Commit 1a5e3f26 authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
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s390/ftrace: make use of epsw to get psw mask 



Finally use epsw to create a complete psw mask within pt_regs. Without
this only some bits are correct, while other bits are (incorrectly)
always zero.

The epsw instruction is quite heavy weight, however given that this
only effects ftrace_regs_caller this seems to be the right thing, so
we finally get a complete psw mask for ftrace kprobed functions.

Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Acked-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 96f6641a

arch/s390/kernel/mcount.S

+10 −4
Original line number Diff line number Diff line
@@ -33,9 +33,16 @@ ENDPROC(ftrace_stub) 
	stg	%r14,(__SF_GPRS+8*8)(%r15)	# save traced function caller



	.if \allregs == 1

	lghi	%r14,0				# save condition code

	ipm	%r14				# don't put any instructions

	sllg	%r14,%r14,16			# clobbering CC before this point

	# save psw mask

	# don't put any instructions clobbering CC before this point

#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES

	epsw	%r1,%r14

	risbg	%r14,%r1,0,31,32

#else

	epsw	%r14,%r1

	sllg	%r14,%r14,32

	lr	%r14,%r1

#endif

	.endif



	lgr	%r1,%r15
@@ -51,7 +58,6 @@ ENDPROC(ftrace_stub) 


	.if \allregs == 1

	stg	%r14,(STACK_PTREGS_PSW)(%r15)

	stosm	(STACK_PTREGS_PSW)(%r15),0

#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES

	mvghi	STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS

#else