1 files changed, 21 insertions, 24 deletions

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 1423a341978..e7714f367eb 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -1,7 +1,7 @@
 /*
  *  linux/arch/arm/kernel/signal.c
  *
- *  Copyright (C) 1995-2002 Russell King
+ *  Copyright (C) 1995-2009 Russell King
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -29,6 +29,7 @@
  */
 #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.
@@ -49,6 +50,18 @@ 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)
@@ -645,32 +658,16 @@ static void do_signal(struct pt_regs *regs, int syscall)
                                 regs->ARM_pc -= 4;
 #else
                                 u32 __user *usp;
-                                u32 swival = __NR_restart_syscall;
 
-                                regs->ARM_sp -= 12;
+                                regs->ARM_sp -= 4;
                                 usp = (u32 __user *)regs->ARM_sp;
 
-                                /*
-                                 * Either we supports 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.
-                                 */
-                                swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;
-
-                                put_user(regs->ARM_pc, &usp[0]);
-                                /* swi __NR_restart_syscall */
-                                put_user(0xef000000 | swival, &usp[1]);
-                                /* ldr  pc, [sp], #12 */
-                                put_user(0xe49df00c, &usp[2]);
-
-                                flush_icache_range((unsigned long)usp,
-                                                   (unsigned long)(usp + 3));
-
-                                regs->ARM_pc = regs->ARM_sp + 4;
+                                if (put_user(regs->ARM_pc, usp) == 0) {
+                                        regs->ARM_pc = KERN_RESTART_CODE;
+                                } else {
+                                        regs->ARM_sp += 4;
+                                        force_sigsegv(0, current);
+                                }
 #endif
                         }
                 }