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authorRabin Vincent <rabin@rab.in>2015-02-08 18:19:17 +0100
committerJesper Nilsson <jespern@axis.com>2015-03-25 10:53:54 +0100
commit9a7449d3e975fe5c5ca12b7fea4f4bd69188a5f9 (patch)
treef0e601428db322438e1c14a054955340804106be /arch/cris
parent0f72e5c0df732658d5e9e3c556c9c6928034e291 (diff)
CRISv32: handle multiple signals
Al Viro noted that CRIS fails to handle multiple signals. This fixes the problem for CRISv32 by making it use a C work_pending handling loop similar to the ARM implementation in 0a267fa6a15d41c ("ARM: 7472/1: pull all work_pending logics into C function"). This also happens to fixes the warnings which currently trigger on CRISv32 due to do_signal() being called with interrupts disabled. Test case (should die of the SIGSEGV which gets raised when setting up the stack for SIGALRM, but instead reaches and executes the _exit(1)): #include <unistd.h> #include <signal.h> #include <sys/time.h> #include <err.h> static void handler(int sig) { } int main(int argc, char *argv[]) { int ret; struct itimerval t1 = { .it_value = {1} }; stack_t ss = { .ss_sp = NULL, .ss_size = SIGSTKSZ, }; struct sigaction action = { .sa_handler = handler, .sa_flags = SA_ONSTACK, }; ret = sigaltstack(&ss, NULL); if (ret < 0) err(1, "sigaltstack"); sigaction(SIGALRM, &action, NULL); setitimer(ITIMER_REAL, &t1, NULL); pause(); _exit(1); return 0; } Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/r/20121208074429.GC4939@ZenIV.linux.org.uk Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Jesper Nilsson <jespern@axis.com>
Diffstat (limited to 'arch/cris')
-rw-r--r--arch/cris/arch-v32/kernel/entry.S35
-rw-r--r--arch/cris/kernel/ptrace.c23
2 files changed, 26 insertions, 32 deletions
diff --git a/arch/cris/arch-v32/kernel/entry.S b/arch/cris/arch-v32/kernel/entry.S
index 1ea29b7f263c..026a0b21b8f0 100644
--- a/arch/cris/arch-v32/kernel/entry.S
+++ b/arch/cris/arch-v32/kernel/entry.S
@@ -281,43 +281,14 @@ _syscall_exit_work:
.type _work_pending,@function
_work_pending:
addoq +TI_flags, $r0, $acr
- move.d [$acr], $r10
- btstq TIF_NEED_RESCHED, $r10 ; Need resched?
- bpl _work_notifysig ; No, must be signal/notify.
- nop
- .size _work_pending, . - _work_pending
-
- .type _work_resched,@function
-_work_resched:
- move.d $r9, $r1 ; Preserve R9.
- jsr schedule
- nop
- move.d $r1, $r9
- di
-
- addoq +TI_flags, $r0, $acr
- move.d [$acr], $r1
- and.d _TIF_WORK_MASK, $r1 ; Ignore sycall trace counter.
- beq _Rexit
- nop
- btstq TIF_NEED_RESCHED, $r1
- bmi _work_resched ; current->work.need_resched.
- nop
- .size _work_resched, . - _work_resched
-
- .type _work_notifysig,@function
-_work_notifysig:
- ;; Deal with pending signals and notify-resume requests.
-
- addoq +TI_flags, $r0, $acr
move.d [$acr], $r12 ; The thread_info_flags parameter.
move.d $sp, $r11 ; The regs param.
- jsr do_notify_resume
- move.d $r9, $r10 ; do_notify_resume syscall/irq param.
+ jsr do_work_pending
+ move.d $r9, $r10 ; The syscall/irq param.
ba _Rexit
nop
- .size _work_notifysig, . - _work_notifysig
+ .size _work_pending, . - _work_pending
;; We get here as a sidetrack when we've entered a syscall with the
;; trace-bit set. We need to call do_syscall_trace and then continue
diff --git a/arch/cris/kernel/ptrace.c b/arch/cris/kernel/ptrace.c
index 58d44ee1a71f..fd3427e563c5 100644
--- a/arch/cris/kernel/ptrace.c
+++ b/arch/cris/kernel/ptrace.c
@@ -42,3 +42,26 @@ void do_notify_resume(int canrestart, struct pt_regs *regs,
tracehook_notify_resume(regs);
}
}
+
+void do_work_pending(int syscall, struct pt_regs *regs,
+ unsigned int thread_flags)
+{
+ do {
+ if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+ schedule();
+ } else {
+ if (unlikely(!user_mode(regs)))
+ return;
+ local_irq_enable();
+ if (thread_flags & _TIF_SIGPENDING) {
+ do_signal(syscall, regs);
+ syscall = 0;
+ } else {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+ }
+ local_irq_disable();
+ thread_flags = current_thread_info()->flags;
+ } while (thread_flags & _TIF_WORK_MASK);
+}