s390/facility: Disable compile time optimization for decompressor code

BugLink: https://bugs.launchpad.net/bugs/2097301

[ 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@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
This commit is contained in:
Heiko Carstens
2024-09-04 11:39:24 +02:00
committed by Mehmet Basaran
parent c467dbcd0d
commit ebc2e91b73
+4 -2
View File
@@ -60,8 +60,10 @@ 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);
}