commit ae952eea6f4a7e2193f8721a5366049946e012e7 upstream.

Note: the GET_LC macro and all the infrastructe that comes with this does not exist for this kernel release. Therefore the patch is slightly different to the upstream variant.

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 --- arch/s390/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 160290049e8c..14a5eff4d027 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -676,7 +676,7 @@ ENTRY(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 + mvc __PT_ORIG_GPR2(8,%r11),__LC_LAST_BREAK xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) lgr %r2,%r11 # pass pointer to pt_regs jg kernel_stack_overflow