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authorHeiko Carstens <hca@linux.ibm.com>2023-01-17 19:00:59 +0100
committerHeiko Carstens <hca@linux.ibm.com>2023-01-17 19:00:59 +0100
commit41e1992665a2701fa025a8b76970c43b4148446f (patch)
treee104e90d36c50f476f98594a840f26576276dc5c /arch
parent1ecf7bd9c267ab85aff3c4a17fe56bc9754a13be (diff)
downloadlinux-41e1992665a2701fa025a8b76970c43b4148446f.tar.bz2
s390: workaround invalid gcc-11 out of bounds read warning
GCC 11.1.0 and 11.2.0 generate a wrong warning when compiling the kernel e.g. with allmodconfig: arch/s390/kernel/setup.c: In function ‘setup_lowcore_dat_on’: ./include/linux/fortify-string.h:57:33: error: ‘__builtin_memcpy’ reading 128 bytes from a region of size 0 [-Werror=stringop-overread] ... arch/s390/kernel/setup.c:526:9: note: in expansion of macro ‘memcpy’ 526 | memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area, | ^~~~~~ This could be addressed by using absolute_pointer() with the S390_lowcore macro, but this is not a good idea since this generates worse code for performance critical paths. Therefore simply use a for loop to copy the array in question and get rid of the warning. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/kernel/setup.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2b6091349daa..696c9e007a36 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -508,6 +508,7 @@ static void __init setup_lowcore_dat_on(void)
{
struct lowcore *abs_lc;
unsigned long flags;
+ int i;
__ctl_clear_bit(0, 28);
S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
@@ -523,8 +524,8 @@ static void __init setup_lowcore_dat_on(void)
abs_lc = get_abs_lowcore(&flags);
abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
abs_lc->program_new_psw = S390_lowcore.program_new_psw;
- memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area,
- sizeof(abs_lc->cregs_save_area));
+ for (i = 0; i < 16; i++)
+ abs_lc->cregs_save_area[i] = S390_lowcore.cregs_save_area[i];
put_abs_lowcore(abs_lc, flags);
}