diff mbox series

[bpf-next,03/11] tools, bpf: fix bpftool build with !CONFIG_BPF_EVENTS

Message ID 20220414223704.341028-4-alobakin@pm.me (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series bpf: random unpopular userspace fixes (32 bit et al.) | expand

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Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 14 this patch: 14
netdev/cc_maintainers success CCed 14 of 14 maintainers
netdev/build_clang success Errors and warnings before: 11 this patch: 11
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 14 this patch: 14
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 7 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-1 success Logs for Kernel LATEST on ubuntu-latest + selftests
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Kernel LATEST on z15 + selftests

Commit Message

Alexander Lobakin April 14, 2022, 10:45 p.m. UTC 
Fix the following error when building bpftool:

  CLANG   profiler.bpf.o
  CLANG   pid_iter.bpf.o
skeleton/profiler.bpf.c:18:21: error: invalid application of 'sizeof' to an incomplete type 'struct bpf_perf_event_value'
        __uint(value_size, sizeof(struct bpf_perf_event_value));
                           ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:13:39: note: expanded from macro '__uint'
                                      ^~~
tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helper_defs.h:7:8: note: forward declaration of 'struct bpf_perf_event_value'
struct bpf_perf_event_value;
       ^

struct bpf_perf_event_value is being used in the kernel only when
CONFIG_BPF_EVENTS is enabled, so it misses a BTF entry then.
Emit the type unconditionally to fix the problem.

Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
---
 kernel/bpf/syscall.c | 1 +
 1 file changed, 1 insertion(+)

--
2.35.2

Comments

Song Liu April 15, 2022, 11:34 p.m. UTC | #1 
On Thu, Apr 14, 2022 at 3:45 PM Alexander Lobakin <alobakin@pm.me> wrote:
>
> Fix the following error when building bpftool:
>
>   CLANG   profiler.bpf.o
>   CLANG   pid_iter.bpf.o
> skeleton/profiler.bpf.c:18:21: error: invalid application of 'sizeof' to an incomplete type 'struct bpf_perf_event_value'
>         __uint(value_size, sizeof(struct bpf_perf_event_value));
>                            ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:13:39: note: expanded from macro '__uint'
>                                       ^~~
> tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helper_defs.h:7:8: note: forward declaration of 'struct bpf_perf_event_value'
> struct bpf_perf_event_value;
>        ^
>
> struct bpf_perf_event_value is being used in the kernel only when
> CONFIG_BPF_EVENTS is enabled, so it misses a BTF entry then.
> Emit the type unconditionally to fix the problem.
>
> Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
> Signed-off-by: Alexander Lobakin <alobakin@pm.me>

Acked-by: Song Liu <songliubraving@fb.com>

> ---
>  kernel/bpf/syscall.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 34fdf27d14cf..dd8284a60a8e 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -4286,6 +4286,7 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr)
>                 goto out;
>         case BPF_PROG_TYPE_PERF_EVENT:
>         case BPF_PROG_TYPE_TRACEPOINT:
> +               BTF_TYPE_EMIT(struct bpf_perf_event_value);
>                 if (attr->link_create.attach_type != BPF_PERF_EVENT) {
>                         ret = -EINVAL;
>                         goto out;
> --
> 2.35.2
>
>
Andrii Nakryiko April 20, 2022, 5:12 p.m. UTC | #2 
On Thu, Apr 14, 2022 at 3:45 PM Alexander Lobakin <alobakin@pm.me> wrote:
>
> Fix the following error when building bpftool:
>
>   CLANG   profiler.bpf.o
>   CLANG   pid_iter.bpf.o
> skeleton/profiler.bpf.c:18:21: error: invalid application of 'sizeof' to an incomplete type 'struct bpf_perf_event_value'
>         __uint(value_size, sizeof(struct bpf_perf_event_value));
>                            ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helpers.h:13:39: note: expanded from macro '__uint'
>                                       ^~~
> tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_helper_defs.h:7:8: note: forward declaration of 'struct bpf_perf_event_value'
> struct bpf_perf_event_value;
>        ^
>
> struct bpf_perf_event_value is being used in the kernel only when
> CONFIG_BPF_EVENTS is enabled, so it misses a BTF entry then.
> Emit the type unconditionally to fix the problem.
>
> Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
> Signed-off-by: Alexander Lobakin <alobakin@pm.me>
> ---
>  kernel/bpf/syscall.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 34fdf27d14cf..dd8284a60a8e 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -4286,6 +4286,7 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr)
>                 goto out;
>         case BPF_PROG_TYPE_PERF_EVENT:
>         case BPF_PROG_TYPE_TRACEPOINT:
> +               BTF_TYPE_EMIT(struct bpf_perf_event_value);

same as for previous two patches, if there are types that bpftool
expects and might not be in vmlinux.h due to different kernel
configurations, it's cleaner to just define their minimal local
definitions with __attribute__((preserve_access_index))

>                 if (attr->link_create.attach_type != BPF_PERF_EVENT) {
>                         ret = -EINVAL;
>                         goto out;
> --
> 2.35.2
>
>
diff mbox series

Patch

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 34fdf27d14cf..dd8284a60a8e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4286,6 +4286,7 @@  static int link_create(union bpf_attr *attr, bpfptr_t uattr)
 		goto out;
 	case BPF_PROG_TYPE_PERF_EVENT:
 	case BPF_PROG_TYPE_TRACEPOINT:
+		BTF_TYPE_EMIT(struct bpf_perf_event_value);
 		if (attr->link_create.attach_type != BPF_PERF_EVENT) {
 			ret = -EINVAL;
 			goto out;