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DEFINITIONS
This source file includes following definitions.
- copy_siginfo_to_user32
- copy_siginfo_from_user32
- sys32_sigsuspend
- sys32_sigaltstack
- ia32_restore_sigcontext
- sys32_sigreturn
- sys32_rt_sigreturn
- ia32_setup_sigcontext
- get_sigframe
- ia32_setup_frame
- ia32_setup_rt_frame
/*
* linux/arch/x86_64/ia32/ia32_signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
* 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/compat.h>
#include <linux/binfmts.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
#include <asm/ia32.h>
#include <asm/ptrace.h>
#include <asm/ia32_unistd.h>
#include <asm/user32.h>
#include <asm/sigcontext32.h>
#include <asm/proto.h>
#include <asm/vdso.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
#define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
X86_EFLAGS_CF)
asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
int err;
if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
return -EFAULT;
/* If you change siginfo_t structure, please make sure that
this code is fixed accordingly.
It should never copy any pad contained in the structure
to avoid security leaks, but must copy the generic
3 ints plus the relevant union member. */
err = __put_user(from->si_signo, &to->si_signo);
err |= __put_user(from->si_errno, &to->si_errno);
err |= __put_user((short)from->si_code, &to->si_code);
if (from->si_code < 0) {
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
} else {
/*
* First 32bits of unions are always present:
* si_pid === si_band === si_tid === si_addr(LS half)
*/
err |= __put_user(from->_sifields._pad[0],
&to->_sifields._pad[0]);
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
break;
case __SI_CHLD >> 16:
err |= __put_user(from->si_utime, &to->si_utime);
err |= __put_user(from->si_stime, &to->si_stime);
err |= __put_user(from->si_status, &to->si_status);
/* FALL THROUGH */
default:
case __SI_KILL >> 16:
err |= __put_user(from->si_uid, &to->si_uid);
break;
case __SI_POLL >> 16:
err |= __put_user(from->si_fd, &to->si_fd);
break;
case __SI_TIMER >> 16:
err |= __put_user(from->si_overrun, &to->si_overrun);
err |= __put_user(ptr_to_compat(from->si_ptr),
&to->si_ptr);
break;
/* This is not generated by the kernel as of now. */
case __SI_RT >> 16:
case __SI_MESGQ >> 16:
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_int, &to->si_int);
break;
}
}
return err;
}
int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
int err;
u32 ptr32;
if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
return -EFAULT;
err = __get_user(to->si_signo, &from->si_signo);
err |= __get_user(to->si_errno, &from->si_errno);
err |= __get_user(to->si_code, &from->si_code);
err |= __get_user(to->si_pid, &from->si_pid);
err |= __get_user(to->si_uid, &from->si_uid);
err |= __get_user(ptr32, &from->si_ptr);
to->si_ptr = compat_ptr(ptr32);
return err;
}
asmlinkage long sys32_sigsuspend(int history0, int history1, old_sigset_t mask)
{
mask &= _BLOCKABLE;
spin_lock_irq(¤t->sighand->siglock);
current->saved_sigmask = current->blocked;
siginitset(¤t->blocked, mask);
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
current->state = TASK_INTERRUPTIBLE;
schedule();
set_restore_sigmask();
return -ERESTARTNOHAND;
}
asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
stack_ia32_t __user *uoss_ptr,
struct pt_regs *regs)
{
stack_t uss, uoss;
int ret;
mm_segment_t seg;
if (uss_ptr) {
u32 ptr;
memset(&uss, 0, sizeof(stack_t));
if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)) ||
__get_user(ptr, &uss_ptr->ss_sp) ||
__get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
__get_user(uss.ss_size, &uss_ptr->ss_size))
return -EFAULT;
uss.ss_sp = compat_ptr(ptr);
}
seg = get_fs();
set_fs(KERNEL_DS);
ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp);
set_fs(seg);
if (ret >= 0 && uoss_ptr) {
if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)) ||
__put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
__put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
__put_user(uoss.ss_size, &uoss_ptr->ss_size))
ret = -EFAULT;
}
return ret;
}
/*
* Do a signal return; undo the signal stack.
*/
struct sigframe
{
u32 pretcode;
int sig;
struct sigcontext_ia32 sc;
struct _fpstate_ia32 fpstate_unused; /* look at kernel/sigframe.h */
unsigned int extramask[_COMPAT_NSIG_WORDS-1];
char retcode[8];
/* fp state follows here */
};
struct rt_sigframe
{
u32 pretcode;
int sig;
u32 pinfo;
u32 puc;
compat_siginfo_t info;
struct ucontext_ia32 uc;
char retcode[8];
/* fp state follows here */
};
#define COPY(x) { \
unsigned int reg; \
err |= __get_user(reg, &sc->x); \
regs->x = reg; \
}
#define RELOAD_SEG(seg,mask) \
{ unsigned int cur; \
unsigned short pre; \
err |= __get_user(pre, &sc->seg); \
savesegment(seg, cur); \
pre |= mask; \
if (pre != cur) loadsegment(seg, pre); }
static int ia32_restore_sigcontext(struct pt_regs *regs,
struct sigcontext_ia32 __user *sc,
unsigned int *peax)
{
unsigned int tmpflags, gs, oldgs, err = 0;
void __user *buf;
u32 tmp;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
#if DEBUG_SIG
printk(KERN_DEBUG "SIG restore_sigcontext: "
"sc=%p err(%x) eip(%x) cs(%x) flg(%x)\n",
sc, sc->err, sc->ip, sc->cs, sc->flags);
#endif
/*
* Reload fs and gs if they have changed in the signal
* handler. This does not handle long fs/gs base changes in
* the handler, but does not clobber them at least in the
* normal case.
*/
err |= __get_user(gs, &sc->gs);
gs |= 3;
savesegment(gs, oldgs);
if (gs != oldgs)
load_gs_index(gs);
RELOAD_SEG(fs, 3);
RELOAD_SEG(ds, 3);
RELOAD_SEG(es, 3);
COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
COPY(dx); COPY(cx); COPY(ip);
/* Don't touch extended registers */
err |= __get_user(regs->cs, &sc->cs);
regs->cs |= 3;
err |= __get_user(regs->ss, &sc->ss);
regs->ss |= 3;
err |= __get_user(tmpflags, &sc->flags);
regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
/* disable syscall checks */
regs->orig_ax = -1;
err |= __get_user(tmp, &sc->fpstate);
buf = compat_ptr(tmp);
err |= restore_i387_xstate_ia32(buf);
err |= __get_user(tmp, &sc->ax);
*peax = tmp;
return err;
}
asmlinkage long sys32_sigreturn(struct pt_regs *regs)
{
struct sigframe __user *frame = (struct sigframe __user *)(regs->sp-8);
sigset_t set;
unsigned int ax;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (_COMPAT_NSIG_WORDS > 1
&& __copy_from_user((((char *) &set.sig) + 4),
&frame->extramask,
sizeof(frame->extramask))))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(¤t->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
if (ia32_restore_sigcontext(regs, &frame->sc, &ax))
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "32bit sigreturn");
return 0;
}
asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
sigset_t set;
unsigned int ax;
struct pt_regs tregs;
frame = (struct rt_sigframe __user *)(regs->sp - 4);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(¤t->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
tregs = *regs;
if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "32bit rt sigreturn");
return 0;
}
/*
* Set up a signal frame.
*/
static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
void __user *fpstate,
struct pt_regs *regs, unsigned int mask)
{
int tmp, err = 0;
savesegment(gs, tmp);
err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
savesegment(fs, tmp);
err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
savesegment(ds, tmp);
err |= __put_user(tmp, (unsigned int __user *)&sc->ds);
savesegment(es, tmp);
err |= __put_user(tmp, (unsigned int __user *)&sc->es);
err |= __put_user(regs->di, &sc->di);
err |= __put_user(regs->si, &sc->si);
err |= __put_user(regs->bp, &sc->bp);
err |= __put_user(regs->sp, &sc->sp);
err |= __put_user(regs->bx, &sc->bx);
err |= __put_user(regs->dx, &sc->dx);
err |= __put_user(regs->cx, &sc->cx);
err |= __put_user(regs->ax, &sc->ax);
err |= __put_user(regs->cs, &sc->cs);
err |= __put_user(regs->ss, &sc->ss);
err |= __put_user(current->thread.trap_no, &sc->trapno);
err |= __put_user(current->thread.error_code, &sc->err);
err |= __put_user(regs->ip, &sc->ip);
err |= __put_user(regs->flags, &sc->flags);
err |= __put_user(regs->sp, &sc->sp_at_signal);
tmp = save_i387_xstate_ia32(fpstate);
if (tmp < 0)
err = -EFAULT;
else
err |= __put_user(ptr_to_compat(tmp ? fpstate : NULL),
&sc->fpstate);
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
err |= __put_user(current->thread.cr2, &sc->cr2);
return err;
}
/*
* Determine which stack to use..
*/
static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
size_t frame_size,
void **fpstate)
{
unsigned long sp;
/* Default to using normal stack */
sp = regs->sp;
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
/* This is the legacy signal stack switching. */
else if ((regs->ss & 0xffff) != __USER_DS &&
!(ka->sa.sa_flags & SA_RESTORER) &&
ka->sa.sa_restorer)
sp = (unsigned long) ka->sa.sa_restorer;
if (used_math()) {
sp = sp - sig_xstate_ia32_size;
*fpstate = (struct _fpstate_ia32 *) sp;
}
sp -= frame_size;
/* Align the stack pointer according to the i386 ABI,
* i.e. so that on function entry ((sp + 4) & 15) == 0. */
sp = ((sp + 4) & -16ul) - 4;
return (void __user *) sp;
}
int ia32_setup_frame(int sig, struct k_sigaction *ka,
compat_sigset_t *set, struct pt_regs *regs)
{
struct sigframe __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
/* copy_to_user optimizes that into a single 8 byte store */
static const struct {
u16 poplmovl;
u32 val;
u16 int80;
u16 pad;
} __attribute__((packed)) code = {
0xb858, /* popl %eax ; movl $...,%eax */
__NR_ia32_sigreturn,
0x80cd, /* int $0x80 */
0,
};
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (__put_user(sig, &frame->sig))
return -EFAULT;
if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
return -EFAULT;
if (_COMPAT_NSIG_WORDS > 1) {
if (__copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask)))
return -EFAULT;
}
if (ka->sa.sa_flags & SA_RESTORER) {
restorer = ka->sa.sa_restorer;
} else {
/* Return stub is in 32bit vsyscall page */
if (current->mm->context.vdso)
restorer = VDSO32_SYMBOL(current->mm->context.vdso,
sigreturn);
else
restorer = &frame->retcode;
}
err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
/*
* These are actually not used anymore, but left because some
* gdb versions depend on them as a marker.
*/
err |= __copy_to_user(frame->retcode, &code, 8);
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
regs->ip = (unsigned long) ka->sa.sa_handler;
/* Make -mregparm=3 work */
regs->ax = sig;
regs->dx = 0;
regs->cx = 0;
loadsegment(ds, __USER32_DS);
loadsegment(es, __USER32_DS);
regs->cs = __USER32_CS;
regs->ss = __USER32_DS;
#if DEBUG_SIG
printk(KERN_DEBUG "SIG deliver (%s:%d): sp=%p pc=%lx ra=%u\n",
current->comm, current->pid, frame, regs->ip, frame->pretcode);
#endif
return 0;
}
int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
compat_sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
/* __copy_to_user optimizes that into a single 8 byte store */
static const struct {
u8 movl;
u32 val;
u16 int80;
u16 pad;
u8 pad2;
} __attribute__((packed)) code = {
0xb8,
__NR_ia32_rt_sigreturn,
0x80cd,
0,
};
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
err |= __put_user(sig, &frame->sig);
err |= __put_user(ptr_to_compat(&frame->info), &frame->pinfo);
err |= __put_user(ptr_to_compat(&frame->uc), &frame->puc);
err |= copy_siginfo_to_user32(&frame->info, info);
if (err)
return -EFAULT;
/* Create the ucontext. */
if (cpu_has_xsave)
err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
else
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
else
restorer = VDSO32_SYMBOL(current->mm->context.vdso,
rt_sigreturn);
err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
/*
* Not actually used anymore, but left because some gdb
* versions need it.
*/
err |= __copy_to_user(frame->retcode, &code, 8);
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
regs->ip = (unsigned long) ka->sa.sa_handler;
/* Make -mregparm=3 work */
regs->ax = sig;
regs->dx = (unsigned long) &frame->info;
regs->cx = (unsigned long) &frame->uc;
/* Make -mregparm=3 work */
regs->ax = sig;
regs->dx = (unsigned long) &frame->info;
regs->cx = (unsigned long) &frame->uc;
loadsegment(ds, __USER32_DS);
loadsegment(es, __USER32_DS);
regs->cs = __USER32_CS;
regs->ss = __USER32_DS;
#if DEBUG_SIG
printk(KERN_DEBUG "SIG deliver (%s:%d): sp=%p pc=%lx ra=%u\n",
current->comm, current->pid, frame, regs->ip, frame->pretcode);
#endif
return 0;
}