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/perf/util/perf-hooks.c | 90 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 tools/perf/util/perf-hooks.c (limited to 'tools/perf/util/perf-hooks.c') diff --git a/tools/perf/util/perf-hooks.c b/tools/perf/util/perf-hooks.c new file mode 100644 index 000000000..7a0ab3507 --- /dev/null +++ b/tools/perf/util/perf-hooks.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * perf_hooks.c + * + * Copyright (C) 2016 Wang Nan + * Copyright (C) 2016 Huawei Inc. + */ + +#include +#include +#include +#include +#include +#include +#include "util/debug.h" +#include "util/perf-hooks.h" + +static sigjmp_buf jmpbuf; +static const struct perf_hook_desc *current_perf_hook; + +void perf_hooks__invoke(const struct perf_hook_desc *desc) +{ + if (!(desc && desc->p_hook_func && *desc->p_hook_func)) + return; + + if (sigsetjmp(jmpbuf, 1)) { + pr_warning("Fatal error (SEGFAULT) in perf hook '%s'\n", + desc->hook_name); + *(current_perf_hook->p_hook_func) = NULL; + } else { + current_perf_hook = desc; + (**desc->p_hook_func)(desc->hook_ctx); + } + current_perf_hook = NULL; +} + +void perf_hooks__recover(void) +{ + if (current_perf_hook) + siglongjmp(jmpbuf, 1); +} + +#define PERF_HOOK(name) \ +perf_hook_func_t __perf_hook_func_##name = NULL; \ +struct perf_hook_desc __perf_hook_desc_##name = \ + {.hook_name = #name, \ + .p_hook_func = &__perf_hook_func_##name, \ + .hook_ctx = NULL}; +#include "perf-hooks-list.h" +#undef PERF_HOOK + +#define PERF_HOOK(name) \ + &__perf_hook_desc_##name, + +static struct perf_hook_desc *perf_hooks[] = { +#include "perf-hooks-list.h" +}; +#undef PERF_HOOK + +int perf_hooks__set_hook(const char *hook_name, + perf_hook_func_t hook_func, + void *hook_ctx) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) { + if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0) + continue; + + if (*(perf_hooks[i]->p_hook_func)) + pr_warning("Overwrite existing hook: %s\n", hook_name); + *(perf_hooks[i]->p_hook_func) = hook_func; + perf_hooks[i]->hook_ctx = hook_ctx; + return 0; + } + return -ENOENT; +} + +perf_hook_func_t perf_hooks__get_hook(const char *hook_name) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(perf_hooks); i++) { + if (strcmp(hook_name, perf_hooks[i]->hook_name) != 0) + continue; + + return *(perf_hooks[i]->p_hook_func); + } + return ERR_PTR(-ENOENT); +} -- cgit v1.3.1