From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com> With the powerpc next commit e7e81847478 (powerpc/mce: Fix SLB rebolting during MCE recovery path.), the SLB error recovery is broken. The new change now does not add index value to RB[52-63] that selects the SLB entry while rebolting, instead it assumes that the shadow save area already have index embeded correctly in esid field. While all valid bolted save areas do contain index value set correctly, there is a case where 3rd (KSTACK_INDEX) entry for kernel stack does not embed index for NULL esid entry. This patch fixes that.
Without this patch the SLB rebolt code overwrites the 1st entry of kernel linear mapping and causes SLB recovery to fail. Signed-off-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npig...@gmail.com> Reviewed-by: Nicholas Piggin <npig...@gmail.com> --- arch/powerpc/mm/slb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index 0b095fa54049..9f574e59d178 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -70,7 +70,7 @@ static inline void slb_shadow_update(unsigned long ea, int ssize, static inline void slb_shadow_clear(enum slb_index index) { - WRITE_ONCE(get_slb_shadow()->save_area[index].esid, 0); + WRITE_ONCE(get_slb_shadow()->save_area[index].esid, cpu_to_be64(index)); } static inline void create_shadowed_slbe(unsigned long ea, int ssize,