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libbpf: Fix btf dump error caused by #75

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libbpf: Fix btf dump error caused by #75

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Pull request for series with
subject: libbpf: Fix btf dump error caused by
version: 2
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492

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Master branch: 08d4dba
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492
version: 2

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Master branch: 80bebeb
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492
version: 2

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Master branch: dda7596
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492
version: 2

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Master branch: 5e214f2
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492
version: 2

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Master branch: c62dd8a
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492
version: 2

Nobody and others added 2 commits February 28, 2022 07:39
adding ci files
bcba888
libbpf: Skip forward declaration when
8dc1c07 
Currently if a forward declaration appears in the BTF before the definition,
the definition is dumped as a conflicting name, eg:

    $ bpftool btf dump file vmlinux format raw | grep "'unix_sock'"
    [81287] FWD 'unix_sock' fwd_kind=struct
    [89336] STRUCT 'unix_sock' size=1024 vlen=14

    $ bpftool btf dump file vmlinux format c | grep "struct unix_sock"
    struct unix_sock;
    struct unix_sock___2 {	<--- conflict, the "___2" is unexpected
		    struct unix_sock___2 *unix_sk;

This causes a "definition not found" compilation error if the dump output
is used as a header file.

Fix it by skipping forward declaration when counting duplicated type names.

Fixes: 351131b ("libbpf: add btf_dump API for BTF-to-C conversion")
Signed-off-by: Xu Kuohai <[email protected]>
Acked-by: Song Liu <[email protected]>
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Master branch: 07609c1
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=617492
version: 2

selftests/bpf: Update btf_dump case for conflicting type names
dbade19 
Update btf_dump case for conflicting names caused by forward declaration.

Signed-off-by: Xu Kuohai <[email protected]>
Acked-by: Song Liu <[email protected]>
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=617492 irrelevant now. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/617492=>bpf-next branch February 28, 2022 15:46
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 26, 2023
bpf: Prevent inlining of bpf_fentry_test7()
12688f9 
With latest clang18, I hit test_progs failures for the following test:
  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are
  ...
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  ...
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used
in the above tests, is inlined by the compiler although it is
marked as noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 27, 2023
bpf: Prevent inlining of bpf_fentry_test7()
b93ab7c 
With latest clang18, I hit test_progs failures for the following test:
  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are
  ...
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  ...
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used
in the above tests, is inlined by the compiler although it is
marked as noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song <[email protected]>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 28, 2023
bpf: Prevent inlining of bpf_fentry_test7()
76d363e 
With latest clang18, I hit test_progs failures for the following test:
  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are
  ...
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  ...
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used
in the above tests, is inlined by the compiler although it is
marked as noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song <[email protected]>
Tested-by: Eduard Zingerman <[email protected]>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 30, 2023
@borkmann
bpf: Prevent inlining of bpf_fentry_test7()
32337c0 
With latest clang18, I hit test_progs failures for the following test:

  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are:

  [...]
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  [...]
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used in
the above tests, is inlined by the compiler although it is marked as
noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Tested-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 30, 2023
bpf: Prevent inlining of bpf_fentry_test7()
395baa5 
With latest clang18, I hit test_progs failures for the following test:
  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are
  ...
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  ...
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used
in the above tests, is inlined by the compiler although it is
marked as noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song <[email protected]>
Tested-by: Eduard Zingerman <[email protected]>
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