[PATCH 3/6] test: fix race condition in ELF load tests

[Stephen Hemminger]

On Sun, 18 Jan 2026 12:09:10 -0800
Stephen Hemminger <stephen at networkplumber.org> wrote:

> The BPF ELF tests sporadically fail with EINVAL when loading from
> the temporary file. This is a race condition where the BPF loader
> reads the file before the data is fully flushed to disk.
> 
> Add fsync() before close() in create_temp_bpf_file() to ensure the
> BPF object data is visible on the filesystem before attempting to
> load it.
> 
> Also fix two related issues found during review
> - Add missing TEST_ASSERT for mempool creation in test_bpf_elf_tx_load
> - Initialize port variable in test_bpf_elf_rx_load to avoid undefined
>   behavior in cleanup path if null_vdev_setup fails early
> 
> Fixes: cf1e03f881af ("test/bpf: add ELF loading")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>  app/test/test_bpf.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/app/test/test_bpf.c b/app/test/test_bpf.c
> index a7d56f8d86..03705075d8 100644
> --- a/app/test/test_bpf.c
> +++ b/app/test/test_bpf.c
> @@ -3311,6 +3311,8 @@ create_temp_bpf_file(const uint8_t *data, size_t size, const char *name)
>  
>  	/* Write BPF object data */
>  	written = write(fd, data, size);
> +	if (written == (ssize_t)size)
> +		fsync(fd);

Agree, I don't think fsync is really needed.
This was a bandaid that changed the timing. The root cause of the
test failures was the overlap of parallel tests, so let me drop this bit.