6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Heiko Carstens <hca@xxxxxxxxxxxxx>
[ Upstream commit f101b305a7b9513a8042a2cf09018de4ff371af2 ]
Add the missing pieces so the early program check handler also works
with a relocated lowcore. Right now the result of an early program
check in case of a relocated lowcore would be a program check loop.
Fixes: 8f1e70adb1a3 ("s390/boot: Add cmdline option to relocate lowcore")
Reviewed-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/kernel/early.c | 7 +++++--
arch/s390/kernel/entry.S | 11 ++++++-----
2 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 14d324865e33f..ee051ad81c711 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -183,12 +183,15 @@ void __do_early_pgm_check(struct pt_regs *regs)
static noinline __init void setup_lowcore_early(void)
{
+ struct lowcore *lc = get_lowcore();
psw_t psw;
psw.addr = (unsigned long)early_pgm_check_handler;
psw.mask = PSW_KERNEL_BITS;
- get_lowcore()->program_new_psw = psw;
- get_lowcore()->preempt_count = INIT_PREEMPT_COUNT;
+ lc->program_new_psw = psw;
+ lc->preempt_count = INIT_PREEMPT_COUNT;
+ lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
+ lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
}
static __init void detect_diag9c(void)
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index b01f4ac43f729..6539ec4800cd1 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -600,18 +600,19 @@ SYM_CODE_START(restart_int_handler)
SYM_CODE_END(restart_int_handler)
SYM_CODE_START(early_pgm_check_handler)
- stmg %r8,%r15,__LC_SAVE_AREA_SYNC
+ STMG_LC %r8,%r15,__LC_SAVE_AREA_SYNC
+ GET_LC %r13
aghi %r15,-(STACK_FRAME_OVERHEAD+__PT_SIZE)
la %r11,STACK_FRAME_OVERHEAD(%r15)
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stmg %r0,%r7,__PT_R0(%r11)
- mvc __PT_PSW(16,%r11),__LC_PGM_OLD_PSW
- mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
+ mvc __PT_PSW(16,%r11),__LC_PGM_OLD_PSW(%r13)
+ mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC(%r13)
lgr %r2,%r11
brasl %r14,__do_early_pgm_check
- mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
+ mvc __LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
- lpswe __LC_RETURN_PSW
+ LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE
SYM_CODE_END(early_pgm_check_handler)
.section .kprobes.text, "ax"
--
2.43.0
