arm64: fix rodata=full again

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: 2e8cff0a0eee ("arm64: fix rodata=full")
Cc: <stable@vger.kernel.org> # 6.0.x
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221103170015.4124426-1-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index d107c3d..5922178 100644 (file)
--- 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]),