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-rw-r--r--arch/x86/kernel/signal.c915
1 files changed, 915 insertions, 0 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
new file mode 100644
index 000000000000..b1f4d34e0a38
--- /dev/null
+++ b/arch/x86/kernel/signal.c
@@ -0,0 +1,915 @@
+/*
+ * 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
+ */
+
+#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/tracehook.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/uaccess.h>
+
+#include <asm/processor.h>
+#include <asm/ucontext.h>
+#include <asm/i387.h>
+#include <asm/vdso.h>
+
+#ifdef CONFIG_X86_64
+#include <asm/proto.h>
+#include <asm/ia32_unistd.h>
+#include <asm/mce.h>
+#endif /* CONFIG_X86_64 */
+
+#include <asm/syscall.h>
+#include <asm/syscalls.h>
+
+#include "sigframe.h"
+
+#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)
+
+#ifdef CONFIG_X86_32
+# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
+#else
+# define FIX_EFLAGS __FIX_EFLAGS
+#endif
+
+#define COPY(x) { \
+ err |= __get_user(regs->x, &sc->x); \
+}
+
+#define COPY_SEG(seg) { \
+ unsigned short tmp; \
+ err |= __get_user(tmp, &sc->seg); \
+ regs->seg = tmp; \
+}
+
+#define COPY_SEG_CPL3(seg) { \
+ unsigned short tmp; \
+ err |= __get_user(tmp, &sc->seg); \
+ regs->seg = tmp | 3; \
+}
+
+#define GET_SEG(seg) { \
+ unsigned short tmp; \
+ err |= __get_user(tmp, &sc->seg); \
+ loadsegment(seg, tmp); \
+}
+
+static 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;
+
+#ifdef CONFIG_X86_32
+ 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 */
+
+ err |= __get_user(tmpflags, &sc->flags);
+ regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+ regs->orig_ax = -1; /* disable syscall checks */
+
+ err |= __get_user(buf, &sc->fpstate);
+ err |= restore_i387_xstate(buf);
+
+ err |= __get_user(*pax, &sc->ax);
+ return err;
+}
+
+static int
+setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
+ struct pt_regs *regs, unsigned long mask)
+{
+ int err = 0;
+
+#ifdef CONFIG_X86_32
+ {
+ unsigned int tmp;
+
+ savesegment(gs, tmp);
+ err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
+ }
+ err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
+ err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
+ err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
+#endif /* CONFIG_X86_32 */
+
+ 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);
+#ifdef CONFIG_X86_64
+ err |= __put_user(regs->r8, &sc->r8);
+ err |= __put_user(regs->r9, &sc->r9);
+ err |= __put_user(regs->r10, &sc->r10);
+ err |= __put_user(regs->r11, &sc->r11);
+ err |= __put_user(regs->r12, &sc->r12);
+ err |= __put_user(regs->r13, &sc->r13);
+ err |= __put_user(regs->r14, &sc->r14);
+ err |= __put_user(regs->r15, &sc->r15);
+#endif /* CONFIG_X86_64 */
+
+ 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);
+#ifdef CONFIG_X86_32
+ err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
+ err |= __put_user(regs->flags, &sc->flags);
+ err |= __put_user(regs->sp, &sc->sp_at_signal);
+ err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
+#else /* !CONFIG_X86_32 */
+ err |= __put_user(regs->flags, &sc->flags);
+ err |= __put_user(regs->cs, &sc->cs);
+ err |= __put_user(0, &sc->gs);
+ err |= __put_user(0, &sc->fs);
+#endif /* CONFIG_X86_32 */
+
+ err |= __put_user(fpstate, &sc->fpstate);
+
+ /* non-iBCS2 extensions.. */
+ err |= __put_user(mask, &sc->oldmask);
+ err |= __put_user(current->thread.cr2, &sc->cr2);
+
+ return err;
+}
+
+/*
+ * Set up a signal frame.
+ */
+#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
+};
+
+/*
+ * Determine which stack to use..
+ */
+static inline 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;
+
+ /*
+ * 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 (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
+ return (void __user *) -1L;
+
+ /* 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;
+ } else {
+ /* This is the legacy signal stack switching. */
+ 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_size;
+ *fpstate = (struct _fpstate *) sp;
+ if (save_i387_xstate(*fpstate) < 0)
+ return (void __user *)-1L;
+ }
+
+ 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;
+}
+
+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;
+
+ err |= __put_user(sig, &frame->sig);
+ err |= __put_user(&frame->info, &frame->pinfo);
+ err |= __put_user(&frame->uc, &frame->puc);
+ err |= copy_siginfo_to_user(&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 |= 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 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;
+ err |= __put_user(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.
+ */
+ err |= __put_user(*((u64 *)&rt_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 = (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 */
+/*
+ * Determine which stack to use..
+ */
+static void __user *
+get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
+{
+ /* Default to using normal stack - redzone*/
+ sp -= 128;
+
+ /* 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;
+ }
+
+ return (void __user *)round_down(sp - size, 64);
+}
+
+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;
+
+ if (used_math()) {
+ fp = get_stack(ka, regs->sp, sig_xstate_size);
+ frame = (void __user *)round_down(
+ (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
+
+ if (save_i387_xstate(fp) < 0)
+ return -EFAULT;
+ } else
+ frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;
+
+ 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;
+ }
+
+ /* 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(me->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(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+ /* 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) {
+ err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
+ } else {
+ /* could use a vstub here */
+ return -EFAULT;
+ }
+
+ 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 */
+
+#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)
+{
+ mask &= _BLOCKABLE;
+ spin_lock_irq(&current->sighand->siglock);
+ current->saved_sigmask = current->blocked;
+ siginitset(&current->blocked, mask);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ current->state = TASK_INTERRUPTIBLE;
+ schedule();
+ set_restore_sigmask();
+
+ return -ERESTARTNOHAND;
+}
+
+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;
+
+ if (act) {
+ old_sigset_t mask;
+
+ if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+ __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+ __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+ return -EFAULT;
+
+ __get_user(new_ka.sa.sa_flags, &act->sa_flags);
+ __get_user(mask, &act->sa_mask);
+ 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)) ||
+ __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+ __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+ return -EFAULT;
+
+ __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+ __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+ }
+
+ return ret;
+}
+#endif /* CONFIG_X86_32 */
+
+#ifdef CONFIG_X86_32
+asmlinkage int sys_sigaltstack(unsigned long bx)
+{
+ /*
+ * This is needed to make gcc realize it doesn't own the
+ * "struct pt_regs"
+ */
+ struct pt_regs *regs = (struct pt_regs *)&bx;
+ const stack_t __user *uss = (const stack_t __user *)bx;
+ stack_t __user *uoss = (stack_t __user *)regs->cx;
+
+ return do_sigaltstack(uss, uoss, regs->sp);
+}
+#else /* !CONFIG_X86_32 */
+asmlinkage long
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+ struct pt_regs *regs)
+{
+ return do_sigaltstack(uss, uoss, regs->sp);
+}
+#endif /* CONFIG_X86_32 */
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+#ifdef CONFIG_X86_32
+asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
+{
+ struct sigframe __user *frame;
+ struct pt_regs *regs;
+ unsigned long ax;
+ sigset_t set;
+
+ regs = (struct pt_regs *) &__unused;
+ 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;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ if (restore_sigcontext(regs, &frame->sc, &ax))
+ goto badframe;
+ return ax;
+
+badframe:
+ if (show_unhandled_signals && printk_ratelimit()) {
+ printk("%s%s[%d] bad frame in sigreturn frame:"
+ "%p ip:%lx sp:%lx oeax:%lx",
+ task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
+ current->comm, task_pid_nr(current), frame, regs->ip,
+ regs->sp, regs->orig_ax);
+ print_vma_addr(" in ", regs->ip);
+ printk(KERN_CONT "\n");
+ }
+
+ force_sig(SIGSEGV, current);
+
+ return 0;
+}
+#endif /* CONFIG_X86_32 */
+
+static long do_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;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ 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;
+}
+
+#ifdef CONFIG_X86_32
+asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+{
+ struct pt_regs *regs = (struct pt_regs *)&__unused;
+
+ return do_rt_sigreturn(regs);
+}
+#else /* !CONFIG_X86_32 */
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+ return do_rt_sigreturn(regs);
+}
+#endif /* CONFIG_X86_32 */
+
+/*
+ * 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;
+}
+
+#ifdef CONFIG_X86_32
+
+#define is_ia32 1
+#define ia32_setup_frame __setup_frame
+#define ia32_setup_rt_frame __setup_rt_frame
+
+#else /* !CONFIG_X86_32 */
+
+#ifdef CONFIG_IA32_EMULATION
+#define is_ia32 test_thread_flag(TIF_IA32)
+#else /* !CONFIG_IA32_EMULATION */
+#define is_ia32 0
+#endif /* CONFIG_IA32_EMULATION */
+
+#endif /* CONFIG_X86_32 */
+
+static int
+setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
+{
+ int usig = signr_convert(sig);
+ int ret;
+
+ /* Set up the stack frame */
+ if (is_ia32) {
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
+ else
+ ret = ia32_setup_frame(usig, ka, set, regs);
+ } else
+ ret = __setup_rt_frame(sig, ka, info, set, regs);
+
+ if (ret) {
+ force_sigsegv(sig, current);
+ return -EFAULT;
+ }
+
+ return ret;
+}
+
+static int
+handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
+ sigset_t *oldset, struct pt_regs *regs)
+{
+ int ret;
+
+ /* 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;
+
+ ret = setup_rt_frame(sig, ka, info, oldset, regs);
+
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_X86_64
+ /*
+ * This has nothing to do with segment registers,
+ * despite the name. This magic affects uaccess.h
+ * macros' behavior. Reset it to the normal setting.
+ */
+ set_fs(USER_DS);
+#endif
+
+ /*
+ * 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;
+
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&current->blocked, sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ tracehook_signal_handler(sig, info, ka, regs,
+ test_thread_flag(TIF_SINGLESTEP));
+
+ return 0;
+}
+
+#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;
+ sigset_t *oldset;
+
+ /*
+ * We want the common case to go fast, which is why we may in certain
+ * cases get here from kernel mode. Just return without doing anything
+ * if so.
+ * X86_32: vm86 regs switched out by assembly code before reaching
+ * here, so testing against kernel CS suffices.
+ */
+ if (!user_mode(regs))
+ return;
+
+ if (current_thread_info()->status & TS_RESTORE_SIGMASK)
+ oldset = &current->saved_sigmask;
+ else
+ oldset = &current->blocked;
+
+ signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+ if (signr > 0) {
+ /*
+ * Re-enable any watchpoints before delivering the
+ * signal to user space. The processor register will
+ * have been cleared if the watchpoint triggered
+ * inside the kernel.
+ */
+ if (current->thread.debugreg7)
+ set_debugreg(current->thread.debugreg7, 7);
+
+ /* Whee! Actually deliver the signal. */
+ if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
+ /*
+ * A signal was successfully delivered; the saved
+ * sigmask will have been stored in the signal frame,
+ * and will be restored by sigreturn, so we can simply
+ * clear the TS_RESTORE_SIGMASK flag.
+ */
+ current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+ }
+ 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.
+ */
+ if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
+ current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+ sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+ }
+}
+
+/*
+ * 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)
+{
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
+ /* notify userspace of pending MCEs */
+ if (thread_info_flags & _TIF_MCE_NOTIFY)
+ mce_notify_user();
+#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
+
+ /* 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);
+ }
+
+#ifdef CONFIG_X86_32
+ clear_thread_flag(TIF_IRET);
+#endif /* CONFIG_X86_32 */
+}
+
+void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
+{
+ struct task_struct *me = current;
+
+ if (show_unhandled_signals && printk_ratelimit()) {
+ printk(KERN_INFO
+ "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
+ me->comm, me->pid, where, frame,
+ regs->ip, regs->sp, regs->orig_ax);
+ print_vma_addr(" in ", regs->ip);
+ printk(KERN_CONT "\n");
+ }
+
+ force_sig(SIGSEGV, me);
+}