From: Alexander Gordeev agordeev@linux.ibm.com
[ Upstream commit 12dd19c159659ec9050f45dc8a2ff3c3917f4be3 ]
Crash dump always starts on CPU0. In case CPU0 is offline the prefix page is not installed and the absolute zero lowcore is used. However, struct lowcore::mcesad is never assigned and stays zero. That leads to __machine_kdump() -> save_vx_regs() call silently stores vector registers to the absolute lowcore at 0x11b0 offset.
Fixes: a62bc0739253 ("s390/kdump: add support for vector extension") Reviewed-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kernel/nmi.c | 2 +- arch/s390/kernel/setup.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index a50f2ff1b00e8..383b4799b6dd3 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -62,7 +62,7 @@ static inline unsigned long nmi_get_mcesa_size(void) * The structure is required for machine check happening early in * the boot process. */ -static struct mcesa boot_mcesa __initdata __aligned(MCESA_MAX_SIZE); +static struct mcesa boot_mcesa __aligned(MCESA_MAX_SIZE);
void __init nmi_alloc_boot_cpu(struct lowcore *lc) { diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 6b1a8697fae8d..4dfe37b068898 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -484,6 +484,7 @@ static void __init setup_lowcore_dat_off(void) put_abs_lowcore(restart_data, lc->restart_data); put_abs_lowcore(restart_source, lc->restart_source); put_abs_lowcore(restart_psw, lc->restart_psw); + put_abs_lowcore(mcesad, lc->mcesad);
lc->spinlock_lockval = arch_spin_lockval(0); lc->spinlock_index = 0;