diff --git a/sys/i386/i386/exec_machdep.c b/sys/i386/i386/exec_machdep.c index 01602e43733f..0463615d96d9 100644 --- a/sys/i386/i386/exec_machdep.c +++ b/sys/i386/i386/exec_machdep.c @@ -1,1443 +1,1447 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (c) 2018 The FreeBSD Foundation * Copyright (c) 1992 Terrence R. Lambert. * Copyright (c) 1982, 1987, 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * Portions of this software were developed by A. Joseph Koshy under * sponsorship from the FreeBSD Foundation and Google, 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. 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: @(#)machdep.c 7.4 (Berkeley) 6/3/91 */ #include __FBSDID("$FreeBSD$"); #include "opt_cpu.h" #include "opt_ddb.h" #include "opt_kstack_pages.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #ifndef KDB #error KDB must be enabled in order for DDB to work! #endif #include #include #endif #include #include #include #include #include #include #include #include #include #include static void fpstate_drop(struct thread *td); static void get_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpusave, size_t xfpusave_len); static int set_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpustate, size_t xfpustate_len); #ifdef COMPAT_43 static void osendsig(sig_t catcher, ksiginfo_t *, sigset_t *mask); #endif #ifdef COMPAT_FREEBSD4 static void freebsd4_sendsig(sig_t catcher, ksiginfo_t *, sigset_t *mask); #endif extern struct sysentvec elf32_freebsd_sysvec; +_Static_assert(sizeof(mcontext_t) == 640, "mcontext_t size incorrect"); +_Static_assert(sizeof(ucontext_t) == 704, "ucontext_t size incorrect"); +_Static_assert(sizeof(siginfo_t) == 64, "siginfo_t size incorrect"); + /* * Send an interrupt to process. * * Stack is set up to allow sigcode stored at top to call routine, * followed by call to sigreturn routine below. After sigreturn * resets the signal mask, the stack, and the frame pointer, it * returns to the user specified pc, psl. */ #ifdef COMPAT_43 static void osendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) { struct osigframe sf, *fp; struct proc *p; struct thread *td; struct sigacts *psp; struct trapframe *regs; int sig; int oonstack; td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); sig = ksi->ksi_signo; psp = p->p_sigacts; mtx_assert(&psp->ps_mtx, MA_OWNED); regs = td->td_frame; oonstack = sigonstack(regs->tf_esp); /* Allocate space for the signal handler context. */ if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && SIGISMEMBER(psp->ps_sigonstack, sig)) { fp = (struct osigframe *)((uintptr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size - sizeof(struct osigframe)); #if defined(COMPAT_43) td->td_sigstk.ss_flags |= SS_ONSTACK; #endif } else fp = (struct osigframe *)regs->tf_esp - 1; /* Build the argument list for the signal handler. */ sf.sf_signum = sig; sf.sf_scp = (register_t)&fp->sf_siginfo.si_sc; bzero(&sf.sf_siginfo, sizeof(sf.sf_siginfo)); if (SIGISMEMBER(psp->ps_siginfo, sig)) { /* Signal handler installed with SA_SIGINFO. */ sf.sf_arg2 = (register_t)&fp->sf_siginfo; sf.sf_siginfo.si_signo = sig; sf.sf_siginfo.si_code = ksi->ksi_code; sf.sf_ahu.sf_action = (__osiginfohandler_t *)catcher; sf.sf_addr = 0; } else { /* Old FreeBSD-style arguments. */ sf.sf_arg2 = ksi->ksi_code; sf.sf_addr = (register_t)ksi->ksi_addr; sf.sf_ahu.sf_handler = catcher; } mtx_unlock(&psp->ps_mtx); PROC_UNLOCK(p); /* Save most if not all of trap frame. */ sf.sf_siginfo.si_sc.sc_eax = regs->tf_eax; sf.sf_siginfo.si_sc.sc_ebx = regs->tf_ebx; sf.sf_siginfo.si_sc.sc_ecx = regs->tf_ecx; sf.sf_siginfo.si_sc.sc_edx = regs->tf_edx; sf.sf_siginfo.si_sc.sc_esi = regs->tf_esi; sf.sf_siginfo.si_sc.sc_edi = regs->tf_edi; sf.sf_siginfo.si_sc.sc_cs = regs->tf_cs; sf.sf_siginfo.si_sc.sc_ds = regs->tf_ds; sf.sf_siginfo.si_sc.sc_ss = regs->tf_ss; sf.sf_siginfo.si_sc.sc_es = regs->tf_es; sf.sf_siginfo.si_sc.sc_fs = regs->tf_fs; sf.sf_siginfo.si_sc.sc_gs = rgs(); sf.sf_siginfo.si_sc.sc_isp = regs->tf_isp; /* Build the signal context to be used by osigreturn(). */ sf.sf_siginfo.si_sc.sc_onstack = (oonstack) ? 1 : 0; SIG2OSIG(*mask, sf.sf_siginfo.si_sc.sc_mask); sf.sf_siginfo.si_sc.sc_sp = regs->tf_esp; sf.sf_siginfo.si_sc.sc_fp = regs->tf_ebp; sf.sf_siginfo.si_sc.sc_pc = regs->tf_eip; sf.sf_siginfo.si_sc.sc_ps = regs->tf_eflags; sf.sf_siginfo.si_sc.sc_trapno = regs->tf_trapno; sf.sf_siginfo.si_sc.sc_err = regs->tf_err; /* * If we're a vm86 process, we want to save the segment registers. * We also change eflags to be our emulated eflags, not the actual * eflags. */ if (regs->tf_eflags & PSL_VM) { /* XXX confusing names: `tf' isn't a trapframe; `regs' is. */ struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86; sf.sf_siginfo.si_sc.sc_gs = tf->tf_vm86_gs; sf.sf_siginfo.si_sc.sc_fs = tf->tf_vm86_fs; sf.sf_siginfo.si_sc.sc_es = tf->tf_vm86_es; sf.sf_siginfo.si_sc.sc_ds = tf->tf_vm86_ds; if (vm86->vm86_has_vme == 0) sf.sf_siginfo.si_sc.sc_ps = (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) | (vm86->vm86_eflags & (PSL_VIF | PSL_VIP)); /* See sendsig() for comments. */ tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP); } /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, fp, sizeof(*fp)) != 0) { PROC_LOCK(p); sigexit(td, SIGILL); } regs->tf_esp = (int)fp; if (p->p_sysent->sv_sigcode_base != 0) { regs->tf_eip = p->p_sysent->sv_sigcode_base + szsigcode - szosigcode; } else { /* a.out sysentvec does not use shared page */ regs->tf_eip = PROC_PS_STRINGS(p) - szosigcode; } regs->tf_eflags &= ~(PSL_T | PSL_D); regs->tf_cs = _ucodesel; regs->tf_ds = _udatasel; regs->tf_es = _udatasel; regs->tf_fs = _udatasel; load_gs(_udatasel); regs->tf_ss = _udatasel; PROC_LOCK(p); mtx_lock(&psp->ps_mtx); } #endif /* COMPAT_43 */ #ifdef COMPAT_FREEBSD4 static void freebsd4_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) { struct freebsd4_sigframe sf, *sfp; struct proc *p; struct thread *td; struct sigacts *psp; struct trapframe *regs; int sig; int oonstack; td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); sig = ksi->ksi_signo; psp = p->p_sigacts; mtx_assert(&psp->ps_mtx, MA_OWNED); regs = td->td_frame; oonstack = sigonstack(regs->tf_esp); /* Save user context. */ bzero(&sf, sizeof(sf)); sf.sf_uc.uc_sigmask = *mask; sf.sf_uc.uc_stack = td->td_sigstk; sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; sf.sf_uc.uc_mcontext.mc_gs = rgs(); bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(*regs)); bzero(sf.sf_uc.uc_mcontext.mc_fpregs, sizeof(sf.sf_uc.uc_mcontext.mc_fpregs)); bzero(sf.sf_uc.uc_mcontext.__spare__, sizeof(sf.sf_uc.uc_mcontext.__spare__)); bzero(sf.sf_uc.__spare__, sizeof(sf.sf_uc.__spare__)); /* Allocate space for the signal handler context. */ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && SIGISMEMBER(psp->ps_sigonstack, sig)) { sfp = (struct freebsd4_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size - sizeof(struct freebsd4_sigframe)); #if defined(COMPAT_43) td->td_sigstk.ss_flags |= SS_ONSTACK; #endif } else sfp = (struct freebsd4_sigframe *)regs->tf_esp - 1; /* Build the argument list for the signal handler. */ sf.sf_signum = sig; sf.sf_ucontext = (register_t)&sfp->sf_uc; bzero(&sf.sf_si, sizeof(sf.sf_si)); if (SIGISMEMBER(psp->ps_siginfo, sig)) { /* Signal handler installed with SA_SIGINFO. */ sf.sf_siginfo = (register_t)&sfp->sf_si; sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher; /* Fill in POSIX parts */ sf.sf_si.si_signo = sig; sf.sf_si.si_code = ksi->ksi_code; sf.sf_si.si_addr = ksi->ksi_addr; } else { /* Old FreeBSD-style arguments. */ sf.sf_siginfo = ksi->ksi_code; sf.sf_addr = (register_t)ksi->ksi_addr; sf.sf_ahu.sf_handler = catcher; } mtx_unlock(&psp->ps_mtx); PROC_UNLOCK(p); /* * If we're a vm86 process, we want to save the segment registers. * We also change eflags to be our emulated eflags, not the actual * eflags. */ if (regs->tf_eflags & PSL_VM) { struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86; sf.sf_uc.uc_mcontext.mc_gs = tf->tf_vm86_gs; sf.sf_uc.uc_mcontext.mc_fs = tf->tf_vm86_fs; sf.sf_uc.uc_mcontext.mc_es = tf->tf_vm86_es; sf.sf_uc.uc_mcontext.mc_ds = tf->tf_vm86_ds; if (vm86->vm86_has_vme == 0) sf.sf_uc.uc_mcontext.mc_eflags = (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) | (vm86->vm86_eflags & (PSL_VIF | PSL_VIP)); /* * Clear PSL_NT to inhibit T_TSSFLT faults on return from * syscalls made by the signal handler. This just avoids * wasting time for our lazy fixup of such faults. PSL_NT * does nothing in vm86 mode, but vm86 programs can set it * almost legitimately in probes for old cpu types. */ tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP); } /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { PROC_LOCK(p); sigexit(td, SIGILL); } regs->tf_esp = (int)sfp; regs->tf_eip = p->p_sysent->sv_sigcode_base + szsigcode - szfreebsd4_sigcode; regs->tf_eflags &= ~(PSL_T | PSL_D); regs->tf_cs = _ucodesel; regs->tf_ds = _udatasel; regs->tf_es = _udatasel; regs->tf_fs = _udatasel; regs->tf_ss = _udatasel; PROC_LOCK(p); mtx_lock(&psp->ps_mtx); } #endif /* COMPAT_FREEBSD4 */ void sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) { struct sigframe sf, *sfp; struct proc *p; struct thread *td; struct sigacts *psp; char *sp; struct trapframe *regs; struct segment_descriptor *sdp; char *xfpusave; size_t xfpusave_len; int sig; int oonstack; td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); sig = ksi->ksi_signo; psp = p->p_sigacts; mtx_assert(&psp->ps_mtx, MA_OWNED); #ifdef COMPAT_FREEBSD4 if (SIGISMEMBER(psp->ps_freebsd4, sig)) { freebsd4_sendsig(catcher, ksi, mask); return; } #endif #ifdef COMPAT_43 if (SIGISMEMBER(psp->ps_osigset, sig)) { osendsig(catcher, ksi, mask); return; } #endif regs = td->td_frame; oonstack = sigonstack(regs->tf_esp); if (cpu_max_ext_state_size > sizeof(union savefpu) && use_xsave) { xfpusave_len = cpu_max_ext_state_size - sizeof(union savefpu); xfpusave = __builtin_alloca(xfpusave_len); } else { xfpusave_len = 0; xfpusave = NULL; } /* Save user context. */ bzero(&sf, sizeof(sf)); sf.sf_uc.uc_sigmask = *mask; sf.sf_uc.uc_stack = td->td_sigstk; sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0; sf.sf_uc.uc_mcontext.mc_gs = rgs(); bcopy(regs, &sf.sf_uc.uc_mcontext.mc_fs, sizeof(*regs)); sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */ get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len); fpstate_drop(td); /* * Unconditionally fill the fsbase and gsbase into the mcontext. */ sdp = &td->td_pcb->pcb_fsd; sf.sf_uc.uc_mcontext.mc_fsbase = sdp->sd_hibase << 24 | sdp->sd_lobase; sdp = &td->td_pcb->pcb_gsd; sf.sf_uc.uc_mcontext.mc_gsbase = sdp->sd_hibase << 24 | sdp->sd_lobase; bzero(sf.sf_uc.uc_mcontext.mc_spare2, sizeof(sf.sf_uc.uc_mcontext.mc_spare2)); /* Allocate space for the signal handler context. */ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && SIGISMEMBER(psp->ps_sigonstack, sig)) { sp = (char *)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; #if defined(COMPAT_43) td->td_sigstk.ss_flags |= SS_ONSTACK; #endif } else sp = (char *)regs->tf_esp - 128; if (xfpusave != NULL) { sp -= xfpusave_len; sp = (char *)((unsigned int)sp & ~0x3F); sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp; } sp -= sizeof(struct sigframe); /* Align to 16 bytes. */ sfp = (struct sigframe *)((unsigned int)sp & ~0xF); /* Build the argument list for the signal handler. */ sf.sf_signum = sig; sf.sf_ucontext = (register_t)&sfp->sf_uc; bzero(&sf.sf_si, sizeof(sf.sf_si)); if (SIGISMEMBER(psp->ps_siginfo, sig)) { /* Signal handler installed with SA_SIGINFO. */ sf.sf_siginfo = (register_t)&sfp->sf_si; sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher; /* Fill in POSIX parts */ sf.sf_si = ksi->ksi_info; sf.sf_si.si_signo = sig; /* maybe a translated signal */ } else { /* Old FreeBSD-style arguments. */ sf.sf_siginfo = ksi->ksi_code; sf.sf_addr = (register_t)ksi->ksi_addr; sf.sf_ahu.sf_handler = catcher; } mtx_unlock(&psp->ps_mtx); PROC_UNLOCK(p); /* * If we're a vm86 process, we want to save the segment registers. * We also change eflags to be our emulated eflags, not the actual * eflags. */ if (regs->tf_eflags & PSL_VM) { struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86; sf.sf_uc.uc_mcontext.mc_gs = tf->tf_vm86_gs; sf.sf_uc.uc_mcontext.mc_fs = tf->tf_vm86_fs; sf.sf_uc.uc_mcontext.mc_es = tf->tf_vm86_es; sf.sf_uc.uc_mcontext.mc_ds = tf->tf_vm86_ds; if (vm86->vm86_has_vme == 0) sf.sf_uc.uc_mcontext.mc_eflags = (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) | (vm86->vm86_eflags & (PSL_VIF | PSL_VIP)); /* * Clear PSL_NT to inhibit T_TSSFLT faults on return from * syscalls made by the signal handler. This just avoids * wasting time for our lazy fixup of such faults. PSL_NT * does nothing in vm86 mode, but vm86 programs can set it * almost legitimately in probes for old cpu types. */ tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP); } /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, sfp, sizeof(*sfp)) != 0 || (xfpusave != NULL && copyout(xfpusave, (void *)sf.sf_uc.uc_mcontext.mc_xfpustate, xfpusave_len) != 0)) { PROC_LOCK(p); sigexit(td, SIGILL); } regs->tf_esp = (int)sfp; regs->tf_eip = p->p_sysent->sv_sigcode_base; if (regs->tf_eip == 0) regs->tf_eip = PROC_PS_STRINGS(p) - szsigcode; regs->tf_eflags &= ~(PSL_T | PSL_D); regs->tf_cs = _ucodesel; regs->tf_ds = _udatasel; regs->tf_es = _udatasel; regs->tf_fs = _udatasel; regs->tf_ss = _udatasel; PROC_LOCK(p); mtx_lock(&psp->ps_mtx); } /* * System call to cleanup state after a signal has been taken. Reset * signal mask and stack state from context left by sendsig (above). * Return to previous pc and psl as specified by context left by * sendsig. Check carefully to make sure that the user has not * modified the state to gain improper privileges. */ #ifdef COMPAT_43 int osigreturn(struct thread *td, struct osigreturn_args *uap) { struct osigcontext sc; struct trapframe *regs; struct osigcontext *scp; int eflags, error; ksiginfo_t ksi; regs = td->td_frame; error = copyin(uap->sigcntxp, &sc, sizeof(sc)); if (error != 0) return (error); scp = ≻ eflags = scp->sc_ps; if (eflags & PSL_VM) { struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; struct vm86_kernel *vm86; /* * if pcb_ext == 0 or vm86_inited == 0, the user hasn't * set up the vm86 area, and we can't enter vm86 mode. */ if (td->td_pcb->pcb_ext == 0) return (EINVAL); vm86 = &td->td_pcb->pcb_ext->ext_vm86; if (vm86->vm86_inited == 0) return (EINVAL); /* Go back to user mode if both flags are set. */ if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) { ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_addr = (void *)regs->tf_eip; trapsignal(td, &ksi); } if (vm86->vm86_has_vme) { eflags = (tf->tf_eflags & ~VME_USERCHANGE) | (eflags & VME_USERCHANGE) | PSL_VM; } else { vm86->vm86_eflags = eflags; /* save VIF, VIP */ eflags = (tf->tf_eflags & ~VM_USERCHANGE) | (eflags & VM_USERCHANGE) | PSL_VM; } tf->tf_vm86_ds = scp->sc_ds; tf->tf_vm86_es = scp->sc_es; tf->tf_vm86_fs = scp->sc_fs; tf->tf_vm86_gs = scp->sc_gs; tf->tf_ds = _udatasel; tf->tf_es = _udatasel; tf->tf_fs = _udatasel; } else { /* * Don't allow users to change privileged or reserved flags. */ if (!EFL_SECURE(eflags, regs->tf_eflags)) { return (EINVAL); } /* * Don't allow users to load a valid privileged %cs. Let the * hardware check for invalid selectors, excess privilege in * other selectors, invalid %eip's and invalid %esp's. */ if (!CS_SECURE(scp->sc_cs)) { ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_trapno = T_PROTFLT; ksi.ksi_addr = (void *)regs->tf_eip; trapsignal(td, &ksi); return (EINVAL); } regs->tf_ds = scp->sc_ds; regs->tf_es = scp->sc_es; regs->tf_fs = scp->sc_fs; } /* Restore remaining registers. */ regs->tf_eax = scp->sc_eax; regs->tf_ebx = scp->sc_ebx; regs->tf_ecx = scp->sc_ecx; regs->tf_edx = scp->sc_edx; regs->tf_esi = scp->sc_esi; regs->tf_edi = scp->sc_edi; regs->tf_cs = scp->sc_cs; regs->tf_ss = scp->sc_ss; regs->tf_isp = scp->sc_isp; regs->tf_ebp = scp->sc_fp; regs->tf_esp = scp->sc_sp; regs->tf_eip = scp->sc_pc; regs->tf_eflags = eflags; #if defined(COMPAT_43) if (scp->sc_onstack & 1) td->td_sigstk.ss_flags |= SS_ONSTACK; else td->td_sigstk.ss_flags &= ~SS_ONSTACK; #endif kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL, SIGPROCMASK_OLD); return (EJUSTRETURN); } #endif /* COMPAT_43 */ #ifdef COMPAT_FREEBSD4 int freebsd4_sigreturn(struct thread *td, struct freebsd4_sigreturn_args *uap) { struct freebsd4_ucontext uc; struct trapframe *regs; struct freebsd4_ucontext *ucp; int cs, eflags, error; ksiginfo_t ksi; error = copyin(uap->sigcntxp, &uc, sizeof(uc)); if (error != 0) return (error); ucp = &uc; regs = td->td_frame; eflags = ucp->uc_mcontext.mc_eflags; if (eflags & PSL_VM) { struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; struct vm86_kernel *vm86; /* * if pcb_ext == 0 or vm86_inited == 0, the user hasn't * set up the vm86 area, and we can't enter vm86 mode. */ if (td->td_pcb->pcb_ext == 0) return (EINVAL); vm86 = &td->td_pcb->pcb_ext->ext_vm86; if (vm86->vm86_inited == 0) return (EINVAL); /* Go back to user mode if both flags are set. */ if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) { ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_addr = (void *)regs->tf_eip; trapsignal(td, &ksi); } if (vm86->vm86_has_vme) { eflags = (tf->tf_eflags & ~VME_USERCHANGE) | (eflags & VME_USERCHANGE) | PSL_VM; } else { vm86->vm86_eflags = eflags; /* save VIF, VIP */ eflags = (tf->tf_eflags & ~VM_USERCHANGE) | (eflags & VM_USERCHANGE) | PSL_VM; } bcopy(&ucp->uc_mcontext.mc_fs, tf, sizeof(struct trapframe)); tf->tf_eflags = eflags; tf->tf_vm86_ds = tf->tf_ds; tf->tf_vm86_es = tf->tf_es; tf->tf_vm86_fs = tf->tf_fs; tf->tf_vm86_gs = ucp->uc_mcontext.mc_gs; tf->tf_ds = _udatasel; tf->tf_es = _udatasel; tf->tf_fs = _udatasel; } else { /* * Don't allow users to change privileged or reserved flags. */ if (!EFL_SECURE(eflags, regs->tf_eflags)) { uprintf( "pid %d (%s): freebsd4_sigreturn eflags = 0x%x\n", td->td_proc->p_pid, td->td_name, eflags); return (EINVAL); } /* * Don't allow users to load a valid privileged %cs. Let the * hardware check for invalid selectors, excess privilege in * other selectors, invalid %eip's and invalid %esp's. */ cs = ucp->uc_mcontext.mc_cs; if (!CS_SECURE(cs)) { uprintf("pid %d (%s): freebsd4_sigreturn cs = 0x%x\n", td->td_proc->p_pid, td->td_name, cs); ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_trapno = T_PROTFLT; ksi.ksi_addr = (void *)regs->tf_eip; trapsignal(td, &ksi); return (EINVAL); } bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs)); } #if defined(COMPAT_43) if (ucp->uc_mcontext.mc_onstack & 1) td->td_sigstk.ss_flags |= SS_ONSTACK; else td->td_sigstk.ss_flags &= ~SS_ONSTACK; #endif kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0); return (EJUSTRETURN); } #endif /* COMPAT_FREEBSD4 */ int sys_sigreturn(struct thread *td, struct sigreturn_args *uap) { ucontext_t uc; struct proc *p; struct trapframe *regs; ucontext_t *ucp; char *xfpustate; size_t xfpustate_len; int cs, eflags, error, ret; ksiginfo_t ksi; p = td->td_proc; error = copyin(uap->sigcntxp, &uc, sizeof(uc)); if (error != 0) return (error); ucp = &uc; if ((ucp->uc_mcontext.mc_flags & ~_MC_FLAG_MASK) != 0) { uprintf("pid %d (%s): sigreturn mc_flags %x\n", p->p_pid, td->td_name, ucp->uc_mcontext.mc_flags); return (EINVAL); } regs = td->td_frame; eflags = ucp->uc_mcontext.mc_eflags; if (eflags & PSL_VM) { struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; struct vm86_kernel *vm86; /* * if pcb_ext == 0 or vm86_inited == 0, the user hasn't * set up the vm86 area, and we can't enter vm86 mode. */ if (td->td_pcb->pcb_ext == 0) return (EINVAL); vm86 = &td->td_pcb->pcb_ext->ext_vm86; if (vm86->vm86_inited == 0) return (EINVAL); /* Go back to user mode if both flags are set. */ if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) { ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_addr = (void *)regs->tf_eip; trapsignal(td, &ksi); } if (vm86->vm86_has_vme) { eflags = (tf->tf_eflags & ~VME_USERCHANGE) | (eflags & VME_USERCHANGE) | PSL_VM; } else { vm86->vm86_eflags = eflags; /* save VIF, VIP */ eflags = (tf->tf_eflags & ~VM_USERCHANGE) | (eflags & VM_USERCHANGE) | PSL_VM; } bcopy(&ucp->uc_mcontext.mc_fs, tf, sizeof(struct trapframe)); tf->tf_eflags = eflags; tf->tf_vm86_ds = tf->tf_ds; tf->tf_vm86_es = tf->tf_es; tf->tf_vm86_fs = tf->tf_fs; tf->tf_vm86_gs = ucp->uc_mcontext.mc_gs; tf->tf_ds = _udatasel; tf->tf_es = _udatasel; tf->tf_fs = _udatasel; } else { /* * Don't allow users to change privileged or reserved flags. */ if (!EFL_SECURE(eflags, regs->tf_eflags)) { uprintf("pid %d (%s): sigreturn eflags = 0x%x\n", td->td_proc->p_pid, td->td_name, eflags); return (EINVAL); } /* * Don't allow users to load a valid privileged %cs. Let the * hardware check for invalid selectors, excess privilege in * other selectors, invalid %eip's and invalid %esp's. */ cs = ucp->uc_mcontext.mc_cs; if (!CS_SECURE(cs)) { uprintf("pid %d (%s): sigreturn cs = 0x%x\n", td->td_proc->p_pid, td->td_name, cs); ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_trapno = T_PROTFLT; ksi.ksi_addr = (void *)regs->tf_eip; trapsignal(td, &ksi); return (EINVAL); } if ((uc.uc_mcontext.mc_flags & _MC_HASFPXSTATE) != 0) { xfpustate_len = uc.uc_mcontext.mc_xfpustate_len; if (xfpustate_len > cpu_max_ext_state_size - sizeof(union savefpu)) { uprintf( "pid %d (%s): sigreturn xfpusave_len = 0x%zx\n", p->p_pid, td->td_name, xfpustate_len); return (EINVAL); } xfpustate = __builtin_alloca(xfpustate_len); error = copyin( (const void *)uc.uc_mcontext.mc_xfpustate, xfpustate, xfpustate_len); if (error != 0) { uprintf( "pid %d (%s): sigreturn copying xfpustate failed\n", p->p_pid, td->td_name); return (error); } } else { xfpustate = NULL; xfpustate_len = 0; } ret = set_fpcontext(td, &ucp->uc_mcontext, xfpustate, xfpustate_len); if (ret != 0) return (ret); bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs)); } #if defined(COMPAT_43) if (ucp->uc_mcontext.mc_onstack & 1) td->td_sigstk.ss_flags |= SS_ONSTACK; else td->td_sigstk.ss_flags &= ~SS_ONSTACK; #endif kern_sigprocmask(td, SIG_SETMASK, &ucp->uc_sigmask, NULL, 0); return (EJUSTRETURN); } /* * Reset the hardware debug registers if they were in use. * They won't have any meaning for the newly exec'd process. */ void x86_clear_dbregs(struct pcb *pcb) { if ((pcb->pcb_flags & PCB_DBREGS) == 0) return; pcb->pcb_dr0 = 0; pcb->pcb_dr1 = 0; pcb->pcb_dr2 = 0; pcb->pcb_dr3 = 0; pcb->pcb_dr6 = 0; pcb->pcb_dr7 = 0; if (pcb == curpcb) { /* * Clear the debug registers on the running CPU, * otherwise they will end up affecting the next * process we switch to. */ reset_dbregs(); } pcb->pcb_flags &= ~PCB_DBREGS; } #ifdef COMPAT_43 static void setup_priv_lcall_gate(struct proc *p) { struct i386_ldt_args uap; union descriptor desc; u_int lcall_addr; bzero(&uap, sizeof(uap)); uap.start = 0; uap.num = 1; lcall_addr = p->p_sysent->sv_psstrings - sz_lcall_tramp; bzero(&desc, sizeof(desc)); desc.sd.sd_type = SDT_MEMERA; desc.sd.sd_dpl = SEL_UPL; desc.sd.sd_p = 1; desc.sd.sd_def32 = 1; desc.sd.sd_gran = 1; desc.sd.sd_lolimit = 0xffff; desc.sd.sd_hilimit = 0xf; desc.sd.sd_lobase = lcall_addr; desc.sd.sd_hibase = lcall_addr >> 24; i386_set_ldt(curthread, &uap, &desc); } #endif /* * Reset registers to default values on exec. */ void exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack) { struct trapframe *regs; struct pcb *pcb; register_t saved_eflags; regs = td->td_frame; pcb = td->td_pcb; /* Reset pc->pcb_gs and %gs before possibly invalidating it. */ pcb->pcb_gs = _udatasel; load_gs(_udatasel); mtx_lock_spin(&dt_lock); if (td->td_proc->p_md.md_ldt != NULL) user_ldt_free(td); else mtx_unlock_spin(&dt_lock); #ifdef COMPAT_43 if (td->td_proc->p_sysent->sv_psstrings != elf32_freebsd_sysvec.sv_psstrings) setup_priv_lcall_gate(td->td_proc); #endif /* * Reset the fs and gs bases. The values from the old address * space do not make sense for the new program. In particular, * gsbase might be the TLS base for the old program but the new * program has no TLS now. */ set_fsbase(td, 0); set_gsbase(td, 0); /* Make sure edx is 0x0 on entry. Linux binaries depend on it. */ saved_eflags = regs->tf_eflags & PSL_T; bzero((char *)regs, sizeof(struct trapframe)); regs->tf_eip = imgp->entry_addr; regs->tf_esp = stack; regs->tf_eflags = PSL_USER | saved_eflags; regs->tf_ss = _udatasel; regs->tf_ds = _udatasel; regs->tf_es = _udatasel; regs->tf_fs = _udatasel; regs->tf_cs = _ucodesel; /* PS_STRINGS value for BSD/OS binaries. It is 0 for non-BSD/OS. */ regs->tf_ebx = (register_t)imgp->ps_strings; x86_clear_dbregs(pcb); pcb->pcb_initial_npxcw = __INITIAL_NPXCW__; /* * Drop the FP state if we hold it, so that the process gets a * clean FP state if it uses the FPU again. */ fpstate_drop(td); } int fill_regs(struct thread *td, struct reg *regs) { struct pcb *pcb; struct trapframe *tp; tp = td->td_frame; pcb = td->td_pcb; regs->r_gs = pcb->pcb_gs; return (fill_frame_regs(tp, regs)); } int fill_frame_regs(struct trapframe *tp, struct reg *regs) { regs->r_fs = tp->tf_fs; regs->r_es = tp->tf_es; regs->r_ds = tp->tf_ds; regs->r_edi = tp->tf_edi; regs->r_esi = tp->tf_esi; regs->r_ebp = tp->tf_ebp; regs->r_ebx = tp->tf_ebx; regs->r_edx = tp->tf_edx; regs->r_ecx = tp->tf_ecx; regs->r_eax = tp->tf_eax; regs->r_eip = tp->tf_eip; regs->r_cs = tp->tf_cs; regs->r_eflags = tp->tf_eflags; regs->r_esp = tp->tf_esp; regs->r_ss = tp->tf_ss; regs->r_err = 0; regs->r_trapno = 0; return (0); } int set_regs(struct thread *td, struct reg *regs) { struct pcb *pcb; struct trapframe *tp; tp = td->td_frame; if (!EFL_SECURE(regs->r_eflags, tp->tf_eflags) || !CS_SECURE(regs->r_cs)) return (EINVAL); pcb = td->td_pcb; tp->tf_fs = regs->r_fs; tp->tf_es = regs->r_es; tp->tf_ds = regs->r_ds; tp->tf_edi = regs->r_edi; tp->tf_esi = regs->r_esi; tp->tf_ebp = regs->r_ebp; tp->tf_ebx = regs->r_ebx; tp->tf_edx = regs->r_edx; tp->tf_ecx = regs->r_ecx; tp->tf_eax = regs->r_eax; tp->tf_eip = regs->r_eip; tp->tf_cs = regs->r_cs; tp->tf_eflags = regs->r_eflags; tp->tf_esp = regs->r_esp; tp->tf_ss = regs->r_ss; pcb->pcb_gs = regs->r_gs; return (0); } int fill_fpregs(struct thread *td, struct fpreg *fpregs) { KASSERT(td == curthread || TD_IS_SUSPENDED(td) || P_SHOULDSTOP(td->td_proc), ("not suspended thread %p", td)); npxgetregs(td); if (cpu_fxsr) npx_fill_fpregs_xmm(&get_pcb_user_save_td(td)->sv_xmm, (struct save87 *)fpregs); else bcopy(&get_pcb_user_save_td(td)->sv_87, fpregs, sizeof(*fpregs)); return (0); } int set_fpregs(struct thread *td, struct fpreg *fpregs) { critical_enter(); if (cpu_fxsr) npx_set_fpregs_xmm((struct save87 *)fpregs, &get_pcb_user_save_td(td)->sv_xmm); else bcopy(fpregs, &get_pcb_user_save_td(td)->sv_87, sizeof(*fpregs)); npxuserinited(td); critical_exit(); return (0); } /* * Get machine context. */ int get_mcontext(struct thread *td, mcontext_t *mcp, int flags) { struct trapframe *tp; struct segment_descriptor *sdp; tp = td->td_frame; PROC_LOCK(curthread->td_proc); mcp->mc_onstack = sigonstack(tp->tf_esp); PROC_UNLOCK(curthread->td_proc); mcp->mc_gs = td->td_pcb->pcb_gs; mcp->mc_fs = tp->tf_fs; mcp->mc_es = tp->tf_es; mcp->mc_ds = tp->tf_ds; mcp->mc_edi = tp->tf_edi; mcp->mc_esi = tp->tf_esi; mcp->mc_ebp = tp->tf_ebp; mcp->mc_isp = tp->tf_isp; mcp->mc_eflags = tp->tf_eflags; if (flags & GET_MC_CLEAR_RET) { mcp->mc_eax = 0; mcp->mc_edx = 0; mcp->mc_eflags &= ~PSL_C; } else { mcp->mc_eax = tp->tf_eax; mcp->mc_edx = tp->tf_edx; } mcp->mc_ebx = tp->tf_ebx; mcp->mc_ecx = tp->tf_ecx; mcp->mc_eip = tp->tf_eip; mcp->mc_cs = tp->tf_cs; mcp->mc_esp = tp->tf_esp; mcp->mc_ss = tp->tf_ss; mcp->mc_len = sizeof(*mcp); get_fpcontext(td, mcp, NULL, 0); sdp = &td->td_pcb->pcb_fsd; mcp->mc_fsbase = sdp->sd_hibase << 24 | sdp->sd_lobase; sdp = &td->td_pcb->pcb_gsd; mcp->mc_gsbase = sdp->sd_hibase << 24 | sdp->sd_lobase; mcp->mc_flags = 0; mcp->mc_xfpustate = 0; mcp->mc_xfpustate_len = 0; bzero(mcp->mc_spare2, sizeof(mcp->mc_spare2)); return (0); } /* * Set machine context. * * However, we don't set any but the user modifiable flags, and we won't * touch the cs selector. */ int set_mcontext(struct thread *td, mcontext_t *mcp) { struct trapframe *tp; char *xfpustate; int eflags, ret; tp = td->td_frame; if (mcp->mc_len != sizeof(*mcp) || (mcp->mc_flags & ~_MC_FLAG_MASK) != 0) return (EINVAL); eflags = (mcp->mc_eflags & PSL_USERCHANGE) | (tp->tf_eflags & ~PSL_USERCHANGE); if (mcp->mc_flags & _MC_HASFPXSTATE) { if (mcp->mc_xfpustate_len > cpu_max_ext_state_size - sizeof(union savefpu)) return (EINVAL); xfpustate = __builtin_alloca(mcp->mc_xfpustate_len); ret = copyin((void *)mcp->mc_xfpustate, xfpustate, mcp->mc_xfpustate_len); if (ret != 0) return (ret); } else xfpustate = NULL; ret = set_fpcontext(td, mcp, xfpustate, mcp->mc_xfpustate_len); if (ret != 0) return (ret); tp->tf_fs = mcp->mc_fs; tp->tf_es = mcp->mc_es; tp->tf_ds = mcp->mc_ds; tp->tf_edi = mcp->mc_edi; tp->tf_esi = mcp->mc_esi; tp->tf_ebp = mcp->mc_ebp; tp->tf_ebx = mcp->mc_ebx; tp->tf_edx = mcp->mc_edx; tp->tf_ecx = mcp->mc_ecx; tp->tf_eax = mcp->mc_eax; tp->tf_eip = mcp->mc_eip; tp->tf_eflags = eflags; tp->tf_esp = mcp->mc_esp; tp->tf_ss = mcp->mc_ss; td->td_pcb->pcb_gs = mcp->mc_gs; return (0); } static void get_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpusave, size_t xfpusave_len) { size_t max_len, len; mcp->mc_ownedfp = npxgetregs(td); bcopy(get_pcb_user_save_td(td), &mcp->mc_fpstate[0], sizeof(mcp->mc_fpstate)); mcp->mc_fpformat = npxformat(); if (!use_xsave || xfpusave_len == 0) return; max_len = cpu_max_ext_state_size - sizeof(union savefpu); len = xfpusave_len; if (len > max_len) { len = max_len; bzero(xfpusave + max_len, len - max_len); } mcp->mc_flags |= _MC_HASFPXSTATE; mcp->mc_xfpustate_len = len; bcopy(get_pcb_user_save_td(td) + 1, xfpusave, len); } static int set_fpcontext(struct thread *td, mcontext_t *mcp, char *xfpustate, size_t xfpustate_len) { int error; if (mcp->mc_fpformat == _MC_FPFMT_NODEV) return (0); else if (mcp->mc_fpformat != _MC_FPFMT_387 && mcp->mc_fpformat != _MC_FPFMT_XMM) return (EINVAL); else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE) { /* We don't care what state is left in the FPU or PCB. */ fpstate_drop(td); error = 0; } else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU || mcp->mc_ownedfp == _MC_FPOWNED_PCB) { error = npxsetregs(td, (union savefpu *)&mcp->mc_fpstate, xfpustate, xfpustate_len); } else return (EINVAL); return (error); } static void fpstate_drop(struct thread *td) { KASSERT(PCB_USER_FPU(td->td_pcb), ("fpstate_drop: kernel-owned fpu")); critical_enter(); if (PCPU_GET(fpcurthread) == td) npxdrop(); /* * XXX force a full drop of the npx. The above only drops it if we * owned it. npxgetregs() has the same bug in the !cpu_fxsr case. * * XXX I don't much like npxgetregs()'s semantics of doing a full * drop. Dropping only to the pcb matches fnsave's behaviour. * We only need to drop to !PCB_INITDONE in sendsig(). But * sendsig() is the only caller of npxgetregs()... perhaps we just * have too many layers. */ curthread->td_pcb->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE); critical_exit(); } int fill_dbregs(struct thread *td, struct dbreg *dbregs) { struct pcb *pcb; if (td == NULL) { dbregs->dr[0] = rdr0(); dbregs->dr[1] = rdr1(); dbregs->dr[2] = rdr2(); dbregs->dr[3] = rdr3(); dbregs->dr[6] = rdr6(); dbregs->dr[7] = rdr7(); } else { pcb = td->td_pcb; dbregs->dr[0] = pcb->pcb_dr0; dbregs->dr[1] = pcb->pcb_dr1; dbregs->dr[2] = pcb->pcb_dr2; dbregs->dr[3] = pcb->pcb_dr3; dbregs->dr[6] = pcb->pcb_dr6; dbregs->dr[7] = pcb->pcb_dr7; } dbregs->dr[4] = 0; dbregs->dr[5] = 0; return (0); } int set_dbregs(struct thread *td, struct dbreg *dbregs) { struct pcb *pcb; int i; if (td == NULL) { load_dr0(dbregs->dr[0]); load_dr1(dbregs->dr[1]); load_dr2(dbregs->dr[2]); load_dr3(dbregs->dr[3]); load_dr6(dbregs->dr[6]); load_dr7(dbregs->dr[7]); } else { /* * Don't let an illegal value for dr7 get set. Specifically, * check for undefined settings. Setting these bit patterns * result in undefined behaviour and can lead to an unexpected * TRCTRAP. */ for (i = 0; i < 4; i++) { if (DBREG_DR7_ACCESS(dbregs->dr[7], i) == 0x02) return (EINVAL); if (DBREG_DR7_LEN(dbregs->dr[7], i) == 0x02) return (EINVAL); } pcb = td->td_pcb; /* * Don't let a process set a breakpoint that is not within the * process's address space. If a process could do this, it * could halt the system by setting a breakpoint in the kernel * (if ddb was enabled). Thus, we need to check to make sure * that no breakpoints are being enabled for addresses outside * process's address space. * * XXX - what about when the watched area of the user's * address space is written into from within the kernel * ... wouldn't that still cause a breakpoint to be generated * from within kernel mode? */ if (DBREG_DR7_ENABLED(dbregs->dr[7], 0)) { /* dr0 is enabled */ if (dbregs->dr[0] >= VM_MAXUSER_ADDRESS) return (EINVAL); } if (DBREG_DR7_ENABLED(dbregs->dr[7], 1)) { /* dr1 is enabled */ if (dbregs->dr[1] >= VM_MAXUSER_ADDRESS) return (EINVAL); } if (DBREG_DR7_ENABLED(dbregs->dr[7], 2)) { /* dr2 is enabled */ if (dbregs->dr[2] >= VM_MAXUSER_ADDRESS) return (EINVAL); } if (DBREG_DR7_ENABLED(dbregs->dr[7], 3)) { /* dr3 is enabled */ if (dbregs->dr[3] >= VM_MAXUSER_ADDRESS) return (EINVAL); } pcb->pcb_dr0 = dbregs->dr[0]; pcb->pcb_dr1 = dbregs->dr[1]; pcb->pcb_dr2 = dbregs->dr[2]; pcb->pcb_dr3 = dbregs->dr[3]; pcb->pcb_dr6 = dbregs->dr[6]; pcb->pcb_dr7 = dbregs->dr[7]; pcb->pcb_flags |= PCB_DBREGS; } return (0); } /* * Return > 0 if a hardware breakpoint has been hit, and the * breakpoint was in user space. Return 0, otherwise. */ int user_dbreg_trap(register_t dr6) { u_int32_t dr7; u_int32_t bp; /* breakpoint bits extracted from dr6 */ int nbp; /* number of breakpoints that triggered */ caddr_t addr[4]; /* breakpoint addresses */ int i; bp = dr6 & DBREG_DR6_BMASK; if (bp == 0) { /* * None of the breakpoint bits are set meaning this * trap was not caused by any of the debug registers */ return (0); } dr7 = rdr7(); if ((dr7 & 0x000000ff) == 0) { /* * all GE and LE bits in the dr7 register are zero, * thus the trap couldn't have been caused by the * hardware debug registers */ return (0); } nbp = 0; /* * at least one of the breakpoints were hit, check to see * which ones and if any of them are user space addresses */ if (bp & 0x01) { addr[nbp++] = (caddr_t)rdr0(); } if (bp & 0x02) { addr[nbp++] = (caddr_t)rdr1(); } if (bp & 0x04) { addr[nbp++] = (caddr_t)rdr2(); } if (bp & 0x08) { addr[nbp++] = (caddr_t)rdr3(); } for (i = 0; i < nbp; i++) { if (addr[i] < (caddr_t)VM_MAXUSER_ADDRESS) { /* * addr[i] is in user space */ return (nbp); } } /* * None of the breakpoints are in user space. */ return (0); }