6 files changed, 63 insertions, 12 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 60fe8015756..d2e39e69aaf 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -261,7 +261,7 @@ static void convert_from_fxsr(struct user_i387_ia32_struct *env,
 	}
 #else
 	env->fip = fxsave->fip;
-	env->fcs = fxsave->fcs;
+	env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
 	env->foo = fxsave->foo;
 	env->fos = fxsave->fos;
 #endif
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index f41fdc98efb..d5904eef1d3 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -323,6 +323,16 @@ static int putreg(struct task_struct *child,
 		return set_flags(child, value);
 
 #ifdef CONFIG_X86_64
+	/*
+	 * Orig_ax is really just a flag with small positive and
+	 * negative values, so make sure to always sign-extend it
+	 * from 32 bits so that it works correctly regardless of
+	 * whether we come from a 32-bit environment or not.
+	 */
+	case offsetof(struct user_regs_struct, orig_ax):
+		value = (long) (s32) value;
+		break;
+
 	case offsetof(struct user_regs_struct,fs_base):
 		if (value >= TASK_SIZE_OF(child))
 			return -EIO;
@@ -1045,10 +1055,17 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 	R32(esi, si);
 	R32(ebp, bp);
 	R32(eax, ax);
-	R32(orig_eax, orig_ax);
 	R32(eip, ip);
 	R32(esp, sp);
 
+	case offsetof(struct user32, regs.orig_eax):
+		/*
+		 * Sign-extend the value so that orig_eax = -1
+		 * causes (long)orig_ax < 0 tests to fire correctly.
+		 */
+		regs->orig_ax = (long) (s32) value;
+		break;
+
 	case offsetof(struct user32, regs.eflags):
 		return set_flags(child, value);
 
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 7fd6ac43e4a..55ceb8cdef7 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -326,6 +326,10 @@ static inline void kb_wait(void)
 	}
 }
 
+void __attribute__((weak)) mach_reboot_fixups(void)
+{
+}
+
 static void native_machine_emergency_restart(void)
 {
 	int i;
@@ -337,6 +341,8 @@ static void native_machine_emergency_restart(void)
 		/* Could also try the reset bit in the Hammer NB */
 		switch (reboot_type) {
 		case BOOT_KBD:
+			mach_reboot_fixups(); /* for board specific fixups */
+
 			for (i = 0; i < 10; i++) {
 				kb_wait();
 				udelay(50);
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index caee1f002fe..0157a6f0f41 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -407,7 +407,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 	 * The tracer may want to single-step inside the
 	 * handler too.
 	 */
-	regs->flags &= ~TF_MASK;
+	regs->flags &= ~(TF_MASK | X86_EFLAGS_DF);
 	if (test_thread_flag(TIF_SINGLESTEP))
 		ptrace_notify(SIGTRAP);
 
@@ -500,7 +500,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	 * The tracer may want to single-step inside the
 	 * handler too.
 	 */
-	regs->flags &= ~TF_MASK;
+	regs->flags &= ~(TF_MASK | X86_EFLAGS_DF);
 	if (test_thread_flag(TIF_SINGLESTEP))
 		ptrace_notify(SIGTRAP);
 
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 7347bb14e30..1c83e5124c6 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -295,7 +295,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	   see include/asm-x86_64/uaccess.h for details. */
 	set_fs(USER_DS);
 
-	regs->flags &= ~X86_EFLAGS_TF;
+	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);
 	if (test_thread_flag(TIF_SINGLESTEP))
 		ptrace_notify(SIGTRAP);
 #ifdef DEBUG_SIG
@@ -311,6 +311,35 @@ give_sigsegv:
 }
 
 /*
+ * Return -1L or the syscall number that @regs is executing.
+ */
+static long current_syscall(struct pt_regs *regs)
+{
+	/*
+	 * We always sign-extend a -1 value being set here,
+	 * so this is always either -1L or a syscall number.
+	 */
+	return regs->orig_ax;
+}
+
+/*
+ * Return a value that is -EFOO if the system call in @regs->orig_ax
+ * returned an error.  This only works for @regs from @current.
+ */
+static long current_syscall_ret(struct pt_regs *regs)
+{
+#ifdef CONFIG_IA32_EMULATION
+	if (test_thread_flag(TIF_IA32))
+		/*
+		 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
+		 * and will match correctly in comparisons.
+		 */
+		return (int) regs->ax;
+#endif
+	return regs->ax;
+}
+
+/*
  * OK, we're invoking a handler
  */	
 
@@ -327,9 +356,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 #endif
 
 	/* Are we from a system call? */
-	if ((long)regs->orig_ax >= 0) {
+	if (current_syscall(regs) >= 0) {
 		/* If so, check system call restarting.. */
-		switch (regs->ax) {
+		switch (current_syscall_ret(regs)) {
 		        case -ERESTART_RESTARTBLOCK:
 			case -ERESTARTNOHAND:
 				regs->ax = -EINTR;
@@ -426,10 +455,9 @@ static void do_signal(struct pt_regs *regs)
 	}
 
 	/* Did we come from a system call? */
-	if ((long)regs->orig_ax >= 0) {
+	if (current_syscall(regs) >= 0) {
 		/* Restart the system call - no handlers present */
-		long res = regs->ax;
-		switch (res) {
+		switch (current_syscall_ret(regs)) {
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 2ef1a5f8d67..9d406cdc847 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -166,7 +166,7 @@ static void enable_step(struct task_struct *child, bool block)
 				  child->thread.debugctlmsr | DEBUGCTLMSR_BTF);
 	} else {
 	    write_debugctlmsr(child,
-			      child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR);
+			      child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
 
 	    if (!child->thread.debugctlmsr)
 		    clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
@@ -189,7 +189,7 @@ void user_disable_single_step(struct task_struct *child)
 	 * Make sure block stepping (BTF) is disabled.
 	 */
 	write_debugctlmsr(child,
-			  child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR);
+			  child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
 
 	if (!child->thread.debugctlmsr)
 		clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);