From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- scripts/misc-check | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100755 scripts/misc-check (limited to 'scripts/misc-check') diff --git a/scripts/misc-check b/scripts/misc-check new file mode 100755 index 000000000..40e5a4b01 --- /dev/null +++ b/scripts/misc-check @@ -0,0 +1,76 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-only + +set -e + +# Detect files that are tracked but ignored by git. +check_tracked_ignored_files () { + git -C "${srctree:-.}" ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null | + sed 's/$/: warning: ignored by one of the .gitignore files/' >&2 +} + +# Check for missing #include +# +# The rule for including is very simple: +# Include only when you use EXPORT_SYMBOL(). That's it. +# +# However, some headers include even though they are completely +# unrelated to EXPORT_SYMBOL(). +# +# One example is include/linux/module.h. Please note and +# are orthogonal. should be included by files +# that can be compiled as modules. In other words, should be +# included by EXPORT_SYMBOL consumers. In contrast, should be +# included from EXPORT_SYMBOL providers, which may or may not be modular. +# Hence, include/linux/module.h should *not* include . +# +# Another example is include/linux/linkage.h, which is completely unrelated to +# EXPORT_SYMBOL(). Worse, it is included by most C files, which means, most C +# files end up including , even though only some of them +# actually export symbols. Hence, include/linux/linkage.h should *not* include +# . +# +# Before fixing such headers, we must ensure that C files using EXPORT_SYMBOL() +# include directly, since many C files currently rely on +# being included indirectly (likely, via etc.). +# +# Therefore, this check. +# +# The problem is simple - the warned files use EXPORT_SYMBOL(), but do not +# include . Please add #include to them. +# +# If the included headers are sorted alphabetically, please insert +# in the appropriate position to maintain the sort order. +# For this reason, this script only checks missing , but +# does not automatically fix it. +check_missing_include_linux_export_h () { + + git -C "${srctree:-.}" grep --files-with-matches -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_FOR_MODULES)\(.*\)' \ + -- '*.[ch]' :^tools/ :^include/linux/export.h | + xargs -r git -C "${srctree:-.}" grep --files-without-match '#include[[:space:]]*' | + xargs -r printf "%s: warning: EXPORT_SYMBOL() is used, but #include is missing\n" >&2 +} + +# If you do not use EXPORT_SYMBOL(), please do not include . +# Currently, this is checked for *.c files, but not for *.h files, because some +# *.c files rely on being included indirectly. +check_unnecessary_include_linux_export_h () { + + git -C "${srctree:-.}" grep --files-with-matches '#include[[:space:]]*' \ + -- '*.[c]' :^tools/ | + xargs -r git -C "${srctree:-.}" grep --files-without-match -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_FOR_MODULES)\(.*\)' | + xargs -r printf "%s: warning: EXPORT_SYMBOL() is not used, but #include is present\n" >&2 +} + +case "${KBUILD_EXTRA_WARN}" in +*1*) + check_tracked_ignored_files + ;; +esac + +case "${KBUILD_EXTRA_WARN}" in +*2*) + check_missing_include_linux_export_h + check_unnecessary_include_linux_export_h + ;; +esac -- cgit v1.3.1