Memory protection keys (pkeys) uapi previously used two macros: - 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. --- Applies to 42f7652d3eb5 (tag: v6.12-rc4). For context, this change will also allow for more consistent update of the Glibc manual [1] which in turn will help with introducing memory protection keys on AArch64 targets [2]. [1] https://inbox.sourceware.org/libc-alpha/20241022073837.151355-1-yury.khrustalev@xxxxxxx/ [2] https://inbox.sourceware.org/libc-alpha/20241011153614.3189334-1-yury.khrustalev@xxxxxxx/ Is this patch OK? Kind regards, Yury --- 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 6ce1f1ceb432..ea40e27e6dea 100644 --- a/include/uapi/asm-generic/mman-common.h +++ b/include/uapi/asm-generic/mman-common.h @@ -82,6 +82,7 @@ /* 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 |\ -- 2.39.5
