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Commit f5cdac27 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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[S390] Fix IRQ tracing in case of PER 



In case user space is single stepped (PER) the program check handler
claims too early that IRQs are enabled on the return path.
Subsequent checks will notice that the IRQ mask in the PSW and
what lockdep thinks the IRQ mask should be do not correlate and
therefore will print a warning to the console and disable lockdep.

Fix this by doing all the work within the correct context.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 1a041a23

arch/s390/kernel/entry.S

+10 −2
Original line number Diff line number Diff line
@@ -535,8 +535,16 @@ pgm_no_vtime2: 
	l	%r3,__LC_PGM_ILC	# load program interruption code

	la	%r8,0x7f

	nr	%r8,%r3 		# clear per-event-bit and ilc

	be	BASED(pgm_exit)		# only per or per+check ?

	b	BASED(pgm_do_call)

	be	BASED(pgm_exit2)	# only per or per+check ?

	l	%r7,BASED(.Ljump_table)

	sll	%r8,2

	l	%r7,0(%r8,%r7)		# load address of handler routine

	la	%r2,SP_PTREGS(%r15)	# address of register-save area

	basr	%r14,%r7		# branch to interrupt-handler

pgm_exit2:

	TRACE_IRQS_ON

	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts

	b	BASED(sysc_return)



#

# it was a single stepped SVC that is causing all the trouble

arch/s390/kernel/entry64.S

+10 −2
Original line number Diff line number Diff line
@@ -544,8 +544,16 @@ pgm_no_vtime2: 
	lgf	%r3,__LC_PGM_ILC	# load program interruption code

	lghi	%r8,0x7f

	ngr	%r8,%r3			# clear per-event-bit and ilc

	je	pgm_exit

	j	pgm_do_call

	je	pgm_exit2

	sll	%r8,3

	larl	%r1,pgm_check_table

	lg	%r1,0(%r8,%r1)		# load address of handler routine

	la	%r2,SP_PTREGS(%r15)	# address of register-save area

	basr	%r14,%r1		# branch to interrupt-handler

pgm_exit2:

	TRACE_IRQS_ON

	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts

	j	sysc_return



#

# it was a single stepped SVC that is causing all the trouble