On Wed, Sep 02, 2026 at 11:47:09AM +0100, Vincent Donnefort wrote:
quoted hunk ↗ jump to hunk
Add implementation for the unsafe functions __set_direct_map*(). They do
not verify for can_set_direct_map() and expect the caller to do so
beforehand.
Signed-off-by: Vincent Donnefort <redacted>
diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
index 1a37f4ef130b..080a40846bbe 100644
--- a/arch/arm64/include/asm/set_memory.h
+++ b/arch/arm64/include/asm/set_memory.h
@@ -16,6 +16,10 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
+int __set_direct_map_invalid_noflush(struct page *page);
+#define __set_direct_map_invalid_noflush __set_direct_map_invalid_noflush
+int __set_direct_map_default_noflush(struct page *page);
+#define __set_direct_map_default_noflush __set_direct_map_default_noflush
int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
bool kernel_page_present(struct page *page);
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index c59ef17eb0d0..28adab0edace 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -294,28 +294,38 @@ int set_memory_valid(unsigned long addr, int numpages, int enable)
__pgprot(PTE_PRESENT_VALID_KERNEL));
}
-int set_direct_map_invalid_noflush(struct page *page)
+int __set_direct_map_invalid_noflush(struct page *page)
{
pgprot_t clear_mask = __pgprot(PTE_PRESENT_VALID_KERNEL);
pgprot_t set_mask = __pgprot(PTE_PRESENT_INVALID);
+ return update_range_prot((unsigned long)page_address(page),
+ PAGE_SIZE, set_mask, clear_mask);
+}
I think these would work quite nicely if you rebase the series onto
linux-next, which contains the patches that add the number of pages to
these functions.
You can then keep can_set_direct_map_range() from the previous patch and
call that from the set_direct_map_*_noflush() functions instead of the
simple can_set_direct_map() (which is a shortcut path in the _range
check anyway.
I've used that locally in my tree and it seems to be working just fine.
Thierry