Index: head/sys/kern/subr_syscall.c =================================================================== --- head/sys/kern/subr_syscall.c (revision 367444) +++ head/sys/kern/subr_syscall.c (revision 367445) @@ -1,263 +1,264 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (C) 1994, David Greenman * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * Copyright (C) 2010 Konstantin Belousov * * This code is derived from software contributed to Berkeley by * the University of Utah, and William Jolitz. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. * * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 */ #include "opt_capsicum.h" #include "opt_ktrace.h" __FBSDID("$FreeBSD$"); #include #include #include #ifdef KTRACE #include #include #endif #include static inline void syscallenter(struct thread *td) { struct proc *p; struct syscall_args *sa; struct sysent *se; int error, traced; VM_CNT_INC(v_syscall); p = td->td_proc; sa = &td->td_sa; td->td_pticks = 0; if (__predict_false(td->td_cowgen != p->p_cowgen)) thread_cow_update(td); traced = (p->p_flag & P_TRACED) != 0; if (__predict_false(traced || td->td_dbgflags & TDB_USERWR)) { PROC_LOCK(p); td->td_dbgflags &= ~TDB_USERWR; if (traced) td->td_dbgflags |= TDB_SCE; PROC_UNLOCK(p); } error = (p->p_sysent->sv_fetch_syscall_args)(td); se = sa->callp; #ifdef KTRACE if (KTRPOINT(td, KTR_SYSCALL)) ktrsyscall(sa->code, se->sy_narg, sa->args); #endif KTR_START4(KTR_SYSC, "syscall", syscallname(p, sa->code), (uintptr_t)td, "pid:%d", td->td_proc->p_pid, "arg0:%p", sa->args[0], "arg1:%p", sa->args[1], "arg2:%p", sa->args[2]); if (__predict_false(error != 0)) { td->td_errno = error; goto retval; } if (__predict_false(traced)) { PROC_LOCK(p); if (p->p_ptevents & PTRACE_SCE) ptracestop((td), SIGTRAP, NULL); PROC_UNLOCK(p); - } - if (__predict_false((td->td_dbgflags & TDB_USERWR) != 0)) { - /* - * Reread syscall number and arguments if debugger - * modified registers or memory. - */ - error = (p->p_sysent->sv_fetch_syscall_args)(td); - se = sa->callp; + + if ((td->td_dbgflags & TDB_USERWR) != 0) { + /* + * Reread syscall number and arguments if debugger + * modified registers or memory. + */ + error = (p->p_sysent->sv_fetch_syscall_args)(td); + se = sa->callp; #ifdef KTRACE - if (KTRPOINT(td, KTR_SYSCALL)) - ktrsyscall(sa->code, se->sy_narg, sa->args); + if (KTRPOINT(td, KTR_SYSCALL)) + ktrsyscall(sa->code, se->sy_narg, sa->args); #endif - if (error != 0) { - td->td_errno = error; - goto retval; + if (error != 0) { + td->td_errno = error; + goto retval; + } } } #ifdef CAPABILITY_MODE /* * In capability mode, we only allow access to system calls * flagged with SYF_CAPENABLED. */ if (__predict_false(IN_CAPABILITY_MODE(td) && (se->sy_flags & SYF_CAPENABLED) == 0)) { td->td_errno = error = ECAPMODE; goto retval; } #endif error = syscall_thread_enter(td, se); if (error != 0) { td->td_errno = error; goto retval; } /* * Fetch fast sigblock value at the time of syscall entry to * handle sleepqueue primitives which might call cursig(). */ if (__predict_false(sigfastblock_fetch_always)) (void)sigfastblock_fetch(td); /* Let system calls set td_errno directly. */ KASSERT((td->td_pflags & TDP_NERRNO) == 0, ("%s: TDP_NERRNO set", __func__)); if (__predict_false(SYSTRACE_ENABLED() || AUDIT_SYSCALL_ENTER(sa->code, td))) { #ifdef KDTRACE_HOOKS /* Give the syscall:::entry DTrace probe a chance to fire. */ if (__predict_false(se->sy_entry != 0)) (*systrace_probe_func)(sa, SYSTRACE_ENTRY, 0); #endif error = (se->sy_call)(td, sa->args); /* Save the latest error return value. */ if (__predict_false((td->td_pflags & TDP_NERRNO) != 0)) td->td_pflags &= ~TDP_NERRNO; else td->td_errno = error; /* * Note that some syscall implementations (e.g., sys_execve) * will commit the audit record just before their final return. * These were done under the assumption that nothing of interest * would happen between their return and here, where we would * normally commit the audit record. These assumptions will * need to be revisited should any substantial logic be added * above. */ AUDIT_SYSCALL_EXIT(error, td); #ifdef KDTRACE_HOOKS /* Give the syscall:::return DTrace probe a chance to fire. */ if (__predict_false(se->sy_return != 0)) (*systrace_probe_func)(sa, SYSTRACE_RETURN, error ? -1 : td->td_retval[0]); #endif } else { error = (se->sy_call)(td, sa->args); /* Save the latest error return value. */ if (__predict_false((td->td_pflags & TDP_NERRNO) != 0)) td->td_pflags &= ~TDP_NERRNO; else td->td_errno = error; } syscall_thread_exit(td, se); retval: KTR_STOP4(KTR_SYSC, "syscall", syscallname(p, sa->code), (uintptr_t)td, "pid:%d", td->td_proc->p_pid, "error:%d", error, "retval0:%#lx", td->td_retval[0], "retval1:%#lx", td->td_retval[1]); if (__predict_false(traced)) { PROC_LOCK(p); td->td_dbgflags &= ~TDB_SCE; PROC_UNLOCK(p); } (p->p_sysent->sv_set_syscall_retval)(td, error); } static inline void syscallret(struct thread *td) { struct proc *p; struct syscall_args *sa; ksiginfo_t ksi; int traced; KASSERT((td->td_pflags & TDP_FORKING) == 0, ("fork() did not clear TDP_FORKING upon completion")); p = td->td_proc; sa = &td->td_sa; if (__predict_false(td->td_errno == ENOTCAPABLE || td->td_errno == ECAPMODE)) { if ((trap_enotcap || (p->p_flag2 & P2_TRAPCAP) != 0) && IN_CAPABILITY_MODE(td)) { ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGTRAP; ksi.ksi_errno = td->td_errno; ksi.ksi_code = TRAP_CAP; trapsignal(td, &ksi); } } /* * Handle reschedule and other end-of-syscall issues */ userret(td, td->td_frame); #ifdef KTRACE if (KTRPOINT(td, KTR_SYSRET)) { ktrsysret(sa->code, td->td_errno, td->td_retval[0]); } #endif traced = 0; if (__predict_false(p->p_flag & P_TRACED)) { traced = 1; PROC_LOCK(p); td->td_dbgflags |= TDB_SCX; PROC_UNLOCK(p); } if (__predict_false(traced || (td->td_dbgflags & (TDB_EXEC | TDB_FORK)) != 0)) { PROC_LOCK(p); /* * If tracing the execed process, trap to the debugger * so that breakpoints can be set before the program * executes. If debugger requested tracing of syscall * returns, do it now too. */ if (traced && ((td->td_dbgflags & (TDB_FORK | TDB_EXEC)) != 0 || (p->p_ptevents & PTRACE_SCX) != 0)) ptracestop(td, SIGTRAP, NULL); td->td_dbgflags &= ~(TDB_SCX | TDB_EXEC | TDB_FORK); PROC_UNLOCK(p); } if (__predict_false(td->td_pflags & TDP_RFPPWAIT)) fork_rfppwait(td); }