Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm

Pull ARM fixes from Russell King:
 "Last merge window, we had some updates from Al cleaning up the signal
  restart handling.  These have caused some problems on ARM, and while
  Al has some fixes, we have some concerns with Al's patches but we've
  been unsuccesful with discussing this.

  We have got to the point where we need to do something, and we've
  decided that the best solution is to revert the appropriate commits
  until Al is able to reply to us.

  Also included here are four patches to fix warnings that I've noticed
  in my build system, and one fix for kprobes test code."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: fix warning caused by wrongly typed arm_dma_limit
  ARM: fix warnings about atomic64_read
  ARM: 7440/1: kprobes: only test 'sub pc, pc, #1b-2b+8-2' on ARMv6
  ARM: 7441/1: perf: return -EOPNOTSUPP if requested mode exclusion is unavailable
  ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK"
  ARM: 7442/1: Revert "remove unused restart trampoline"
  ARM: fix set_domain() macro
  ARM: fix mach-versatile/pci.c warning

1 files changed, 40 insertions, 6 deletions

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index fd2392a17ac1..536c5d6b340b 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -27,6 +27,7 @@
  */
 #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.
@@ -47,6 +48,18 @@ 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)
@@ -592,10 +605,12 @@ 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;
 		}
 	}
 
@@ -611,14 +626,12 @@ 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 ||
-			    retval == -ERESTART_RESTARTBLOCK
+			if (retval == -ERESTARTNOHAND
 			    || (retval == -ERESTARTSYS
 				&& !(ka.sa.sa_flags & SA_RESTART))) {
 				regs->ARM_r0 = -EINTR;
 				regs->ARM_pc = continue_addr;
 			}
-			clear_thread_flag(TIF_SYSCALL_RESTARTSYS);
 		}
 
 		handle_signal(signr, &ka, &info, regs);
@@ -632,8 +645,29 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		 * ignore the restart.
 		 */
 		if (retval == -ERESTART_RESTARTBLOCK
-		    && regs->ARM_pc == restart_addr)
-			set_thread_flag(TIF_SYSCALL_RESTARTSYS);
+		    && 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
+			}
+		}
 	}
 
 	restore_saved_sigmask();