[PATCH] arm64: fix rodata=full again
Ard Biesheuvel
ardb at kernel.org
Thu Nov 3 10:00:15 PDT 2022
Commit 2e8cff0a0eee87b2 ("arm64: fix rodata=full") addressed a couple of
issues with the rodata= kernel command line option, which is not a
simple boolean on arm64, and inadvertently got broken due to changes in
the generic bool handling.
Unfortunately, the resulting code never clears the rodata_full boolean
variable if it defaults to true and rodata=on or rodata=off is passed,
as the generic code is not aware of the existence of this variable.
Given the way this code is plumbed together, clearing rodata_full when
returning false from arch_parse_debug_rodata() may result in
inconsistencies if the generic code decides that it cannot parse the
right hand side, so the best way to deal with this is to only take
rodata_full in account if rodata_enabled is also true.
Fixes: 2e8cff0a0eee87b2 ("arm64: fix rodata=full")
Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
arch/arm64/mm/pageattr.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index d107c3d434e22455..5922178d7a064c1c 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -26,7 +26,7 @@ bool can_set_direct_map(void)
* mapped at page granularity, so that it is possible to
* protect/unprotect single pages.
*/
- return rodata_full || debug_pagealloc_enabled() ||
+ return (rodata_enabled && rodata_full) || debug_pagealloc_enabled() ||
IS_ENABLED(CONFIG_KFENCE);
}
@@ -102,7 +102,8 @@ static int change_memory_common(unsigned long addr, int numpages,
* If we are manipulating read-only permissions, apply the same
* change to the linear mapping of the pages that back this VM area.
*/
- if (rodata_full && (pgprot_val(set_mask) == PTE_RDONLY ||
+ if (rodata_enabled &&
+ rodata_full && (pgprot_val(set_mask) == PTE_RDONLY ||
pgprot_val(clear_mask) == PTE_RDONLY)) {
for (i = 0; i < area->nr_pages; i++) {
__change_memory_common((u64)page_address(area->pages[i]),
--
2.35.1
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