/*- * Copyright (c) 2003 Peter Wemm * 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. * * 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. * 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. */ #include __FBSDID("$FreeBSD$"); #include "opt_compat.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 #include #include #include #include #include #include #include #include #include #ifdef COMPAT_FREEBSD4 static void freebsd4_ia32_sendsig(sig_t, int, sigset_t *, u_long); #endif static void ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp); static int ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp); extern int _ucode32sel, _udatasel; #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) #define EFL_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) static void ia32_get_fpcontext(struct thread *td, struct ia32_mcontext *mcp) { struct savefpu *addr; /* * XXX mc_fpstate might be misaligned, since its declaration is not * unportabilized using __attribute__((aligned(16))) like the * declaration of struct savemm, and anyway, alignment doesn't work * for auto variables since we don't use gcc's pessimal stack * alignment. Work around this by abusing the spare fields after * mcp->mc_fpstate. * * XXX unpessimize most cases by only aligning when fxsave might be * called, although this requires knowing too much about * fpugetregs()'s internals. */ addr = (struct savefpu *)&mcp->mc_fpstate; if (td == PCPU_GET(fpcurthread) && ((uintptr_t)(void *)addr & 0xF)) { do addr = (void *)((char *)addr + 4); while ((uintptr_t)(void *)addr & 0xF); } mcp->mc_ownedfp = fpugetregs(td, addr); if (addr != (struct savefpu *)&mcp->mc_fpstate) { bcopy(addr, &mcp->mc_fpstate, sizeof(mcp->mc_fpstate)); bzero(&mcp->mc_spare2, sizeof(mcp->mc_spare2)); } mcp->mc_fpformat = fpuformat(); } static int ia32_set_fpcontext(struct thread *td, const struct ia32_mcontext *mcp) { struct savefpu *addr; if (mcp->mc_fpformat == _MC_FPFMT_NODEV) return (0); else if (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); else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU || mcp->mc_ownedfp == _MC_FPOWNED_PCB) { /* XXX align as above. */ addr = (struct savefpu *)&mcp->mc_fpstate; if (td == PCPU_GET(fpcurthread) && ((uintptr_t)(void *)addr & 0xF)) { do addr = (void *)((char *)addr + 4); while ((uintptr_t)(void *)addr & 0xF); bcopy(&mcp->mc_fpstate, addr, sizeof(mcp->mc_fpstate)); } /* * XXX we violate the dubious requirement that fpusetregs() * be called with interrupts disabled. */ fpusetregs(td, addr); /* * Don't bother putting things back where they were in the * misaligned case, since we know that the caller won't use * them again. */ } else return (EINVAL); return (0); } /* * Send an interrupt to process. * * Stack is set up to allow sigcode stored * at top to call routine, followed by kcall * 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_FREEBSD4 static void freebsd4_ia32_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code) { struct ia32_sigframe4 sf, *sfp; struct proc *p; struct thread *td; struct sigacts *psp; struct trapframe *regs; int oonstack; td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); psp = p->p_sigacts; mtx_assert(&psp->ps_mtx, MA_OWNED); regs = td->td_frame; oonstack = sigonstack(regs->tf_rsp); /* Save user context. */ bzero(&sf, sizeof(sf)); sf.sf_uc.uc_sigmask = *mask; sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 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(); sf.sf_uc.uc_mcontext.mc_fs = rfs(); __asm __volatile("movl %%es,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_es)); __asm __volatile("movl %%ds,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_ds)); sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; /* Allocate space for the signal handler context. */ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && SIGISMEMBER(psp->ps_sigonstack, sig)) { sfp = (struct ia32_sigframe4 *)(td->td_sigstk.ss_sp + td->td_sigstk.ss_size - sizeof(sf)); } else sfp = (struct ia32_sigframe4 *)regs->tf_rsp - 1; PROC_UNLOCK(p); /* Translate the signal if appropriate. */ if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; /* Build the argument list for the signal handler. */ sf.sf_signum = sig; sf.sf_ucontext = (register_t)&sfp->sf_uc; if (SIGISMEMBER(psp->ps_siginfo, sig)) { /* Signal handler installed with SA_SIGINFO. */ sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; sf.sf_ah = (u_int32_t)(uintptr_t)catcher; /* Fill in POSIX parts */ sf.sf_si.si_signo = sig; sf.sf_si.si_code = code; sf.sf_si.si_addr = regs->tf_addr; } else { /* Old FreeBSD-style arguments. */ sf.sf_siginfo = code; sf.sf_addr = regs->tf_addr; sf.sf_ah = (u_int32_t)(uintptr_t)catcher; } mtx_unlock(&psp->ps_mtx); /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { #ifdef DEBUG printf("process %ld has trashed its stack\n", (long)p->p_pid); #endif PROC_LOCK(p); sigexit(td, SIGILL); } regs->tf_rsp = (uintptr_t)sfp; regs->tf_rip = FREEBSD32_PS_STRINGS - sz_freebsd4_ia32_sigcode; regs->tf_rflags &= ~PSL_T; regs->tf_cs = _ucode32sel; regs->tf_ss = _udatasel; load_ds(_udatasel); td->td_pcb->pcb_ds = _udatasel; load_es(_udatasel); td->td_pcb->pcb_es = _udatasel; /* leave user %fs and %gs untouched */ PROC_LOCK(p); mtx_lock(&psp->ps_mtx); } #endif /* COMPAT_FREEBSD4 */ void ia32_sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code) { struct ia32_sigframe sf, *sfp; struct proc *p; struct thread *td; struct sigacts *psp; char *sp; struct trapframe *regs; int oonstack; td = curthread; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); psp = p->p_sigacts; #ifdef COMPAT_FREEBSD4 if (SIGISMEMBER(psp->ps_freebsd4, sig)) { freebsd4_ia32_sendsig(catcher, sig, mask, code); return; } #endif mtx_assert(&psp->ps_mtx, MA_OWNED); regs = td->td_frame; oonstack = sigonstack(regs->tf_rsp); /* Save user context. */ bzero(&sf, sizeof(sf)); sf.sf_uc.uc_sigmask = *mask; sf.sf_uc.uc_stack.ss_sp = (uintptr_t)td->td_sigstk.ss_sp; sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 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(); sf.sf_uc.uc_mcontext.mc_fs = rfs(); __asm __volatile("movl %%es,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_es)); __asm __volatile("movl %%ds,%0" : "=rm" (sf.sf_uc.uc_mcontext.mc_ds)); sf.sf_uc.uc_mcontext.mc_edi = regs->tf_rdi; sf.sf_uc.uc_mcontext.mc_esi = regs->tf_rsi; sf.sf_uc.uc_mcontext.mc_ebp = regs->tf_rbp; sf.sf_uc.uc_mcontext.mc_isp = regs->tf_rsp; /* XXX */ sf.sf_uc.uc_mcontext.mc_ebx = regs->tf_rbx; sf.sf_uc.uc_mcontext.mc_edx = regs->tf_rdx; sf.sf_uc.uc_mcontext.mc_ecx = regs->tf_rcx; sf.sf_uc.uc_mcontext.mc_eax = regs->tf_rax; sf.sf_uc.uc_mcontext.mc_trapno = regs->tf_trapno; sf.sf_uc.uc_mcontext.mc_err = regs->tf_err; sf.sf_uc.uc_mcontext.mc_eip = regs->tf_rip; sf.sf_uc.uc_mcontext.mc_cs = regs->tf_cs; sf.sf_uc.uc_mcontext.mc_eflags = regs->tf_rflags; sf.sf_uc.uc_mcontext.mc_esp = regs->tf_rsp; sf.sf_uc.uc_mcontext.mc_ss = regs->tf_ss; sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */ ia32_get_fpcontext(td, &sf.sf_uc.uc_mcontext); fpstate_drop(td); /* Allocate space for the signal handler context. */ if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && SIGISMEMBER(psp->ps_sigonstack, sig)) { sp = td->td_sigstk.ss_sp + td->td_sigstk.ss_size - sizeof(sf); } else sp = (char *)regs->tf_rsp - sizeof(sf); /* Align to 16 bytes. */ sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF); PROC_UNLOCK(p); /* Translate the signal if appropriate. */ if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize) sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)]; /* Build the argument list for the signal handler. */ sf.sf_signum = sig; sf.sf_ucontext = (register_t)&sfp->sf_uc; if (SIGISMEMBER(psp->ps_siginfo, sig)) { /* Signal handler installed with SA_SIGINFO. */ sf.sf_siginfo = (u_int32_t)(uintptr_t)&sfp->sf_si; sf.sf_ah = (u_int32_t)(uintptr_t)catcher; /* Fill in POSIX parts */ sf.sf_si.si_signo = sig; sf.sf_si.si_code = code; sf.sf_si.si_addr = regs->tf_addr; } else { /* Old FreeBSD-style arguments. */ sf.sf_siginfo = code; sf.sf_addr = regs->tf_addr; sf.sf_ah = (u_int32_t)(uintptr_t)catcher; } mtx_unlock(&psp->ps_mtx); /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { #ifdef DEBUG printf("process %ld has trashed its stack\n", (long)p->p_pid); #endif PROC_LOCK(p); sigexit(td, SIGILL); } regs->tf_rsp = (uintptr_t)sfp; regs->tf_rip = FREEBSD32_PS_STRINGS - *(p->p_sysent->sv_szsigcode); regs->tf_rflags &= ~PSL_T; regs->tf_cs = _ucode32sel; regs->tf_ss = _udatasel; load_ds(_udatasel); td->td_pcb->pcb_ds = _udatasel; load_es(_udatasel); td->td_pcb->pcb_es = _udatasel; /* leave user %fs and %gs untouched */ 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_FREEBSD4 /* * MPSAFE */ int freebsd4_freebsd32_sigreturn(td, uap) struct thread *td; struct freebsd4_freebsd32_sigreturn_args /* { const struct freebsd4_freebsd32_ucontext *sigcntxp; } */ *uap; { struct ia32_ucontext4 uc; struct proc *p = td->td_proc; struct trapframe *regs; const struct ia32_ucontext4 *ucp; int cs, eflags, error; error = copyin(uap->sigcntxp, &uc, sizeof(uc)); if (error != 0) return (error); ucp = &uc; regs = td->td_frame; eflags = ucp->uc_mcontext.mc_eflags; /* * Don't allow users to change privileged or reserved flags. */ /* * XXX do allow users to change the privileged flag PSL_RF. * The cpu sets PSL_RF in tf_eflags for faults. Debuggers * should sometimes set it there too. tf_eflags is kept in * the signal context during signal handling and there is no * other place to remember it, so the PSL_RF bit may be * corrupted by the signal handler without us knowing. * Corruption of the PSL_RF bit at worst causes one more or * one less debugger trap, so allowing it is fairly harmless. */ if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { printf("freebsd4_freebsd32_sigreturn: eflags = 0x%x\n", 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)) { printf("freebsd4_sigreturn: cs = 0x%x\n", cs); trapsignal(td, SIGBUS, T_PROTFLT); return (EINVAL); } /* Segment selectors restored by sigtramp.S */ regs->tf_rdi = ucp->uc_mcontext.mc_edi; regs->tf_rsi = ucp->uc_mcontext.mc_esi; regs->tf_rbp = ucp->uc_mcontext.mc_ebp; regs->tf_rbx = ucp->uc_mcontext.mc_ebx; regs->tf_rdx = ucp->uc_mcontext.mc_edx; regs->tf_rcx = ucp->uc_mcontext.mc_ecx; regs->tf_rax = ucp->uc_mcontext.mc_eax; regs->tf_trapno = ucp->uc_mcontext.mc_trapno; regs->tf_err = ucp->uc_mcontext.mc_err; regs->tf_rip = ucp->uc_mcontext.mc_eip; regs->tf_cs = cs; regs->tf_rflags = ucp->uc_mcontext.mc_eflags; regs->tf_rsp = ucp->uc_mcontext.mc_esp; regs->tf_ss = ucp->uc_mcontext.mc_ss; PROC_LOCK(p); td->td_sigmask = ucp->uc_sigmask; SIG_CANTMASK(td->td_sigmask); signotify(td); PROC_UNLOCK(p); return (EJUSTRETURN); } #endif /* COMPAT_FREEBSD4 */ /* * MPSAFE */ int freebsd32_sigreturn(td, uap) struct thread *td; struct freebsd32_sigreturn_args /* { const struct freebsd32_ucontext *sigcntxp; } */ *uap; { struct ia32_ucontext uc; struct proc *p = td->td_proc; struct trapframe *regs; const struct ia32_ucontext *ucp; int cs, eflags, error, ret; error = copyin(uap->sigcntxp, &uc, sizeof(uc)); if (error != 0) return (error); ucp = &uc; regs = td->td_frame; eflags = ucp->uc_mcontext.mc_eflags; /* * Don't allow users to change privileged or reserved flags. */ /* * XXX do allow users to change the privileged flag PSL_RF. * The cpu sets PSL_RF in tf_eflags for faults. Debuggers * should sometimes set it there too. tf_eflags is kept in * the signal context during signal handling and there is no * other place to remember it, so the PSL_RF bit may be * corrupted by the signal handler without us knowing. * Corruption of the PSL_RF bit at worst causes one more or * one less debugger trap, so allowing it is fairly harmless. */ if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { printf("freebsd32_sigreturn: eflags = 0x%x\n", 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)) { printf("sigreturn: cs = 0x%x\n", cs); trapsignal(td, SIGBUS, T_PROTFLT); return (EINVAL); } ret = ia32_set_fpcontext(td, &ucp->uc_mcontext); if (ret != 0) return (ret); /* Segment selectors restored by sigtramp.S */ regs->tf_rdi = ucp->uc_mcontext.mc_edi; regs->tf_rsi = ucp->uc_mcontext.mc_esi; regs->tf_rbp = ucp->uc_mcontext.mc_ebp; regs->tf_rbx = ucp->uc_mcontext.mc_ebx; regs->tf_rdx = ucp->uc_mcontext.mc_edx; regs->tf_rcx = ucp->uc_mcontext.mc_ecx; regs->tf_rax = ucp->uc_mcontext.mc_eax; regs->tf_trapno = ucp->uc_mcontext.mc_trapno; regs->tf_err = ucp->uc_mcontext.mc_err; regs->tf_rip = ucp->uc_mcontext.mc_eip; regs->tf_cs = cs; regs->tf_rflags = ucp->uc_mcontext.mc_eflags; regs->tf_rsp = ucp->uc_mcontext.mc_esp; regs->tf_ss = ucp->uc_mcontext.mc_ss; PROC_LOCK(p); td->td_sigmask = ucp->uc_sigmask; SIG_CANTMASK(td->td_sigmask); signotify(td); PROC_UNLOCK(p); return (EJUSTRETURN); } /* * Clear registers on exec */ void ia32_setregs(td, entry, stack, ps_strings) struct thread *td; u_long entry; u_long stack; u_long ps_strings; { struct trapframe *regs = td->td_frame; struct pcb *pcb = td->td_pcb; wrmsr(MSR_FSBASE, 0); wrmsr(MSR_KGSBASE, 0); /* User value while we're in the kernel */ pcb->pcb_fsbase = 0; pcb->pcb_gsbase = 0; load_ds(_udatasel); load_es(_udatasel); load_fs(_udatasel); load_gs(_udatasel); pcb->pcb_ds = _udatasel; pcb->pcb_es = _udatasel; pcb->pcb_fs = _udatasel; pcb->pcb_gs = _udatasel; bzero((char *)regs, sizeof(struct trapframe)); regs->tf_rip = entry; regs->tf_rsp = stack; regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); regs->tf_ss = _udatasel; regs->tf_cs = _ucode32sel; regs->tf_rbx = ps_strings; load_cr0(rcr0() | CR0_MP | CR0_TS); fpstate_drop(td); /* Return via doreti so that we can change to a different %cs */ pcb->pcb_flags |= PCB_FULLCTX; td->td_retval[1] = 0; }