[IA64] fix interrupt masking for pending works on kernel leave
[Bug-fix for "[BUG?][2.6.25-mm1] sleeping during IRQ disabled"]
This patch does:
- enable interrupts before calling schedule() as same as others, ex. x86
- enable interrupts during ia64_do_signal() and ia64_sync_krbs()
- do_notify_resume_user() is still called with interrupts disabled, since
we can take short path of fsys_mode if-statement quickly.
- pfm_handle_work() is also called with interrupts disabled, since
it can deal interrupt mask within itself.
- fix/add some comments/notes
Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 58dcfac..a3a34b4 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -167,11 +167,18 @@
clear_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME);
}
+/*
+ * do_notify_resume_user():
+ * Called from notify_resume_user at entry.S, with interrupts disabled.
+ */
void
-do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall)
+do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
{
if (fsys_mode(current, &scr->pt)) {
- /* defer signal-handling etc. until we return to privilege-level 0. */
+ /*
+ * defer signal-handling etc. until we return to
+ * privilege-level 0.
+ */
if (!ia64_psr(&scr->pt)->lp)
ia64_psr(&scr->pt)->lp = 1;
return;
@@ -179,16 +186,26 @@
#ifdef CONFIG_PERFMON
if (current->thread.pfm_needs_checking)
+ /*
+ * Note: pfm_handle_work() allow us to call it with interrupts
+ * disabled, and may enable interrupts within the function.
+ */
pfm_handle_work();
#endif
/* deal with pending signal delivery */
- if (test_thread_flag(TIF_SIGPENDING))
+ if (test_thread_flag(TIF_SIGPENDING)) {
+ local_irq_enable(); /* force interrupt enable */
ia64_do_signal(scr, in_syscall);
+ }
/* copy user rbs to kernel rbs */
- if (unlikely(test_thread_flag(TIF_RESTORE_RSE)))
+ if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
+ local_irq_enable(); /* force interrupt enable */
ia64_sync_krbs();
+ }
+
+ local_irq_disable(); /* force interrupt disable */
}
static int pal_halt = 1;