From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- scripts/check-function-names.sh | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100755 scripts/check-function-names.sh (limited to 'scripts/check-function-names.sh') diff --git a/scripts/check-function-names.sh b/scripts/check-function-names.sh new file mode 100755 index 000000000..08071133e --- /dev/null +++ b/scripts/check-function-names.sh @@ -0,0 +1,25 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# Certain function names are disallowed due to section name ambiguities +# introduced by -ffunction-sections. +# +# See the comment above TEXT_MAIN in include/asm-generic/vmlinux.lds.h. + +objfile="$1" + +if [ ! -f "$objfile" ]; then + echo "usage: $0 " >&2 + exit 1 +fi + +bad_symbols=$(${NM:-nm} "$objfile" | awk '$2 ~ /^[TtWw]$/ {print $3}' | grep -E '^(startup|exit|split|unlikely|hot|unknown)(\.|$)') + +if [ -n "$bad_symbols" ]; then + echo "$bad_symbols" | while read -r sym; do + echo "$objfile: error: $sym() function name creates ambiguity with -ffunction-sections" >&2 + done + exit 1 +fi + +exit 0 -- cgit v1.3.1