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bpf: Enforce NULL check on new _OR_NULL return types #247

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wants to merge 4 commits into from
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bpf: Enforce NULL check on new _OR_NULL return types #247

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kernel-patches-bot
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Pull request for series with
subject: bpf: Enforce NULL check on new _OR_NULL return types
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=367027

kernel-patches-bot and others added 4 commits October 19, 2020 12:48
@kernel-patches-bot
adding ci files
07cfcce
@iamkafai @kernel-patches-bot
bpf: Enforce id generation for all may-be-null register type
82f80ac 
The commit af7ec13 ("bpf: Add bpf_skc_to_tcp6_sock() helper")
introduces RET_PTR_TO_BTF_ID_OR_NULL and
the commit eaa6bcb ("bpf: Introduce bpf_per_cpu_ptr()")
introduces RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL.
Note that for RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL, the reg0->type
could become PTR_TO_MEM_OR_NULL which is not covered by
BPF_PROBE_MEM.

The BPF_REG_0 will then hold a _OR_NULL pointer type. This _OR_NULL
pointer type requires the bpf program to explicitly do a NULL check first.
After NULL check, the verifier will mark all registers having
the same reg->id as safe to use.  However, the reg->id
is not set for those new _OR_NULL return types.  One of the ways
that may be wrong is, checking NULL for one btf_id typed pointer will
end up validating all other btf_id typed pointers because
all of them have id == 0.  The later tests will exercise
this path.

To fix it and also avoid similar issue in the future, this patch
moves the id generation logic out of each individual RET type
test in check_helper_call().  Instead, it does one
reg_type_may_be_null() test and then do the id generation
if needed.

This patch also adds a WARN_ON_ONCE in mark_ptr_or_null_reg()
to catch future breakage.

The _OR_NULL pointer usage in the bpf_iter_reg.ctx_arg_info is
fine because it just happens that the existing id generation after
check_ctx_access() has covered it.  It is also using the
reg_type_may_be_null() to decide if id generation is needed or not.

Fixes: af7ec13 ("bpf: Add bpf_skc_to_tcp6_sock() helper")
Fixes: eaa6bcb ("bpf: Introduce bpf_per_cpu_ptr()")
Cc: Yonghong Song <yhs@fb.com>
Cc: Hao Luo <haoluo@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
@iamkafai @kernel-patches-bot
bpf: selftest: Ensure the return value of bpf_skc_to helpers must be …
df106b9 
…checked

This patch tests:

int bpf_cls(struct __sk_buff *skb)
{
	/* REG_6: sk
	 * REG_7: tp
	 * REG_8: req_sk
	 */

	sk = skb->sk;
	if (!sk)
		return 0;

	tp = bpf_skc_to_tcp_sock(sk);
	req_sk = bpf_skc_to_tcp_request_sock(sk);
	if (!req_sk)
		return 0;

	/* !tp has not been tested, so verifier should reject. */
	return *(__u8 *)tp;
}

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
@iamkafai @kernel-patches-bot
bpf: selftest: Ensure the return value of the bpf_per_cpu_ptr() must …
2b74f0d 
…be checked

This patch tests all pointers returned by bpf_per_cpu_ptr() must be
tested for NULL first before it can be accessed.

This patch adds a subtest "null_check", so it moves the ".data..percpu"
existence check to the very beginning and before doing any subtest.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
@kernel-patches-bot
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Author

Master branch: 76702a2
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=367027
version: 1

@kernel-patches-bot
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=367027 irrelevant now. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/367027=>bpf branch October 19, 2020 23:32
borkmann added a commit to cilium/kernel-bpf-ci that referenced this pull request Jun 7, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
fbc46ad 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  kernel-patches#237     tc_opts_after:OK
  kernel-patches#238     tc_opts_append:OK
  kernel-patches#239     tc_opts_basic:OK
  kernel-patches#240     tc_opts_before:OK
  kernel-patches#241     tc_opts_both:OK
  kernel-patches#242     tc_opts_chain_classic:OK
  kernel-patches#243     tc_opts_demixed:OK
  kernel-patches#244     tc_opts_detach:OK
  kernel-patches#245     tc_opts_detach_after:OK
  kernel-patches#246     tc_opts_detach_before:OK
  kernel-patches#247     tc_opts_dev_cleanup:OK
  kernel-patches#248     tc_opts_first:OK
  kernel-patches#249     tc_opts_invalid:OK
  kernel-patches#250     tc_opts_last:OK
  kernel-patches#251     tc_opts_mixed:OK
  kernel-patches#252     tc_opts_prepend:OK
  kernel-patches#253     tc_opts_replace:OK
  kernel-patches#254     tc_opts_revision:OK
  Summary: 18/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jun 7, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
197b593 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #237     tc_opts_after:OK
  #238     tc_opts_append:OK
  #239     tc_opts_basic:OK
  #240     tc_opts_before:OK
  #241     tc_opts_both:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_first:OK
  #249     tc_opts_invalid:OK
  #250     tc_opts_last:OK
  #251     tc_opts_mixed:OK
  #252     tc_opts_prepend:OK
  #253     tc_opts_replace:OK
  #254     tc_opts_revision:OK
  Summary: 18/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
yurinnick pushed a commit to yurinnick/kernel-patches-bpf that referenced this pull request Jun 7, 2023
@borkmann @yurinnick
selftests/bpf: Add mprog API tests for BPF tcx opts
beabaad 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  kernel-patches#237     tc_opts_after:OK
  kernel-patches#238     tc_opts_append:OK
  kernel-patches#239     tc_opts_basic:OK
  kernel-patches#240     tc_opts_before:OK
  kernel-patches#241     tc_opts_both:OK
  kernel-patches#242     tc_opts_chain_classic:OK
  kernel-patches#243     tc_opts_demixed:OK
  kernel-patches#244     tc_opts_detach:OK
  kernel-patches#245     tc_opts_detach_after:OK
  kernel-patches#246     tc_opts_detach_before:OK
  kernel-patches#247     tc_opts_dev_cleanup:OK
  kernel-patches#248     tc_opts_first:OK
  kernel-patches#249     tc_opts_invalid:OK
  kernel-patches#250     tc_opts_last:OK
  kernel-patches#251     tc_opts_mixed:OK
  kernel-patches#252     tc_opts_prepend:OK
  kernel-patches#253     tc_opts_replace:OK
  kernel-patches#254     tc_opts_revision:OK
  Summary: 18/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jun 8, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
87744a7 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #237     tc_opts_after:OK
  #238     tc_opts_append:OK
  #239     tc_opts_basic:OK
  #240     tc_opts_before:OK
  #241     tc_opts_both:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_first:OK
  #249     tc_opts_invalid:OK
  #250     tc_opts_last:OK
  #251     tc_opts_mixed:OK
  #252     tc_opts_prepend:OK
  #253     tc_opts_replace:OK
  #254     tc_opts_revision:OK
  Summary: 18/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
yurinnick pushed a commit to yurinnick/kernel-patches-bpf that referenced this pull request Jun 8, 2023
@borkmann @yurinnick
selftests/bpf: Add mprog API tests for BPF tcx opts
3a26907 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  kernel-patches#237     tc_opts_after:OK
  kernel-patches#238     tc_opts_append:OK
  kernel-patches#239     tc_opts_basic:OK
  kernel-patches#240     tc_opts_before:OK
  kernel-patches#241     tc_opts_both:OK
  kernel-patches#242     tc_opts_chain_classic:OK
  kernel-patches#243     tc_opts_demixed:OK
  kernel-patches#244     tc_opts_detach:OK
  kernel-patches#245     tc_opts_detach_after:OK
  kernel-patches#246     tc_opts_detach_before:OK
  kernel-patches#247     tc_opts_dev_cleanup:OK
  kernel-patches#248     tc_opts_first:OK
  kernel-patches#249     tc_opts_invalid:OK
  kernel-patches#250     tc_opts_last:OK
  kernel-patches#251     tc_opts_mixed:OK
  kernel-patches#252     tc_opts_prepend:OK
  kernel-patches#253     tc_opts_replace:OK
  kernel-patches#254     tc_opts_revision:OK
  Summary: 18/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 7, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
0a3b0c3 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 7, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
05957b3 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 9, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
fca42db 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 10, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
8e89291 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 10, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
e8733c1 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 11, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
cd750e6 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 14, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
e111fb6 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 17, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
b4fa859 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
f1b0163 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
fcc3b16 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
64ca752 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
75dcadf 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
f971d4a 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
8c3f629 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Jul 19, 2023
@borkmann
selftests/bpf: Add mprog API tests for BPF tcx opts
cd13c91 
Add a big batch of test coverage to assert all aspects of the tcx opts
attach, detach and query API:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  #238     tc_opts_after:OK
  #239     tc_opts_append:OK
  #240     tc_opts_basic:OK
  #241     tc_opts_before:OK
  #242     tc_opts_chain_classic:OK
  #243     tc_opts_demixed:OK
  #244     tc_opts_detach:OK
  #245     tc_opts_detach_after:OK
  #246     tc_opts_detach_before:OK
  #247     tc_opts_dev_cleanup:OK
  #248     tc_opts_invalid:OK
  #249     tc_opts_mixed:OK
  #250     tc_opts_prepend:OK
  #251     tc_opts_replace:OK
  #252     tc_opts_revision:OK
  Summary: 15/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20230719140858.13224-8-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Aug 4, 2023
@borkmann
selftests/bpf: Add test for detachment on empty mprog entry
c348227 
Add a detachment test case with miniq present to assert that with and
without the miniq we get the same error.

  # ./test_progs -t tc_opts
  #244     tc_opts_after:OK
  #245     tc_opts_append:OK
  #246     tc_opts_basic:OK
  #247     tc_opts_before:OK
  #248     tc_opts_chain_classic:OK
  #249     tc_opts_delete_empty:OK
  #250     tc_opts_demixed:OK
  #251     tc_opts_detach:OK
  #252     tc_opts_detach_after:OK
  #253     tc_opts_detach_before:OK
  #254     tc_opts_dev_cleanup:OK
  #255     tc_opts_invalid:OK
  #256     tc_opts_mixed:OK
  #257     tc_opts_prepend:OK
  #258     tc_opts_replace:OK
  #259     tc_opts_revision:OK
  Summary: 16/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Aug 4, 2023
@borkmann
selftests/bpf: Add test for detachment on empty mprog entry
21ce6ab 
Add a detachment test case with miniq present to assert that with and
without the miniq we get the same error.

  # ./test_progs -t tc_opts
  #244     tc_opts_after:OK
  #245     tc_opts_append:OK
  #246     tc_opts_basic:OK
  #247     tc_opts_before:OK
  #248     tc_opts_chain_classic:OK
  #249     tc_opts_delete_empty:OK
  #250     tc_opts_demixed:OK
  #251     tc_opts_detach:OK
  #252     tc_opts_detach_after:OK
  #253     tc_opts_detach_before:OK
  #254     tc_opts_dev_cleanup:OK
  #255     tc_opts_invalid:OK
  #256     tc_opts_mixed:OK
  #257     tc_opts_prepend:OK
  #258     tc_opts_replace:OK
  #259     tc_opts_revision:OK
  Summary: 16/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20230804131112.11012-2-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Aug 14, 2023
@borkmann
selftests/bpf: Add various more tcx test cases
dbd1540 
Add several new tcx test cases to improve test coverage. This also includes
a few new tests with ingress instead of clsact qdisc, to cover the fix from
commit dc644b5 ("tcx: Fix splat in ingress_destroy upon tcx_entry_free").

  # ./test_progs -t tc
  [...]
  #234     tc_links_after:OK
  #235     tc_links_append:OK
  #236     tc_links_basic:OK
  #237     tc_links_before:OK
  #238     tc_links_chain_classic:OK
  #239     tc_links_chain_mixed:OK
  #240     tc_links_dev_cleanup:OK
  #241     tc_links_dev_mixed:OK
  #242     tc_links_ingress:OK
  #243     tc_links_invalid:OK
  #244     tc_links_prepend:OK
  #245     tc_links_replace:OK
  #246     tc_links_revision:OK
  #247     tc_opts_after:OK
  #248     tc_opts_append:OK
  #249     tc_opts_basic:OK
  #250     tc_opts_before:OK
  #251     tc_opts_chain_classic:OK
  #252     tc_opts_chain_mixed:OK
  #253     tc_opts_delete_empty:OK
  #254     tc_opts_demixed:OK
  #255     tc_opts_detach:OK
  #256     tc_opts_detach_after:OK
  #257     tc_opts_detach_before:OK
  #258     tc_opts_dev_cleanup:OK
  #259     tc_opts_invalid:OK
  #260     tc_opts_mixed:OK
  #261     tc_opts_prepend:OK
  #262     tc_opts_replace:OK
  #263     tc_opts_revision:OK
  [...]
  Summary: 44/38 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Aug 14, 2023
@borkmann
selftests/bpf: Add various more tcx test cases
4f741af 
Add several new tcx test cases to improve test coverage. This also includes
a few new tests with ingress instead of clsact qdisc, to cover the fix from
commit dc644b5 ("tcx: Fix splat in ingress_destroy upon tcx_entry_free").

  # ./test_progs -t tc
  [...]
  #234     tc_links_after:OK
  #235     tc_links_append:OK
  #236     tc_links_basic:OK
  #237     tc_links_before:OK
  #238     tc_links_chain_classic:OK
  #239     tc_links_chain_mixed:OK
  #240     tc_links_dev_cleanup:OK
  #241     tc_links_dev_mixed:OK
  #242     tc_links_ingress:OK
  #243     tc_links_invalid:OK
  #244     tc_links_prepend:OK
  #245     tc_links_replace:OK
  #246     tc_links_revision:OK
  #247     tc_opts_after:OK
  #248     tc_opts_append:OK
  #249     tc_opts_basic:OK
  #250     tc_opts_before:OK
  #251     tc_opts_chain_classic:OK
  #252     tc_opts_chain_mixed:OK
  #253     tc_opts_delete_empty:OK
  #254     tc_opts_demixed:OK
  #255     tc_opts_detach:OK
  #256     tc_opts_detach_after:OK
  #257     tc_opts_detach_before:OK
  #258     tc_opts_dev_cleanup:OK
  #259     tc_opts_invalid:OK
  #260     tc_opts_mixed:OK
  #261     tc_opts_prepend:OK
  #262     tc_opts_replace:OK
  #263     tc_opts_revision:OK
  [...]
  Summary: 44/38 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
chantra pushed a commit to chantra/kernel-patches-bpf that referenced this pull request Aug 14, 2023
@borkmann @chantra
selftests/bpf: Add various more tcx test cases
0e1fa14 
Add several new tcx test cases to improve test coverage. This also includes
a few new tests with ingress instead of clsact qdisc, to cover the fix from
commit dc644b5 ("tcx: Fix splat in ingress_destroy upon tcx_entry_free").

  # ./test_progs -t tc
  [...]
  kernel-patches#234     tc_links_after:OK
  kernel-patches#235     tc_links_append:OK
  kernel-patches#236     tc_links_basic:OK
  kernel-patches#237     tc_links_before:OK
  kernel-patches#238     tc_links_chain_classic:OK
  kernel-patches#239     tc_links_chain_mixed:OK
  kernel-patches#240     tc_links_dev_cleanup:OK
  kernel-patches#241     tc_links_dev_mixed:OK
  kernel-patches#242     tc_links_ingress:OK
  kernel-patches#243     tc_links_invalid:OK
  kernel-patches#244     tc_links_prepend:OK
  kernel-patches#245     tc_links_replace:OK
  kernel-patches#246     tc_links_revision:OK
  kernel-patches#247     tc_opts_after:OK
  kernel-patches#248     tc_opts_append:OK
  kernel-patches#249     tc_opts_basic:OK
  kernel-patches#250     tc_opts_before:OK
  kernel-patches#251     tc_opts_chain_classic:OK
  kernel-patches#252     tc_opts_chain_mixed:OK
  kernel-patches#253     tc_opts_delete_empty:OK
  kernel-patches#254     tc_opts_demixed:OK
  kernel-patches#255     tc_opts_detach:OK
  kernel-patches#256     tc_opts_detach_after:OK
  kernel-patches#257     tc_opts_detach_before:OK
  kernel-patches#258     tc_opts_dev_cleanup:OK
  kernel-patches#259     tc_opts_invalid:OK
  kernel-patches#260     tc_opts_mixed:OK
  kernel-patches#261     tc_opts_prepend:OK
  kernel-patches#262     tc_opts_replace:OK
  kernel-patches#263     tc_opts_revision:OK
  [...]
  Summary: 44/38 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Aug 15, 2023
@borkmann
selftests/bpf: Add various more tcx test cases
ccd9a8b 
Add several new tcx test cases to improve test coverage. This also includes
a few new tests with ingress instead of clsact qdisc, to cover the fix from
commit dc644b5 ("tcx: Fix splat in ingress_destroy upon tcx_entry_free").

  # ./test_progs -t tc
  [...]
  #234     tc_links_after:OK
  #235     tc_links_append:OK
  #236     tc_links_basic:OK
  #237     tc_links_before:OK
  #238     tc_links_chain_classic:OK
  #239     tc_links_chain_mixed:OK
  #240     tc_links_dev_cleanup:OK
  #241     tc_links_dev_mixed:OK
  #242     tc_links_ingress:OK
  #243     tc_links_invalid:OK
  #244     tc_links_prepend:OK
  #245     tc_links_replace:OK
  #246     tc_links_revision:OK
  #247     tc_opts_after:OK
  #248     tc_opts_append:OK
  #249     tc_opts_basic:OK
  #250     tc_opts_before:OK
  #251     tc_opts_chain_classic:OK
  #252     tc_opts_chain_mixed:OK
  #253     tc_opts_delete_empty:OK
  #254     tc_opts_demixed:OK
  #255     tc_opts_detach:OK
  #256     tc_opts_detach_after:OK
  #257     tc_opts_detach_before:OK
  #258     tc_opts_dev_cleanup:OK
  #259     tc_opts_invalid:OK
  #260     tc_opts_mixed:OK
  #261     tc_opts_prepend:OK
  #262     tc_opts_replace:OK
  #263     tc_opts_revision:OK
  [...]
  Summary: 44/38 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/8699efc284b75ccdc51ddf7062fa2370330dc6c0.1692029283.git.daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Sep 1, 2023
bpf: bpf_sk_storage: Fix invalid wait context lockdep report
35e5ad6 
'./test_progs -t test_local_storage' reported a splat:
[   27.137569] =============================
[   27.138122] [ BUG: Invalid wait context ]
[   27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G           O
[   27.139542] -----------------------------
[   27.140106] test_progs/1729 is trying to lock:
[   27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130
[   27.141834] other info that might help us debug this:
[   27.142437] context-{5:5}
[   27.142856] 2 locks held by test_progs/1729:
[   27.143352]  #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40
[   27.144492]  #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0
[   27.145855] stack backtrace:
[   27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G           O       6.5.0-03980-gd11ae1b16b0a #247
[   27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   27.149127] Call Trace:
[   27.149490]  <TASK>
[   27.149867]  dump_stack_lvl+0x130/0x1d0
[   27.152609]  dump_stack+0x14/0x20
[   27.153131]  __lock_acquire+0x1657/0x2220
[   27.153677]  lock_acquire+0x1b8/0x510
[   27.157908]  local_lock_acquire+0x29/0x130
[   27.159048]  obj_cgroup_charge+0xf4/0x3c0
[   27.160794]  slab_pre_alloc_hook+0x28e/0x2b0
[   27.161931]  __kmem_cache_alloc_node+0x51/0x210
[   27.163557]  __kmalloc+0xaa/0x210
[   27.164593]  bpf_map_kzalloc+0xbc/0x170
[   27.165147]  bpf_selem_alloc+0x130/0x510
[   27.166295]  bpf_local_storage_update+0x5aa/0x8e0
[   27.167042]  bpf_fd_sk_storage_update_elem+0xdb/0x1a0
[   27.169199]  bpf_map_update_value+0x415/0x4f0
[   27.169871]  map_update_elem+0x413/0x550
[   27.170330]  __sys_bpf+0x5e9/0x640
[   27.174065]  __x64_sys_bpf+0x80/0x90
[   27.174568]  do_syscall_64+0x48/0xa0
[   27.175201]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[   27.175932] RIP: 0033:0x7effb40e41ad
[   27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8
[   27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141
[   27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad
[   27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002
[   27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788
[   27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000
[   27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000
[   27.184958]  </TASK>

It complains about acquiring a local_lock while holding a raw_spin_lock.
It means it should not allocate memory while holding a raw_spin_lock
since it is not safe for RT.

raw_spin_lock is needed because bpf_local_storage supports tracing
context. In particular for task local storage, it is easy to
get a "current" task PTR_TO_BTF_ID in tracing bpf prog.
However, task (and cgroup) local storage has already been moved to
bpf mem allocator which can be used after raw_spin_lock.

The splat is for the sk storage. For sk (and inode) storage,
it has not been moved to bpf mem allocator. Using raw_spin_lock or not,
kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context.
However, the local storage helper requires a verifier accepted
sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running
a bpf prog in a kzalloc unsafe context and also able to hold a verifier
accepted sk pointer) could happen.

This patch avoids kzalloc after raw_spin_lock to silent the splat.
There is an existing kzalloc before the raw_spin_lock. At that point,
a kzalloc is very likely required because a lookup has just been done
before. Thus, this patch always does the kzalloc before acquiring
the raw_spin_lock and remove the later kzalloc usage after the
raw_spin_lock. After this change, it will have a charge and then
uncharge during the syscall bpf_map_update_elem() code path.
This patch opts for simplicity and not continue the old
optimization to save one charge and uncharge.

This issue is dated back to the very first commit of bpf_sk_storage
which had been refactored multiple times to create task, inode, and
cgroup storage. This patch uses a Fixes tag with a more recent
commit that should be easier to do backport.

Fixes: b00fa38 ("bpf: Enable non-atomic allocations in local storage")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Sep 4, 2023
bpf: bpf_sk_storage: Fix invalid wait context lockdep report
4260e28 
'./test_progs -t test_local_storage' reported a splat:
[   27.137569] =============================
[   27.138122] [ BUG: Invalid wait context ]
[   27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G           O
[   27.139542] -----------------------------
[   27.140106] test_progs/1729 is trying to lock:
[   27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130
[   27.141834] other info that might help us debug this:
[   27.142437] context-{5:5}
[   27.142856] 2 locks held by test_progs/1729:
[   27.143352]  #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40
[   27.144492]  #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0
[   27.145855] stack backtrace:
[   27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G           O       6.5.0-03980-gd11ae1b16b0a #247
[   27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   27.149127] Call Trace:
[   27.149490]  <TASK>
[   27.149867]  dump_stack_lvl+0x130/0x1d0
[   27.152609]  dump_stack+0x14/0x20
[   27.153131]  __lock_acquire+0x1657/0x2220
[   27.153677]  lock_acquire+0x1b8/0x510
[   27.157908]  local_lock_acquire+0x29/0x130
[   27.159048]  obj_cgroup_charge+0xf4/0x3c0
[   27.160794]  slab_pre_alloc_hook+0x28e/0x2b0
[   27.161931]  __kmem_cache_alloc_node+0x51/0x210
[   27.163557]  __kmalloc+0xaa/0x210
[   27.164593]  bpf_map_kzalloc+0xbc/0x170
[   27.165147]  bpf_selem_alloc+0x130/0x510
[   27.166295]  bpf_local_storage_update+0x5aa/0x8e0
[   27.167042]  bpf_fd_sk_storage_update_elem+0xdb/0x1a0
[   27.169199]  bpf_map_update_value+0x415/0x4f0
[   27.169871]  map_update_elem+0x413/0x550
[   27.170330]  __sys_bpf+0x5e9/0x640
[   27.174065]  __x64_sys_bpf+0x80/0x90
[   27.174568]  do_syscall_64+0x48/0xa0
[   27.175201]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[   27.175932] RIP: 0033:0x7effb40e41ad
[   27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8
[   27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141
[   27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad
[   27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002
[   27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788
[   27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000
[   27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000
[   27.184958]  </TASK>

It complains about acquiring a local_lock while holding a raw_spin_lock.
It means it should not allocate memory while holding a raw_spin_lock
since it is not safe for RT.

raw_spin_lock is needed because bpf_local_storage supports tracing
context. In particular for task local storage, it is easy to
get a "current" task PTR_TO_BTF_ID in tracing bpf prog.
However, task (and cgroup) local storage has already been moved to
bpf mem allocator which can be used after raw_spin_lock.

The splat is for the sk storage. For sk (and inode) storage,
it has not been moved to bpf mem allocator. Using raw_spin_lock or not,
kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context.
However, the local storage helper requires a verifier accepted
sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running
a bpf prog in a kzalloc unsafe context and also able to hold a verifier
accepted sk pointer) could happen.

This patch avoids kzalloc after raw_spin_lock to silent the splat.
There is an existing kzalloc before the raw_spin_lock. At that point,
a kzalloc is very likely required because a lookup has just been done
before. Thus, this patch always does the kzalloc before acquiring
the raw_spin_lock and remove the later kzalloc usage after the
raw_spin_lock. After this change, it will have a charge and then
uncharge during the syscall bpf_map_update_elem() code path.
This patch opts for simplicity and not continue the old
optimization to save one charge and uncharge.

This issue is dated back to the very first commit of bpf_sk_storage
which had been refactored multiple times to create task, inode, and
cgroup storage. This patch uses a Fixes tag with a more recent
commit that should be easier to do backport.

Fixes: b00fa38 ("bpf: Enable non-atomic allocations in local storage")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Sep 6, 2023
bpf: bpf_sk_storage: Fix invalid wait context lockdep report
dba8721 
'./test_progs -t test_local_storage' reported a splat:
[   27.137569] =============================
[   27.138122] [ BUG: Invalid wait context ]
[   27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G           O
[   27.139542] -----------------------------
[   27.140106] test_progs/1729 is trying to lock:
[   27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130
[   27.141834] other info that might help us debug this:
[   27.142437] context-{5:5}
[   27.142856] 2 locks held by test_progs/1729:
[   27.143352]  #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40
[   27.144492]  #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0
[   27.145855] stack backtrace:
[   27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G           O       6.5.0-03980-gd11ae1b16b0a #247
[   27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   27.149127] Call Trace:
[   27.149490]  <TASK>
[   27.149867]  dump_stack_lvl+0x130/0x1d0
[   27.152609]  dump_stack+0x14/0x20
[   27.153131]  __lock_acquire+0x1657/0x2220
[   27.153677]  lock_acquire+0x1b8/0x510
[   27.157908]  local_lock_acquire+0x29/0x130
[   27.159048]  obj_cgroup_charge+0xf4/0x3c0
[   27.160794]  slab_pre_alloc_hook+0x28e/0x2b0
[   27.161931]  __kmem_cache_alloc_node+0x51/0x210
[   27.163557]  __kmalloc+0xaa/0x210
[   27.164593]  bpf_map_kzalloc+0xbc/0x170
[   27.165147]  bpf_selem_alloc+0x130/0x510
[   27.166295]  bpf_local_storage_update+0x5aa/0x8e0
[   27.167042]  bpf_fd_sk_storage_update_elem+0xdb/0x1a0
[   27.169199]  bpf_map_update_value+0x415/0x4f0
[   27.169871]  map_update_elem+0x413/0x550
[   27.170330]  __sys_bpf+0x5e9/0x640
[   27.174065]  __x64_sys_bpf+0x80/0x90
[   27.174568]  do_syscall_64+0x48/0xa0
[   27.175201]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[   27.175932] RIP: 0033:0x7effb40e41ad
[   27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8
[   27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141
[   27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad
[   27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002
[   27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788
[   27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000
[   27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000
[   27.184958]  </TASK>

It complains about acquiring a local_lock while holding a raw_spin_lock.
It means it should not allocate memory while holding a raw_spin_lock
since it is not safe for RT.

raw_spin_lock is needed because bpf_local_storage supports tracing
context. In particular for task local storage, it is easy to
get a "current" task PTR_TO_BTF_ID in tracing bpf prog.
However, task (and cgroup) local storage has already been moved to
bpf mem allocator which can be used after raw_spin_lock.

The splat is for the sk storage. For sk (and inode) storage,
it has not been moved to bpf mem allocator. Using raw_spin_lock or not,
kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context.
However, the local storage helper requires a verifier accepted
sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running
a bpf prog in a kzalloc unsafe context and also able to hold a verifier
accepted sk pointer) could happen.

This patch avoids kzalloc after raw_spin_lock to silent the splat.
There is an existing kzalloc before the raw_spin_lock. At that point,
a kzalloc is very likely required because a lookup has just been done
before. Thus, this patch always does the kzalloc before acquiring
the raw_spin_lock and remove the later kzalloc usage after the
raw_spin_lock. After this change, it will have a charge and then
uncharge during the syscall bpf_map_update_elem() code path.
This patch opts for simplicity and not continue the old
optimization to save one charge and uncharge.

This issue is dated back to the very first commit of bpf_sk_storage
which had been refactored multiple times to create task, inode, and
cgroup storage. This patch uses a Fixes tag with a more recent
commit that should be easier to do backport.

Fixes: b00fa38 ("bpf: Enable non-atomic allocations in local storage")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
kernel-patches-daemon-bpf bot pushed a commit that referenced this pull request Sep 6, 2023
@borkmann
bpf: bpf_sk_storage: Fix invalid wait context lockdep report
a96a44a 
'./test_progs -t test_local_storage' reported a splat:

[   27.137569] =============================
[   27.138122] [ BUG: Invalid wait context ]
[   27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G           O
[   27.139542] -----------------------------
[   27.140106] test_progs/1729 is trying to lock:
[   27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130
[   27.141834] other info that might help us debug this:
[   27.142437] context-{5:5}
[   27.142856] 2 locks held by test_progs/1729:
[   27.143352]  #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40
[   27.144492]  #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0
[   27.145855] stack backtrace:
[   27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G           O       6.5.0-03980-gd11ae1b16b0a #247
[   27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   27.149127] Call Trace:
[   27.149490]  <TASK>
[   27.149867]  dump_stack_lvl+0x130/0x1d0
[   27.152609]  dump_stack+0x14/0x20
[   27.153131]  __lock_acquire+0x1657/0x2220
[   27.153677]  lock_acquire+0x1b8/0x510
[   27.157908]  local_lock_acquire+0x29/0x130
[   27.159048]  obj_cgroup_charge+0xf4/0x3c0
[   27.160794]  slab_pre_alloc_hook+0x28e/0x2b0
[   27.161931]  __kmem_cache_alloc_node+0x51/0x210
[   27.163557]  __kmalloc+0xaa/0x210
[   27.164593]  bpf_map_kzalloc+0xbc/0x170
[   27.165147]  bpf_selem_alloc+0x130/0x510
[   27.166295]  bpf_local_storage_update+0x5aa/0x8e0
[   27.167042]  bpf_fd_sk_storage_update_elem+0xdb/0x1a0
[   27.169199]  bpf_map_update_value+0x415/0x4f0
[   27.169871]  map_update_elem+0x413/0x550
[   27.170330]  __sys_bpf+0x5e9/0x640
[   27.174065]  __x64_sys_bpf+0x80/0x90
[   27.174568]  do_syscall_64+0x48/0xa0
[   27.175201]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[   27.175932] RIP: 0033:0x7effb40e41ad
[   27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8
[   27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141
[   27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad
[   27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002
[   27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788
[   27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000
[   27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000
[   27.184958]  </TASK>

It complains about acquiring a local_lock while holding a raw_spin_lock.
It means it should not allocate memory while holding a raw_spin_lock
since it is not safe for RT.

raw_spin_lock is needed because bpf_local_storage supports tracing
context. In particular for task local storage, it is easy to
get a "current" task PTR_TO_BTF_ID in tracing bpf prog.
However, task (and cgroup) local storage has already been moved to
bpf mem allocator which can be used after raw_spin_lock.

The splat is for the sk storage. For sk (and inode) storage,
it has not been moved to bpf mem allocator. Using raw_spin_lock or not,
kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context.
However, the local storage helper requires a verifier accepted
sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running
a bpf prog in a kzalloc unsafe context and also able to hold a verifier
accepted sk pointer) could happen.

This patch avoids kzalloc after raw_spin_lock to silent the splat.
There is an existing kzalloc before the raw_spin_lock. At that point,
a kzalloc is very likely required because a lookup has just been done
before. Thus, this patch always does the kzalloc before acquiring
the raw_spin_lock and remove the later kzalloc usage after the
raw_spin_lock. After this change, it will have a charge and then
uncharge during the syscall bpf_map_update_elem() code path.
This patch opts for simplicity and not continue the old
optimization to save one charge and uncharge.

This issue is dated back to the very first commit of bpf_sk_storage
which had been refactored multiple times to create task, inode, and
cgroup storage. This patch uses a Fixes tag with a more recent
commit that should be easier to do backport.

Fixes: b00fa38 ("bpf: Enable non-atomic allocations in local storage")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230901231129.578493-2-martin.lau@linux.dev
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