diff options
| -rw-r--r-- | arch/s390/kernel/entry.S | 19 |
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) |