This is a note to let you know that I've just added the patch titled s390/facility: Disable compile time optimization for decompressor code to the 6.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-facility-disable-compile-time-optimization-for-.patch and it can be found in the queue-6.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 72401c24515a9d7dc53b181a14409161df6ac783 Author: Heiko Carstens <hca@xxxxxxxxxxxxx> Date: Wed Sep 4 11:39:24 2024 +0200 s390/facility: Disable compile time optimization for decompressor code [ Upstream commit 0147addc4fb72a39448b8873d8acdf3a0f29aa65 ] Disable compile time optimizations of test_facility() for the decompressor. The decompressor should not contain any optimized code depending on the architecture level set the kernel image is compiled for to avoid unexpected operation exceptions. Add a __DECOMPRESSOR check to test_facility() to enforce that facilities are always checked during runtime for the decompressor. Reviewed-by: Sven Schnelle <svens@xxxxxxxxxxxxx> Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h index b7d234838a366..65ebf86506cde 100644 --- a/arch/s390/include/asm/facility.h +++ b/arch/s390/include/asm/facility.h @@ -59,8 +59,10 @@ static inline int test_facility(unsigned long nr) unsigned long facilities_als[] = { FACILITIES_ALS }; if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) { - if (__test_facility(nr, &facilities_als)) - return 1; + if (__test_facility(nr, &facilities_als)) { + if (!__is_defined(__DECOMPRESSOR)) + return 1; + } } return __test_facility(nr, &stfle_fac_list); }