RE: [PATCH] ci: display UBSan stack trace

[Marat Khalili <marat.khalili@huawei.com>]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Wednesday 28 January 2026 11:05
> To: dev@dpdk.org
> Cc: scott.k.mitch1@gmail.com; Aaron Conole <aconole@redhat.com>
> Subject: [PATCH] ci: display UBSan stack trace
> 
> When UBSan raises an error, we get really few context.
> 
> Example, on a recently submitted patch:
> 
> RTE>>cksum_fuzz_autotest
> ../lib/net/rte_cksum.h:49:10: runtime error: load of misaligned address
> 	0x0001816c2e81 for type 'const unaligned_uint16_t' (aka 'const
> 	unsigned short'), which requires 2 byte alignment
> 0x0001816c2e81: note: pointer points here
>  00 00 00  00 70 f2 00 00 00 00 00  00 00 00 00 00 00 00 00
>               ^
> 	00 00 00 00 00 00 00 00  00 00 00 00 00
> SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
> 	../lib/net/rte_cksum.h:49:10 in
> 
> Ask for the full stack.
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>  .ci/linux-build.sh | 22 ++++++++++++++--------
>  1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/.ci/linux-build.sh b/.ci/linux-build.sh
> index 084d9642fc..091d239fae 100755
> --- a/.ci/linux-build.sh
> +++ b/.ci/linux-build.sh
> @@ -7,7 +7,11 @@ if [ -z "${DEF_LIB:-}" ]; then
>  fi
> 
>  # Builds are run as root in containers, no need for sudo
> -[ "$(id -u)" != '0' ] || alias sudo=
> +if [ "$(id -u)" = '0' ]; then
> +    run_as_root=""
> +else
> +    run_as_root="sudo -E"

Just out of general principles, can we have --preserve-env=UBSAN_OPTIONS (or
necessary list) instead?

And/or, do we need to preserve environment for all commands below?

> +fi
> 
>  install_libabigail() {
>      version=$1
> @@ -28,15 +32,15 @@ configure_coredump() {
>      # No point in configuring coredump without gdb
>      which gdb >/dev/null || return 0
>      ulimit -c unlimited
> -    sudo sysctl -w kernel.core_pattern=/tmp/dpdk-core.%e.%p
> +    $run_as_root sysctl -w kernel.core_pattern=/tmp/dpdk-core.%e.%p
>  }
> 
>  catch_coredump() {
>      ls /tmp/dpdk-core.*.* 2>/dev/null || return 0
>      for core in /tmp/dpdk-core.*.*; do
> -        binary=$(sudo readelf -n $core |grep $(pwd)/build/ 2>/dev/null |head -n1)
> +        binary=$($run_as_root readelf -n $core |grep $(pwd)/build/ 2>/dev/null |head -n1)
>          [ -x $binary ] || binary=
> -        sudo gdb $binary -c $core \
> +        $run_as_root gdb $binary -c $core \
>              -ex 'info threads' \
>              -ex 'thread apply all bt full' \
>              -ex 'quit'
> @@ -53,9 +57,9 @@ catch_ubsan() {
> 
>  check_traces() {
>      which babeltrace >/dev/null || return 0
> -    for file in $(sudo find $HOME -name metadata); do
> -        ! sudo babeltrace $(dirname $file) >/dev/null 2>&1 || continue
> -        sudo babeltrace $(dirname $file)
> +    for file in $($run_as_root find $HOME -name metadata); do
> +        ! $run_as_root babeltrace $(dirname $file) >/dev/null 2>&1 || continue
> +        $run_as_root babeltrace $(dirname $file)
>      done
>  }
> 
> @@ -136,6 +140,7 @@ fi
> 
>  if [ "$UBSAN" = "true" ]; then
>      sanitizer=${sanitizer:+$sanitizer,}undefined
> +    export UBSAN_OPTIONS=print_stacktrace=1

Won't it replace options meson sets by default? I actually see
print_stacktrace=1 among them, although maybe depends on version and
environment.

Also, do we care only about UBSAN_OPTIONS, or also ASAN_OPTIONS and
LSAN_OPTIONS here?

I will share ones we are using in case you find some of them interesting:

ASAN_OPTIONS=abort_on_error=true:color=never:halt_on_error=true:print_summary=true:strict_string_checks=true:check_initialization_order=true:detect_stack_use_after_return=true:heap_profile=false:print_scariness=true:strict_init_order=true:verify_asan_link_order=false
LSAN_OPTIONS=abort_on_error=true:color=never:halt_on_error=true:print_summary=true:strict_string_checks=true
UBSAN_OPTIONS=abort_on_error=true:color=never:halt_on_error=true:print_summary=true:strict_string_checks=true:print_stacktrace=true:report_error_type=true

(Admittedly some of them might be unnecessary or nonsensical, they depend on
compiler and it's not easy to find documentation.)

>      if [ "$RUN_TESTS" = "true" ]; then
>          # UBSan takes too much memory with -O2
>          buildtype=plain
> @@ -218,7 +223,8 @@ fi
>  if [ "$RUN_TESTS" = "true" ]; then
>      failed=
>      configure_coredump
> -    sudo meson test -C build --suite fast-tests -t 3 --no-stdsplit --print-errorlogs || failed="true"
> +    $run_as_root meson test -C build --suite fast-tests -t 3 --no-stdsplit --print-errorlogs ||
> +        failed="true"
>      catch_coredump
>      catch_ubsan DPDK:fast-tests build/meson-logs/testlog.txt
>      check_traces
> --
> 2.52.0

With or without comments above addressed,

Acked-by: Marat Khalili <marat.khalili@huawei.com>