From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- tools/include/asm/alternative.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 tools/include/asm/alternative.h (limited to 'tools/include/asm/alternative.h') diff --git a/tools/include/asm/alternative.h b/tools/include/asm/alternative.h new file mode 100644 index 000000000..8e548ac8f --- /dev/null +++ b/tools/include/asm/alternative.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TOOLS_ASM_ALTERNATIVE_ASM_H +#define _TOOLS_ASM_ALTERNATIVE_ASM_H + +#if defined(__s390x__) +#ifdef __ASSEMBLY__ +.macro ALTERNATIVE oldinstr, newinstr, feature + \oldinstr +.endm +#endif +#else + +/* Just disable it so we can build arch/x86/lib/memcpy_64.S for perf bench: */ + +#define ALTERNATIVE # + +#endif + +#endif -- cgit v1.3.1