Florian Westphal found a bug in and suggested a fix for test_loader.c processing of __retval tag. Because of this bug the function test_loader.c:do_prog_test_run() never executed and all __retval test tags were ignored. If this bug is fixed a number of test cases from progs/verifier_array_access.c fail with retval not matching the expected value. This test was recently converted to use test_loader.c and inline assembly in [1]. When doing the conversion I missed the important detail of test_verifier.c operation: when it creates fixup_map_array_ro, fixup_map_array_wo and fixup_map_array_small it populates these maps with a dummy record. Disabling the __retval checks for the affected verifier_array_access in this commit to avoid false-postivies in any potential bisects. The issue is addressed in the next patch. I verified that the __retval tags are now respected by changing expected return values for all tests annotated with __retval, and checking that these tests started to fail. [1] https://lore.kernel.org/bpf/20230325025524.144043-1-eddyz87@xxxxxxxxx/ Fixes: 19a8e06f5f91 ("selftests/bpf: Tests execution support for test_loader.c") Reported-by: Florian Westphal <fw@xxxxxxxxx> Link: https://lore.kernel.org/bpf/f4c4aee644425842ee6aa8edf1da68f0a8260e7c.camel@xxxxxxxxx/T/ Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx> --- tools/testing/selftests/bpf/progs/verifier_array_access.c | 4 ++-- tools/testing/selftests/bpf/test_loader.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/verifier_array_access.c b/tools/testing/selftests/bpf/progs/verifier_array_access.c index 95d7ecc12963..fceeeef78721 100644 --- a/tools/testing/selftests/bpf/progs/verifier_array_access.c +++ b/tools/testing/selftests/bpf/progs/verifier_array_access.c @@ -330,7 +330,7 @@ l0_%=: exit; \ SEC("socket") __description("valid read map access into a read-only array 1") -__success __success_unpriv __retval(28) +__success __success_unpriv /* __retval(28) temporarily disable */ __naked void a_read_only_array_1_1(void) { asm volatile (" \ @@ -351,7 +351,7 @@ l0_%=: exit; \ SEC("tc") __description("valid read map access into a read-only array 2") -__success __retval(65507) +__success /* __retval(65507) temporarily disable */ __naked void a_read_only_array_2_1(void) { asm volatile (" \ diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c index 47e9e076bc8f..e2a1bdc5a570 100644 --- a/tools/testing/selftests/bpf/test_loader.c +++ b/tools/testing/selftests/bpf/test_loader.c @@ -587,7 +587,7 @@ void run_subtest(struct test_loader *tester, /* For some reason test_verifier executes programs * with all capabilities restored. Do the same here. */ - if (!restore_capabilities(&caps)) + if (restore_capabilities(&caps)) goto tobj_cleanup; do_prog_test_run(bpf_program__fd(tprog), &retval); -- 2.40.0
