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Diffstat (limited to 'arch/arm/kernel/signal.c')
-rw-r--r--arch/arm/kernel/signal.c90
1 files changed, 53 insertions, 37 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index cb8398317644..0340224cf73c 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -597,19 +597,13 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
return err;
}
-static inline void setup_syscall_restart(struct pt_regs *regs)
-{
- regs->ARM_r0 = regs->ARM_ORIG_r0;
- regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
-}
-
/*
* OK, we're invoking a handler
*/
static int
handle_signal(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset,
- struct pt_regs * regs, int syscall)
+ struct pt_regs * regs)
{
struct thread_info *thread = current_thread_info();
struct task_struct *tsk = current;
@@ -617,26 +611,6 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
int ret;
/*
- * If we were from a system call, check for system call restarting...
- */
- if (syscall) {
- switch (regs->ARM_r0) {
- case -ERESTART_RESTARTBLOCK:
- case -ERESTARTNOHAND:
- regs->ARM_r0 = -EINTR;
- break;
- case -ERESTARTSYS:
- if (!(ka->sa.sa_flags & SA_RESTART)) {
- regs->ARM_r0 = -EINTR;
- break;
- }
- /* fallthrough */
- case -ERESTARTNOINTR:
- setup_syscall_restart(regs);
- }
- }
-
- /*
* translate the signal
*/
if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
@@ -685,6 +659,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
*/
static void do_signal(struct pt_regs *regs, int syscall)
{
+ unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
struct k_sigaction ka;
siginfo_t info;
int signr;
@@ -698,18 +673,61 @@ static void do_signal(struct pt_regs *regs, int syscall)
if (!user_mode(regs))
return;
+ /*
+ * If we were from a system call, check for system call restarting...
+ */
+ if (syscall) {
+ continue_addr = regs->ARM_pc;
+ restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
+ retval = regs->ARM_r0;
+
+ /*
+ * Prepare for system call restart. We do this here so that a
+ * debugger will see the already changed PSW.
+ */
+ switch (retval) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ 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 ...
+ */
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
sigset_t *oldset;
+ /*
+ * Depending on the signal settings we may need to revert the
+ * decision to restart the system call. But skip this if a
+ * debugger has chosen to restart at a different PC.
+ */
+ if (regs->ARM_pc == restart_addr) {
+ if (retval == -ERESTARTNOHAND
+ || (retval == -ERESTARTSYS
+ && !(ka.sa.sa_flags & SA_RESTART))) {
+ regs->ARM_r0 = -EINTR;
+ regs->ARM_pc = continue_addr;
+ }
+ }
+
if (test_thread_flag(TIF_RESTORE_SIGMASK))
oldset = &current->saved_sigmask;
else
oldset = &current->blocked;
- if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 0) {
+ if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
/*
* A signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
@@ -723,11 +741,14 @@ static void do_signal(struct pt_regs *regs, int syscall)
}
no_signal:
- /*
- * No signal to deliver to the process - restart the syscall.
- */
if (syscall) {
- if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
+ /*
+ * Handle restarting a different system call. As above,
+ * if a debugger has chosen to restart at a different PC,
+ * 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;
@@ -750,11 +771,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
#endif
}
}
- if (regs->ARM_r0 == -ERESTARTNOHAND ||
- regs->ARM_r0 == -ERESTARTSYS ||
- regs->ARM_r0 == -ERESTARTNOINTR) {
- setup_syscall_restart(regs);
- }
/* If there's no signal to deliver, we just put the saved sigmask
* back.
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