Merge branch 'x86/signal' into core/signal

3 files changed, 133 insertions, 90 deletions

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index e47bed2440ee..4bc02b23674b 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -351,31 +351,28 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
         savesegment(es, tmp);
         err |= __put_user(tmp, (unsigned int __user *)&sc->es);
 
-        err |= __put_user((u32)regs->di, &sc->di);
-        err |= __put_user((u32)regs->si, &sc->si);
-        err |= __put_user((u32)regs->bp, &sc->bp);
-        err |= __put_user((u32)regs->sp, &sc->sp);
-        err |= __put_user((u32)regs->bx, &sc->bx);
-        err |= __put_user((u32)regs->dx, &sc->dx);
-        err |= __put_user((u32)regs->cx, &sc->cx);
-        err |= __put_user((u32)regs->ax, &sc->ax);
-        err |= __put_user((u32)regs->cs, &sc->cs);
-        err |= __put_user((u32)regs->ss, &sc->ss);
+        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((u32)regs->ip, &sc->ip);
-        err |= __put_user((u32)regs->flags, &sc->flags);
-        err |= __put_user((u32)regs->sp, &sc->sp_at_signal);
+        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 {
-                clear_used_math();
-                stts();
+        else
                 err |= __put_user(ptr_to_compat(tmp ? fpstate : NULL),
                                         &sc->fpstate);
-        }
 
         /* non-iBCS2 extensions.. */
         err |= __put_user(mask, &sc->oldmask);
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index da3cf3270f83..d6dd057d0f22 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -113,6 +113,27 @@ asmlinkage int sys_sigaltstack(unsigned long bx)
         return do_sigaltstack(uss, uoss, regs->sp);
 }
 
+#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_STRICT(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);                  \
+}
 
 /*
  * Do a signal return; undo the signal stack.
@@ -121,28 +142,13 @@ 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;
 
-#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_STRICT(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); }
-
         GET_SEG(gs);
         COPY_SEG(fs);
         COPY_SEG(es);
@@ -152,21 +158,12 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         COPY_SEG_STRICT(cs);
         COPY_SEG_STRICT(ss);
 
-        {
-                unsigned int tmpflags;
-
-                err |= __get_user(tmpflags, &sc->flags);
-                regs->flags = (regs->flags & ~FIX_EFLAGS) |
-                                                (tmpflags & FIX_EFLAGS);
-                regs->orig_ax = -1;             /* disable syscall checks */
-        }
-
-        {
-                void __user *buf;
+        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(buf, &sc->fpstate);
+        err |= restore_i387_xstate(buf);
 
         err |= __get_user(*pax, &sc->ax);
         return err;
@@ -482,24 +479,34 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 /*
  * OK, we're invoking a handler:
  */
+static int signr_convert(int sig)
+{
+        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];
+        return sig;
+}
+
+#define is_ia32 1
+#define ia32_setup_frame        __setup_frame
+#define ia32_setup_rt_frame     __setup_rt_frame
+
 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;
-        int usig;
-
-        usig = current_thread_info()->exec_domain
-                && current_thread_info()->exec_domain->signal_invmap
-                && sig < 32
-                ? current_thread_info()->exec_domain->signal_invmap[sig]
-                : sig;
 
         /* Set up the stack frame */
-        if (ka->sa.sa_flags & SA_SIGINFO)
-                ret = __setup_rt_frame(usig, ka, info, set, regs);
-        else
-                ret = __setup_frame(usig, ka, set, regs);
+        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);
@@ -550,6 +557,15 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
         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.
          */
@@ -663,6 +679,12 @@ static void do_signal(struct pt_regs *regs)
 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);
@@ -672,7 +694,9 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
                 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)
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index bf77d4789a2d..a5c9627f4db9 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -52,6 +52,16 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
         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.
  */
@@ -59,13 +69,13 @@ 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;
 
-#define COPY(x)         (err |= __get_user(regs->x, &sc->x))
-
         COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
         COPY(dx); COPY(cx); COPY(ip);
         COPY(r8);
@@ -80,25 +90,14 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         /* 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->flags);
-                regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
-                regs->orig_ax = -1;             /* disable syscall checks */
-        }
-
-        {
-                void __user *buf;
+        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(buf, &sc->fpstate);
+        err |= restore_i387_xstate(buf);
 
         err |= __get_user(*pax, &sc->ax);
         return err;
@@ -281,21 +280,32 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 /*
  * 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
 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 CONFIG_IA32_EMULATION
-        if (test_thread_flag(TIF_IA32)) {
+        /* Set up the stack frame */
+        if (is_ia32) {
                 if (ka->sa.sa_flags & SA_SIGINFO)
-                        ret = ia32_setup_rt_frame(sig, ka, info, set, regs);
+                        ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
                 else
-                        ret = ia32_setup_frame(sig, ka, set, regs);
+                        ret = ia32_setup_frame(usig, ka, set, regs);
         } else
-#endif
-        ret = __setup_rt_frame(sig, ka, info, set, regs);
+                ret = __setup_rt_frame(sig, ka, info, set, regs);
 
         if (ret) {
                 force_sigsegv(sig, current);
@@ -346,12 +356,14 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
         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.
@@ -410,7 +422,8 @@ static void do_signal(struct pt_regs *regs)
 
         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.
@@ -418,7 +431,7 @@ 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
@@ -441,6 +454,7 @@ static void do_signal(struct pt_regs *regs)
                         regs->ax = regs->orig_ax;
                         regs->ip -= 2;
                         break;
+
                 case -ERESTART_RESTARTBLOCK:
                         regs->ax = NR_restart_syscall;
                         regs->ip -= 2;
@@ -458,14 +472,18 @@ static void do_signal(struct pt_regs *regs)
         }
 }
 
-void do_notify_resume(struct pt_regs *regs, void *unused,
-                      __u32 thread_info_flags)
+/*
+ * 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 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)
@@ -475,6 +493,10 @@ void do_notify_resume(struct pt_regs *regs, void *unused,
                 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)