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| author | Heiko Carstens <hca@linux.ibm.com> | 2024-05-13 12:16:20 +0200 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2024-05-14 20:21:23 +0200 |
| commit | 207ddb918995369f716e2b1d987ca6880c2bc21d (patch) | |
| tree | 140ee6459aadef5a0e40211130e6207138d4107a | |
| parent | effb83572685eaa70d05a8dd6307ca574a11fcf3 (diff) | |
| download | linux-stable-207ddb918995369f716e2b1d987ca6880c2bc21d.tar.gz linux-stable-207ddb918995369f716e2b1d987ca6880c2bc21d.tar.bz2 linux-stable-207ddb918995369f716e2b1d987ca6880c2bc21d.zip | |
s390/alternatives: Convert runtime sanity check into compile time check
__apply_alternatives() contains a runtime check which verifies that the
size of the to be patched code area is even. Convert this to a compile time
check using a similar ".org" trick, which is already used to verify that
old and new code areas have the same size.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/alternative-asm.h | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/alternative.h | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/alternative.c | 7 |
3 files changed, 2 insertions, 7 deletions
diff --git a/arch/s390/include/asm/alternative-asm.h b/arch/s390/include/asm/alternative-asm.h index 7db046596b93..608f6287ca9c 100644 --- a/arch/s390/include/asm/alternative-asm.h +++ b/arch/s390/include/asm/alternative-asm.h @@ -15,6 +15,7 @@ .long \alt_start - . .word \feature .byte \orig_end - \orig_start + .org . - ( \orig_end - \orig_start ) & 1 .org . - ( \orig_end - \orig_start ) + ( \alt_end - \alt_start ) .org . - ( \alt_end - \alt_start ) + ( \orig_end - \orig_start ) .endm diff --git a/arch/s390/include/asm/alternative.h b/arch/s390/include/asm/alternative.h index 904dd049f954..dd93b92c3ab6 100644 --- a/arch/s390/include/asm/alternative.h +++ b/arch/s390/include/asm/alternative.h @@ -53,6 +53,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); "\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \ "\t.word " __stringify(facility) "\n" /* facility bit */ \ "\t.byte " oldinstr_len "\n" /* instruction len */ \ + "\t.org . - (" oldinstr_len ") & 1\n" \ "\t.org . - (" oldinstr_len ") + (" altinstr_len(num) ")\n" \ "\t.org . - (" altinstr_len(num) ") + (" oldinstr_len ")\n" diff --git a/arch/s390/kernel/alternative.c b/arch/s390/kernel/alternative.c index e7bca29f9c34..1ac5f707dd70 100644 --- a/arch/s390/kernel/alternative.c +++ b/arch/s390/kernel/alternative.c @@ -33,13 +33,6 @@ static void __init_or_module __apply_alternatives(struct alt_instr *start, if (!__test_facility(a->facility, alt_stfle_fac_list)) continue; - - if (unlikely(a->instrlen % 2)) { - WARN_ONCE(1, "cpu alternatives instructions length is " - "odd, skipping patching\n"); - continue; - } - s390_kernel_write(instr, replacement, a->instrlen); } } |