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authorHeiko Carstens <hca@linux.ibm.com>2025-04-24 17:07:01 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-05-18 08:24:47 +0200
commit5c3b8f05756b17c30b8272b63d80fba6b0c7934f (patch)
tree3d5a348abefcb32ad4070d8d7fb7cc478b02f57f
parent2148d34371b06dac696c0497a98a6bf905a51650 (diff)
s390/entry: Fix last breaking event handling in case of stack corruption
[ Upstream commit ae952eea6f4a7e2193f8721a5366049946e012e7 ] In case of stack corruption stack_invalid() is called and the expectation is that register r10 contains the last breaking event address. This dependency is quite subtle and broke a couple of years ago without that anybody noticed. Fix this by getting rid of the dependency and read the last breaking event address from lowcore. Fixes: 56e62a737028 ("s390: convert to generic entry") Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--arch/s390/kernel/entry.S3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index a7de838f8031..669d335c87ab 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -636,7 +636,8 @@ SYM_CODE_START(stack_overflow)
stmg %r0,%r7,__PT_R0(%r11)
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_R8(64,%r11),0(%r14)
- stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
+ GET_LC %r2
+ mvc __PT_ORIG_GPR2(8,%r11),__LC_PGM_LAST_BREAK(%r2)
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
jg kernel_stack_overflow