On Thu, Aug 22, 2024 at 06:45:14PM GMT, Sherry Yang wrote:
> Hi All,
>
> We found BPF sefltest fail to build with following error:
>
> 08-09 20:39:59 DBG: |output|: progs/test_global_func10.c:24:1: error: unknown type name '__failure'
> 08-09 20:39:59 DBG: |output|: __failure __msg("invalid indirect access to stack")
> 08-09 20:39:59 DBG: |output|: ^
> 08-09 20:39:59 DBG: |output|: progs/test_global_func10.c:24:17: error: expected parameter declarator
> 08-09 20:39:59 DBG: |output|: __failure __msg("invalid indirect access to stack")
> 08-09 20:39:59 DBG: |output|: ^
> 08-09 20:39:59 DBG: |output|: progs/test_global_func10.c:24:17: error: expected ')'
> 08-09 20:39:59 DBG: |output|: progs/test_global_func10.c:24:16: note: to match this '('
> 08-09 20:39:59 DBG: |output|: __failure __msg("invalid indirect access to stack")
> 08-09 20:39:59 DBG: |output|: ^
> 08-09 20:39:59 DBG: |output|: progs/test_global_func10.c:24:52: error: expected ';' after top level declarator
> 08-09 20:39:59 DBG: |output|: __failure __msg("invalid indirect access to stack")
> 08-09 20:39:59 DBG: |output|: ^
> 08-09 20:39:59 DBG: |output|: ;
> 08-09 20:39:59 DBG: |output|: 4 errors generated.
> 08-09 20:39:59 DBG: |output|: make: *** [Makefile:470: /root/oltf/work/linux-bpf-qa/tools/testing/selftests/bpf/test_global_func10.o] Error 1
> 08-09 20:39:59 DBG: |output|: make: *** Waiting for unfinished jobs....
>
> It happens from the commit e30bc19a9ee8("bpf: Allow reads from uninit
> stack"). We did a further look, '__failure' is defined in
> tools/testing/selftests/bpf/progs/bpf_misc.h, and was 1st introduced
> in commit 537c3f66eac1("selftests/bpf: add generic BPF program
> tester-loader") which is not backported to linux-5.15.y.
>
> So we may need to revert the patch, or fix it.
To fix it I think we just need to drop the use of __failure and __msg in
progs/test_global_func10.c, and update the "struct test_def tests[]"
table in prog_tests/test_global_funcs.c with the new verifier rejection
message.
On the other hand I believe commit 537c3f66eac1("selftests/bpf: add
generic BPF program tester-loader") should be relatively easy to
backport, just picking that commit up and resolving simple conflict in
Makefile should be enough. It will also save a lot of future headaches
like this one.
(Note: the generic test-loader patch will need to backport it to stable
6.1 first before it an be backported to 5.15, as per the stable rule[1])
1: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#procedure-for-submitting-patches-to-the-stable-tree
