[PATCH 5.7 267/376] powerpc/mm: Fix conditions to perform MMU specific management by blocks on PPC32.

From: Greg Kroah-Hartman
Date: Fri Jun 19 2020 - 11:44:08 EST


From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>

commit 4e3319c23a66dabfd6c35f4d2633d64d99b68096 upstream.

Setting init mem to NX shall depend on sinittext being mapped by
block, not on stext being mapped by block.

Setting text and rodata to RO shall depend on stext being mapped by
block, not on sinittext being mapped by block.

Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/7d565fb8f51b18a3d98445a830b2f6548cb2da2a.1589866984.git.christophe.leroy@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/mm/pgtable_32.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -169,7 +169,7 @@ void mark_initmem_nx(void)
unsigned long numpages = PFN_UP((unsigned long)_einittext) -
PFN_DOWN((unsigned long)_sinittext);

- if (v_block_mapped((unsigned long)_stext + 1))
+ if (v_block_mapped((unsigned long)_sinittext))
mmu_mark_initmem_nx();
else
change_page_attr(page, numpages, PAGE_KERNEL);
@@ -181,7 +181,7 @@ void mark_rodata_ro(void)
struct page *page;
unsigned long numpages;

- if (v_block_mapped((unsigned long)_sinittext)) {
+ if (v_block_mapped((unsigned long)_stext + 1)) {
mmu_mark_rodata_ro();
ptdump_check_wx();
return;