From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- scripts/check-uapi.sh | 578 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 578 insertions(+) create mode 100755 scripts/check-uapi.sh (limited to 'scripts/check-uapi.sh') diff --git a/scripts/check-uapi.sh b/scripts/check-uapi.sh new file mode 100755 index 000000000..c8beec588 --- /dev/null +++ b/scripts/check-uapi.sh @@ -0,0 +1,578 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only +# Script to check commits for UAPI backwards compatibility + +set -o errexit +set -o pipefail + +print_usage() { + name=$(basename "$0") + cat << EOF +$name - check for UAPI header stability across Git commits + +By default, the script will check to make sure the latest commit (or current +dirty changes) did not introduce ABI changes when compared to HEAD^1. You can +check against additional commit ranges with the -b and -p options. + +The script will not check UAPI headers for architectures other than the one +defined in ARCH. + +Usage: $name [-b BASE_REF] [-p PAST_REF] [-j N] [-l ERROR_LOG] [-i] [-q] [-v] + +Options: + -b BASE_REF Base git reference to use for comparison. If unspecified or empty, + will use any dirty changes in tree to UAPI files. If there are no + dirty changes, HEAD will be used. + -p PAST_REF Compare BASE_REF to PAST_REF (e.g. -p v6.1). If unspecified or empty, + will use BASE_REF^1. Must be an ancestor of BASE_REF. Only headers + that exist on PAST_REF will be checked for compatibility. + -j JOBS Number of checks to run in parallel (default: number of CPU cores). + -l ERROR_LOG Write error log to file (default: no error log is generated). + -i Ignore ambiguous changes that may or may not break UAPI compatibility. + -q Quiet operation. + -v Verbose operation (print more information about each header being checked). + +Environmental args: + ABIDIFF Custom path to abidiff binary + CROSS_COMPILE Toolchain prefix for compiler + CC C compiler (default is "\${CROSS_COMPILE}gcc") + ARCH Target architecture for the UAPI check (default is host arch) + +Exit codes: + $SUCCESS) Success + $FAIL_ABI) ABI difference detected + $FAIL_PREREQ) Prerequisite not met +EOF +} + +readonly SUCCESS=0 +readonly FAIL_ABI=1 +readonly FAIL_PREREQ=2 + +# Print to stderr +eprintf() { + # shellcheck disable=SC2059 + printf "$@" >&2 +} + +# Expand an array with a specific character (similar to Python string.join()) +join() { + local IFS="$1" + shift + printf "%s" "$*" +} + +# Create abidiff suppressions +gen_suppressions() { + # Common enum variant names which we don't want to worry about + # being shifted when new variants are added. + local -a enum_regex=( + ".*_AFTER_LAST$" + ".*_CNT$" + ".*_COUNT$" + ".*_END$" + ".*_LAST$" + ".*_MASK$" + ".*_MAX$" + ".*_MAX_BIT$" + ".*_MAX_BPF_ATTACH_TYPE$" + ".*_MAX_ID$" + ".*_MAX_SHIFT$" + ".*_NBITS$" + ".*_NETDEV_NUMHOOKS$" + ".*_NFT_META_IIFTYPE$" + ".*_NL80211_ATTR$" + ".*_NLDEV_NUM_OPS$" + ".*_NUM$" + ".*_NUM_ELEMS$" + ".*_NUM_IRQS$" + ".*_SIZE$" + ".*_TLSMAX$" + "^MAX_.*" + "^NUM_.*" + ) + + # Common padding field names which can be expanded into + # without worrying about users. + local -a padding_regex=( + ".*end$" + ".*pad$" + ".*pad[0-9]?$" + ".*pad_[0-9]?$" + ".*padding$" + ".*padding[0-9]?$" + ".*padding_[0-9]?$" + ".*res$" + ".*resv$" + ".*resv[0-9]?$" + ".*resv_[0-9]?$" + ".*reserved$" + ".*reserved[0-9]?$" + ".*reserved_[0-9]?$" + ".*rsvd[0-9]?$" + ".*unused$" + ) + + cat << EOF +[suppress_type] + type_kind = enum + changed_enumerators_regexp = $(join , "${enum_regex[@]}") +EOF + + for p in "${padding_regex[@]}"; do + cat << EOF +[suppress_type] + type_kind = struct + has_data_member_inserted_at = offset_of_first_data_member_regexp(${p}) +EOF + done + +if [ "$IGNORE_AMBIGUOUS_CHANGES" = "true" ]; then + cat << EOF +[suppress_type] + type_kind = struct + has_data_member_inserted_at = end + has_size_change = yes +EOF +fi +} + +# Check if git tree is dirty +tree_is_dirty() { + ! git diff --quiet +} + +# Get list of files installed in $ref +get_file_list() { + local -r ref="$1" + local -r tree="$(get_header_tree "$ref")" + + # Print all installed headers, filtering out ones that can't be compiled + find "$tree" -type f -name '*.h' -printf '%P\n' | grep -v -f "$INCOMPAT_LIST" +} + +# Add to the list of incompatible headers +add_to_incompat_list() { + local -r ref="$1" + + # Start with the usr/include/Makefile to get a list of the headers + # that don't compile using this method. + if [ ! -f usr/include/Makefile ]; then + eprintf "error - no usr/include/Makefile present at %s\n" "$ref" + eprintf "Note: usr/include/Makefile was added in the v5.3 kernel release\n" + exit "$FAIL_PREREQ" + fi + { + # shellcheck disable=SC2016 + printf 'all: ; @echo $(no-header-test)\n' + cat usr/include/Makefile + } | SRCARCH="$ARCH" make --always-make -f - | tr " " "\n" \ + | grep -v "asm-generic" >> "$INCOMPAT_LIST" + + # The makefile also skips all asm-generic files, but prints "asm-generic/%" + # which won't work for our grep match. Instead, print something grep will match. + printf "asm-generic/.*\.h\n" >> "$INCOMPAT_LIST" +} + +# Compile the simple test app +do_compile() { + local -r inc_dir="$1" + local -r header="$2" + local -r out="$3" + printf "int f(void) { return 0; }\n" | \ + "$CC" \ + -shared \ + -nostdlib \ + -fPIC \ + -o "$out" \ + -x c \ + -O0 \ + -std=c90 \ + -fno-eliminate-unused-debug-types \ + -g \ + "-I${inc_dir}" \ + "-Iusr/dummy-include" \ + -include "$header" \ + - +} + +# Run make headers_install +run_make_headers_install() { + local -r ref="$1" + local -r install_dir="$(get_header_tree "$ref")" + make -j "$MAX_THREADS" CROSS_COMPILE="${CROSS_COMPILE}" ARCH="$ARCH" INSTALL_HDR_PATH="$install_dir" \ + headers_install > /dev/null +} + +# Install headers for both git refs +install_headers() { + local -r base_ref="$1" + local -r past_ref="$2" + + for ref in "$base_ref" "$past_ref"; do + printf "Installing user-facing UAPI headers from %s... " "${ref:-dirty tree}" + if [ -n "$ref" ]; then + git archive --format=tar --prefix="${ref}-archive/" "$ref" \ + | (cd "$TMP_DIR" && tar xf -) + ( + cd "${TMP_DIR}/${ref}-archive" + run_make_headers_install "$ref" + add_to_incompat_list "$ref" "$INCOMPAT_LIST" + ) + else + run_make_headers_install "$ref" + add_to_incompat_list "$ref" "$INCOMPAT_LIST" + fi + printf "OK\n" + done + sort -u -o "$INCOMPAT_LIST" "$INCOMPAT_LIST" + sed -i -e '/^$/d' "$INCOMPAT_LIST" +} + +# Print the path to the headers_install tree for a given ref +get_header_tree() { + local -r ref="$1" + printf "%s" "${TMP_DIR}/${ref}/usr" +} + +# Check file list for UAPI compatibility +check_uapi_files() { + local -r base_ref="$1" + local -r past_ref="$2" + local -r abi_error_log="$3" + + local passed=0; + local failed=0; + local -a threads=() + set -o errexit + + printf "Checking changes to UAPI headers between %s and %s...\n" "$past_ref" "${base_ref:-dirty tree}" + # Loop over all UAPI headers that were installed by $past_ref (if they only exist on $base_ref, + # there's no way they're broken and no way to compare anyway) + while read -r file; do + if [ "${#threads[@]}" -ge "$MAX_THREADS" ]; then + if wait "${threads[0]}"; then + passed=$((passed + 1)) + else + failed=$((failed + 1)) + fi + threads=("${threads[@]:1}") + fi + + check_individual_file "$base_ref" "$past_ref" "$file" & + threads+=("$!") + done < <(get_file_list "$past_ref") + + for t in "${threads[@]}"; do + if wait "$t"; then + passed=$((passed + 1)) + else + failed=$((failed + 1)) + fi + done + + if [ -n "$abi_error_log" ]; then + printf 'Generated by "%s %s" from git ref %s\n\n' \ + "$0" "$*" "$(git rev-parse HEAD)" > "$abi_error_log" + fi + + while read -r error_file; do + { + cat "$error_file" + printf "\n\n" + } | tee -a "${abi_error_log:-/dev/null}" >&2 + done < <(find "$TMP_DIR" -type f -name '*.error' | sort) + + total="$((passed + failed))" + if [ "$failed" -gt 0 ]; then + eprintf "error - %d/%d UAPI headers compatible with %s appear _not_ to be backwards compatible\n" \ + "$failed" "$total" "$ARCH" + if [ -n "$abi_error_log" ]; then + eprintf "Failure summary saved to %s\n" "$abi_error_log" + fi + else + printf "All %d UAPI headers compatible with %s appear to be backwards compatible\n" \ + "$total" "$ARCH" + fi + + return "$failed" +} + +# Check an individual file for UAPI compatibility +check_individual_file() { + local -r base_ref="$1" + local -r past_ref="$2" + local -r file="$3" + + local -r base_header="$(get_header_tree "$base_ref")/${file}" + local -r past_header="$(get_header_tree "$past_ref")/${file}" + + if [ ! -f "$base_header" ]; then + mkdir -p "$(dirname "$base_header")" + printf "==== UAPI header %s was removed between %s and %s ====" \ + "$file" "$past_ref" "$base_ref" \ + > "${base_header}.error" + return 1 + fi + + compare_abi "$file" "$base_header" "$past_header" "$base_ref" "$past_ref" +} + +# Perform the A/B compilation and compare output ABI +compare_abi() { + local -r file="$1" + local -r base_header="$2" + local -r past_header="$3" + local -r base_ref="$4" + local -r past_ref="$5" + local -r log="${TMP_DIR}/log/${file}.log" + local -r error_log="${TMP_DIR}/log/${file}.error" + + mkdir -p "$(dirname "$log")" + + if ! do_compile "$(get_header_tree "$base_ref")/include" "$base_header" "${base_header}.bin" 2> "$log"; then + { + warn_str=$(printf "==== Could not compile version of UAPI header %s at %s ====\n" \ + "$file" "$base_ref") + printf "%s\n" "$warn_str" + cat "$log" + printf -- "=%.0s" $(seq 0 ${#warn_str}) + } > "$error_log" + return 1 + fi + + if ! do_compile "$(get_header_tree "$past_ref")/include" "$past_header" "${past_header}.bin" 2> "$log"; then + { + warn_str=$(printf "==== Could not compile version of UAPI header %s at %s ====\n" \ + "$file" "$past_ref") + printf "%s\n" "$warn_str" + cat "$log" + printf -- "=%.0s" $(seq 0 ${#warn_str}) + } > "$error_log" + return 1 + fi + + local ret=0 + "$ABIDIFF" --non-reachable-types \ + --suppressions "$SUPPRESSIONS" \ + "${past_header}.bin" "${base_header}.bin" > "$log" || ret="$?" + if [ "$ret" -eq 0 ]; then + if [ "$VERBOSE" = "true" ]; then + printf "No ABI differences detected in %s from %s -> %s\n" \ + "$file" "$past_ref" "$base_ref" + fi + else + # Bits in abidiff's return code can be used to determine the type of error + if [ $((ret & 0x2)) -gt 0 ]; then + eprintf "error - abidiff did not run properly\n" + exit 1 + fi + + if [ "$IGNORE_AMBIGUOUS_CHANGES" = "true" ] && [ "$ret" -eq 4 ]; then + return 0 + fi + + # If the only changes were additions (not modifications to existing APIs), then + # there's no problem. Ignore these diffs. + if grep "Unreachable types summary" "$log" | grep -q "0 removed" && + grep "Unreachable types summary" "$log" | grep -q "0 changed"; then + return 0 + fi + + { + warn_str=$(printf "==== ABI differences detected in %s from %s -> %s ====" \ + "$file" "$past_ref" "$base_ref") + printf "%s\n" "$warn_str" + sed -e '/summary:/d' -e '/changed type/d' -e '/^$/d' -e 's/^/ /g' "$log" + printf -- "=%.0s" $(seq 0 ${#warn_str}) + if cmp "$past_header" "$base_header" > /dev/null 2>&1; then + printf "\n%s did not change between %s and %s...\n" "$file" "$past_ref" "${base_ref:-dirty tree}" + printf "It's possible a change to one of the headers it includes caused this error:\n" + grep '^#include' "$base_header" + printf "\n" + fi + } > "$error_log" + + return 1 + fi +} + +# Check that a minimum software version number is satisfied +min_version_is_satisfied() { + local -r min_version="$1" + local -r version_installed="$2" + + printf "%s\n%s\n" "$min_version" "$version_installed" \ + | sort -Vc > /dev/null 2>&1 +} + +# Make sure we have the tools we need and the arguments make sense +check_deps() { + ABIDIFF="${ABIDIFF:-abidiff}" + CC="${CC:-${CROSS_COMPILE}gcc}" + ARCH="${ARCH:-$(uname -m)}" + if [ "$ARCH" = "x86_64" ]; then + ARCH="x86" + fi + + local -r abidiff_min_version="2.4" + local -r libdw_min_version_if_clang="0.171" + + if ! command -v "$ABIDIFF" > /dev/null 2>&1; then + eprintf "error - abidiff not found!\n" + eprintf "Please install abigail-tools version %s or greater\n" "$abidiff_min_version" + eprintf "See: https://sourceware.org/libabigail/manual/libabigail-overview.html\n" + return 1 + fi + + local -r abidiff_version="$("$ABIDIFF" --version | cut -d ' ' -f 2)" + if ! min_version_is_satisfied "$abidiff_min_version" "$abidiff_version"; then + eprintf "error - abidiff version too old: %s\n" "$abidiff_version" + eprintf "Please install abigail-tools version %s or greater\n" "$abidiff_min_version" + eprintf "See: https://sourceware.org/libabigail/manual/libabigail-overview.html\n" + return 1 + fi + + if ! command -v "$CC" > /dev/null 2>&1; then + eprintf 'error - %s not found\n' "$CC" + return 1 + fi + + if "$CC" --version | grep -q clang; then + local -r libdw_version="$(ldconfig -v 2>/dev/null | grep -v SKIPPED | grep -m 1 -o 'libdw-[0-9]\+.[0-9]\+' | cut -c 7-)" + if ! min_version_is_satisfied "$libdw_min_version_if_clang" "$libdw_version"; then + eprintf "error - libdw version too old for use with clang: %s\n" "$libdw_version" + eprintf "Please install libdw from elfutils version %s or greater\n" "$libdw_min_version_if_clang" + eprintf "See: https://sourceware.org/elfutils/\n" + return 1 + fi + fi + + if [ ! -d "arch/${ARCH}" ]; then + eprintf 'error - ARCH "%s" is not a subdirectory under arch/\n' "$ARCH" + eprintf "Please set ARCH to one of:\n%s\n" "$(find arch -maxdepth 1 -mindepth 1 -type d -printf '%f ' | fmt)" + return 1 + fi + + if ! git rev-parse --is-inside-work-tree > /dev/null 2>&1; then + eprintf "error - this script requires the kernel tree to be initialized with Git\n" + return 1 + fi + + if ! git rev-parse --verify "$past_ref" > /dev/null 2>&1; then + printf 'error - invalid git reference "%s"\n' "$past_ref" + return 1 + fi + + if [ -n "$base_ref" ]; then + if ! git merge-base --is-ancestor "$past_ref" "$base_ref" > /dev/null 2>&1; then + printf 'error - "%s" is not an ancestor of base ref "%s"\n' "$past_ref" "$base_ref" + return 1 + fi + if [ "$(git rev-parse "$base_ref")" = "$(git rev-parse "$past_ref")" ]; then + printf 'error - "%s" and "%s" are the same reference\n' "$past_ref" "$base_ref" + return 1 + fi + fi +} + +run() { + local base_ref="$1" + local past_ref="$2" + local abi_error_log="$3" + shift 3 + + if [ -z "$KERNEL_SRC" ]; then + KERNEL_SRC="$(realpath "$(dirname "$0")"/..)" + fi + + cd "$KERNEL_SRC" + + if [ -z "$base_ref" ] && ! tree_is_dirty; then + base_ref=HEAD + fi + + if [ -z "$past_ref" ]; then + if [ -n "$base_ref" ]; then + past_ref="${base_ref}^1" + else + past_ref=HEAD + fi + fi + + if ! check_deps; then + exit "$FAIL_PREREQ" + fi + + TMP_DIR=$(mktemp -d) + readonly TMP_DIR + trap 'rm -rf "$TMP_DIR"' EXIT + + readonly INCOMPAT_LIST="${TMP_DIR}/incompat_list.txt" + touch "$INCOMPAT_LIST" + + readonly SUPPRESSIONS="${TMP_DIR}/suppressions.txt" + gen_suppressions > "$SUPPRESSIONS" + + # Run make install_headers for both refs + install_headers "$base_ref" "$past_ref" + + # Check for any differences in the installed header trees + if diff -r -q "$(get_header_tree "$base_ref")" "$(get_header_tree "$past_ref")" > /dev/null 2>&1; then + printf "No changes to UAPI headers were applied between %s and %s\n" "$past_ref" "${base_ref:-dirty tree}" + exit "$SUCCESS" + fi + + if ! check_uapi_files "$base_ref" "$past_ref" "$abi_error_log"; then + exit "$FAIL_ABI" + fi +} + +main() { + MAX_THREADS=$(nproc) + VERBOSE="false" + IGNORE_AMBIGUOUS_CHANGES="false" + quiet="false" + local base_ref="" + while getopts "hb:p:j:l:iqv" opt; do + case $opt in + h) + print_usage + exit "$SUCCESS" + ;; + b) + base_ref="$OPTARG" + ;; + p) + past_ref="$OPTARG" + ;; + j) + MAX_THREADS="$OPTARG" + ;; + l) + abi_error_log="$OPTARG" + ;; + i) + IGNORE_AMBIGUOUS_CHANGES="true" + ;; + q) + quiet="true" + VERBOSE="false" + ;; + v) + VERBOSE="true" + quiet="false" + ;; + *) + exit "$FAIL_PREREQ" + esac + done + + if [ "$quiet" = "true" ]; then + exec > /dev/null 2>&1 + fi + + run "$base_ref" "$past_ref" "$abi_error_log" "$@" +} + +main "$@" -- cgit v1.3.1