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-rw-r--r--arch/s390/kernel/entry.S19
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index e408d9cc5b96..6315037335ba 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -231,12 +231,17 @@ ENTRY(sie64a)
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
.Lsie_done:
# some program checks are suppressing. C code (e.g. do_protection_exception)
-# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
-# instructions between sie64a and .Lsie_done should not cause program
-# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
+# will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There
+# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable.
+# Other instructions between sie64a and .Lsie_done should not cause program
+# interrupts. So lets use 3 nops as a landing pad for all possible rewinds.
# See also .Lcleanup_sie
-.Lrewind_pad:
- nop 0
+.Lrewind_pad6:
+ nopr 7
+.Lrewind_pad4:
+ nopr 7
+.Lrewind_pad2:
+ nopr 7
.globl sie_exit
sie_exit:
lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
@@ -249,7 +254,9 @@ sie_exit:
stg %r14,__SF_EMPTY+16(%r15) # set exit reason code
j sie_exit
- EX_TABLE(.Lrewind_pad,.Lsie_fault)
+ EX_TABLE(.Lrewind_pad6,.Lsie_fault)
+ EX_TABLE(.Lrewind_pad4,.Lsie_fault)
+ EX_TABLE(.Lrewind_pad2,.Lsie_fault)
EX_TABLE(sie_exit,.Lsie_fault)
EXPORT_SYMBOL(sie64a)
EXPORT_SYMBOL(sie_exit)