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linux-sg2042/arch/x86/kernel/signal.c

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/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
* 2000-2002 x86-64 support by Andi Kleen
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <linux/user-return-notifier.h>
#include <linux/uprobes.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/i387.h>
#include <asm/fpu-internal.h>
#include <asm/vdso.h>
#include <asm/mce.h>
#include <asm/sighandling.h>
#ifdef CONFIG_X86_64
#include <asm/proto.h>
#include <asm/ia32_unistd.h>
#include <asm/sys_ia32.h>
#endif /* CONFIG_X86_64 */
#include <asm/syscall.h>
#include <asm/syscalls.h>
#include <asm/sigframe.h>
#ifdef CONFIG_X86_32
# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
#else
# define FIX_EFLAGS __FIX_EFLAGS
#endif
#define COPY(x) do { \
get_user_ex(regs->x, &sc->x); \
} while (0)
#define GET_SEG(seg) ({ \
unsigned short tmp; \
get_user_ex(tmp, &sc->seg); \
tmp; \
})
#define COPY_SEG(seg) do { \
regs->seg = GET_SEG(seg); \
} while (0)
#define COPY_SEG_CPL3(seg) do { \
regs->seg = GET_SEG(seg) | 3; \
} while (0)
int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
unsigned long *pax)
{
void __user *buf;
unsigned int tmpflags;
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
get_user_try {
#ifdef CONFIG_X86_32
set_user_gs(regs, GET_SEG(gs));
COPY_SEG(fs);
COPY_SEG(es);
COPY_SEG(ds);
#endif /* CONFIG_X86_32 */
COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
COPY(dx); COPY(cx); COPY(ip);
#ifdef CONFIG_X86_64
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
COPY(r13);
COPY(r14);
COPY(r15);
#endif /* CONFIG_X86_64 */
#ifdef CONFIG_X86_32
COPY_SEG_CPL3(cs);
COPY_SEG_CPL3(ss);
#else /* !CONFIG_X86_32 */
/* Kernel saves and restores only the CS segment register on signals,
* which is the bare minimum needed to allow mixed 32/64-bit code.
* App's signal handler can save/restore other segments if needed. */
COPY_SEG_CPL3(cs);
#endif /* CONFIG_X86_32 */
get_user_ex(tmpflags, &sc->flags);
regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
regs->orig_ax = -1; /* disable syscall checks */
get_user_ex(buf, &sc->fpstate);
get_user_ex(*pax, &sc->ax);
} get_user_catch(err);
err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32));
return err;
}
int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
struct pt_regs *regs, unsigned long mask)
{
int err = 0;
put_user_try {
#ifdef CONFIG_X86_32
put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
put_user_ex(regs->es, (unsigned int __user *)&sc->es);
put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
#endif /* CONFIG_X86_32 */
put_user_ex(regs->di, &sc->di);
put_user_ex(regs->si, &sc->si);
put_user_ex(regs->bp, &sc->bp);
put_user_ex(regs->sp, &sc->sp);
put_user_ex(regs->bx, &sc->bx);
put_user_ex(regs->dx, &sc->dx);
put_user_ex(regs->cx, &sc->cx);
put_user_ex(regs->ax, &sc->ax);
#ifdef CONFIG_X86_64
put_user_ex(regs->r8, &sc->r8);
put_user_ex(regs->r9, &sc->r9);
put_user_ex(regs->r10, &sc->r10);
put_user_ex(regs->r11, &sc->r11);
put_user_ex(regs->r12, &sc->r12);
put_user_ex(regs->r13, &sc->r13);
put_user_ex(regs->r14, &sc->r14);
put_user_ex(regs->r15, &sc->r15);
#endif /* CONFIG_X86_64 */
put_user_ex(current->thread.trap_nr, &sc->trapno);
put_user_ex(current->thread.error_code, &sc->err);
put_user_ex(regs->ip, &sc->ip);
#ifdef CONFIG_X86_32
put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
put_user_ex(regs->flags, &sc->flags);
put_user_ex(regs->sp, &sc->sp_at_signal);
put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
#else /* !CONFIG_X86_32 */
put_user_ex(regs->flags, &sc->flags);
put_user_ex(regs->cs, &sc->cs);
put_user_ex(0, &sc->gs);
put_user_ex(0, &sc->fs);
#endif /* CONFIG_X86_32 */
put_user_ex(fpstate, &sc->fpstate);
/* non-iBCS2 extensions.. */
put_user_ex(mask, &sc->oldmask);
put_user_ex(current->thread.cr2, &sc->cr2);
} put_user_catch(err);
return err;
}
/*
* Set up a signal frame.
*/
/*
* Determine which stack to use..
*/
static unsigned long align_sigframe(unsigned long sp)
{
#ifdef CONFIG_X86_32
/*
* 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;
#else /* !CONFIG_X86_32 */
sp = round_down(sp, 16) - 8;
#endif
return sp;
}
static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
void __user **fpstate)
{
/* Default to using normal stack */
unsigned long math_size = 0;
unsigned long sp = regs->sp;
unsigned long buf_fx = 0;
int onsigstack = on_sig_stack(sp);
/* redzone */
if (config_enabled(CONFIG_X86_64))
sp -= 128;
if (!onsigstack) {
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (current->sas_ss_size)
sp = current->sas_ss_sp + current->sas_ss_size;
} else if (config_enabled(CONFIG_X86_32) &&
(regs->ss & 0xffff) != __USER_DS &&
!(ka->sa.sa_flags & SA_RESTORER) &&
ka->sa.sa_restorer) {
/* This is the legacy signal stack switching. */
sp = (unsigned long) ka->sa.sa_restorer;
}
}
if (used_math()) {
sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
&buf_fx, &math_size);
*fpstate = (void __user *)sp;
}
sp = align_sigframe(sp - frame_size);
/*
* If we are on the alternate signal stack and would overflow it, don't.
* Return an always-bogus address instead so we will die with SIGSEGV.
*/
if (onsigstack && !likely(on_sig_stack(sp)))
return (void __user *)-1L;
/* save i387 and extended state */
if (used_math() &&
save_xstate_sig(*fpstate, (void __user *)buf_fx, math_size) < 0)
return (void __user *)-1L;
return (void __user *)sp;
}
#ifdef CONFIG_X86_32
static const struct {
u16 poplmovl;
u32 val;
u16 int80;
} __attribute__((packed)) retcode = {
0xb858, /* popl %eax; movl $..., %eax */
__NR_sigreturn,
0x80cd, /* int $0x80 */
};
static const struct {
u8 movl;
u32 val;
u16 int80;
u8 pad;
} __attribute__((packed)) rt_retcode = {
0xb8, /* movl $..., %eax */
__NR_rt_sigreturn,
0x80cd, /* int $0x80 */
0
};
static int
__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
struct pt_regs *regs)
{
struct sigframe __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
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 (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
return -EFAULT;
if (_NSIG_WORDS > 1) {
if (__copy_to_user(&frame->extramask, &set->sig[1],
sizeof(frame->extramask)))
return -EFAULT;
}
if (current->mm->context.vdso)
restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
else
restorer = &frame->retcode;
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
/* Set up to return from userspace. */
err |= __put_user(restorer, &frame->pretcode);
/*
* This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
*
* WE DO NOT USE IT ANY MORE! It's only left here for historical
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->sp = (unsigned long)frame;
regs->ip = (unsigned long)ka->sa.sa_handler;
regs->ax = (unsigned long)sig;
regs->dx = 0;
regs->cx = 0;
regs->ds = __USER_DS;
regs->es = __USER_DS;
regs->ss = __USER_DS;
regs->cs = __USER_CS;
return 0;
}
static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
put_user_try {
put_user_ex(sig, &frame->sig);
put_user_ex(&frame->info, &frame->pinfo);
put_user_ex(&frame->uc, &frame->puc);
/* Create the ucontext. */
if (cpu_has_xsave)
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
/* Set up to return from userspace. */
restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
put_user_ex(restorer, &frame->pretcode);
/*
* This is movl $__NR_rt_sigreturn, %ax ; int $0x80
*
* WE DO NOT USE IT ANY MORE! It's only left here for historical
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
} put_user_catch(err);
err |= copy_siginfo_to_user(&frame->info, info);
err |= 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;
/* Set up registers for signal handler */
regs->sp = (unsigned long)frame;
regs->ip = (unsigned long)ka->sa.sa_handler;
regs->ax = (unsigned long)sig;
regs->dx = (unsigned long)&frame->info;
regs->cx = (unsigned long)&frame->uc;
regs->ds = __USER_DS;
regs->es = __USER_DS;
regs->ss = __USER_DS;
regs->cs = __USER_CS;
return 0;
}
#else /* !CONFIG_X86_32 */
static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
void __user *fp = NULL;
int err = 0;
struct task_struct *me = current;
frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (ka->sa.sa_flags & SA_SIGINFO) {
if (copy_siginfo_to_user(&frame->info, info))
return -EFAULT;
}
put_user_try {
/* Create the ucontext. */
if (cpu_has_xsave)
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
/* x86-64 should always use SA_RESTORER. */
if (ka->sa.sa_flags & SA_RESTORER) {
put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
} else {
/* could use a vstub here */
err |= -EFAULT;
}
} put_user_catch(err);
err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->di = sig;
/* In case the signal handler was declared without prototypes */
regs->ax = 0;
/* This also works for non SA_SIGINFO handlers because they expect the
next argument after the signal number on the stack. */
regs->si = (unsigned long)&frame->info;
regs->dx = (unsigned long)&frame->uc;
regs->ip = (unsigned long) ka->sa.sa_handler;
regs->sp = (unsigned long)frame;
/* Set up the CS register to run signal handlers in 64-bit mode,
even if the handler happens to be interrupting 32-bit code. */
regs->cs = __USER_CS;
return 0;
}
#endif /* CONFIG_X86_32 */
static int x32_setup_rt_frame(int sig, struct k_sigaction *ka,
siginfo_t *info, compat_sigset_t *set,
struct pt_regs *regs)
{
#ifdef CONFIG_X86_X32_ABI
struct rt_sigframe_x32 __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (ka->sa.sa_flags & SA_SIGINFO) {
if (copy_siginfo_to_user32(&frame->info, info))
return -EFAULT;
}
put_user_try {
/* Create the ucontext. */
if (cpu_has_xsave)
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
put_user_ex(0, &frame->uc.uc__pad0);
if (ka->sa.sa_flags & SA_RESTORER) {
restorer = ka->sa.sa_restorer;
} else {
/* could use a vstub here */
restorer = NULL;
err |= -EFAULT;
}
put_user_ex(restorer, &frame->pretcode);
} put_user_catch(err);
err |= 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;
/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
regs->ip = (unsigned long) ka->sa.sa_handler;
/* We use the x32 calling convention here... */
regs->di = sig;
regs->si = (unsigned long) &frame->info;
regs->dx = (unsigned long) &frame->uc;
loadsegment(ds, __USER_DS);
loadsegment(es, __USER_DS);
regs->cs = __USER_CS;
regs->ss = __USER_DS;
#endif /* CONFIG_X86_X32_ABI */
return 0;
}
#ifdef CONFIG_X86_32
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
asmlinkage int
sys_sigsuspend(int history0, int history1, old_sigset_t mask)
{
sigset_t blocked;
siginitset(&blocked, mask);
return sigsuspend(&blocked);
}
asmlinkage int
sys_sigaction(int sig, const struct old_sigaction __user *act,
struct old_sigaction __user *oact)
{
struct k_sigaction new_ka, old_ka;
int ret = 0;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)))
return -EFAULT;
get_user_try {
get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
get_user_ex(mask, &act->sa_mask);
get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
} get_user_catch(ret);
if (ret)
return -EFAULT;
siginitset(&new_ka.sa.sa_mask, mask);
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
return -EFAULT;
put_user_try {
put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
} put_user_catch(ret);
if (ret)
return -EFAULT;
}
return ret;
}
#endif /* CONFIG_X86_32 */
long
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
struct pt_regs *regs)
{
return do_sigaltstack(uss, uoss, regs->sp);
}
/*
* Do a signal return; undo the signal stack.
*/
#ifdef CONFIG_X86_32
unsigned long sys_sigreturn(struct pt_regs *regs)
{
struct sigframe __user *frame;
unsigned long ax;
sigset_t set;
frame = (struct sigframe __user *)(regs->sp - 8);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->sc, &ax))
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "sigreturn");
return 0;
}
#endif /* CONFIG_X86_32 */
long sys_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
unsigned long ax;
sigset_t set;
frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "rt_sigreturn");
return 0;
}
/*
* OK, we're invoking a handler:
*/
static int signr_convert(int sig)
{
#ifdef CONFIG_X86_32
struct thread_info *info = current_thread_info();
if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
return info->exec_domain->signal_invmap[sig];
#endif /* CONFIG_X86_32 */
return sig;
}
static int
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
struct pt_regs *regs)
{
int usig = signr_convert(sig);
sigset_t *set = sigmask_to_save();
compat_sigset_t *cset = (compat_sigset_t *) set;
/* Set up the stack frame */
if (is_ia32_frame()) {
if (ka->sa.sa_flags & SA_SIGINFO)
return ia32_setup_rt_frame(usig, ka, info, cset, regs);
else
return ia32_setup_frame(usig, ka, cset, regs);
} else if (is_x32_frame()) {
return x32_setup_rt_frame(usig, ka, info, cset, regs);
} else {
return __setup_rt_frame(sig, ka, info, set, regs);
}
}
static void
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
struct pt_regs *regs)
{
/* Are we from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
/* If so, check system call restarting.. */
switch (syscall_get_error(current, regs)) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->ax = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->ax = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->ax = regs->orig_ax;
regs->ip -= 2;
break;
}
}
/*
* If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
* flag so that register information in the sigcontext is correct.
*/
if (unlikely(regs->flags & X86_EFLAGS_TF) &&
likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
regs->flags &= ~X86_EFLAGS_TF;
if (setup_rt_frame(sig, ka, info, regs) < 0) {
force_sigsegv(sig, current);
return;
}
/*
* Clear the direction flag as per the ABI for function entry.
*/
regs->flags &= ~X86_EFLAGS_DF;
/*
* Clear TF when entering the signal handler, but
* notify any tracer that was single-stepping it.
* The tracer may want to single-step inside the
* handler too.
*/
regs->flags &= ~X86_EFLAGS_TF;
signal_delivered(sig, info, ka, regs,
test_thread_flag(TIF_SINGLESTEP));
}
#ifdef CONFIG_X86_32
#define NR_restart_syscall __NR_restart_syscall
#else /* !CONFIG_X86_32 */
#define NR_restart_syscall \
test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
#endif /* CONFIG_X86_32 */
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*/
static void do_signal(struct pt_regs *regs)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Whee! Actually deliver the signal. */
handle_signal(signr, &info, &ka, regs);
return;
}
/* Did we come from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
/* Restart the system call - no handlers present */
switch (syscall_get_error(current, regs)) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->ax = regs->orig_ax;
regs->ip -= 2;
break;
case -ERESTART_RESTARTBLOCK:
regs->ax = NR_restart_syscall;
regs->ip -= 2;
break;
}
}
/*
* If there's no signal to deliver, we just put the saved sigmask
* back.
*/
restore_saved_sigmask();
}
/*
* notification of userspace execution resumption
* - triggered by the TIF_WORK_MASK flags
*/
void
do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
{
rcu_user_exit();
#ifdef CONFIG_X86_MCE
/* notify userspace of pending MCEs */
if (thread_info_flags & _TIF_MCE_NOTIFY)
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
fire_user_return_notifiers();
rcu_user_enter();
}
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
{
struct task_struct *me = current;
if (show_unhandled_signals && printk_ratelimit()) {
printk("%s"
"%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
me->comm, me->pid, where, frame,
regs->ip, regs->sp, regs->orig_ax);
print_vma_addr(" in ", regs->ip);
pr_cont("\n");
}
force_sig(SIGSEGV, me);
}
#ifdef CONFIG_X86_X32_ABI
asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe_x32 __user *frame;
sigset_t set;
unsigned long ax;
struct pt_regs tregs;
frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (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, "x32 rt_sigreturn");
return 0;
}
#endif
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