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s390/ftrace: make use of epsw to get psw mask

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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: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2022-02-22 15:27:52 +01:00 committed by Vasily Gorbik
parent 96f6641a6a
commit 1a5e3f262e
1 changed files with 10 additions and 4 deletions
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14
arch/s390/kernel/mcount.S
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@ -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