mbox series

[bpf-next,0/4] fix __retval() being always ignored

Message ID 20230420232317.2181776-1-eddyz87@gmail.com (mailing list archive)
Headers show
Series fix __retval() being always ignored | expand

Message

Eduard Zingerman April 20, 2023, 11:23 p.m. UTC
Florian Westphal found a bug in 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. See [1].

Fix for this bug uncovers two additional bugs:
- During test_verifier tests migration to inline assembly (see [2])
  I missed the fact that some tests require maps to contain mock values;
- Some issue with a new refcounted_kptr test, which causes kernel to
  produce dead lock and refcount saturation warnings when subject to
  libbpf's bpf_test_run_opts().
  
This series fixes the bug in __retval() processing, and address the
issue with test maps not being populated. The issue in refcounted_kptr
is not addressed, __retval tags in those tests are commented out.

I found that the following tests depend on test maps being populated:
- progs/verifier_array_access.c
- verifier/value_ptr_arith.c (planned for migration to inline assembly)

Given the small amount of these tests I decided to opt for simple
non-generic solution (see patch #4).

[1] https://lore.kernel.org/bpf/f4c4aee644425842ee6aa8edf1da68f0a8260e7c.camel@gmail.com/T/
[2] https://lore.kernel.org/bpf/20230325025524.144043-1-eddyz87@gmail.com/

Eduard Zingerman (4):
  selftests/bpf: disable program test run for progs/refcounted_kptr.c
  selftests/bpf: fix __retval() being always ignored
  selftests/bpf: add pre bpf_prog_test_run_opts() callback for
    test_loader
  selftests/bpf: populate map_array_ro map for verifier_array_access
    test

 .../selftests/bpf/prog_tests/verifier.c       | 42 +++++++++++++++++--
 .../selftests/bpf/progs/refcounted_kptr.c     |  8 ++--
 tools/testing/selftests/bpf/test_loader.c     | 10 ++++-
 tools/testing/selftests/bpf/test_progs.h      |  9 ++++
 4 files changed, 61 insertions(+), 8 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org April 21, 2023, 2 a.m. UTC | #1
Hello:

This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Fri, 21 Apr 2023 02:23:13 +0300 you wrote:
> Florian Westphal found a bug in 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. See [1].
> 
> Fix for this bug uncovers two additional bugs:
> - During test_verifier tests migration to inline assembly (see [2])
>   I missed the fact that some tests require maps to contain mock values;
> - Some issue with a new refcounted_kptr test, which causes kernel to
>   produce dead lock and refcount saturation warnings when subject to
>   libbpf's bpf_test_run_opts().
> 
> [...]

Here is the summary with links:
  - [bpf-next,1/4] selftests/bpf: disable program test run for progs/refcounted_kptr.c
    https://git.kernel.org/bpf/bpf-next/c/7c4b96c00043
  - [bpf-next,2/4] selftests/bpf: fix __retval() being always ignored
    https://git.kernel.org/bpf/bpf-next/c/7cdddb99e4a6
  - [bpf-next,3/4] selftests/bpf: add pre bpf_prog_test_run_opts() callback for test_loader
    https://git.kernel.org/bpf/bpf-next/c/5b22f4d1436b
  - [bpf-next,4/4] selftests/bpf: populate map_array_ro map for verifier_array_access test
    https://git.kernel.org/bpf/bpf-next/c/cbb110bc6672

You are awesome, thank you!