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authorHeiko Carstens <hca@linux.ibm.com>2020-12-04 17:56:57 +0100
committerHeiko Carstens <hca@linux.ibm.com>2020-12-16 14:55:48 +0100
commit9365965db0c7ca7fc81eee27c21d8522d7102c32 (patch)
tree21d9ac15de120e72e9c17952580392d0bf26b4bf /arch/s390/kernel/entry.S
parent586592478b1fa8bb8cd6875a9191468e9b1a8b13 (diff)
s390: always clear kernel stack backchain before calling functions
Clear the kernel stack backchain before potentially calling the lockdep trace_hardirqs_off/on functions. Without this walking the kernel backchain, e.g. during a panic, might stop too early. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry.S')
-rw-r--r--arch/s390/kernel/entry.S12
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 8bb9ebb71c4b..aa445203f5a5 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -413,6 +413,7 @@ ENTRY(system_call)
mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
stg %r14,__PT_FLAGS(%r11)
+ xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
ENABLE_INTS
.Lsysc_do_svc:
# clear user controlled register to prevent speculative use
@@ -429,7 +430,6 @@ ENTRY(system_call)
jnl .Lsysc_nr_ok
slag %r8,%r1,3
.Lsysc_nr_ok:
- xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stg %r2,__PT_ORIG_GPR2(%r11)
stg %r7,STACK_FRAME_OVERHEAD(%r15)
lg %r9,0(%r8,%r10) # get system call add.
@@ -698,8 +698,8 @@ ENTRY(pgm_check_handler)
mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS
mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE
mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
-6: RESTORE_SM_CLEAR_PER
- xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+6: xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+ RESTORE_SM_CLEAR_PER
larl %r1,pgm_check_table
llgh %r10,__PT_INT_CODE+2(%r11)
nill %r10,0x007f
@@ -730,8 +730,8 @@ ENTRY(pgm_check_handler)
# PER event in supervisor state, must be kprobes
#
.Lpgm_kprobe:
- RESTORE_SM_CLEAR_PER
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+ RESTORE_SM_CLEAR_PER
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,do_per_trap
j .Lpgm_return
@@ -777,10 +777,10 @@ ENTRY(io_int_handler)
.Lio_skip_asce:
mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
+ xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
jo .Lio_restore
TRACE_IRQS_OFF
- xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
.Lio_loop:
lgr %r2,%r11 # pass pointer to pt_regs
lghi %r3,IO_INTERRUPT
@@ -965,10 +965,10 @@ ENTRY(ext_int_handler)
mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
mvc __PT_INT_PARM_LONG(8,%r11),0(%r1)
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
+ xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
jo .Lio_restore
TRACE_IRQS_OFF
- xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
lghi %r3,EXT_INTERRUPT
brasl %r14,do_IRQ

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