Merge branch 'for-arm' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal.git into for-linus

Conflicts:
	arch/arm/kernel/ptrace.c

5 files changed, 27 insertions, 73 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 7bd2d3cb895..4afed88d250 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -53,9 +53,13 @@ fast_work_pending:
 work_pending:
 	tst	r1, #_TIF_NEED_RESCHED
 	bne	work_resched
-	tst	r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME
-	beq	no_work_pending
+	/*
+	 * TIF_SIGPENDING or TIF_NOTIFY_RESUME must've been set if we got here
+	 */
+	ldr	r2, [sp, #S_PSR]
 	mov	r0, sp				@ 'regs'
+	tst	r2, #15				@ are we returning to user mode?
+	bne	no_work_pending			@ no?  just leave, then...
 	mov	r2, why				@ 'syscall'
 	tst	r1, #_TIF_SIGPENDING		@ delivering a signal?
 	movne	why, #0				@ prevent further restarts
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 14e38261cd3..5700a7ae7f0 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -25,6 +25,7 @@
 #include <linux/regset.h>
 #include <linux/audit.h>
 #include <linux/tracehook.h>
+#include <linux/unistd.h>
 
 #include <asm/pgtable.h>
 #include <asm/traps.h>
@@ -917,6 +918,8 @@ asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 		audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0,
 				    regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
 
+	if (why == 0 && test_and_clear_thread_flag(TIF_SYSCALL_RESTARTSYS))
+		scno = __NR_restart_syscall - __NR_SYSCALL_BASE;
 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 		return scno;
 
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 73d9a420850..b7ffda1ad8f 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -29,7 +29,6 @@
  */
 #define SWI_SYS_SIGRETURN	(0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
 #define SWI_SYS_RT_SIGRETURN	(0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
-#define SWI_SYS_RESTART		(0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE)
 
 /*
  * With EABI, the syscall number has to be loaded into r7.
@@ -50,18 +49,6 @@ const unsigned long sigreturn_codes[7] = {
 };
 
 /*
- * Either we support OABI only, or we have EABI with the OABI
- * compat layer enabled.  In the later case we don't know if
- * user space is EABI or not, and if not we must not clobber r7.
- * Always using the OABI syscall solves that issue and works for
- * all those cases.
- */
-const unsigned long syscall_restart_code[2] = {
-	SWI_SYS_RESTART,	/* swi	__NR_restart_syscall */
-	0xe49df004,		/* ldr	pc, [sp], #4 */
-};
-
-/*
  * atomically swap in the new signal mask, and wait for a signal.
  */
 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
@@ -91,10 +78,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *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))
+		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
 			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);
 	}
 
@@ -103,10 +90,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 	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))
+		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
 			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;
@@ -611,15 +598,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
 	int signr;
 
 	/*
-	 * 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.
-	 */
-	if (!user_mode(regs))
-		return;
-
-	/*
 	 * If we were from a system call, check for system call restarting...
 	 */
 	if (syscall) {
@@ -635,18 +613,13 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
+		case -ERESTART_RESTARTBLOCK:
 			regs->ARM_r0 = regs->ARM_ORIG_r0;
 			regs->ARM_pc = restart_addr;
 			break;
-		case -ERESTART_RESTARTBLOCK:
-			regs->ARM_r0 = -EINTR;
-			break;
 		}
 	}
 
-	if (try_to_freeze())
-		goto no_signal;
-
 	/*
 	 * Get the signal to deliver.  When running under ptrace, at this
 	 * point the debugger may change all our registers ...
@@ -661,12 +634,14 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		 * debugger has chosen to restart at a different PC.
 		 */
 		if (regs->ARM_pc == restart_addr) {
-			if (retval == -ERESTARTNOHAND
+			if (retval == -ERESTARTNOHAND ||
+			    retval == -ERESTART_RESTARTBLOCK
 			    || (retval == -ERESTARTSYS
 				&& !(ka.sa.sa_flags & SA_RESTART))) {
 				regs->ARM_r0 = -EINTR;
 				regs->ARM_pc = continue_addr;
 			}
+			clear_thread_flag(TIF_SYSCALL_RESTARTSYS);
 		}
 
 		if (test_thread_flag(TIF_RESTORE_SIGMASK))
@@ -686,7 +661,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		return;
 	}
 
- no_signal:
 	if (syscall) {
 		/*
 		 * Handle restarting a different system call.  As above,
@@ -694,38 +668,15 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		 * ignore the restart.
 		 */
 		if (retval == -ERESTART_RESTARTBLOCK
-		    && regs->ARM_pc == continue_addr) {
-			if (thumb_mode(regs)) {
-				regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
-				regs->ARM_pc -= 2;
-			} else {
-#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
-				regs->ARM_r7 = __NR_restart_syscall;
-				regs->ARM_pc -= 4;
-#else
-				u32 __user *usp;
-
-				regs->ARM_sp -= 4;
-				usp = (u32 __user *)regs->ARM_sp;
-
-				if (put_user(regs->ARM_pc, usp) == 0) {
-					regs->ARM_pc = KERN_RESTART_CODE;
-				} else {
-					regs->ARM_sp += 4;
-					force_sigsegv(0, current);
-				}
-#endif
-			}
-		}
-
-		/* 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);
-			sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
-		}
+		    && regs->ARM_pc == restart_addr)
+			set_thread_flag(TIF_SYSCALL_RESTARTSYS);
 	}
+
+	/* If there's no signal to deliver, we just put the saved sigmask
+	 * back.
+	 */
+	if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK))
+		set_current_blocked(&current->saved_sigmask);
 }
 
 asmlinkage void
diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h
index 6fcfe8398aa..5ff067b7c75 100644
--- a/arch/arm/kernel/signal.h
+++ b/arch/arm/kernel/signal.h
@@ -8,7 +8,5 @@
  * published by the Free Software Foundation.
  */
 #define KERN_SIGRETURN_CODE	(CONFIG_VECTORS_BASE + 0x00000500)
-#define KERN_RESTART_CODE	(KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))
 
 extern const unsigned long sigreturn_codes[7];
-extern const unsigned long syscall_restart_code[2];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 3647170e9a1..4928d89758f 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -820,8 +820,6 @@ void __init early_trap_init(void *vectors_base)
 	 */
 	memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
 	       sigreturn_codes, sizeof(sigreturn_codes));
-	memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
-	       syscall_restart_code, sizeof(syscall_restart_code));
 
 	flush_icache_range(vectors, vectors + PAGE_SIZE);
 	modify_domain(DOMAIN_USER, DOMAIN_CLIENT);