[RESEND v4 1/3] mm/pkey: Add PKEY_UNRESTRICTED macro
From: Yury Khrustalev <hidden>
Date: 2025-01-13 17:06:42
Also in:
linux-arch, linux-kselftest, linux-mm, linuxppc-dev
Subsystem:
generic include/asm header files, memory mapping - madvise (memory advice), the rest · Maintainers:
Arnd Bergmann, Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, David Hildenbrand, Linus Torvalds
Memory protection keys (pkeys) uapi has two macros for pkeys restrictions: - PKEY_DISABLE_ACCESS 0x1 - PKEY_DISABLE_WRITE 0x2 with implicit literal value of 0x0 that means "unrestricted". Code that works with pkeys has to use this literal value when implying that a pkey imposes no restrictions. This may reduce readability because 0 can be written in various ways (e.g. 0x0 or 0) and also because 0 in the context of pkeys can be mistaken for "no permissions" (akin PROT_NONE) while it actually means "no restrictions". This is important because pkeys are oftentimes used near mprotect() that uses PROT_ macros. This patch adds PKEY_UNRESTRICTED macro defined as 0x0. Signed-off-by: Yury Khrustalev <redacted> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> --- include/uapi/asm-generic/mman-common.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 1ea2c4c33b86..ef1c27fa3c57 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h@@ -85,6 +85,7 @@ /* compatibility flags */ #define MAP_FILE 0 +#define PKEY_UNRESTRICTED 0x0 #define PKEY_DISABLE_ACCESS 0x1 #define PKEY_DISABLE_WRITE 0x2 #define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\
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2.39.5