From: Christophe Leroy christophe.leroy@csgroup.eu
commit 9bb162fa26ed76031ed0e7dbc77ccea0bf977758 upstream.
Allthough kernel text is always mapped with BATs, we still have inittext mapped with pages, so TLB miss handling is required when CONFIG_DEBUG_PAGEALLOC or CONFIG_KFENCE is set.
The final solution should be to set a BAT that also maps inittext but that BAT then needs to be cleared at end of init, and it will require more changes to be able to do it properly.
As DEBUG_PAGEALLOC or KFENCE are debugging, performance is not a big deal so let's fix it simply for now to enable easy stable application.
Fixes: 035b19a15a98 ("powerpc/32s: Always map kernel text and rodata with BATs") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Maxime Bizon mbizon@freebox.fr Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/aea33b4813a26bdb9378b5f273f00bd5d4abe240.163885736... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/kernel/head_book3s_32.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/powerpc/kernel/head_book3s_32.S +++ b/arch/powerpc/kernel/head_book3s_32.S @@ -421,14 +421,14 @@ InstructionTLBMiss: */ /* Get PTE (linux-style) and check access */ mfspr r3,SPRN_IMISS -#ifdef CONFIG_MODULES +#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) lis r1, TASK_SIZE@h /* check if kernel address */ cmplw 0,r1,r3 #endif mfspr r2, SPRN_SDR1 li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC | _PAGE_USER rlwinm r2, r2, 28, 0xfffff000 -#ifdef CONFIG_MODULES +#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) bgt- 112f lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ li r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC