From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- tools/perf/perf-read-vdso.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 tools/perf/perf-read-vdso.c (limited to 'tools/perf/perf-read-vdso.c') diff --git a/tools/perf/perf-read-vdso.c b/tools/perf/perf-read-vdso.c new file mode 100644 index 000000000..aaa5210ea --- /dev/null +++ b/tools/perf/perf-read-vdso.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +#define VDSO__MAP_NAME "[vdso]" + +/* + * Include definition of find_map() also used in util/vdso.c for + * building perf. + */ +#include "util/find-map.c" + +int main(void) +{ + void *start, *end; + size_t size, written; + + if (find_map(&start, &end, VDSO__MAP_NAME)) + return 1; + + size = end - start; + + while (size) { + written = fwrite(start, 1, size, stdout); + if (!written) + return 1; + start += written; + size -= written; + } + + if (fflush(stdout)) + return 1; + + return 0; +} -- cgit v1.3.1