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.
Reported-by: Maxime Bizon <mbi...@freebox.fr>
Fixes: 035b19a15a98 ("powerpc/32s: Always map kernel text and rodata with BATs")
Cc: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
arch/powerpc/kernel/head_book3s_32.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/head_book3s_32.S
b/arch/powerpc/kernel/head_book3s_32.S
index 68e5c0a7e99d..2e2a8211b17b 100644
--- 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
--
2.33.1
