On 17/10/25 00:20, David Faust wrote:
On 10/12/25 21:26, Piyush Raj wrote:
This patch adds new DejaGnu target board for BPF for runtime testing of
BPF programs using the `bpf-vmtest-tool` script in the contrib directory.
The kernel version used for the tests can be specified via KERNEL_VERSION,
for example:
make check-gcc RUNTESTFLAGS="--target_board=bpf bpf-torture.exp
KERNEL_VERSION=6.14"
If not specified, the default kernel version used is 6.15.
It also adds a new torture subdirectory for running torture tests on BPF
programs.
Passed tests covered in bpf.exp and bpf-torture.exp
I noticed that depending on the local vmlinux.h, we may get some extraneous
"excess error" FAILs originating from warnings like with -Wattributes
in vmlinux.h. I think we could also potentially end up with things like
#pragmas that are specific to clang in vmlinux.h or elsewhere, depending
on where those files are coming from.
I didn’t encounter this issue while developing on 6.15, but after
upgrading to 6.16 and regenerating my vmlinux.h, I ran into the issue
you described.
In my case, it was triggered by a single attribute:
/usr/local/include/vmlinux.h:161258:1: warning: 'btf_type_tag' attribute
directive ignored [-Wattributes]
I'm not sure what is the best way to deal with that for this testsuite.
Disabling -Wattributes doesn't seem ideal, but neither does annotating
each individual test #including vmlinux.h to suppress the warning...
Opinions/thoughts anyone?
(I don't think this should be a blocker, but it would be nice to deal
with it somehow.)
Are the attributes that GCC is warning about actually required by GCC to
compile the program correctly, or are they something that needs to be
implemented in the backend? If it’s the latter, I don’t think ignoring
them for a testcase is ideal.
For btf_type_tag, it seems to be the latter case (see:
https://gcc.gnu.org/pipermail/gcc-patches/2025-January/673841.html)
Should we consider including the testcases for features that haven’t
been implemented yet, but maintain a denylist similar to what BPF CI
does for GCC?
See:
https://github.com/kernel-patches/vmtest/blob/master/ci/vmtest/configs/DENYLIST.test_progs-bpf_gcc
Would this approach be useful?
