Re: [PATCH v9 03/10] set_memory.h: Introduce can_set_direct_map_range()

On Sun, Sep 06, 2026 at 10:39:02PM +0300, Mike Rapoport wrote:

On Wed, Sep 02, 2026 at 11:47:05AM +0100, Vincent Donnefort wrote:

quoted

While can_set_direct_map() tells whether the direct map can be modified
globally, can_set_direct_map_range() checks if a specific range can be
modified. e.g. if mapped at PTE-level.

set_direct_map are going to have number of pages parameter soon:

https://lore.kernel.org/all/20260903-execmem-set-vm-perms-v0-2-v3-1-949b64a9f755@kernel.org (local)

so this check can be a part of arm64::set_direct_map

ack.

I wouldn't expose can_set_direct_map_range() as a public API and rely on
the callers to "Do The Right Thing".

ack.

Thanks for having a look at the series.

-- 
Vincent

quoted

Signed-off-by: Vincent Donnefort <redacted>

diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
index 3030d9245f5a..88175c3fa751 100644
--- a/include/linux/set_memory.h
+++ b/include/linux/set_memory.h

@@ -44,6 +44,12 @@ static inline bool kernel_page_present(struct page *page)
 {
 	return true;
 }
+
+static inline bool can_set_direct_map_range(struct page *page,
+					    unsigned long nr_pages)
+{
+	return false;
+}
 #else /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
 /*
  * Some architectures, e.g. ARM64 can disable direct map modifications at

@@ -56,6 +62,14 @@ static inline bool can_set_direct_map(void)
 }
 #define can_set_direct_map can_set_direct_map
 #endif
+
+#ifndef can_set_direct_map_range
+static inline bool can_set_direct_map_range(struct page *page, unsigned long nr_pages)
+{
+	return can_set_direct_map();
+}
+#define can_set_direct_map_range can_set_direct_map_range
+#endif
 #endif /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
 
 #ifdef CONFIG_X86_64

-- 
2.55.0.970.g62bdec98f9-goog

-- 
Sincerely yours,
Mike.