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-rw-r--r--arch/arm/kernel/signal.c46
1 files changed, 40 insertions, 6 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index fd2392a17ac..536c5d6b340 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();