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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 18:21:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 18:21:44 -0700
commit227d1e4319ffd8729781941d92f4ae4d85beecd9 (patch)
tree22dd4d85386dd3bdd228b7be988bebbb9607d0fa /arch/arm/kernel/signal.c
parent7d36014b972a3833b883a7ef41e6bd3b0d187850 (diff)
parente94c805f0c234ef54609f23695b60add6b25ad40 (diff)
downloadlinux-227d1e4319ffd8729781941d92f4ae4d85beecd9.tar.gz
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull arm updates from Russell King:
 "This contains both some fixes found when trying to get the
  Assabet+neponset setup as a replacement firewall with a 3c589 PCMCIA
  card, and a bunch of changes from Al to fix up the ARM signal
  handling, particularly some of the restart behaviour."

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: neponset: make sure neponset_ncr_frob() is exported
  ARM: fix out[bwl]()
  arm: don't open-code ptrace_report_syscall()
  arm: bury unused _TIF_RESTORE_SIGMASK
  arm: remove unused restart trampoline
  arm: new way of handling ERESTART_RESTARTBLOCK
  arm: if we get into work_pending while returning to kernel mode, just go away
  arm: don't call try_to_freeze() from do_signal()
  arm: if there's no handler we need to restore sigmask, syscall or no syscall
  arm: trim _TIF_WORK_MASK, get rid of useless test and branch...
  arm: missing checks of __get_user()/__put_user() return values
Diffstat (limited to 'arch/arm/kernel/signal.c')
-rw-r--r--arch/arm/kernel/signal.c85
1 files changed, 18 insertions, 67 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 4e5fdd9bd9e3..17fc36c41cff 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)
@@ -82,10 +69,10 @@ 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);
 	}
 
@@ -94,10 +81,10 @@ 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;
@@ -602,15 +589,6 @@ 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) {
@@ -626,18 +604,13 @@ 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 ...
@@ -652,12 +625,14 @@ 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))
@@ -677,7 +652,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		return;
 	}
 
- no_signal:
 	if (syscall) {
 		/*
 		 * Handle restarting a different system call.  As above,
@@ -685,38 +659,15 @@ 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