From c22ef5684b64a3a1ac08db06a6f327f2695fd377 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Tue, 18 Apr 2023 08:42:28 +0200 Subject: [PATCH] x86/alternatives: Do not use integer constant suffixes in inline asm The usage of the BIT() macro in inline asm code was introduced in 6.3 by the commit in the Fixes tag. However, this macro uses "1UL" for integer constant suffixes in its shift operation, while gas before 2.28 does not support the "L" suffix after a number, and gas before 2.27 does not support the "U" suffix, resulting in build errors such as the following with such versions: ./arch/x86/include/asm/uaccess_64.h:124: Error: found 'L', expected: ')' ./arch/x86/include/asm/uaccess_64.h:124: Error: junk at end of line, first unrecognized character is `L' However, the currently minimal binutils version the kernel supports is 2.25. There's a single use of this macro here, revert to (1 << 0) that works with such older binutils. As an additional info, the binutils PRs which add support for those suffixes are: https://sourceware.org/bugzilla/show_bug.cgi?id=19910 https://sourceware.org/bugzilla/show_bug.cgi?id=20732 [ bp: Massage and extend commit message. ] Fixes: 5d1dd961e743 ("x86/alternatives: Add alt_instr.flags") Signed-off-by: Willy Tarreau Signed-off-by: Borislav Petkov (AMD) Tested-by: Jingbo Xu Link: https://lore.kernel.org/lkml/a9aae568-3046-306c-bd71-92c1fc8eeddc@linux.alibaba.com/ --- arch/x86/include/asm/alternative.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index e2975a32d443..d7da28fada87 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -8,7 +8,7 @@ #define ALT_FLAGS_SHIFT 16 -#define ALT_FLAG_NOT BIT(0) +#define ALT_FLAG_NOT (1 << 0) #define ALT_NOT(feature) ((ALT_FLAG_NOT << ALT_FLAGS_SHIFT) | (feature)) #ifndef __ASSEMBLY__