diff options
Diffstat (limited to 'arch/arm/kernel/signal.c')
| -rw-r--r-- | arch/arm/kernel/signal.c | 90 |
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 = ¤t->saved_sigmask; else oldset = ¤t->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. |
