From 533ab223aa1a036cfe5d6747fa3be92069f80988 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 22 Sep 2024 10:55:42 -0700 Subject: [PATCH] x86: make the masked_user_access_begin() macro use its argument only once This doesn't actually matter for any of the current users, but before merging it mainline, make sure we don't have any surprising semantics. We don't actually want to use an inline function here, because we want to allow - but not require - const pointer arguments, and return them as such. But we already had a local auto-type variable, so let's just use it to avoid any possible double evaluation. Signed-off-by: Linus Torvalds --- arch/x86/include/asm/uaccess_64.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 92859c1ef59c..afce8ee5d7b7 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -59,8 +59,9 @@ static inline unsigned long __untagged_addr_remote(struct mm_struct *mm, * for dense accesses starting at the address. */ #define mask_user_address(x) ((typeof(x))((long)(x)|((long)(x)>>63))) -#define masked_user_access_begin(x) ({ \ - __auto_type __masked_ptr = mask_user_address(x); \ +#define masked_user_access_begin(x) ({ \ + __auto_type __masked_ptr = (x); \ + __masked_ptr = mask_user_address(__masked_ptr); \ __uaccess_begin(); __masked_ptr; }) /* -- 2.49.0