Merge branch 'x86/signal' into core/signal

2 files changed, 119 insertions, 73 deletions

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)