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 --- scripts/include/hash.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 scripts/include/hash.h (limited to 'scripts/include/hash.h') diff --git a/scripts/include/hash.h b/scripts/include/hash.h new file mode 100644 index 000000000..efa904368 --- /dev/null +++ b/scripts/include/hash.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef HASH_H +#define HASH_H + +static inline unsigned int hash_str(const char *s) +{ + /* fnv32 hash */ + unsigned int hash = 2166136261U; + + for (; *s; s++) + hash = (hash ^ *s) * 0x01000193; + return hash; +} + +/* simplified version of functions from include/linux/hash.h */ +#define GOLDEN_RATIO_32 0x61C88647 + +static inline unsigned int hash_32(unsigned int val) +{ + return 0x61C88647 * val; +} + +static inline unsigned int hash_ptr(const void *ptr) +{ + return hash_32((unsigned int)(unsigned long)ptr); +} + +#endif /* HASH_H */ -- cgit v1.3.1