Merge git://git.infradead.org/iommu-2.6
[safe/jmp/linux-2.6] / arch / x86 / kernel / signal_64.c
index ab086b0..a5c9627 100644 (file)
 #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/compiler.h>
+#include <linux/uaccess.h>
+
+#include <asm/processor.h>
 #include <asm/ucontext.h>
-#include <asm/uaccess.h>
 #include <asm/i387.h>
 #include <asm/proto.h>
 #include <asm/ia32_unistd.h>
 #include <asm/mce.h>
-
-/* #define DEBUG_SIG 1 */
+#include <asm/syscall.h>
+#include <asm/syscalls.h>
+#include "sigframe.h"
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
-               sigset_t *set, struct pt_regs * regs); 
-int ia32_setup_frame(int sig, struct k_sigaction *ka,
-            sigset_t *set, struct pt_regs * regs); 
+#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
 
 asmlinkage long
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
                struct pt_regs *regs)
 {
-       return do_sigaltstack(uss, uoss, regs->rsp);
+       return do_sigaltstack(uss, uoss, regs->sp);
 }
 
+#define COPY(x)                        {               \
+       err |= __get_user(regs->x, &sc->x);     \
+}
+
+#define COPY_SEG_STRICT(seg)   {                       \
+               unsigned short tmp;                     \
+               err |= __get_user(tmp, &sc->seg);       \
+               regs->seg = tmp | 3;                    \
+}
 
 /*
  * Do a signal return; undo the signal stack.
  */
-
-struct rt_sigframe
-{
-       char __user *pretcode;
-       struct ucontext uc;
-       struct siginfo info;
-};
-
 static int
-restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned long *prax)
+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;
 
-#define COPY(x)                err |= __get_user(regs->x, &sc->x)
-
-       COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
-       COPY(rdx); COPY(rcx); COPY(rip);
+       COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+       COPY(dx); COPY(cx); COPY(ip);
        COPY(r8);
        COPY(r9);
        COPY(r10);
@@ -78,86 +90,62 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned
        /* 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. */
-       {
-               unsigned cs;
-               err |= __get_user(cs, &sc->cs);
-               regs->cs = cs | 3;      /* Force into user mode */
-       }
+       COPY_SEG_STRICT(cs);
 
-       {
-               unsigned int tmpflags;
-               err |= __get_user(tmpflags, &sc->eflags);
-               regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
-               regs->orig_rax = -1;            /* disable syscall checks */
-       }
+       err |= __get_user(tmpflags, &sc->flags);
+       regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+       regs->orig_ax = -1;             /* disable syscall checks */
 
-       {
-               struct _fpstate __user * buf;
-               err |= __get_user(buf, &sc->fpstate);
-
-               if (buf) {
-                       if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
-                               goto badframe;
-                       err |= restore_i387(buf);
-               } else {
-                       struct task_struct *me = current;
-                       if (used_math()) {
-                               clear_fpu(me);
-                               clear_used_math();
-                       }
-               }
-       }
+       err |= __get_user(buf, &sc->fpstate);
+       err |= restore_i387_xstate(buf);
 
-       err |= __get_user(*prax, &sc->rax);
+       err |= __get_user(*pax, &sc->ax);
        return err;
-
-badframe:
-       return 1;
 }
 
-asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+static long do_rt_sigreturn(struct pt_regs *regs)
 {
        struct rt_sigframe __user *frame;
+       unsigned long ax;
        sigset_t set;
-       unsigned long eax;
 
-       frame = (struct rt_sigframe __user *)(regs->rsp - 8);
-       if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) {
+       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))) { 
+       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, &eax))
-               goto badframe;
 
-#ifdef DEBUG_SIG
-       printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs->rip,regs->rsp,frame,eax);
-#endif
+       if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
+               goto badframe;
 
-       if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
+       if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
                goto badframe;
 
-       return eax;
+       return ax;
 
 badframe:
-       signal_fault(regs,frame,"sigreturn");
+       signal_fault(regs, frame, "rt_sigreturn");
        return 0;
-}      
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+       return do_rt_sigreturn(regs);
+}
 
 /*
  * Set up a signal frame.
  */
 
 static inline int
-setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me)
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+               unsigned long mask, struct task_struct *me)
 {
        int err = 0;
 
@@ -165,14 +153,14 @@ setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned lo
        err |= __put_user(0, &sc->gs);
        err |= __put_user(0, &sc->fs);
 
-       err |= __put_user(regs->rdi, &sc->rdi);
-       err |= __put_user(regs->rsi, &sc->rsi);
-       err |= __put_user(regs->rbp, &sc->rbp);
-       err |= __put_user(regs->rsp, &sc->rsp);
-       err |= __put_user(regs->rbx, &sc->rbx);
-       err |= __put_user(regs->rdx, &sc->rdx);
-       err |= __put_user(regs->rcx, &sc->rcx);
-       err |= __put_user(regs->rax, &sc->rax);
+       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->r8, &sc->r8);
        err |= __put_user(regs->r9, &sc->r9);
        err |= __put_user(regs->r10, &sc->r10);
@@ -183,8 +171,8 @@ setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned lo
        err |= __put_user(regs->r15, &sc->r15);
        err |= __put_user(me->thread.trap_no, &sc->trapno);
        err |= __put_user(me->thread.error_code, &sc->err);
-       err |= __put_user(regs->rip, &sc->rip);
-       err |= __put_user(regs->eflags, &sc->eflags);
+       err |= __put_user(regs->ip, &sc->ip);
+       err |= __put_user(regs->flags, &sc->flags);
        err |= __put_user(mask, &sc->oldmask);
        err |= __put_user(me->thread.cr2, &sc->cr2);
 
@@ -198,62 +186,61 @@ setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned lo
 static void __user *
 get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
 {
-       unsigned long rsp;
+       unsigned long sp;
 
        /* Default to using normal stack - redzone*/
-       rsp = regs->rsp - 128;
+       sp = regs->sp - 128;
 
        /* This is the X/Open sanctioned signal stack switching.  */
        if (ka->sa.sa_flags & SA_ONSTACK) {
-               if (sas_ss_flags(rsp) == 0)
-                       rsp = current->sas_ss_sp + current->sas_ss_size;
+               if (sas_ss_flags(sp) == 0)
+                       sp = current->sas_ss_sp + current->sas_ss_size;
        }
 
-       return (void __user *)round_down(rsp - size, 16); 
+       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)
+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;
-       struct _fpstate __user *fp = NULL; 
+       void __user *fp = NULL;
        int err = 0;
        struct task_struct *me = current;
 
        if (used_math()) {
-               fp = get_stack(ka, regs, sizeof(struct _fpstate)); 
+               fp = get_stack(ka, regs, sig_xstate_size);
                frame = (void __user *)round_down(
                        (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
 
-               if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
-                       goto give_sigsegv;
-
-               if (save_i387(fp) < 0) 
-                       err |= -1; 
+               if (save_i387_xstate(fp) < 0)
+                       return -EFAULT;
        } else
                frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
 
        if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
-               goto give_sigsegv;
+               return -EFAULT;
 
-       if (ka->sa.sa_flags & SA_SIGINFO) { 
-               err |= copy_siginfo_to_user(&frame->info, info);
-               if (err)
-                       goto give_sigsegv;
+       if (ka->sa.sa_flags & SA_SIGINFO) {
+               if (copy_siginfo_to_user(&frame->info, info))
+                       return -EFAULT;
        }
-               
+
        /* Create the ucontext.  */
-       err |= __put_user(0, &frame->uc.uc_flags);
+       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->rsp),
+       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, regs, set->sig[0], me);
        err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
-       if (sizeof(*set) == 16) { 
+       if (sizeof(*set) == 16) {
                __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
-               __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); 
+               __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
        } else
                err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
@@ -264,124 +251,148 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
        } else {
                /* could use a vstub here */
-               goto give_sigsegv; 
+               return -EFAULT;
        }
 
        if (err)
-               goto give_sigsegv;
-
-#ifdef DEBUG_SIG
-       printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
-#endif
+               return -EFAULT;
 
        /* Set up registers for signal handler */
-       regs->rdi = sig;
-       /* In case the signal handler was declared without prototypes */ 
-       regs->rax = 0;  
+       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->rsi = (unsigned long)&frame->info; 
-       regs->rdx = (unsigned long)&frame->uc; 
-       regs->rip = (unsigned long) ka->sa.sa_handler;
+       regs->si = (unsigned long)&frame->info;
+       regs->dx = (unsigned long)&frame->uc;
+       regs->ip = (unsigned long) ka->sa.sa_handler;
 
-       regs->rsp = (unsigned long)frame;
+       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;
 
-       /* This, by contrast, has nothing to do with segment registers -
-          see include/asm-x86_64/uaccess.h for details. */
-       set_fs(USER_DS);
-
-       regs->eflags &= ~TF_MASK;
-       if (test_thread_flag(TIF_SINGLESTEP))
-               ptrace_notify(SIGTRAP);
-#ifdef DEBUG_SIG
-       printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%p\n",
-               current->comm, current->pid, frame, regs->rip, frame->pretcode);
-#endif
-
        return 0;
-
-give_sigsegv:
-       force_sigsegv(sig, current);
-       return -EFAULT;
 }
 
 /*
  * OK, we're invoking a handler
- */    
+ */
+static int signr_convert(int sig)
+{
+       return sig;
+}
+
+#ifdef CONFIG_IA32_EMULATION
+#define is_ia32        test_thread_flag(TIF_IA32)
+#else
+#define is_ia32        0
+#endif
 
 static int
-handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
-               sigset_t *oldset, struct pt_regs *regs)
+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;
 
-#ifdef DEBUG_SIG
-       printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
-               current->pid, sig,
-               regs->rip, regs->rsp, regs);
-#endif
+       /* 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 ((long)regs->orig_rax >= 0) {
+       if (syscall_get_nr(current, regs) >= 0) {
                /* If so, check system call restarting.. */
-               switch (regs->rax) {
-                       case -ERESTART_RESTARTBLOCK:
-                       case -ERESTARTNOHAND:
-                               regs->rax = -EINTR;
-                               break;
+               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->rax = -EINTR;
-                                       break;
-                               }
-                               /* fallthrough */
-                       case -ERESTARTNOINTR:
-                               regs->rax = regs->orig_rax;
-                               regs->rip -= 2;
+               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 (PT_DTRACE), clear the TF
-        * flag so that register information in the sigcontext is
-        * correct.
+        * 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->eflags & TF_MASK)) {
-               if (likely(current->ptrace & PT_DTRACE)) {
-                       current->ptrace &= ~PT_DTRACE;
-                       regs->eflags &= ~TF_MASK;
-               }
-       }
+       if (unlikely(regs->flags & X86_EFLAGS_TF) &&
+           likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
+               regs->flags &= ~X86_EFLAGS_TF;
 
-#ifdef CONFIG_IA32_EMULATION
-       if (test_thread_flag(TIF_IA32)) {
-               if (ka->sa.sa_flags & SA_SIGINFO)
-                       ret = ia32_setup_rt_frame(sig, ka, info, oldset, regs);
-               else
-                       ret = ia32_setup_frame(sig, ka, oldset, regs);
-       } else 
-#endif
        ret = setup_rt_frame(sig, ka, info, oldset, regs);
 
-       if (ret == 0) {
-               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);
-       }
+       if (ret)
+               return 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;
 }
 
+#define NR_restart_syscall     \
+       test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
 /*
  * 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
@@ -395,22 +406,24 @@ static void do_signal(struct pt_regs *regs)
        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
+        * 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 (test_thread_flag(TIF_RESTORE_SIGMASK))
+       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
+               /*
+                * 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.
@@ -418,76 +431,86 @@ static void do_signal(struct pt_regs *regs)
                if (current->thread.debugreg7)
                        set_debugreg(current->thread.debugreg7, 7);
 
-               /* Whee!  Actually deliver the signal.  */
+               /* Whee! Actually deliver the signal.  */
                if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
-                       /* a signal was successfully delivered; the saved
+                       /*
+                        * 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 TIF_RESTORE_SIGMASK flag */
-                       clear_thread_flag(TIF_RESTORE_SIGMASK);
+                        * clear the TS_RESTORE_SIGMASK flag.
+                        */
+                       current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
                }
                return;
        }
 
        /* Did we come from a system call? */
-       if ((long)regs->orig_rax >= 0) {
+       if (syscall_get_nr(current, regs) >= 0) {
                /* Restart the system call - no handlers present */
-               long res = regs->rax;
-               switch (res) {
+               switch (syscall_get_error(current, regs)) {
                case -ERESTARTNOHAND:
                case -ERESTARTSYS:
                case -ERESTARTNOINTR:
-                       regs->rax = regs->orig_rax;
-                       regs->rip -= 2;
+                       regs->ax = regs->orig_ax;
+                       regs->ip -= 2;
                        break;
+
                case -ERESTART_RESTARTBLOCK:
-                       regs->rax = test_thread_flag(TIF_IA32) ?
-                                       __NR_ia32_restart_syscall :
-                                       __NR_restart_syscall;
-                       regs->rip -= 2;
+                       regs->ax = NR_restart_syscall;
+                       regs->ip -= 2;
                        break;
                }
        }
 
-       /* if there's no signal to deliver, we just put the saved sigmask
-          back. */
-       if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
-               clear_thread_flag(TIF_RESTORE_SIGMASK);
+       /*
+        * 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)
 {
-#ifdef DEBUG_SIG
-       printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%p pending:%x\n",
-              thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current)); 
-#endif
-              
-       /* Pending single-step? */
-       if (thread_info_flags & _TIF_SINGLESTEP) {
-               regs->eflags |= TF_MASK;
-               clear_thread_flag(TIF_SINGLESTEP);
-       }
-
-#ifdef CONFIG_X86_MCE
+#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_MCE */
+#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
 
        /* deal with pending signal delivery */
-       if (thread_info_flags & (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK))
+       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("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n",
-              me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax); 
-
-       force_sig(SIGSEGV, me); 
-} 
+{
+       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);
+}