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xtensa: check thread flags atomically on return from user exception 

Check pending signals and rescheduling thread flags with interrupts
disabled, and don't enable them if no flags are set. Call
trace_hardirqs_on after thread flags handling, so that rescheduling is
done and hardirqs tracking flag is updated in the correct task context.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
This commit is contained in:
Max Filippov 2013-08-26 15:12:58 +04:00 committed by Chris Zankel
parent 0bc2ba94a6
commit aea8e7c80a
1 changed files with 21 additions and 18 deletions
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39
arch/xtensa/kernel/entry.S
View File

@ -423,29 +423,14 @@ common_exception:
.global common_exception_return
common_exception_return:
#ifdef CONFIG_TRACE_IRQFLAGS
l32i a4, a1, PT_DEPC
/* Double exception means we came here with an exception
* while PS.EXCM was set, i.e. interrupts disabled.
*/
bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f
l32i a4, a1, PT_EXCCAUSE
bnei a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f
/* We came here with an interrupt means interrupts were enabled
* and we'll reenable them on return.
*/
movi a4, trace_hardirqs_on
callx4 a4
1:
#endif
rsil a2, LOCKLEVEL
/* Jump if we are returning from kernel exceptions. */
1: l32i a3, a1, PT_PS
l32i a3, a1, PT_PS
_bbci.l a3, PS_UM_BIT, 4f
rsil a2, 0
/* Specific to a user exception exit:
* We need to check some flags for signal handling and rescheduling,
* and have to restore WB and WS, extra states, and all registers
@ -465,6 +450,7 @@ common_exception_return:
/* Call do_signal() */
rsil a2, 0
movi a4, do_notify_resume # int do_notify_resume(struct pt_regs*)
mov a6, a1
callx4 a4
@ -472,6 +458,7 @@ common_exception_return:
3: /* Reschedule */
rsil a2, 0
movi a4, schedule # void schedule (void)
callx4 a4
j 1b
@ -483,7 +470,23 @@ common_exception_return:
movi a4, check_tlb_sanity
callx4 a4
#endif
4: /* Restore optional registers. */
4:
#ifdef CONFIG_TRACE_IRQFLAGS
l32i a4, a1, PT_DEPC
/* Double exception means we came here with an exception
* while PS.EXCM was set, i.e. interrupts disabled.
*/
bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f
l32i a4, a1, PT_EXCCAUSE
bnei a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f
/* We came here with an interrupt means interrupts were enabled
* and we'll reenable them on return.
*/
movi a4, trace_hardirqs_on
callx4 a4
1:
#endif
/* Restore optional registers. */
load_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT