAFE) { int i, j; if (!msgbufmapped) { db_printf("msgbuf not mapped yet\n"); return; } db_printf("msgbufp = %p\n", msgbufp); db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n", msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq, msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum); for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) { j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq); db_printf("%c", msgbufp->msg_ptr[j]); } db_printf("\n"); } #endif /* DDB */ void hexdump(const void *ptr, int length, const char *hdr, int flags) { int i, j, k; int cols; const unsigned char *cp; char delim; if ((flags & HD_DELIM_MASK) != 0) delim = (flags & HD_DELIM_MASK) >> 8; else delim = ' '; if ((flags & HD_COLUMN_MASK) != 0) cols = flags & HD_COLUMN_MASK; else cols = 16; cp = ptr; for (i = 0; i < length; i+= cols) { if (hdr != NULL) printf("%s", hdr); if ((flags & HD_OMIT_COUNT) == 0) printf("%04x ", i); if ((flags & HD_OMIT_HEX) == 0) { for (j = 0; j < cols; j++) { k = i + j; if (k < length) printf("%c%02x", delim, cp[k]); else printf(" "); } } if ((flags & HD_OMIT_CHARS) == 0) { printf(" |"); for (j = 0; j < cols; j++) { k = i + j; if (k >= length) printf(" "); else if (cp[k] >= ' ' && cp[k] <= '~') printf("%c", cp[k]); else printf("."); } printf("|"); } printf("\n"); } } #endif /* _KERNEL */ void sbuf_hexdump(struct sbuf *sb, const void *ptr, int length, const char *hdr, int flags) { int i, j, k; int cols; const unsigned char *cp; char delim; if ((flags & HD_DELIM_MASK) != 0) delim = (flags & HD_DELIM_MASK) >> 8; else delim = ' '; if ((flags & HD_COLUMN_MASK) != 0) cols = flags & HD_COLUMN_MASK; else cols = 16; cp = ptr; for (i = 0; i < length; i+= cols) { if (hdr != NULL) sbuf_printf(sb, "%s", hdr); if ((flags & HD_OMIT_COUNT) == 0) sbuf_printf(sb, "%04x ", i); if ((flags & HD_OMIT_HEX) == 0) { for (j = 0; j < cols; j++) { k = i + j; if (k < length) sbuf_printf(sb, "%c%02x", delim, cp[k]); else sbuf_cat(sb, " "); } } if ((flags & HD_OMIT_CHARS) == 0) { sbuf_cat(sb, " |"); for (j = 0; j < cols; j++) { k = i + j; if (k >= length) sbuf_putc(sb, ' '); else if (cp[k] >= ' ' && cp[k] <= '~') sbuf_putc(sb, cp[k]); else sbuf_putc(sb, '.'); } sbuf_putc(sb, '|'); } sbuf_putc(sb, '\n'); } } #ifdef _KERNEL void counted_warning(unsigned *counter, const char *msg) { struct thread *td; unsigned c; for (;;) { c = *counter; if (c == 0) break; if (atomic_cmpset_int(counter, c, c - 1)) { td = curthread; log(LOG_INFO, "pid %d (%s) %s%s\n", td->td_proc->p_pid, td->td_name, msg, c > 1 ? "" : " - not logging anymore"); break; } } } #endif #ifdef _KERNEL void sbuf_putbuf(struct sbuf *sb) { prf_putbuf(sbuf_data(sb), TOLOG | TOCONS, -1); } #else void sbuf_putbuf(struct sbuf *sb) { printf("%s", sbuf_data(sb)); } #endif int sbuf_printf_drain(void *arg, const char *data, int len) { size_t *retvalptr; int r; #ifdef _KERNEL char *dataptr; char oldchr; /* * This is allowed as an extra byte is always resvered for * terminating NUL byte. Save and restore the byte because * we might be flushing a record, and there may be valid * data after the buffer. */ oldchr = data[len]; dataptr = __DECONST(char *, data); dataptr[len] = '\0'; prf_putbuf(dataptr, TOLOG | TOCONS, -1); r = len; dataptr[len] = oldchr; #else /* !_KERNEL */ r = printf("%.*s", len, data); if (r < 0) return (-errno); #endif retvalptr = arg; if (retvalptr != NULL) *retvalptr += r; return (r); } + +#if defined(_KERNEL) && defined(DDB) +int +sbuf_db_printf_drain(void *arg __unused, const char *data, int len) +{ + + return (db_printf("%.*s", len, data)); +} +#endif diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c index 85dc0c321797..3c192b2b0dce 100644 --- a/sys/kern/subr_witness.c +++ b/sys/kern/subr_witness.c @@ -1,3479 +1,3473 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 2008 Isilon Systems, Inc. * Copyright (c) 2008 Ilya Maykov * Copyright (c) 1998 Berkeley Software Design, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Berkeley Software Design Inc's name may not be used to endorse or * promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ */ /* * Implementation of the `witness' lock verifier. Originally implemented for * mutexes in BSD/OS. Extended to handle generic lock objects and lock * classes in FreeBSD. */ /* * Main Entry: witness * Pronunciation: 'wit-n&s * Function: noun * Etymology: Middle English witnesse, from Old English witnes knowledge, * testimony, witness, from 2wit * Date: before 12th century * 1 : attestation of a fact or event : TESTIMONY * 2 : one that gives evidence; specifically : one who testifies in * a cause or before a judicial tribunal * 3 : one asked to be present at a transaction so as to be able to * testify to its having taken place * 4 : one who has personal knowledge of something * 5 a : something serving as evidence or proof : SIGN * b : public affirmation by word or example of usually * religious faith or conviction * 6 capitalized : a member of the Jehovah's Witnesses */ /* * Special rules concerning Giant and lock orders: * * 1) Giant must be acquired before any other mutexes. Stated another way, * no other mutex may be held when Giant is acquired. * * 2) Giant must be released when blocking on a sleepable lock. * * This rule is less obvious, but is a result of Giant providing the same * semantics as spl(). Basically, when a thread sleeps, it must release * Giant. When a thread blocks on a sleepable lock, it sleeps. Hence rule * 2). * * 3) Giant may be acquired before or after sleepable locks. * * This rule is also not quite as obvious. Giant may be acquired after * a sleepable lock because it is a non-sleepable lock and non-sleepable * locks may always be acquired while holding a sleepable lock. The second * case, Giant before a sleepable lock, follows from rule 2) above. Suppose * you have two threads T1 and T2 and a sleepable lock X. Suppose that T1 * acquires X and blocks on Giant. Then suppose that T2 acquires Giant and * blocks on X. When T2 blocks on X, T2 will release Giant allowing T1 to * execute. Thus, acquiring Giant both before and after a sleepable lock * will not result in a lock order reversal. */ #include #include "opt_ddb.h" #include "opt_hwpmc_hooks.h" #include "opt_stack.h" #include "opt_witness.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #endif #if !defined(DDB) && !defined(STACK) #error "DDB or STACK options are required for WITNESS" #endif /* Note that these traces do not work with KTR_ALQ. */ #if 0 #define KTR_WITNESS KTR_SUBSYS #else #define KTR_WITNESS 0 #endif #define LI_RECURSEMASK 0x0000ffff /* Recursion depth of lock instance. */ #define LI_EXCLUSIVE 0x00010000 /* Exclusive lock instance. */ #define LI_NORELEASE 0x00020000 /* Lock not allowed to be released. */ #define LI_SLEEPABLE 0x00040000 /* Lock may be held while sleeping. */ #ifndef WITNESS_COUNT #define WITNESS_COUNT 1536 #endif #define WITNESS_HASH_SIZE 251 /* Prime, gives load factor < 2 */ #define WITNESS_PENDLIST (512 + (MAXCPU * 4)) /* Allocate 256 KB of stack data space */ #define WITNESS_LO_DATA_COUNT 2048 /* Prime, gives load factor of ~2 at full load */ #define WITNESS_LO_HASH_SIZE 1021 /* * XXX: This is somewhat bogus, as we assume here that at most 2048 threads * will hold LOCK_NCHILDREN locks. We handle failure ok, and we should * probably be safe for the most part, but it's still a SWAG. */ #define LOCK_NCHILDREN 5 #define LOCK_CHILDCOUNT 2048 #define MAX_W_NAME 64 #define FULLGRAPH_SBUF_SIZE 512 /* * These flags go in the witness relationship matrix and describe the * relationship between any two struct witness objects. */ #define WITNESS_UNRELATED 0x00 /* No lock order relation. */ #define WITNESS_PARENT 0x01 /* Parent, aka direct ancestor. */ #define WITNESS_ANCESTOR 0x02 /* Direct or indirect ancestor. */ #define WITNESS_CHILD 0x04 /* Child, aka direct descendant. */ #define WITNESS_DESCENDANT 0x08 /* Direct or indirect descendant. */ #define WITNESS_ANCESTOR_MASK (WITNESS_PARENT | WITNESS_ANCESTOR) #define WITNESS_DESCENDANT_MASK (WITNESS_CHILD | WITNESS_DESCENDANT) #define WITNESS_RELATED_MASK (WITNESS_ANCESTOR_MASK | WITNESS_DESCENDANT_MASK) #define WITNESS_REVERSAL 0x10 /* A lock order reversal has been observed. */ #define WITNESS_RESERVED1 0x20 /* Unused flag, reserved. */ #define WITNESS_ORDER_LISTS 0x40 /* Relationship set in order_lists[]. */ #define WITNESS_LOCK_ORDER_KNOWN 0x80 /* This lock order is known. */ /* Descendant to ancestor flags */ #define WITNESS_DTOA(x) (((x) & WITNESS_RELATED_MASK) >> 2) /* Ancestor to descendant flags */ #define WITNESS_ATOD(x) (((x) & WITNESS_RELATED_MASK) << 2) #define WITNESS_INDEX_ASSERT(i) \ MPASS((i) > 0 && (i) <= w_max_used_index && (i) < witness_count) static MALLOC_DEFINE(M_WITNESS, "Witness", "Witness"); /* * Lock instances. A lock instance is the data associated with a lock while * it is held by witness. For example, a lock instance will hold the * recursion count of a lock. Lock instances are held in lists. Spin locks * are held in a per-cpu list while sleep locks are held in per-thread list. */ struct lock_instance { struct lock_object *li_lock; const char *li_file; int li_line; u_int li_flags; }; /* * A simple list type used to build the list of locks held by a thread * or CPU. We can't simply embed the list in struct lock_object since a * lock may be held by more than one thread if it is a shared lock. Locks * are added to the head of the list, so we fill up each list entry from * "the back" logically. To ease some of the arithmetic, we actually fill * in each list entry the normal way (children[0] then children[1], etc.) but * when we traverse the list we read children[count-1] as the first entry * down to children[0] as the final entry. */ struct lock_list_entry { struct lock_list_entry *ll_next; struct lock_instance ll_children[LOCK_NCHILDREN]; u_int ll_count; }; /* * The main witness structure. One of these per named lock type in the system * (for example, "vnode interlock"). */ struct witness { char w_name[MAX_W_NAME]; uint32_t w_index; /* Index in the relationship matrix */ struct lock_class *w_class; STAILQ_ENTRY(witness) w_list; /* List of all witnesses. */ STAILQ_ENTRY(witness) w_typelist; /* Witnesses of a type. */ struct witness *w_hash_next; /* Linked list in hash buckets. */ const char *w_file; /* File where last acquired */ uint32_t w_line; /* Line where last acquired */ uint32_t w_refcount; uint16_t w_num_ancestors; /* direct/indirect ancestor count */ uint16_t w_num_descendants; /* direct/indirect descendant count */ int16_t w_ddb_level; unsigned w_displayed:1; unsigned w_reversed:1; }; STAILQ_HEAD(witness_list, witness); /* * The witness hash table. Keys are witness names (const char *), elements are * witness objects (struct witness *). */ struct witness_hash { struct witness *wh_array[WITNESS_HASH_SIZE]; uint32_t wh_size; uint32_t wh_count; }; /* * Key type for the lock order data hash table. */ struct witness_lock_order_key { uint16_t from; uint16_t to; }; struct witness_lock_order_data { struct stack wlod_stack; struct witness_lock_order_key wlod_key; struct witness_lock_order_data *wlod_next; }; /* * The witness lock order data hash table. Keys are witness index tuples * (struct witness_lock_order_key), elements are lock order data objects * (struct witness_lock_order_data). */ struct witness_lock_order_hash { struct witness_lock_order_data *wloh_array[WITNESS_LO_HASH_SIZE]; u_int wloh_size; u_int wloh_count; }; struct witness_blessed { const char *b_lock1; const char *b_lock2; }; struct witness_pendhelp { const char *wh_type; struct lock_object *wh_lock; }; struct witness_order_list_entry { const char *w_name; struct lock_class *w_class; }; /* * Returns 0 if one of the locks is a spin lock and the other is not. * Returns 1 otherwise. */ static __inline int witness_lock_type_equal(struct witness *w1, struct witness *w2) { return ((w1->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK)) == (w2->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK))); } static __inline int witness_lock_order_key_equal(const struct witness_lock_order_key *a, const struct witness_lock_order_key *b) { return (a->from == b->from && a->to == b->to); } static int _isitmyx(struct witness *w1, struct witness *w2, int rmask, const char *fname); static void adopt(struct witness *parent, struct witness *child); static int blessed(struct witness *, struct witness *); static void depart(struct witness *w); static struct witness *enroll(const char *description, struct lock_class *lock_class); static struct lock_instance *find_instance(struct lock_list_entry *list, const struct lock_object *lock); static int isitmychild(struct witness *parent, struct witness *child); static int isitmydescendant(struct witness *parent, struct witness *child); static void itismychild(struct witness *parent, struct witness *child); static int sysctl_debug_witness_badstacks(SYSCTL_HANDLER_ARGS); static int sysctl_debug_witness_watch(SYSCTL_HANDLER_ARGS); static int sysctl_debug_witness_fullgraph(SYSCTL_HANDLER_ARGS); static int sysctl_debug_witness_channel(SYSCTL_HANDLER_ARGS); static void witness_add_fullgraph(struct sbuf *sb, struct witness *parent); #ifdef DDB static void witness_ddb_compute_levels(void); static void witness_ddb_display(int(*)(const char *fmt, ...)); static void witness_ddb_display_descendants(int(*)(const char *fmt, ...), struct witness *, int indent); static void witness_ddb_display_list(int(*prnt)(const char *fmt, ...), struct witness_list *list); static void witness_ddb_level_descendants(struct witness *parent, int l); static void witness_ddb_list(struct thread *td); #endif static void witness_enter_debugger(const char *msg); static void witness_debugger(int cond, const char *msg); static void witness_free(struct witness *m); static struct witness *witness_get(void); static uint32_t witness_hash_djb2(const uint8_t *key, uint32_t size); static struct witness *witness_hash_get(const char *key); static void witness_hash_put(struct witness *w); static void witness_init_hash_tables(void); static void witness_increment_graph_generation(void); static void witness_lock_list_free(struct lock_list_entry *lle); static struct lock_list_entry *witness_lock_list_get(void); static int witness_lock_order_add(struct witness *parent, struct witness *child); static int witness_lock_order_check(struct witness *parent, struct witness *child); static struct witness_lock_order_data *witness_lock_order_get( struct witness *parent, struct witness *child); static void witness_list_lock(struct lock_instance *instance, int (*prnt)(const char *fmt, ...)); static int witness_output(const char *fmt, ...) __printflike(1, 2); static int witness_output_drain(void *arg __unused, const char *data, int len); static int witness_voutput(const char *fmt, va_list ap) __printflike(1, 0); static void witness_setflag(struct lock_object *lock, int flag, int set); FEATURE(witness, "kernel has witness(9) support"); static SYSCTL_NODE(_debug, OID_AUTO, witness, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, "Witness Locking"); /* * If set to 0, lock order checking is disabled. If set to -1, * witness is completely disabled. Otherwise witness performs full * lock order checking for all locks. At runtime, lock order checking * may be toggled. However, witness cannot be reenabled once it is * completely disabled. */ static int witness_watch = 1; SYSCTL_PROC(_debug_witness, OID_AUTO, watch, CTLFLAG_RWTUN | CTLTYPE_INT | CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_watch, "I", "witness is watching lock operations"); #ifdef KDB /* * When KDB is enabled and witness_kdb is 1, it will cause the system * to drop into kdebug() when: * - a lock hierarchy violation occurs * - locks are held when going to sleep. */ #ifdef WITNESS_KDB int witness_kdb = 1; #else int witness_kdb = 0; #endif SYSCTL_INT(_debug_witness, OID_AUTO, kdb, CTLFLAG_RWTUN, &witness_kdb, 0, ""); #endif /* KDB */ #if defined(DDB) || defined(KDB) /* * When DDB or KDB is enabled and witness_trace is > 0, it will cause the system * to print a stack trace when: * - a lock hierarchy violation occurs * - locks are held when going to sleep. * * Additionally, if witness_trace is 2, it will cause the system to search * for all locks which established the known lock ordering and print * stack traces of where the lock ordering was first established. */ int witness_trace = 2; SYSCTL_INT(_debug_witness, OID_AUTO, trace, CTLFLAG_RWTUN, &witness_trace, 0, ""); #endif /* DDB || KDB */ #ifdef WITNESS_SKIPSPIN int witness_skipspin = 1; #else int witness_skipspin = 0; #endif SYSCTL_INT(_debug_witness, OID_AUTO, skipspin, CTLFLAG_RDTUN, &witness_skipspin, 0, ""); int badstack_sbuf_size; int witness_count = WITNESS_COUNT; SYSCTL_INT(_debug_witness, OID_AUTO, witness_count, CTLFLAG_RDTUN, &witness_count, 0, ""); /* * Output channel for witness messages. By default we print to the console. */ enum witness_channel { WITNESS_CONSOLE, WITNESS_LOG, WITNESS_NONE, }; static enum witness_channel witness_channel = WITNESS_CONSOLE; SYSCTL_PROC(_debug_witness, OID_AUTO, output_channel, CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_channel, "A", "Output channel for warnings"); /* * Call this to print out the relations between locks. */ SYSCTL_PROC(_debug_witness, OID_AUTO, fullgraph, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_fullgraph, "A", "Show locks relation graphs"); /* * Call this to print out the witness faulty stacks. */ SYSCTL_PROC(_debug_witness, OID_AUTO, badstacks, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_badstacks, "A", "Show bad witness stacks"); static struct mtx w_mtx; /* w_list */ static struct witness_list w_free = STAILQ_HEAD_INITIALIZER(w_free); static struct witness_list w_all = STAILQ_HEAD_INITIALIZER(w_all); /* w_typelist */ static struct witness_list w_spin = STAILQ_HEAD_INITIALIZER(w_spin); static struct witness_list w_sleep = STAILQ_HEAD_INITIALIZER(w_sleep); /* lock list */ static struct lock_list_entry *w_lock_list_free = NULL; static struct witness_pendhelp pending_locks[WITNESS_PENDLIST]; static u_int pending_cnt; static int w_free_cnt, w_spin_cnt, w_sleep_cnt; SYSCTL_INT(_debug_witness, OID_AUTO, free_cnt, CTLFLAG_RD, &w_free_cnt, 0, ""); SYSCTL_INT(_debug_witness, OID_AUTO, spin_cnt, CTLFLAG_RD, &w_spin_cnt, 0, ""); SYSCTL_INT(_debug_witness, OID_AUTO, sleep_cnt, CTLFLAG_RD, &w_sleep_cnt, 0, ""); static struct witness *w_data; static uint8_t **w_rmatrix; static struct lock_list_entry w_locklistdata[LOCK_CHILDCOUNT]; static struct witness_hash w_hash; /* The witness hash table. */ /* The lock order data hash */ static struct witness_lock_order_data w_lodata[WITNESS_LO_DATA_COUNT]; static struct witness_lock_order_data *w_lofree = NULL; static struct witness_lock_order_hash w_lohash; static int w_max_used_index = 0; static unsigned int w_generation = 0; static const char w_notrunning[] = "Witness not running\n"; static const char w_stillcold[] = "Witness is still cold\n"; #ifdef __i386__ static const char w_notallowed[] = "The sysctl is disabled on the arch\n"; #endif static struct witness_order_list_entry order_lists[] = { /* * sx locks */ { "proctree", &lock_class_sx }, { "allproc", &lock_class_sx }, { "allprison", &lock_class_sx }, { NULL, NULL }, /* * Various mutexes */ { "Giant", &lock_class_mtx_sleep }, { "pipe mutex", &lock_class_mtx_sleep }, { "sigio lock", &lock_class_mtx_sleep }, { "process group", &lock_class_mtx_sleep }, #ifdef HWPMC_HOOKS { "pmc-sleep", &lock_class_mtx_sleep }, #endif { "process lock", &lock_class_mtx_sleep }, { "session", &lock_class_mtx_sleep }, { "uidinfo hash", &lock_class_rw }, { "time lock", &lock_class_mtx_sleep }, { NULL, NULL }, /* * umtx */ { "umtx lock", &lock_class_mtx_sleep }, { NULL, NULL }, /* * Sockets */ { "accept", &lock_class_mtx_sleep }, { "so_snd", &lock_class_mtx_sleep }, { "so_rcv", &lock_class_mtx_sleep }, { "sellck", &lock_class_mtx_sleep }, { NULL, NULL }, /* * Routing */ { "so_rcv", &lock_class_mtx_sleep }, { "radix node head", &lock_class_rm }, { "ifaddr", &lock_class_mtx_sleep }, { NULL, NULL }, /* * IPv4 multicast: * protocol locks before interface locks, after UDP locks. */ { "in_multi_sx", &lock_class_sx }, { "udpinp", &lock_class_rw }, { "in_multi_list_mtx", &lock_class_mtx_sleep }, { "igmp_mtx", &lock_class_mtx_sleep }, { "if_addr_lock", &lock_class_mtx_sleep }, { NULL, NULL }, /* * IPv6 multicast: * protocol locks before interface locks, after UDP locks. */ { "in6_multi_sx", &lock_class_sx }, { "udpinp", &lock_class_rw }, { "in6_multi_list_mtx", &lock_class_mtx_sleep }, { "mld_mtx", &lock_class_mtx_sleep }, { "if_addr_lock", &lock_class_mtx_sleep }, { NULL, NULL }, /* * UNIX Domain Sockets */ { "unp_link_rwlock", &lock_class_rw }, { "unp_list_lock", &lock_class_mtx_sleep }, { "unp", &lock_class_mtx_sleep }, { "so_snd", &lock_class_mtx_sleep }, { NULL, NULL }, /* * UDP/IP */ { "udpinp", &lock_class_rw }, { "udp", &lock_class_mtx_sleep }, { "so_snd", &lock_class_mtx_sleep }, { NULL, NULL }, /* * TCP/IP */ { "tcpinp", &lock_class_rw }, { "tcp", &lock_class_mtx_sleep }, { "so_snd", &lock_class_mtx_sleep }, { NULL, NULL }, /* * IPv6 Addr */ { "tcphash", &lock_class_mtx_sleep }, { "in6_ifaddr_lock", &lock_class_rm }, { NULL, NULL }, /* * BPF */ { "bpf global lock", &lock_class_sx }, { "bpf cdev lock", &lock_class_mtx_sleep }, { NULL, NULL }, /* * NFS server */ { "nfsd_mtx", &lock_class_mtx_sleep }, { "so_snd", &lock_class_mtx_sleep }, { NULL, NULL }, /* * IEEE 802.11 */ { "802.11 com lock", &lock_class_mtx_sleep}, { NULL, NULL }, /* * Network drivers */ { "network driver", &lock_class_mtx_sleep}, { NULL, NULL }, /* * Netgraph */ { "ng_node", &lock_class_mtx_sleep }, { "ng_worklist", &lock_class_mtx_sleep }, { NULL, NULL }, /* * CDEV */ { "vm map (system)", &lock_class_mtx_sleep }, { "vnode interlock", &lock_class_mtx_sleep }, { "cdev", &lock_class_mtx_sleep }, { "devthrd", &lock_class_mtx_sleep }, { NULL, NULL }, /* * VM */ { "vm map (user)", &lock_class_sx }, { "vm object", &lock_class_rw }, { "vm page", &lock_class_mtx_sleep }, { "pmap pv global", &lock_class_rw }, { "pmap", &lock_class_mtx_sleep }, { "pmap pv list", &lock_class_rw }, { "vm page free queue", &lock_class_mtx_sleep }, { "vm pagequeue", &lock_class_mtx_sleep }, { NULL, NULL }, /* * kqueue/VFS interaction */ { "kqueue", &lock_class_mtx_sleep }, { "struct mount mtx", &lock_class_mtx_sleep }, { "vnode interlock", &lock_class_mtx_sleep }, { NULL, NULL }, /* * VFS namecache */ { "ncvn", &lock_class_mtx_sleep }, { "ncbuc", &lock_class_mtx_sleep }, { "vnode interlock", &lock_class_mtx_sleep }, { "ncneg", &lock_class_mtx_sleep }, { NULL, NULL }, /* * ZFS locking */ { "dn->dn_mtx", &lock_class_sx }, { "dr->dt.di.dr_mtx", &lock_class_sx }, { "db->db_mtx", &lock_class_sx }, { NULL, NULL }, /* * TCP log locks */ { "TCP ID tree", &lock_class_rw }, { "tcp log id bucket", &lock_class_mtx_sleep }, { "tcpinp", &lock_class_rw }, { "TCP log expireq", &lock_class_mtx_sleep }, { NULL, NULL }, /* * spin locks */ #ifdef SMP { "ap boot", &lock_class_mtx_spin }, #endif { "rm.mutex_mtx", &lock_class_mtx_spin }, #ifdef __i386__ { "cy", &lock_class_mtx_spin }, #endif { "scc_hwmtx", &lock_class_mtx_spin }, { "uart_hwmtx", &lock_class_mtx_spin }, { "fast_taskqueue", &lock_class_mtx_spin }, { "intr table", &lock_class_mtx_spin }, { "process slock", &lock_class_mtx_spin }, { "syscons video lock", &lock_class_mtx_spin }, { "sleepq chain", &lock_class_mtx_spin }, { "rm_spinlock", &lock_class_mtx_spin }, { "turnstile chain", &lock_class_mtx_spin }, { "turnstile lock", &lock_class_mtx_spin }, { "sched lock", &lock_class_mtx_spin }, { "td_contested", &lock_class_mtx_spin }, { "callout", &lock_class_mtx_spin }, { "entropy harvest mutex", &lock_class_mtx_spin }, #ifdef SMP { "smp rendezvous", &lock_class_mtx_spin }, #endif #ifdef __powerpc__ { "tlb0", &lock_class_mtx_spin }, #endif { NULL, NULL }, { "sched lock", &lock_class_mtx_spin }, #ifdef HWPMC_HOOKS { "pmc-per-proc", &lock_class_mtx_spin }, #endif { NULL, NULL }, /* * leaf locks */ { "intrcnt", &lock_class_mtx_spin }, { "icu", &lock_class_mtx_spin }, #ifdef __i386__ { "allpmaps", &lock_class_mtx_spin }, { "descriptor tables", &lock_class_mtx_spin }, #endif { "clk", &lock_class_mtx_spin }, { "cpuset", &lock_class_mtx_spin }, { "mprof lock", &lock_class_mtx_spin }, { "zombie lock", &lock_class_mtx_spin }, { "ALD Queue", &lock_class_mtx_spin }, #if defined(__i386__) || defined(__amd64__) { "pcicfg", &lock_class_mtx_spin }, { "NDIS thread lock", &lock_class_mtx_spin }, #endif { "tw_osl_io_lock", &lock_class_mtx_spin }, { "tw_osl_q_lock", &lock_class_mtx_spin }, { "tw_cl_io_lock", &lock_class_mtx_spin }, { "tw_cl_intr_lock", &lock_class_mtx_spin }, { "tw_cl_gen_lock", &lock_class_mtx_spin }, #ifdef HWPMC_HOOKS { "pmc-leaf", &lock_class_mtx_spin }, #endif { "blocked lock", &lock_class_mtx_spin }, { NULL, NULL }, { NULL, NULL } }; /* * Pairs of locks which have been blessed. Witness does not complain about * order problems with blessed lock pairs. Please do not add an entry to the * table without an explanatory comment. */ static struct witness_blessed blessed_list[] = { /* * See the comment in ufs_dirhash.c. Basically, a vnode lock serializes * both lock orders, so a deadlock cannot happen as a result of this * LOR. */ { "dirhash", "bufwait" }, /* * A UFS vnode may be locked in vget() while a buffer belonging to the * parent directory vnode is locked. */ { "ufs", "bufwait" }, /* * The tarfs decompression stream vnode may be locked while a * buffer belonging to a tarfs data vnode is locked. */ { "tarfs", "bufwait" }, }; /* * This global is set to 0 once it becomes safe to use the witness code. */ static int witness_cold = 1; /* * This global is set to 1 once the static lock orders have been enrolled * so that a warning can be issued for any spin locks enrolled later. */ static int witness_spin_warn = 0; /* Trim useless garbage from filenames. */ static const char * fixup_filename(const char *file) { if (file == NULL) return (NULL); while (strncmp(file, "../", 3) == 0) file += 3; return (file); } /* * Calculate the size of early witness structures. */ int witness_startup_count(void) { int sz; sz = sizeof(struct witness) * witness_count; sz += sizeof(*w_rmatrix) * (witness_count + 1); sz += sizeof(*w_rmatrix[0]) * (witness_count + 1) * (witness_count + 1); return (sz); } /* * The WITNESS-enabled diagnostic code. Note that the witness code does * assume that the early boot is single-threaded at least until after this * routine is completed. */ void witness_startup(void *mem) { struct lock_object *lock; struct witness_order_list_entry *order; struct witness *w, *w1; uintptr_t p; int i; p = (uintptr_t)mem; w_data = (void *)p; p += sizeof(struct witness) * witness_count; w_rmatrix = (void *)p; p += sizeof(*w_rmatrix) * (witness_count + 1); for (i = 0; i < witness_count + 1; i++) { w_rmatrix[i] = (void *)p; p += sizeof(*w_rmatrix[i]) * (witness_count + 1); } badstack_sbuf_size = witness_count * 256; /* * We have to release Giant before initializing its witness * structure so that WITNESS doesn't get confused. */ mtx_unlock(&Giant); mtx_assert(&Giant, MA_NOTOWNED); CTR1(KTR_WITNESS, "%s: initializing witness", __func__); mtx_init(&w_mtx, "witness lock", NULL, MTX_SPIN | MTX_QUIET | MTX_NOWITNESS | MTX_NOPROFILE); for (i = witness_count - 1; i >= 0; i--) { w = &w_data[i]; memset(w, 0, sizeof(*w)); w_data[i].w_index = i; /* Witness index never changes. */ witness_free(w); } KASSERT(STAILQ_FIRST(&w_free)->w_index == 0, ("%s: Invalid list of free witness objects", __func__)); /* Witness with index 0 is not used to aid in debugging. */ STAILQ_REMOVE_HEAD(&w_free, w_list); w_free_cnt--; for (i = 0; i < witness_count; i++) { memset(w_rmatrix[i], 0, sizeof(*w_rmatrix[i]) * (witness_count + 1)); } for (i = 0; i < LOCK_CHILDCOUNT; i++) witness_lock_list_free(&w_locklistdata[i]); witness_init_hash_tables(); /* First add in all the specified order lists. */ for (order = order_lists; order->w_name != NULL; order++) { w = enroll(order->w_name, order->w_class); if (w == NULL) continue; w->w_file = "order list"; for (order++; order->w_name != NULL; order++) { w1 = enroll(order->w_name, order->w_class); if (w1 == NULL) continue; w1->w_file = "order list"; itismychild(w, w1); w_rmatrix[w->w_index][w1->w_index] |= WITNESS_ORDER_LISTS; w_rmatrix[w1->w_index][w->w_index] |= WITNESS_ORDER_LISTS; w = w1; } } witness_spin_warn = 1; /* Iterate through all locks and add them to witness. */ for (i = 0; pending_locks[i].wh_lock != NULL; i++) { lock = pending_locks[i].wh_lock; KASSERT(lock->lo_flags & LO_WITNESS, ("%s: lock %s is on pending list but not LO_WITNESS", __func__, lock->lo_name)); lock->lo_witness = enroll(pending_locks[i].wh_type, LOCK_CLASS(lock)); } /* Mark the witness code as being ready for use. */ witness_cold = 0; mtx_lock(&Giant); } void witness_init(struct lock_object *lock, const char *type) { struct lock_class *class; /* Various sanity checks. */ class = LOCK_CLASS(lock); if ((lock->lo_flags & LO_RECURSABLE) != 0 && (class->lc_flags & LC_RECURSABLE) == 0) kassert_panic("%s: lock (%s) %s can not be recursable", __func__, class->lc_name, lock->lo_name); if ((lock->lo_flags & LO_SLEEPABLE) != 0 && (class->lc_flags & LC_SLEEPABLE) == 0) kassert_panic("%s: lock (%s) %s can not be sleepable", __func__, class->lc_name, lock->lo_name); if ((lock->lo_flags & LO_UPGRADABLE) != 0 && (class->lc_flags & LC_UPGRADABLE) == 0) kassert_panic("%s: lock (%s) %s can not be upgradable", __func__, class->lc_name, lock->lo_name); /* * If we shouldn't watch this lock, then just clear lo_witness. * Otherwise, if witness_cold is set, then it is too early to * enroll this lock, so defer it to witness_initialize() by adding * it to the pending_locks list. If it is not too early, then enroll * the lock now. */ if (witness_watch < 1 || KERNEL_PANICKED() || (lock->lo_flags & LO_WITNESS) == 0) lock->lo_witness = NULL; else if (witness_cold) { pending_locks[pending_cnt].wh_lock = lock; pending_locks[pending_cnt++].wh_type = type; if (pending_cnt > WITNESS_PENDLIST) panic("%s: pending locks list is too small, " "increase WITNESS_PENDLIST\n", __func__); } else lock->lo_witness = enroll(type, class); } void witness_destroy(struct lock_object *lock) { struct lock_class *class; struct witness *w; class = LOCK_CLASS(lock); if (witness_cold) panic("lock (%s) %s destroyed while witness_cold", class->lc_name, lock->lo_name); /* XXX: need to verify that no one holds the lock */ if ((lock->lo_flags & LO_WITNESS) == 0 || lock->lo_witness == NULL) return; w = lock->lo_witness; mtx_lock_spin(&w_mtx); MPASS(w->w_refcount > 0); w->w_refcount--; if (w->w_refcount == 0) depart(w); mtx_unlock_spin(&w_mtx); } #ifdef DDB static void witness_ddb_compute_levels(void) { struct witness *w; /* * First clear all levels. */ STAILQ_FOREACH(w, &w_all, w_list) w->w_ddb_level = -1; /* * Look for locks with no parents and level all their descendants. */ STAILQ_FOREACH(w, &w_all, w_list) { /* If the witness has ancestors (is not a root), skip it. */ if (w->w_num_ancestors > 0) continue; witness_ddb_level_descendants(w, 0); } } static void witness_ddb_level_descendants(struct witness *w, int l) { int i; if (w->w_ddb_level >= l) return; w->w_ddb_level = l; l++; for (i = 1; i <= w_max_used_index; i++) { if (w_rmatrix[w->w_index][i] & WITNESS_PARENT) witness_ddb_level_descendants(&w_data[i], l); } } static void witness_ddb_display_descendants(int(*prnt)(const char *fmt, ...), struct witness *w, int indent) { int i; for (i = 0; i < indent; i++) prnt(" "); prnt("%s (type: %s, depth: %d, active refs: %d)", w->w_name, w->w_class->lc_name, w->w_ddb_level, w->w_refcount); if (w->w_displayed) { prnt(" -- (already displayed)\n"); return; } w->w_displayed = 1; if (w->w_file != NULL && w->w_line != 0) prnt(" -- last acquired @ %s:%d\n", fixup_filename(w->w_file), w->w_line); else prnt(" -- never acquired\n"); indent++; WITNESS_INDEX_ASSERT(w->w_index); for (i = 1; i <= w_max_used_index; i++) { if (db_pager_quit) return; if (w_rmatrix[w->w_index][i] & WITNESS_PARENT) witness_ddb_display_descendants(prnt, &w_data[i], indent); } } static void witness_ddb_display_list(int(*prnt)(const char *fmt, ...), struct witness_list *list) { struct witness *w; STAILQ_FOREACH(w, list, w_typelist) { if (w->w_file == NULL || w->w_ddb_level > 0) continue; /* This lock has no anscestors - display its descendants. */ witness_ddb_display_descendants(prnt, w, 0); if (db_pager_quit) return; } } static void witness_ddb_display(int(*prnt)(const char *fmt, ...)) { struct witness *w; KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); witness_ddb_compute_levels(); /* Clear all the displayed flags. */ STAILQ_FOREACH(w, &w_all, w_list) w->w_displayed = 0; /* * First, handle sleep locks which have been acquired at least * once. */ prnt("Sleep locks:\n"); witness_ddb_display_list(prnt, &w_sleep); if (db_pager_quit) return; /* * Now do spin locks which have been acquired at least once. */ prnt("\nSpin locks:\n"); witness_ddb_display_list(prnt, &w_spin); if (db_pager_quit) return; /* * Finally, any locks which have not been acquired yet. */ prnt("\nLocks which were never acquired:\n"); STAILQ_FOREACH(w, &w_all, w_list) { if (w->w_file != NULL || w->w_refcount == 0) continue; prnt("%s (type: %s, depth: %d)\n", w->w_name, w->w_class->lc_name, w->w_ddb_level); if (db_pager_quit) return; } } #endif /* DDB */ #define NUM_VERBOSE_STACKS 256 #define MAX_LOCKCHAIN_RECURSION 32 /* * Struct used by the verbose witness functionality. Only sb, generation, * pairs, pair_count, check_generation, and alloc_flags communicate data * between multiple functions. The rest are used to pre-allocate space for * data which would otherwise end up on the stack. */ struct verbose_tracker { struct witness t_w1, t_w2; struct stack t_stack; struct sbuf *sb; int generation; int alloc_flags; int pairs[2 * NUM_VERBOSE_STACKS]; int pair_count; int recursion_list[MAX_LOCKCHAIN_RECURSION]; int found[MAX_LOCKCHAIN_RECURSION + 1]; int iter[MAX_LOCKCHAIN_RECURSION]; bool check_generation; }; static void init_verbose_tracker(struct verbose_tracker *t, struct sbuf *sb, int alloc_flags, bool check_generation) { KASSERT(t != NULL, ("%s: NULL t argument", __func__)); KASSERT(alloc_flags == M_WAITOK || alloc_flags == M_NOWAIT, ("%s: Unexpected alloc_flags %d", __func__, alloc_flags)); t->sb = sb; t->check_generation = check_generation; t->alloc_flags = alloc_flags; } static void reset_verbose_tracker(struct verbose_tracker *t, int generation) { KASSERT(t != NULL, ("%s: NULL t argument", __func__)); t->pair_count = 0; t->generation = generation; } static bool has_verbose_lockpair(const struct verbose_tracker *t, int from, int to) { int i; /* Look for value. */ for (i = 0; i < (2 * t->pair_count); i += 2) if (t->pairs[i] == from && t->pairs[i + 1] == to) return (true); return (false); } static void add_verbose_lockpair(struct verbose_tracker *t, int from, int to) { /* Check for duplicates. */ if (has_verbose_lockpair(t, from, to)) return; /* Add a new value. */ if (t->pair_count < NUM_VERBOSE_STACKS) { t->pairs[t->pair_count * 2] = from; t->pairs[(t->pair_count * 2) + 1] = to; t->pair_count++; } } static void sbuf_print_verbose_witness_chains(struct verbose_tracker *t, int from, int to) { struct witness *w1, *w2; int i, recursion_count; recursion_count = 0; mtx_lock_spin(&w_mtx); if (t->check_generation && t->generation != w_generation) { mtx_unlock_spin(&w_mtx); /* * The graph has changed. Break the recursion loop. * The calling function should figure out what happened and * restart. */ return; } top: t->found[recursion_count] = 0; /* * Check for a direct dependence. If so, print that here. * However, we keep scanning just in case there are other * locking paths between these two locks. */ w1 = &w_data[from]; w2 = &w_data[to]; if (isitmychild(w1, w2)) { t->t_w1 = *w1; t->t_w2 = *w2; mtx_unlock_spin(&w_mtx); sbuf_printf(t->sb, "\"%s\" -> \"%s\"", t->t_w1.w_name, t->t_w2.w_name); /* Add the lockchain which got us here. */ KASSERT(recursion_count >= 0 && recursion_count <= MAX_LOCKCHAIN_RECURSION, ("Invalid recursion_count: %d", recursion_count)); for (i = recursion_count - 1; i >= 0; i--) { mtx_lock_spin(&w_mtx); if (t->check_generation && t->generation != w_generation) { mtx_unlock_spin(&w_mtx); /* The graph has changed. */ return; } /* * Make a local copy, drop the lock, and add the lock * to the sbuf. */ t->t_w1 = w_data[t->recursion_list[i]]; mtx_unlock_spin(&w_mtx); sbuf_printf(t->sb, " -> \"%s\"", t->t_w1.w_name); } sbuf_putc(t->sb, '\n'); add_verbose_lockpair(t, from, to); t->found[recursion_count]++; mtx_lock_spin(&w_mtx); if (t->check_generation && t->generation != w_generation) { mtx_unlock_spin(&w_mtx); return; } } /* * Ensure we aren't recursing too many times. We do this check * after looking for direct dependencies so we don't fail to * catch at least those at the limits of our recursion. */ if (recursion_count >= MAX_LOCKCHAIN_RECURSION) goto end; /* * Record our 'to' lock on the recursion list. We will use this * to build successful lock chains later. */ t->recursion_list[recursion_count] = to; t->iter[recursion_count] = 1; loop: /* Walk all parents of 'to' to see if any have a path to 'from'. */ for (; t->iter[recursion_count] < w_max_used_index; t->iter[recursion_count]++) { if (t->iter[recursion_count] == to || t->iter[recursion_count] == from) continue; if (isitmychild(&w_data[t->iter[recursion_count]], &w_data[to])) { /* Recurse to the parent. */ to = t->iter[recursion_count]; recursion_count++; goto top; } } end: if (recursion_count != 0) { recursion_count--; to = t->recursion_list[recursion_count]; if (t->found[recursion_count + 1] > 0) { add_verbose_lockpair(t, t->iter[recursion_count], to); t->found[recursion_count]++; } t->iter[recursion_count]++; goto loop; } mtx_unlock_spin(&w_mtx); } static void sbuf_print_verbose_witness_stacks(struct verbose_tracker *t) { struct witness_lock_order_data *data; int i; bool hardcoded; for (i = 0; i < (2 * t->pair_count); i += 2) { mtx_lock_spin(&w_mtx); if (t->check_generation && t->generation != w_generation) { /* * The graph has changed. Return to the calling * function so it can restart. */ mtx_unlock_spin(&w_mtx); break; } /* * Make a local copy of the data we need so we can drop * the lock. */ t->t_w1 = w_data[t->pairs[i]]; t->t_w2 = w_data[t->pairs[i + 1]]; data = witness_lock_order_get(&t->t_w1, &t->t_w2); if (data != NULL) stack_copy(&data->wlod_stack, &t->t_stack); hardcoded = (w_rmatrix[t->pairs[i]][t->pairs[i + 1]] & WITNESS_ORDER_LISTS) == WITNESS_ORDER_LISTS; mtx_unlock_spin(&w_mtx); sbuf_printf(t->sb, "%slock order \"%s\"(%s) -> \"%s\"(%s) first seen at:\n", hardcoded ? "hardcoded " : "", t->t_w1.w_name, t->t_w1.w_class->lc_name, t->t_w2.w_name, t->t_w2.w_class->lc_name); if (data != NULL) stack_sbuf_print_flags(t->sb, &t->t_stack, t->alloc_flags, STACK_SBUF_FMT_LONG); else sbuf_printf(t->sb, "(No stack trace)\n"); sbuf_putc(t->sb, '\n'); } } int witness_defineorder(struct lock_object *lock1, struct lock_object *lock2) { if (witness_watch == -1 || KERNEL_PANICKED()) return (0); /* Require locks that witness knows about. */ if (lock1 == NULL || lock1->lo_witness == NULL || lock2 == NULL || lock2->lo_witness == NULL) return (EINVAL); mtx_assert(&w_mtx, MA_NOTOWNED); mtx_lock_spin(&w_mtx); /* * If we already have either an explicit or implied lock order that * is the other way around, then return an error. */ if (witness_watch && isitmydescendant(lock2->lo_witness, lock1->lo_witness)) { mtx_unlock_spin(&w_mtx); return (EDOOFUS); } /* Try to add the new order. */ CTR3(KTR_WITNESS, "%s: adding %s as a child of %s", __func__, lock2->lo_witness->w_name, lock1->lo_witness->w_name); itismychild(lock1->lo_witness, lock2->lo_witness); mtx_unlock_spin(&w_mtx); return (0); } void witness_checkorder(struct lock_object *lock, int flags, const char *file, int line, struct lock_object *interlock) { struct lock_list_entry *lock_list, *lle; struct lock_instance *lock1, *lock2, *plock; struct lock_class *class, *iclass; struct witness *w, *w1; struct thread *td; int i, j; bool print_lock_order; if (witness_cold || witness_watch < 1 || lock->lo_witness == NULL || KERNEL_PANICKED()) return; w = lock->lo_witness; class = LOCK_CLASS(lock); td = curthread; if (class->lc_flags & LC_SLEEPLOCK) { /* * Since spin locks include a critical section, this check * implicitly enforces a lock order of all sleep locks before * all spin locks. */ if (td->td_critnest != 0 && !kdb_active) kassert_panic("acquiring blockable sleep lock with " "spinlock or critical section held (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); /* * If this is the first lock acquired then just return as * no order checking is needed. */ lock_list = td->td_sleeplocks; if (lock_list == NULL || lock_list->ll_count == 0) return; } else { /* * If this is the first lock, just return as no order * checking is needed. Avoid problems with thread * migration pinning the thread while checking if * spinlocks are held. If at least one spinlock is held * the thread is in a safe path and it is allowed to * unpin it. */ sched_pin(); lock_list = PCPU_GET(spinlocks); if (lock_list == NULL || lock_list->ll_count == 0) { sched_unpin(); return; } sched_unpin(); } /* * Check to see if we are recursing on a lock we already own. If * so, make sure that we don't mismatch exclusive and shared lock * acquires. */ lock1 = find_instance(lock_list, lock); if (lock1 != NULL) { if ((lock1->li_flags & LI_EXCLUSIVE) != 0 && (flags & LOP_EXCLUSIVE) == 0) { witness_output("shared lock of (%s) %s @ %s:%d\n", class->lc_name, lock->lo_name, fixup_filename(file), line); witness_output("while exclusively locked from %s:%d\n", fixup_filename(lock1->li_file), lock1->li_line); kassert_panic("excl->share"); } if ((lock1->li_flags & LI_EXCLUSIVE) == 0 && (flags & LOP_EXCLUSIVE) != 0) { witness_output("exclusive lock of (%s) %s @ %s:%d\n", class->lc_name, lock->lo_name, fixup_filename(file), line); witness_output("while share locked from %s:%d\n", fixup_filename(lock1->li_file), lock1->li_line); kassert_panic("share->excl"); } return; } /* Warn if the interlock is not locked exactly once. */ if (interlock != NULL) { iclass = LOCK_CLASS(interlock); lock1 = find_instance(lock_list, interlock); if (lock1 == NULL) kassert_panic("interlock (%s) %s not locked @ %s:%d", iclass->lc_name, interlock->lo_name, fixup_filename(file), line); else if ((lock1->li_flags & LI_RECURSEMASK) != 0) kassert_panic("interlock (%s) %s recursed @ %s:%d", iclass->lc_name, interlock->lo_name, fixup_filename(file), line); } /* * Find the previously acquired lock, but ignore interlocks. */ plock = &lock_list->ll_children[lock_list->ll_count - 1]; if (interlock != NULL && plock->li_lock == interlock) { if (lock_list->ll_count > 1) plock = &lock_list->ll_children[lock_list->ll_count - 2]; else { lle = lock_list->ll_next; /* * The interlock is the only lock we hold, so * simply return. */ if (lle == NULL) return; plock = &lle->ll_children[lle->ll_count - 1]; } } /* * Try to perform most checks without a lock. If this succeeds we * can skip acquiring the lock and return success. Otherwise we redo * the check with the lock held to handle races with concurrent updates. */ w1 = plock->li_lock->lo_witness; if (witness_lock_order_check(w1, w)) return; mtx_lock_spin(&w_mtx); if (witness_lock_order_check(w1, w)) { mtx_unlock_spin(&w_mtx); return; } witness_lock_order_add(w1, w); /* * Check for duplicate locks of the same type. Note that we only * have to check for this on the last lock we just acquired. Any * other cases will be caught as lock order violations. */ if (w1 == w) { i = w->w_index; if (!(lock->lo_flags & LO_DUPOK) && !(flags & LOP_DUPOK) && !(w_rmatrix[i][i] & WITNESS_REVERSAL)) { w_rmatrix[i][i] |= WITNESS_REVERSAL; w->w_reversed = 1; mtx_unlock_spin(&w_mtx); witness_output( "acquiring duplicate lock of same type: \"%s\"\n", w->w_name); witness_output(" 1st %s @ %s:%d\n", plock->li_lock->lo_name, fixup_filename(plock->li_file), plock->li_line); witness_output(" 2nd %s @ %s:%d\n", lock->lo_name, fixup_filename(file), line); witness_debugger(1, __func__); } else mtx_unlock_spin(&w_mtx); return; } mtx_assert(&w_mtx, MA_OWNED); /* * If we know that the lock we are acquiring comes after * the lock we most recently acquired in the lock order tree, * then there is no need for any further checks. */ if (isitmychild(w1, w)) goto out; for (j = 0, lle = lock_list; lle != NULL; lle = lle->ll_next) { for (i = lle->ll_count - 1; i >= 0; i--, j++) { struct stack pstack; int trace; bool pstackv; MPASS(j < LOCK_CHILDCOUNT * LOCK_NCHILDREN); lock1 = &lle->ll_children[i]; /* * Ignore the interlock. */ if (interlock == lock1->li_lock) continue; /* * If this lock doesn't undergo witness checking, * then skip it. */ w1 = lock1->li_lock->lo_witness; if (w1 == NULL) { KASSERT((lock1->li_lock->lo_flags & LO_WITNESS) == 0, ("lock missing witness structure")); continue; } /* * If we are locking Giant and this is a sleepable * lock, then skip it. */ if ((lock1->li_flags & LI_SLEEPABLE) != 0 && lock == &Giant.lock_object) continue; /* * If we are locking a sleepable lock and this lock * is Giant, then skip it. */ if ((lock->lo_flags & LO_SLEEPABLE) != 0 && (flags & LOP_NOSLEEP) == 0 && lock1->li_lock == &Giant.lock_object) continue; /* * If we are locking a sleepable lock and this lock * isn't sleepable, we want to treat it as a lock * order violation to enfore a general lock order of * sleepable locks before non-sleepable locks. */ if ((lock->lo_flags & LO_SLEEPABLE) != 0 && (flags & LOP_NOSLEEP) == 0 && (lock1->li_flags & LI_SLEEPABLE) == 0) goto reversal; /* * If we are locking Giant and this is a non-sleepable * lock, then treat it as a reversal. */ if ((lock1->li_flags & LI_SLEEPABLE) == 0 && lock == &Giant.lock_object) goto reversal; /* * Check the lock order hierarchy for a reveresal. */ if (!isitmydescendant(w, w1)) continue; reversal: /* * We have a lock order violation, check to see if it * is allowed or has already been yelled about. */ /* Bail if this violation is known */ if (w_rmatrix[w1->w_index][w->w_index] & WITNESS_REVERSAL) goto out; /* Record this as a violation */ w_rmatrix[w1->w_index][w->w_index] |= WITNESS_REVERSAL; w_rmatrix[w->w_index][w1->w_index] |= WITNESS_REVERSAL; w->w_reversed = w1->w_reversed = 1; witness_increment_graph_generation(); /* * If the lock order is blessed, bail before logging * anything. We don't look for other lock order * violations though, which may be a bug. */ if (blessed(w, w1)) goto out; trace = atomic_load_int(&witness_trace); if (trace) { struct witness_lock_order_data *data; pstackv = false; data = witness_lock_order_get(w, w1); if (data != NULL) { stack_copy(&data->wlod_stack, &pstack); pstackv = true; } } mtx_unlock_spin(&w_mtx); #ifdef WITNESS_NO_VNODE /* * There are known LORs between VNODE locks. They are * not an indication of a bug. VNODE locks are flagged * as such (LO_IS_VNODE) and we don't yell if the LOR * is between 2 VNODE locks. */ if ((lock->lo_flags & LO_IS_VNODE) != 0 && (lock1->li_lock->lo_flags & LO_IS_VNODE) != 0) return; #endif /* * Ok, yell about it. */ print_lock_order = false; if ((lock->lo_flags & LO_SLEEPABLE) != 0 && (flags & LOP_NOSLEEP) == 0 && (lock1->li_flags & LI_SLEEPABLE) == 0) witness_output( "lock order reversal: (sleepable after non-sleepable)\n"); else if ((lock1->li_flags & LI_SLEEPABLE) == 0 && lock == &Giant.lock_object) witness_output( "lock order reversal: (Giant after non-sleepable)\n"); else { witness_output("lock order reversal:\n"); print_lock_order = true; } /* * Try to locate an earlier lock with * witness w in our list. */ do { lock2 = &lle->ll_children[i]; MPASS(lock2->li_lock != NULL); if (lock2->li_lock->lo_witness == w) break; if (i == 0 && lle->ll_next != NULL) { lle = lle->ll_next; i = lle->ll_count - 1; MPASS(i >= 0 && i < LOCK_NCHILDREN); } else i--; } while (i >= 0); if (i < 0) { witness_output(" 1st %p %s (%s, %s) @ %s:%d\n", lock1->li_lock, lock1->li_lock->lo_name, w1->w_name, w1->w_class->lc_name, fixup_filename(lock1->li_file), lock1->li_line); witness_output(" 2nd %p %s (%s, %s) @ %s:%d\n", lock, lock->lo_name, w->w_name, w->w_class->lc_name, fixup_filename(file), line); } else { struct witness *w2 = lock2->li_lock->lo_witness; witness_output(" 1st %p %s (%s, %s) @ %s:%d\n", lock2->li_lock, lock2->li_lock->lo_name, w2->w_name, w2->w_class->lc_name, fixup_filename(lock2->li_file), lock2->li_line); witness_output(" 2nd %p %s (%s, %s) @ %s:%d\n", lock1->li_lock, lock1->li_lock->lo_name, w1->w_name, w1->w_class->lc_name, fixup_filename(lock1->li_file), lock1->li_line); witness_output(" 3rd %p %s (%s, %s) @ %s:%d\n", lock, lock->lo_name, w->w_name, w->w_class->lc_name, fixup_filename(file), line); } if (trace) { char buf[64]; struct sbuf sb; struct verbose_tracker *t; sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN); sbuf_set_drain(&sb, witness_output_drain, NULL); if (pstackv) { sbuf_printf(&sb, "lock order %s -> %s established at:\n", w->w_name, w1->w_name); stack_sbuf_print_flags(&sb, &pstack, M_NOWAIT, STACK_SBUF_FMT_LONG); } else if (trace > 1 && print_lock_order && (t = malloc(sizeof(struct verbose_tracker), M_TEMP, M_NOWAIT | M_ZERO)) != NULL) { /* * We make a purposeful decision to * ignore generation changes while * printing. The two locks in * question are in use, so won't be * going away. There is a small * chance that intermediate locks * in a lock chain get destroyed * while we are traversing the * chain or printing them, but even * then nothing "bad" should happen * with the current code since the * WITNESS objects are not actually * freed and re-used. If that changes, * we might need to reassess the * decision to ignore generation. */ init_verbose_tracker(t, &sb, M_NOWAIT, false); reset_verbose_tracker(t, 0); sbuf_printf(&sb, "All lock orders from %s -> %s:\n", w->w_name, w1->w_name); sbuf_print_verbose_witness_chains(t, w->w_index, w1->w_index); sbuf_putc(&sb, '\n'); sbuf_print_verbose_witness_stacks(t); free(t, M_TEMP); } sbuf_printf(&sb, "lock order %s -> %s attempted at:\n", w1->w_name, w->w_name); stack_save(&pstack); stack_sbuf_print_flags(&sb, &pstack, M_NOWAIT, STACK_SBUF_FMT_LONG); sbuf_finish(&sb); sbuf_delete(&sb); } witness_enter_debugger(__func__); return; } } /* * If requested, build a new lock order. However, don't build a new * relationship between a sleepable lock and Giant if it is in the * wrong direction. The correct lock order is that sleepable locks * always come before Giant. */ if (flags & LOP_NEWORDER && !(plock->li_lock == &Giant.lock_object && (lock->lo_flags & LO_SLEEPABLE) != 0 && (flags & LOP_NOSLEEP) == 0)) { CTR3(KTR_WITNESS, "%s: adding %s as a child of %s", __func__, w->w_name, plock->li_lock->lo_witness->w_name); itismychild(plock->li_lock->lo_witness, w); } out: mtx_unlock_spin(&w_mtx); } void witness_lock(struct lock_object *lock, int flags, const char *file, int line) { struct lock_list_entry **lock_list, *lle; struct lock_instance *instance; struct witness *w; struct thread *td; if (witness_cold || witness_watch == -1 || lock->lo_witness == NULL || KERNEL_PANICKED()) return; w = lock->lo_witness; td = curthread; /* Determine lock list for this lock. */ if (LOCK_CLASS(lock)->lc_flags & LC_SLEEPLOCK) lock_list = &td->td_sleeplocks; else lock_list = PCPU_PTR(spinlocks); /* Update per-witness last file and line acquire. */ w->w_file = file; w->w_line = line; /* Check to see if we are recursing on a lock we already own. */ instance = find_instance(*lock_list, lock); if (instance != NULL) { instance->li_flags++; CTR4(KTR_WITNESS, "%s: pid %d recursed on %s r=%d", __func__, td->td_proc->p_pid, lock->lo_name, instance->li_flags & LI_RECURSEMASK); return; } /* Find the next open lock instance in the list and fill it. */ lle = *lock_list; if (lle == NULL || lle->ll_count == LOCK_NCHILDREN) { lle = witness_lock_list_get(); if (lle == NULL) return; lle->ll_next = *lock_list; CTR3(KTR_WITNESS, "%s: pid %d added lle %p", __func__, td->td_proc->p_pid, lle); *lock_list = lle; } instance = &lle->ll_children[lle->ll_count++]; instance->li_lock = lock; instance->li_line = line; instance->li_file = file; instance->li_flags = 0; if ((flags & LOP_EXCLUSIVE) != 0) instance->li_flags |= LI_EXCLUSIVE; if ((lock->lo_flags & LO_SLEEPABLE) != 0 && (flags & LOP_NOSLEEP) == 0) instance->li_flags |= LI_SLEEPABLE; CTR4(KTR_WITNESS, "%s: pid %d added %s as lle[%d]", __func__, td->td_proc->p_pid, lock->lo_name, lle->ll_count - 1); } void witness_upgrade(struct lock_object *lock, int flags, const char *file, int line) { struct lock_instance *instance; struct lock_class *class; KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); if (lock->lo_witness == NULL || witness_watch == -1 || KERNEL_PANICKED()) return; class = LOCK_CLASS(lock); if (witness_watch) { if ((lock->lo_flags & LO_UPGRADABLE) == 0) kassert_panic( "upgrade of non-upgradable lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((class->lc_flags & LC_SLEEPLOCK) == 0) kassert_panic( "upgrade of non-sleep lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); } instance = find_instance(curthread->td_sleeplocks, lock); if (instance == NULL) { kassert_panic("upgrade of unlocked lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); return; } if (witness_watch) { if ((instance->li_flags & LI_EXCLUSIVE) != 0) kassert_panic( "upgrade of exclusive lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((instance->li_flags & LI_RECURSEMASK) != 0) kassert_panic( "upgrade of recursed lock (%s) %s r=%d @ %s:%d", class->lc_name, lock->lo_name, instance->li_flags & LI_RECURSEMASK, fixup_filename(file), line); } instance->li_flags |= LI_EXCLUSIVE; } void witness_downgrade(struct lock_object *lock, int flags, const char *file, int line) { struct lock_instance *instance; struct lock_class *class; KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); if (lock->lo_witness == NULL || witness_watch == -1 || KERNEL_PANICKED()) return; class = LOCK_CLASS(lock); if (witness_watch) { if ((lock->lo_flags & LO_UPGRADABLE) == 0) kassert_panic( "downgrade of non-upgradable lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((class->lc_flags & LC_SLEEPLOCK) == 0) kassert_panic( "downgrade of non-sleep lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); } instance = find_instance(curthread->td_sleeplocks, lock); if (instance == NULL) { kassert_panic("downgrade of unlocked lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); return; } if (witness_watch) { if ((instance->li_flags & LI_EXCLUSIVE) == 0) kassert_panic( "downgrade of shared lock (%s) %s @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((instance->li_flags & LI_RECURSEMASK) != 0) kassert_panic( "downgrade of recursed lock (%s) %s r=%d @ %s:%d", class->lc_name, lock->lo_name, instance->li_flags & LI_RECURSEMASK, fixup_filename(file), line); } instance->li_flags &= ~LI_EXCLUSIVE; } void witness_unlock(struct lock_object *lock, int flags, const char *file, int line) { struct lock_list_entry **lock_list, *lle; struct lock_instance *instance; struct lock_class *class; struct thread *td; register_t s; int i, j; if (witness_cold || lock->lo_witness == NULL || KERNEL_PANICKED()) return; td = curthread; class = LOCK_CLASS(lock); /* Find lock instance associated with this lock. */ if (class->lc_flags & LC_SLEEPLOCK) lock_list = &td->td_sleeplocks; else lock_list = PCPU_PTR(spinlocks); lle = *lock_list; for (; *lock_list != NULL; lock_list = &(*lock_list)->ll_next) for (i = 0; i < (*lock_list)->ll_count; i++) { instance = &(*lock_list)->ll_children[i]; if (instance->li_lock == lock) goto found; } /* * When disabling WITNESS through witness_watch we could end up in * having registered locks in the td_sleeplocks queue. * We have to make sure we flush these queues, so just search for * eventual register locks and remove them. */ if (witness_watch > 0) { kassert_panic("lock (%s) %s not locked @ %s:%d", class->lc_name, lock->lo_name, fixup_filename(file), line); return; } else { return; } found: /* First, check for shared/exclusive mismatches. */ if ((instance->li_flags & LI_EXCLUSIVE) != 0 && witness_watch > 0 && (flags & LOP_EXCLUSIVE) == 0) { witness_output("shared unlock of (%s) %s @ %s:%d\n", class->lc_name, lock->lo_name, fixup_filename(file), line); witness_output("while exclusively locked from %s:%d\n", fixup_filename(instance->li_file), instance->li_line); kassert_panic("excl->ushare"); } if ((instance->li_flags & LI_EXCLUSIVE) == 0 && witness_watch > 0 && (flags & LOP_EXCLUSIVE) != 0) { witness_output("exclusive unlock of (%s) %s @ %s:%d\n", class->lc_name, lock->lo_name, fixup_filename(file), line); witness_output("while share locked from %s:%d\n", fixup_filename(instance->li_file), instance->li_line); kassert_panic("share->uexcl"); } /* If we are recursed, unrecurse. */ if ((instance->li_flags & LI_RECURSEMASK) > 0) { CTR4(KTR_WITNESS, "%s: pid %d unrecursed on %s r=%d", __func__, td->td_proc->p_pid, instance->li_lock->lo_name, instance->li_flags); instance->li_flags--; return; } /* The lock is now being dropped, check for NORELEASE flag */ if ((instance->li_flags & LI_NORELEASE) != 0 && witness_watch > 0) { witness_output("forbidden unlock of (%s) %s @ %s:%d\n", class->lc_name, lock->lo_name, fixup_filename(file), line); kassert_panic("lock marked norelease"); } /* Otherwise, remove this item from the list. */ s = intr_disable(); CTR4(KTR_WITNESS, "%s: pid %d removed %s from lle[%d]", __func__, td->td_proc->p_pid, instance->li_lock->lo_name, (*lock_list)->ll_count - 1); for (j = i; j < (*lock_list)->ll_count - 1; j++) (*lock_list)->ll_children[j] = (*lock_list)->ll_children[j + 1]; (*lock_list)->ll_count--; intr_restore(s); /* * In order to reduce contention on w_mtx, we want to keep always an * head object into lists so that frequent allocation from the * free witness pool (and subsequent locking) is avoided. * In order to maintain the current code simple, when the head * object is totally unloaded it means also that we do not have * further objects in the list, so the list ownership needs to be * hand over to another object if the current head needs to be freed. */ if ((*lock_list)->ll_count == 0) { if (*lock_list == lle) { if (lle->ll_next == NULL) return; } else lle = *lock_list; *lock_list = lle->ll_next; CTR3(KTR_WITNESS, "%s: pid %d removed lle %p", __func__, td->td_proc->p_pid, lle); witness_lock_list_free(lle); } } void witness_thread_exit(struct thread *td) { struct lock_list_entry *lle; int i, n; lle = td->td_sleeplocks; if (lle == NULL || KERNEL_PANICKED()) return; if (lle->ll_count != 0) { for (n = 0; lle != NULL; lle = lle->ll_next) for (i = lle->ll_count - 1; i >= 0; i--) { if (n == 0) witness_output( "Thread %p exiting with the following locks held:\n", td); n++; witness_list_lock(&lle->ll_children[i], witness_output); } kassert_panic( "Thread %p cannot exit while holding sleeplocks\n", td); } witness_lock_list_free(lle); } /* * Warn if any locks other than 'lock' are held. Flags can be passed in to * exempt Giant and sleepable locks from the checks as well. If any * non-exempt locks are held, then a supplied message is printed to the * output channel along with a list of the offending locks. If indicated in the * flags then a failure results in a panic as well. */ int witness_warn(int flags, struct lock_object *lock, const char *fmt, ...) { struct lock_list_entry *lock_list, *lle; struct lock_instance *lock1; struct thread *td; va_list ap; int i, n; if (witness_cold || witness_watch < 1 || KERNEL_PANICKED()) return (0); n = 0; td = curthread; for (lle = td->td_sleeplocks; lle != NULL; lle = lle->ll_next) for (i = lle->ll_count - 1; i >= 0; i--) { lock1 = &lle->ll_children[i]; if (lock1->li_lock == lock) continue; if (flags & WARN_GIANTOK && lock1->li_lock == &Giant.lock_object) continue; if (flags & WARN_SLEEPOK && (lock1->li_flags & LI_SLEEPABLE) != 0) continue; if (n == 0) { va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); printf(" with the following %slocks held:\n", (flags & WARN_SLEEPOK) != 0 ? "non-sleepable " : ""); } n++; witness_list_lock(lock1, printf); } /* * Pin the thread in order to avoid problems with thread migration. * Once that all verifies are passed about spinlocks ownership, * the thread is in a safe path and it can be unpinned. */ sched_pin(); lock_list = PCPU_GET(spinlocks); if (lock_list != NULL && lock_list->ll_count != 0) { sched_unpin(); /* * We should only have one spinlock and as long as * the flags cannot match for this locks class, * check if the first spinlock is the one curthread * should hold. */ lock1 = &lock_list->ll_children[lock_list->ll_count - 1]; if (lock_list->ll_count == 1 && lock_list->ll_next == NULL && lock1->li_lock == lock && n == 0) return (0); va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); printf(" with the following %slocks held:\n", (flags & WARN_SLEEPOK) != 0 ? "non-sleepable " : ""); n += witness_list_locks(&lock_list, printf); } else sched_unpin(); if (td->td_no_sleeping != 0 && (flags & WARN_SLEEPOK) != 0) { va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); printf(" with %d sleep inhibitors\n", td->td_no_sleeping); n += td->td_no_sleeping; } if (flags & WARN_PANIC && n) kassert_panic("%s", __func__); else witness_debugger(n, __func__); return (n); } const char * witness_file(struct lock_object *lock) { struct witness *w; if (witness_cold || witness_watch < 1 || lock->lo_witness == NULL) return ("?"); w = lock->lo_witness; return (w->w_file); } int witness_line(struct lock_object *lock) { struct witness *w; if (witness_cold || witness_watch < 1 || lock->lo_witness == NULL) return (0); w = lock->lo_witness; return (w->w_line); } static struct witness * enroll(const char *description, struct lock_class *lock_class) { struct witness *w; MPASS(description != NULL); if (witness_watch == -1 || KERNEL_PANICKED()) return (NULL); if ((lock_class->lc_flags & LC_SPINLOCK)) { if (witness_skipspin) return (NULL); } else if ((lock_class->lc_flags & LC_SLEEPLOCK) == 0) { kassert_panic("lock class %s is not sleep or spin", lock_class->lc_name); return (NULL); } mtx_lock_spin(&w_mtx); w = witness_hash_get(description); if (w) goto found; if ((w = witness_get()) == NULL) return (NULL); MPASS(strlen(description) < MAX_W_NAME); strcpy(w->w_name, description); w->w_class = lock_class; w->w_refcount = 1; STAILQ_INSERT_HEAD(&w_all, w, w_list); if (lock_class->lc_flags & LC_SPINLOCK) { STAILQ_INSERT_HEAD(&w_spin, w, w_typelist); w_spin_cnt++; } else if (lock_class->lc_flags & LC_SLEEPLOCK) { STAILQ_INSERT_HEAD(&w_sleep, w, w_typelist); w_sleep_cnt++; } /* Insert new witness into the hash */ witness_hash_put(w); witness_increment_graph_generation(); mtx_unlock_spin(&w_mtx); return (w); found: w->w_refcount++; if (w->w_refcount == 1) w->w_class = lock_class; mtx_unlock_spin(&w_mtx); if (lock_class != w->w_class) kassert_panic( "lock (%s) %s does not match earlier (%s) lock", description, lock_class->lc_name, w->w_class->lc_name); return (w); } static void depart(struct witness *w) { MPASS(w->w_refcount == 0); if (w->w_class->lc_flags & LC_SLEEPLOCK) { w_sleep_cnt--; } else { w_spin_cnt--; } /* * Set file to NULL as it may point into a loadable module. */ w->w_file = NULL; w->w_line = 0; witness_increment_graph_generation(); } static void adopt(struct witness *parent, struct witness *child) { int pi, ci, i, j; if (witness_cold == 0) mtx_assert(&w_mtx, MA_OWNED); /* If the relationship is already known, there's no work to be done. */ if (isitmychild(parent, child)) return; /* When the structure of the graph changes, bump up the generation. */ witness_increment_graph_generation(); /* * The hard part ... create the direct relationship, then propagate all * indirect relationships. */ pi = parent->w_index; ci = child->w_index; WITNESS_INDEX_ASSERT(pi); WITNESS_INDEX_ASSERT(ci); MPASS(pi != ci); w_rmatrix[pi][ci] |= WITNESS_PARENT; w_rmatrix[ci][pi] |= WITNESS_CHILD; /* * If parent was not already an ancestor of child, * then we increment the descendant and ancestor counters. */ if ((w_rmatrix[pi][ci] & WITNESS_ANCESTOR) == 0) { parent->w_num_descendants++; child->w_num_ancestors++; } /* * Find each ancestor of 'pi'. Note that 'pi' itself is counted as * an ancestor of 'pi' during this loop. */ for (i = 1; i <= w_max_used_index; i++) { if ((w_rmatrix[i][pi] & WITNESS_ANCESTOR_MASK) == 0 && (i != pi)) continue; /* Find each descendant of 'i' and mark it as a descendant. */ for (j = 1; j <= w_max_used_index; j++) { /* * Skip children that are already marked as * descendants of 'i'. */ if (w_rmatrix[i][j] & WITNESS_ANCESTOR_MASK) continue; /* * We are only interested in descendants of 'ci'. Note * that 'ci' itself is counted as a descendant of 'ci'. */ if ((w_rmatrix[ci][j] & WITNESS_ANCESTOR_MASK) == 0 && (j != ci)) continue; w_rmatrix[i][j] |= WITNESS_ANCESTOR; w_rmatrix[j][i] |= WITNESS_DESCENDANT; w_data[i].w_num_descendants++; w_data[j].w_num_ancestors++; /* * Make sure we aren't marking a node as both an * ancestor and descendant. We should have caught * this as a lock order reversal earlier. */ if ((w_rmatrix[i][j] & WITNESS_ANCESTOR_MASK) && (w_rmatrix[i][j] & WITNESS_DESCENDANT_MASK)) { printf("witness rmatrix paradox! [%d][%d]=%d " "both ancestor and descendant\n", i, j, w_rmatrix[i][j]); kdb_backtrace(); printf("Witness disabled.\n"); witness_watch = -1; } if ((w_rmatrix[j][i] & WITNESS_ANCESTOR_MASK) && (w_rmatrix[j][i] & WITNESS_DESCENDANT_MASK)) { printf("witness rmatrix paradox! [%d][%d]=%d " "both ancestor and descendant\n", j, i, w_rmatrix[j][i]); kdb_backtrace(); printf("Witness disabled.\n"); witness_watch = -1; } } } } static void itismychild(struct witness *parent, struct witness *child) { int unlocked; MPASS(child != NULL && parent != NULL); if (witness_cold == 0) mtx_assert(&w_mtx, MA_OWNED); if (!witness_lock_type_equal(parent, child)) { if (witness_cold == 0) { unlocked = 1; mtx_unlock_spin(&w_mtx); } else { unlocked = 0; } kassert_panic( "%s: parent \"%s\" (%s) and child \"%s\" (%s) are not " "the same lock type", __func__, parent->w_name, parent->w_class->lc_name, child->w_name, child->w_class->lc_name); if (unlocked) mtx_lock_spin(&w_mtx); } adopt(parent, child); } /* * Generic code for the isitmy*() functions. The rmask parameter is the * expected relationship of w1 to w2. */ static int _isitmyx(struct witness *w1, struct witness *w2, int rmask, const char *fname) { unsigned char r1, r2; int i1, i2; i1 = w1->w_index; i2 = w2->w_index; WITNESS_INDEX_ASSERT(i1); WITNESS_INDEX_ASSERT(i2); r1 = w_rmatrix[i1][i2] & WITNESS_RELATED_MASK; r2 = w_rmatrix[i2][i1] & WITNESS_RELATED_MASK; /* The flags on one better be the inverse of the flags on the other */ if (!((WITNESS_ATOD(r1) == r2 && WITNESS_DTOA(r2) == r1) || (WITNESS_DTOA(r1) == r2 && WITNESS_ATOD(r2) == r1))) { /* Don't squawk if we're potentially racing with an update. */ if (!mtx_owned(&w_mtx)) return (0); printf("%s: rmatrix mismatch between %s (index %d) and %s " "(index %d): w_rmatrix[%d][%d] == %hhx but " "w_rmatrix[%d][%d] == %hhx\n", fname, w1->w_name, i1, w2->w_name, i2, i1, i2, r1, i2, i1, r2); kdb_backtrace(); printf("Witness disabled.\n"); witness_watch = -1; } return (r1 & rmask); } /* * Checks if @child is a direct child of @parent. */ static int isitmychild(struct witness *parent, struct witness *child) { return (_isitmyx(parent, child, WITNESS_PARENT, __func__)); } /* * Checks if @descendant is a direct or inderect descendant of @ancestor. */ static int isitmydescendant(struct witness *ancestor, struct witness *descendant) { return (_isitmyx(ancestor, descendant, WITNESS_ANCESTOR_MASK, __func__)); } static int blessed(struct witness *w1, struct witness *w2) { int i; struct witness_blessed *b; for (i = 0; i < nitems(blessed_list); i++) { b = &blessed_list[i]; if (strcmp(w1->w_name, b->b_lock1) == 0) { if (strcmp(w2->w_name, b->b_lock2) == 0) return (1); continue; } if (strcmp(w1->w_name, b->b_lock2) == 0) if (strcmp(w2->w_name, b->b_lock1) == 0) return (1); } return (0); } static struct witness * witness_get(void) { struct witness *w; int index; if (witness_cold == 0) mtx_assert(&w_mtx, MA_OWNED); if (witness_watch == -1) { mtx_unlock_spin(&w_mtx); return (NULL); } if (STAILQ_EMPTY(&w_free)) { witness_watch = -1; mtx_unlock_spin(&w_mtx); printf("WITNESS: unable to allocate a new witness object\n"); return (NULL); } w = STAILQ_FIRST(&w_free); STAILQ_REMOVE_HEAD(&w_free, w_list); w_free_cnt--; index = w->w_index; MPASS(index > 0 && index == w_max_used_index + 1 && index < witness_count); bzero(w, sizeof(*w)); w->w_index = index; if (index > w_max_used_index) w_max_used_index = index; return (w); } static void witness_free(struct witness *w) { STAILQ_INSERT_HEAD(&w_free, w, w_list); w_free_cnt++; } static struct lock_list_entry * witness_lock_list_get(void) { struct lock_list_entry *lle; if (witness_watch == -1) return (NULL); mtx_lock_spin(&w_mtx); lle = w_lock_list_free; if (lle == NULL) { witness_watch = -1; mtx_unlock_spin(&w_mtx); printf("%s: witness exhausted\n", __func__); return (NULL); } w_lock_list_free = lle->ll_next; mtx_unlock_spin(&w_mtx); bzero(lle, sizeof(*lle)); return (lle); } static void witness_lock_list_free(struct lock_list_entry *lle) { mtx_lock_spin(&w_mtx); lle->ll_next = w_lock_list_free; w_lock_list_free = lle; mtx_unlock_spin(&w_mtx); } static struct lock_instance * find_instance(struct lock_list_entry *list, const struct lock_object *lock) { struct lock_list_entry *lle; struct lock_instance *instance; int i; for (lle = list; lle != NULL; lle = lle->ll_next) for (i = lle->ll_count - 1; i >= 0; i--) { instance = &lle->ll_children[i]; if (instance->li_lock == lock) return (instance); } return (NULL); } static void witness_list_lock(struct lock_instance *instance, int (*prnt)(const char *fmt, ...)) { struct lock_object *lock; lock = instance->li_lock; prnt("%s %s %s", (instance->li_flags & LI_EXCLUSIVE) != 0 ? "exclusive" : "shared", LOCK_CLASS(lock)->lc_name, lock->lo_name); if (lock->lo_witness->w_name != lock->lo_name) prnt(" (%s)", lock->lo_witness->w_name); prnt(" r = %d (%p) locked @ %s:%d\n", instance->li_flags & LI_RECURSEMASK, lock, fixup_filename(instance->li_file), instance->li_line); } static int witness_output(const char *fmt, ...) { va_list ap; int ret; va_start(ap, fmt); ret = witness_voutput(fmt, ap); va_end(ap); return (ret); } static int witness_voutput(const char *fmt, va_list ap) { int ret; ret = 0; switch (witness_channel) { case WITNESS_CONSOLE: ret = vprintf(fmt, ap); break; case WITNESS_LOG: vlog(LOG_NOTICE, fmt, ap); break; case WITNESS_NONE: break; } return (ret); } #ifdef DDB static int witness_thread_has_locks(struct thread *td) { if (td->td_sleeplocks == NULL) return (0); return (td->td_sleeplocks->ll_count != 0); } static int witness_proc_has_locks(struct proc *p) { struct thread *td; FOREACH_THREAD_IN_PROC(p, td) { if (witness_thread_has_locks(td)) return (1); } return (0); } #endif int witness_list_locks(struct lock_list_entry **lock_list, int (*prnt)(const char *fmt, ...)) { struct lock_list_entry *lle; int i, nheld; nheld = 0; for (lle = *lock_list; lle != NULL; lle = lle->ll_next) for (i = lle->ll_count - 1; i >= 0; i--) { witness_list_lock(&lle->ll_children[i], prnt); nheld++; } return (nheld); } /* * This is a bit risky at best. We call this function when we have timed * out acquiring a spin lock, and we assume that the other CPU is stuck * with this lock held. So, we go groveling around in the other CPU's * per-cpu data to try to find the lock instance for this spin lock to * see when it was last acquired. */ void witness_display_spinlock(struct lock_object *lock, struct thread *owner, int (*prnt)(const char *fmt, ...)) { struct lock_instance *instance; struct pcpu *pc; if (owner->td_critnest == 0 || owner->td_oncpu == NOCPU) return; pc = pcpu_find(owner->td_oncpu); instance = find_instance(pc->pc_spinlocks, lock); if (instance != NULL) witness_list_lock(instance, prnt); } void witness_save(struct lock_object *lock, const char **filep, int *linep) { struct lock_list_entry *lock_list; struct lock_instance *instance; struct lock_class *class; /* Initialize for KMSAN's benefit. */ *filep = NULL; *linep = 0; /* * This function is used independently in locking code to deal with * Giant, SCHEDULER_STOPPED() check can be removed here after Giant * is gone. */ if (SCHEDULER_STOPPED()) return; KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); if (lock->lo_witness == NULL || witness_watch == -1 || KERNEL_PANICKED()) return; class = LOCK_CLASS(lock); if (class->lc_flags & LC_SLEEPLOCK) lock_list = curthread->td_sleeplocks; else { if (witness_skipspin) return; lock_list = PCPU_GET(spinlocks); } instance = find_instance(lock_list, lock); if (instance == NULL) { kassert_panic("%s: lock (%s) %s not locked", __func__, class->lc_name, lock->lo_name); return; } *filep = instance->li_file; *linep = instance->li_line; } void witness_restore(struct lock_object *lock, const char *file, int line) { struct lock_list_entry *lock_list; struct lock_instance *instance; struct lock_class *class; /* * This function is used independently in locking code to deal with * Giant, SCHEDULER_STOPPED() check can be removed here after Giant * is gone. */ if (SCHEDULER_STOPPED()) return; KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); if (lock->lo_witness == NULL || witness_watch == -1 || KERNEL_PANICKED()) return; class = LOCK_CLASS(lock); if (class->lc_flags & LC_SLEEPLOCK) lock_list = curthread->td_sleeplocks; else { if (witness_skipspin) return; lock_list = PCPU_GET(spinlocks); } instance = find_instance(lock_list, lock); if (instance == NULL) kassert_panic("%s: lock (%s) %s not locked", __func__, class->lc_name, lock->lo_name); lock->lo_witness->w_file = file; lock->lo_witness->w_line = line; if (instance == NULL) return; instance->li_file = file; instance->li_line = line; } static bool witness_find_instance(const struct lock_object *lock, struct lock_instance **instance) { #ifdef INVARIANT_SUPPORT struct lock_class *class; if (lock->lo_witness == NULL || witness_watch < 1 || KERNEL_PANICKED()) return (false); class = LOCK_CLASS(lock); if ((class->lc_flags & LC_SLEEPLOCK) != 0) { *instance = find_instance(curthread->td_sleeplocks, lock); return (true); } else if ((class->lc_flags & LC_SPINLOCK) != 0) { *instance = find_instance(PCPU_GET(spinlocks), lock); return (true); } else { kassert_panic("Lock (%s) %s is not sleep or spin!", class->lc_name, lock->lo_name); return (false); } #else return (false); #endif } void witness_assert(const struct lock_object *lock, int flags, const char *file, int line) { #ifdef INVARIANT_SUPPORT struct lock_instance *instance; struct lock_class *class; if (!witness_find_instance(lock, &instance)) return; class = LOCK_CLASS(lock); switch (flags) { case LA_UNLOCKED: if (instance != NULL) kassert_panic("Lock (%s) %s locked @ %s:%d.", class->lc_name, lock->lo_name, fixup_filename(file), line); break; case LA_LOCKED: case LA_LOCKED | LA_RECURSED: case LA_LOCKED | LA_NOTRECURSED: case LA_SLOCKED: case LA_SLOCKED | LA_RECURSED: case LA_SLOCKED | LA_NOTRECURSED: case LA_XLOCKED: case LA_XLOCKED | LA_RECURSED: case LA_XLOCKED | LA_NOTRECURSED: if (instance == NULL) { kassert_panic("Lock (%s) %s not locked @ %s:%d.", class->lc_name, lock->lo_name, fixup_filename(file), line); break; } if ((flags & LA_XLOCKED) != 0 && (instance->li_flags & LI_EXCLUSIVE) == 0) kassert_panic( "Lock (%s) %s not exclusively locked @ %s:%d.", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((flags & LA_SLOCKED) != 0 && (instance->li_flags & LI_EXCLUSIVE) != 0) kassert_panic( "Lock (%s) %s exclusively locked @ %s:%d.", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((flags & LA_RECURSED) != 0 && (instance->li_flags & LI_RECURSEMASK) == 0) kassert_panic("Lock (%s) %s not recursed @ %s:%d.", class->lc_name, lock->lo_name, fixup_filename(file), line); if ((flags & LA_NOTRECURSED) != 0 && (instance->li_flags & LI_RECURSEMASK) != 0) kassert_panic("Lock (%s) %s recursed @ %s:%d.", class->lc_name, lock->lo_name, fixup_filename(file), line); break; default: kassert_panic("Invalid lock assertion at %s:%d.", fixup_filename(file), line); } #endif /* INVARIANT_SUPPORT */ } /* * Checks the ownership of the lock by curthread, consulting the witness list. * Returns: * 0 if witness is disabled or did not work * -1 if not owned * 1 if owned */ int witness_is_owned(const struct lock_object *lock) { #ifdef INVARIANT_SUPPORT struct lock_instance *instance; if (!witness_find_instance(lock, &instance)) return (0); return (instance == NULL ? -1 : 1); #else return (0); #endif } static void witness_setflag(struct lock_object *lock, int flag, int set) { struct lock_list_entry *lock_list; struct lock_instance *instance; struct lock_class *class; if (lock->lo_witness == NULL || witness_watch == -1 || KERNEL_PANICKED()) return; class = LOCK_CLASS(lock); if (class->lc_flags & LC_SLEEPLOCK) lock_list = curthread->td_sleeplocks; else { if (witness_skipspin) return; lock_list = PCPU_GET(spinlocks); } instance = find_instance(lock_list, lock); if (instance == NULL) { kassert_panic("%s: lock (%s) %s not locked", __func__, class->lc_name, lock->lo_name); return; } if (set) instance->li_flags |= flag; else instance->li_flags &= ~flag; } void witness_norelease(struct lock_object *lock) { witness_setflag(lock, LI_NORELEASE, 1); } void witness_releaseok(struct lock_object *lock) { witness_setflag(lock, LI_NORELEASE, 0); } #ifdef DDB static void witness_ddb_list(struct thread *td) { KASSERT(witness_cold == 0, ("%s: witness_cold", __func__)); KASSERT(kdb_active, ("%s: not in the debugger", __func__)); if (witness_watch < 1) return; witness_list_locks(&td->td_sleeplocks, db_printf); /* * We only handle spinlocks if td == curthread. This is somewhat broken * if td is currently executing on some other CPU and holds spin locks * as we won't display those locks. If we had a MI way of getting * the per-cpu data for a given cpu then we could use * td->td_oncpu to get the list of spinlocks for this thread * and "fix" this. * * That still wouldn't really fix this unless we locked the scheduler * lock or stopped the other CPU to make sure it wasn't changing the * list out from under us. It is probably best to just not try to * handle threads on other CPU's for now. */ if (td == curthread && PCPU_GET(spinlocks) != NULL) witness_list_locks(PCPU_PTR(spinlocks), db_printf); } DB_SHOW_COMMAND(locks, db_witness_list) { struct thread *td; if (have_addr) td = db_lookup_thread(addr, true); else td = kdb_thread; witness_ddb_list(td); } DB_SHOW_ALL_COMMAND(locks, db_witness_list_all) { struct thread *td; struct proc *p; /* * It would be nice to list only threads and processes that actually * held sleep locks, but that information is currently not exported * by WITNESS. */ FOREACH_PROC_IN_SYSTEM(p) { if (!witness_proc_has_locks(p)) continue; FOREACH_THREAD_IN_PROC(p, td) { if (!witness_thread_has_locks(td)) continue; db_printf("Process %d (%s) thread %p (%d)\n", p->p_pid, p->p_comm, td, td->td_tid); witness_ddb_list(td); if (db_pager_quit) return; } } } DB_SHOW_ALIAS_FLAGS(alllocks, db_witness_list_all, DB_CMD_MEMSAFE); DB_SHOW_COMMAND_FLAGS(witness, db_witness_display, DB_CMD_MEMSAFE) { witness_ddb_display(db_printf); } #endif static void sbuf_print_witness_badstacks(struct sbuf *sb, size_t *oldidx, bool check_generation) { struct witness_lock_order_data *data1, *data2, *tmp_data1, *tmp_data2; struct witness *tmp_w1, *tmp_w2, *w1, *w2; struct verbose_tracker *t; int generation, i, j; bool w1_is_parent, w2_is_parent; /* Allocate and init temporary storage space. */ tmp_w1 = malloc(sizeof(struct witness), M_TEMP, M_WAITOK | M_ZERO); tmp_w2 = malloc(sizeof(struct witness), M_TEMP, M_WAITOK | M_ZERO); tmp_data1 = malloc(sizeof(struct witness_lock_order_data), M_TEMP, M_WAITOK | M_ZERO); tmp_data2 = malloc(sizeof(struct witness_lock_order_data), M_TEMP, M_WAITOK | M_ZERO); stack_zero(&tmp_data1->wlod_stack); stack_zero(&tmp_data2->wlod_stack); t = malloc(sizeof(struct verbose_tracker), M_TEMP, M_WAITOK | M_ZERO); init_verbose_tracker(t, sb, M_WAITOK, check_generation); restart: mtx_lock_spin(&w_mtx); generation = w_generation; mtx_unlock_spin(&w_mtx); reset_verbose_tracker(t, generation); sbuf_printf(sb, "Number of known direct relationships is %d\n", w_lohash.wloh_count); for (i = 1; i < w_max_used_index; i++) { mtx_lock_spin(&w_mtx); if (check_generation && generation != w_generation) { mtx_unlock_spin(&w_mtx); /* The graph has changed, try again. */ *oldidx = 0; sbuf_clear(sb); goto restart; } w1 = &w_data[i]; if (w1->w_reversed == 0) { mtx_unlock_spin(&w_mtx); continue; } /* Copy w1 locally so we can release the spin lock. */ *tmp_w1 = *w1; mtx_unlock_spin(&w_mtx); if (tmp_w1->w_reversed == 0) continue; for (j = 1; j < w_max_used_index; j++) { if ((w_rmatrix[i][j] & WITNESS_REVERSAL) == 0 || i > j) continue; mtx_lock_spin(&w_mtx); if (check_generation && generation != w_generation) { mtx_unlock_spin(&w_mtx); /* The graph has changed, try again. */ *oldidx = 0; sbuf_clear(sb); goto restart; } w2 = &w_data[j]; data1 = witness_lock_order_get(w1, w2); data2 = witness_lock_order_get(w2, w1); /* * Copy information locally so we can release the * spin lock. */ *tmp_w2 = *w2; if (data1) { stack_zero(&tmp_data1->wlod_stack); stack_copy(&data1->wlod_stack, &tmp_data1->wlod_stack); } if (data2 && data2 != data1) { stack_zero(&tmp_data2->wlod_stack); stack_copy(&data2->wlod_stack, &tmp_data2->wlod_stack); } w1_is_parent = isitmydescendant(w1, w2); w2_is_parent = isitmydescendant(w2, w1); mtx_unlock_spin(&w_mtx); if (blessed(tmp_w1, tmp_w2)) continue; sbuf_printf(sb, "\nLock order reversal between \"%s\"(%s) and \"%s\"(%s)!\n", tmp_w1->w_name, tmp_w1->w_class->lc_name, tmp_w2->w_name, tmp_w2->w_class->lc_name); if (w1_is_parent || data1 != NULL) { sbuf_printf(sb, "All lock orders from \"%s\"(%s) -> \"%s\"(%s):\n", tmp_w1->w_name, tmp_w1->w_class->lc_name, tmp_w2->w_name, tmp_w2->w_class->lc_name); if (w1_is_parent) sbuf_print_verbose_witness_chains(t, i, j); if (data1 && !has_verbose_lockpair(t, i, j)) { sbuf_printf(t->sb, "** \"%s\" -> \"%s\"\n", tmp_w1->w_name, tmp_w2->w_name); add_verbose_lockpair(t, i, j); } sbuf_putc(sb, '\n'); sbuf_print_verbose_witness_stacks(t); sbuf_putc(sb, '\n'); reset_verbose_tracker(t, generation); } if (w2_is_parent || (data2 != NULL && data2 != data1)) { sbuf_printf(sb, "All lock orders from \"%s\"(%s) -> \"%s\"(%s):\n", tmp_w2->w_name, tmp_w2->w_class->lc_name, tmp_w1->w_name, tmp_w1->w_class->lc_name); if (w2_is_parent) sbuf_print_verbose_witness_chains(t, j, i); if (data2 && data2 != data1 && !has_verbose_lockpair(t, j, i)) { sbuf_printf(t->sb, "** \"%s\" -> \"%s\"\n", tmp_w2->w_name, tmp_w1->w_name); add_verbose_lockpair(t, j, i); } sbuf_putc(sb, '\n'); sbuf_print_verbose_witness_stacks(t); sbuf_putc(sb, '\n'); reset_verbose_tracker(t, generation); } } } mtx_lock_spin(&w_mtx); if (check_generation && generation != w_generation) { mtx_unlock_spin(&w_mtx); /* * The graph changed while we were printing stack data, * try again. */ *oldidx = 0; sbuf_clear(sb); goto restart; } mtx_unlock_spin(&w_mtx); /* Free temporary storage space. */ free(tmp_data1, M_TEMP); free(tmp_data2, M_TEMP); free(tmp_w1, M_TEMP); free(tmp_w2, M_TEMP); free(t, M_TEMP); } static int sysctl_debug_witness_badstacks(SYSCTL_HANDLER_ARGS) { struct sbuf *sb; int error; if (witness_watch < 1) { error = SYSCTL_OUT(req, w_notrunning, sizeof(w_notrunning)); return (error); } if (witness_cold) { error = SYSCTL_OUT(req, w_stillcold, sizeof(w_stillcold)); return (error); } error = 0; sb = sbuf_new(NULL, NULL, badstack_sbuf_size, SBUF_AUTOEXTEND); if (sb == NULL) return (ENOMEM); sbuf_print_witness_badstacks(sb, &req->oldidx, true); sbuf_finish(sb); error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); sbuf_delete(sb); return (error); } #ifdef DDB -static int -sbuf_db_printf_drain(void *arg __unused, const char *data, int len) -{ - return (db_printf("%.*s", len, data)); -} - DB_SHOW_COMMAND_FLAGS(badstacks, db_witness_badstacks, DB_CMD_MEMSAFE) { struct sbuf sb; char buffer[128]; size_t dummy; sbuf_new(&sb, buffer, sizeof(buffer), SBUF_FIXEDLEN); sbuf_set_drain(&sb, sbuf_db_printf_drain, NULL); sbuf_print_witness_badstacks(&sb, &dummy, false); sbuf_finish(&sb); } #endif static int sysctl_debug_witness_channel(SYSCTL_HANDLER_ARGS) { static const struct { enum witness_channel channel; const char *name; } channels[] = { { WITNESS_CONSOLE, "console" }, { WITNESS_LOG, "log" }, { WITNESS_NONE, "none" }, }; char buf[16]; u_int i; int error; buf[0] = '\0'; for (i = 0; i < nitems(channels); i++) if (witness_channel == channels[i].channel) { snprintf(buf, sizeof(buf), "%s", channels[i].name); break; } error = sysctl_handle_string(oidp, buf, sizeof(buf), req); if (error != 0 || req->newptr == NULL) return (error); error = EINVAL; for (i = 0; i < nitems(channels); i++) if (strcmp(channels[i].name, buf) == 0) { witness_channel = channels[i].channel; error = 0; break; } return (error); } static int sysctl_debug_witness_fullgraph(SYSCTL_HANDLER_ARGS) { struct witness *w; struct sbuf *sb; int error; #ifdef __i386__ error = SYSCTL_OUT(req, w_notallowed, sizeof(w_notallowed)); return (error); #endif if (witness_watch < 1) { error = SYSCTL_OUT(req, w_notrunning, sizeof(w_notrunning)); return (error); } if (witness_cold) { error = SYSCTL_OUT(req, w_stillcold, sizeof(w_stillcold)); return (error); } error = 0; error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); sb = sbuf_new_for_sysctl(NULL, NULL, FULLGRAPH_SBUF_SIZE, req); if (sb == NULL) return (ENOMEM); sbuf_putc(sb, '\n'); mtx_lock_spin(&w_mtx); STAILQ_FOREACH(w, &w_all, w_list) w->w_displayed = 0; STAILQ_FOREACH(w, &w_all, w_list) witness_add_fullgraph(sb, w); mtx_unlock_spin(&w_mtx); /* * Close the sbuf and return to userland. */ error = sbuf_finish(sb); sbuf_delete(sb); return (error); } static int sysctl_debug_witness_watch(SYSCTL_HANDLER_ARGS) { int error, value; value = witness_watch; error = sysctl_handle_int(oidp, &value, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (value > 1 || value < -1 || (witness_watch == -1 && value != witness_watch)) return (EINVAL); witness_watch = value; return (0); } static void witness_add_fullgraph(struct sbuf *sb, struct witness *w) { int i; if (w->w_displayed != 0 || (w->w_file == NULL && w->w_line == 0)) return; w->w_displayed = 1; WITNESS_INDEX_ASSERT(w->w_index); for (i = 1; i <= w_max_used_index; i++) { if (w_rmatrix[w->w_index][i] & WITNESS_PARENT) { sbuf_printf(sb, "\"%s\",\"%s\"\n", w->w_name, w_data[i].w_name); witness_add_fullgraph(sb, &w_data[i]); } } } /* * A simple hash function. Takes a key pointer and a key size. If size == 0, * interprets the key as a string and reads until the null * terminator. Otherwise, reads the first size bytes. Returns an unsigned 32-bit * hash value computed from the key. */ static uint32_t witness_hash_djb2(const uint8_t *key, uint32_t size) { unsigned int hash = 5381; int i; /* hash = hash * 33 + key[i] */ if (size) for (i = 0; i < size; i++) hash = ((hash << 5) + hash) + (unsigned int)key[i]; else for (i = 0; key[i] != 0; i++) hash = ((hash << 5) + hash) + (unsigned int)key[i]; return (hash); } /* * Initializes the two witness hash tables. Called exactly once from * witness_initialize(). */ static void witness_init_hash_tables(void) { int i; MPASS(witness_cold); /* Initialize the hash tables. */ for (i = 0; i < WITNESS_HASH_SIZE; i++) w_hash.wh_array[i] = NULL; w_hash.wh_size = WITNESS_HASH_SIZE; w_hash.wh_count = 0; /* Initialize the lock order data hash. */ w_lofree = NULL; for (i = 0; i < WITNESS_LO_DATA_COUNT; i++) { memset(&w_lodata[i], 0, sizeof(w_lodata[i])); w_lodata[i].wlod_next = w_lofree; w_lofree = &w_lodata[i]; } w_lohash.wloh_size = WITNESS_LO_HASH_SIZE; w_lohash.wloh_count = 0; for (i = 0; i < WITNESS_LO_HASH_SIZE; i++) w_lohash.wloh_array[i] = NULL; } static struct witness * witness_hash_get(const char *key) { struct witness *w; uint32_t hash; MPASS(key != NULL); if (witness_cold == 0) mtx_assert(&w_mtx, MA_OWNED); hash = witness_hash_djb2(key, 0) % w_hash.wh_size; w = w_hash.wh_array[hash]; while (w != NULL) { if (strcmp(w->w_name, key) == 0) goto out; w = w->w_hash_next; } out: return (w); } static void witness_hash_put(struct witness *w) { uint32_t hash; MPASS(w != NULL); MPASS(w->w_name != NULL); if (witness_cold == 0) mtx_assert(&w_mtx, MA_OWNED); KASSERT(witness_hash_get(w->w_name) == NULL, ("%s: trying to add a hash entry that already exists!", __func__)); KASSERT(w->w_hash_next == NULL, ("%s: w->w_hash_next != NULL", __func__)); hash = witness_hash_djb2(w->w_name, 0) % w_hash.wh_size; w->w_hash_next = w_hash.wh_array[hash]; w_hash.wh_array[hash] = w; w_hash.wh_count++; } static struct witness_lock_order_data * witness_lock_order_get(struct witness *parent, struct witness *child) { struct witness_lock_order_data *data = NULL; struct witness_lock_order_key key; unsigned int hash; MPASS(parent != NULL && child != NULL); key.from = parent->w_index; key.to = child->w_index; WITNESS_INDEX_ASSERT(key.from); WITNESS_INDEX_ASSERT(key.to); if ((w_rmatrix[parent->w_index][child->w_index] & WITNESS_LOCK_ORDER_KNOWN) == 0) goto out; hash = witness_hash_djb2((const char *)&key, sizeof(key)) % w_lohash.wloh_size; data = w_lohash.wloh_array[hash]; while (data != NULL) { if (witness_lock_order_key_equal(&data->wlod_key, &key)) break; data = data->wlod_next; } out: return (data); } /* * Verify that parent and child have a known relationship, are not the same, * and child is actually a child of parent. This is done without w_mtx * to avoid contention in the common case. */ static int witness_lock_order_check(struct witness *parent, struct witness *child) { if (parent != child && w_rmatrix[parent->w_index][child->w_index] & WITNESS_LOCK_ORDER_KNOWN && isitmychild(parent, child)) return (1); return (0); } static int witness_lock_order_add(struct witness *parent, struct witness *child) { struct witness_lock_order_data *data = NULL; struct witness_lock_order_key key; unsigned int hash; MPASS(parent != NULL && child != NULL); key.from = parent->w_index; key.to = child->w_index; WITNESS_INDEX_ASSERT(key.from); WITNESS_INDEX_ASSERT(key.to); if (w_rmatrix[parent->w_index][child->w_index] & WITNESS_LOCK_ORDER_KNOWN) return (1); hash = witness_hash_djb2((const char *)&key, sizeof(key)) % w_lohash.wloh_size; w_rmatrix[parent->w_index][child->w_index] |= WITNESS_LOCK_ORDER_KNOWN; data = w_lofree; if (data == NULL) return (0); w_lofree = data->wlod_next; data->wlod_next = w_lohash.wloh_array[hash]; data->wlod_key = key; w_lohash.wloh_array[hash] = data; w_lohash.wloh_count++; stack_save(&data->wlod_stack); return (1); } /* Call this whenever the structure of the witness graph changes. */ static void witness_increment_graph_generation(void) { if (witness_cold == 0) mtx_assert(&w_mtx, MA_OWNED); w_generation++; } static int witness_output_drain(void *arg __unused, const char *data, int len) { witness_output("%.*s", len, data); return (len); } static void witness_debugger(int cond, const char *msg) { char buf[32]; struct sbuf sb; struct stack st; if (!cond) return; if (witness_trace) { sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN); sbuf_set_drain(&sb, witness_output_drain, NULL); stack_save(&st); witness_output("stack backtrace:\n"); stack_sbuf_print_ddb(&sb, &st); sbuf_finish(&sb); } witness_enter_debugger(msg); } static void witness_enter_debugger(const char *msg) { #ifdef KDB if (witness_kdb) kdb_enter(KDB_WHY_WITNESS, msg); #endif } diff --git a/sys/sys/sbuf.h b/sys/sys/sbuf.h index 60dcda53a461..e9959d7b2a13 100644 --- a/sys/sys/sbuf.h +++ b/sys/sys/sbuf.h @@ -1,120 +1,123 @@ /*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2000-2008 Poul-Henning Kamp * Copyright (c) 2000-2008 Dag-Erling Smørgrav * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _SYS_SBUF_H_ #define _SYS_SBUF_H_ #include struct sbuf; typedef int (sbuf_drain_func)(void *, const char *, int); /* * Structure definition */ struct sbuf { char *s_buf; /* storage buffer */ sbuf_drain_func *s_drain_func; /* drain function */ void *s_drain_arg; /* user-supplied drain argument */ int s_error; /* current error code */ ssize_t s_size; /* size of storage buffer */ ssize_t s_len; /* current length of string */ #define SBUF_FIXEDLEN 0x00000000 /* fixed length buffer (default) */ #define SBUF_AUTOEXTEND 0x00000001 /* automatically extend buffer */ #define SBUF_INCLUDENUL 0x00000002 /* nulterm byte is counted in len */ #define SBUF_DRAINTOEOR 0x00000004 /* use section 0 as drain EOR marker */ #define SBUF_NOWAIT 0x00000008 /* Extend with non-blocking malloc */ #define SBUF_USRFLAGMSK 0x0000ffff /* mask of flags the user may specify */ #define SBUF_DYNAMIC 0x00010000 /* s_buf must be freed */ #define SBUF_FINISHED 0x00020000 /* set by sbuf_finish() */ #define SBUF_DYNSTRUCT 0x00080000 /* sbuf must be freed */ #define SBUF_INSECTION 0x00100000 /* set by sbuf_start_section() */ #define SBUF_DRAINATEOL 0x00200000 /* drained contents ended in \n */ int s_flags; /* flags */ ssize_t s_sect_len; /* current length of section */ ssize_t s_rec_off; /* current record start offset */ }; #ifndef HD_COLUMN_MASK #define HD_COLUMN_MASK 0xff #define HD_DELIM_MASK 0xff00 #define HD_OMIT_COUNT (1 << 16) #define HD_OMIT_HEX (1 << 17) #define HD_OMIT_CHARS (1 << 18) #endif /* HD_COLUMN_MASK */ __BEGIN_DECLS /* * API functions */ struct sbuf *sbuf_new(struct sbuf *, char *, int, int); #define sbuf_new_auto() \ sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND) int sbuf_get_flags(struct sbuf *); void sbuf_clear_flags(struct sbuf *, int); void sbuf_set_flags(struct sbuf *, int); void sbuf_clear(struct sbuf *); int sbuf_setpos(struct sbuf *, ssize_t); int sbuf_bcat(struct sbuf *, const void *, size_t); int sbuf_bcpy(struct sbuf *, const void *, size_t); int sbuf_cat(struct sbuf *, const char *); int sbuf_cpy(struct sbuf *, const char *); int sbuf_printf(struct sbuf *, const char *, ...) __printflike(2, 3); int sbuf_vprintf(struct sbuf *, const char *, __va_list) __printflike(2, 0); int sbuf_nl_terminate(struct sbuf *); int sbuf_putc(struct sbuf *, int); void sbuf_set_drain(struct sbuf *, sbuf_drain_func *, void *); int sbuf_drain(struct sbuf *); int sbuf_trim(struct sbuf *); int sbuf_error(const struct sbuf *); int sbuf_finish(struct sbuf *); char *sbuf_data(struct sbuf *); ssize_t sbuf_len(struct sbuf *); int sbuf_done(const struct sbuf *); void sbuf_delete(struct sbuf *); void sbuf_start_section(struct sbuf *, ssize_t *); ssize_t sbuf_end_section(struct sbuf *, ssize_t, size_t, int); void sbuf_hexdump(struct sbuf *, const void *, int, const char *, int); int sbuf_count_drain(void *arg, const char *data, int len); int sbuf_printf_drain(void *arg, const char *data, int len); void sbuf_putbuf(struct sbuf *); #ifdef _KERNEL struct uio; struct sbuf *sbuf_uionew(struct sbuf *, struct uio *, int *); int sbuf_bcopyin(struct sbuf *, const void *, size_t); int sbuf_copyin(struct sbuf *, const void *, size_t); +#ifdef DDB +int sbuf_db_printf_drain(void *arg, const char *data, int len); +#endif #endif __END_DECLS #endif