freebsd-dev/sys/amd64/ia32/ia32_signal.c
2003-08-23 00:04:53 +00:00

561 lines
18 KiB
C

/*-
* 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.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mman.h>
#include <sys/namei.h>
#include <sys/pioctl.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/resourcevar.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <compat/freebsd32/freebsd32_util.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <compat/ia32/ia32_signal.h>
#include <machine/psl.h>
#include <machine/segments.h>
#include <machine/specialreg.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/cpufunc.h>
#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
* npxgetregs()'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 = npxgetregs(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 = npxformat();
}
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 npxsetregs()
* be called with interrupts disabled.
*/
npxsetregs(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;
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)p->p_sigstk.ss_sp;
sf.sf_uc.uc_stack.ss_size = p->p_sigstk.ss_size;
sf.sf_uc.uc_stack.ss_flags = (p->p_flag & P_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 ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
sfp = (struct ia32_sigframe4 *)(p->p_sigstk.ss_sp +
p->p_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;
PROC_LOCK(p);
if (SIGISMEMBER(p->p_sigacts->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;
}
PROC_UNLOCK(p);
/*
* 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);
}
#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
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)p->p_sigstk.ss_sp;
sf.sf_uc.uc_stack.ss_size = p->p_sigstk.ss_size;
sf.sf_uc.uc_stack.ss_flags = (p->p_flag & P_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 ((p->p_flag & P_ALTSTACK) != 0 && !oonstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
sp = p->p_sigstk.ss_sp +
p->p_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;
PROC_LOCK(p);
if (SIGISMEMBER(p->p_sigacts->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;
}
PROC_UNLOCK(p);
/*
* 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);
}
/*
* 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);
}