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Commit aea8e7c8 authored by Max Filippov's avatar Max Filippov Committed by Chris Zankel
Browse files

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: default avatarMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: default avatarChris Zankel <chris@zankel.net>
parent 0bc2ba94

arch/xtensa/kernel/entry.S

+21 −18
Original line number Diff line number Diff line
@@ -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