/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
static void do_signal(struct pt_regs *regs, int syscall)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (!user_mode(regs))
return;
if (try_to_freeze())
goto no_signal;
single_step_clear(current);
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
sigset_t *oldset;
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) {
/*
* A signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
* and will be restored by sigreturn, so we can simply
* clear the TIF_RESTORE_SIGMASK flag.
*/
if (test_thread_flag(TIF_RESTORE_SIGMASK))
clear_thread_flag(TIF_RESTORE_SIGMASK);
}
single_step_set(current);
return;
}
no_signal:
/*
* No signal to deliver to the process - restart the syscall.
*/
if (syscall) {
if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
regs->ARM_r0 = -EAGAIN; /* prevent multiple restarts */
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
}
}
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.
*/
if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
clear_thread_flag(TIF_RESTORE_SIGMASK);
sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
}
}
single_step_set(current);
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
#ifdef CONFIG_PREEMPT_RT
/*
* Fully-preemptible kernel does not need interrupts disabled:
*/
local_irq_enable();
preempt_check_resched();
#endif
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (!user_mode(regs))
return 0;
if (try_to_freeze())
goto no_signal;
single_step_clear(current);
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
handle_signal(signr, &ka, &info, oldset, regs, syscall);
single_step_set(current);
return 1;
}
no_signal:
/*
* No signal to deliver to the process - restart the syscall.
*/
if (syscall) {
if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
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;
u32 swival = __NR_restart_syscall;
regs->ARM_sp -= 12;
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;
#endif
}
}
if (regs->ARM_r0 == -ERESTARTNOHAND ||
regs->ARM_r0 == -ERESTARTSYS ||
regs->ARM_r0 == -ERESTARTNOINTR) {
restart_syscall(regs);
}
}
single_step_set(current);
return 0;
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
static void do_signal(struct pt_regs *regs, int syscall)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
sigset_t *oldset;
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (!user_mode(regs))
return;
if (try_to_freeze())
goto no_signal;
single_step_clear(current);
if (test_thread_flag(TIF_RESTORE_SIGMASK))
oldset = ¤t->saved_sigmask;
else
oldset = ¤t->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 0) {
/* a signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
* and will be restored by sigreturn, so we can simply
* clear the TIF_RESTORE_SIGMASK flag */
clear_thread_flag(TIF_RESTORE_SIGMASK);
}
single_step_set(current);
return;
}
no_signal:
/*
* No signal to deliver to the process - restart the syscall.
*/
if (syscall) {
if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
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;
u32 swival = __NR_restart_syscall;
regs->ARM_sp -= 12;
usp = (u32 __user *)regs->ARM_sp;
/*
* 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.
*/
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;
#endif
}
}
if (regs->ARM_r0 == -ERESTARTNOHAND ||
regs->ARM_r0 == -ERESTARTSYS ||
regs->ARM_r0 == -ERESTARTNOINTR) {
setup_syscall_restart(regs);
}
}
single_step_set(current);
/* if there's no signal to deliver, we just put the saved sigmask back. */
if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
clear_thread_flag(TIF_RESTORE_SIGMASK);
sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
}
}
static void do_signal(struct pt_regs *regs, int syscall)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
if (!user_mode(regs))
return;
if (try_to_freeze())
goto no_signal;
single_step_clear(current);
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
sigset_t *oldset;
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 (test_thread_flag(TIF_RESTORE_SIGMASK))
clear_thread_flag(TIF_RESTORE_SIGMASK);
}
single_step_set(current);
return;
}
no_signal:
if (syscall) {
if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
regs->ARM_r0 = -EAGAIN;
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
}
}
if (regs->ARM_r0 == -ERESTARTNOHAND ||
regs->ARM_r0 == -ERESTARTSYS ||
regs->ARM_r0 == -ERESTARTNOINTR) {
setup_syscall_restart(regs);
}
if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
clear_thread_flag(TIF_RESTORE_SIGMASK);
sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
}
}
single_step_set(current);
}
