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| author | Daniel Xu <dxu@dxuuu.xyz> | 2024-02-04 22:06:34 +0100 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-02-13 20:05:26 +0100 |
| commit | 5b268d1ebcdceacf992dfda8f9031d56005a274e (patch) | |
| tree | aaadf3248447dd3757ec764eaec06de4025b1afc /kernel/bpf | |
| parent | bpf: Allow compiler to inline most of bpf_local_storage_lookup() (diff) | |
| download | linux-5b268d1ebcdceacf992dfda8f9031d56005a274e.tar.xz linux-5b268d1ebcdceacf992dfda8f9031d56005a274e.zip | |
bpf: Have bpf_rdonly_cast() take a const pointer
Since 20d59ee55172 ("libbpf: add bpf_core_cast() macro"), libbpf is now
exporting a const arg version of bpf_rdonly_cast(). This causes the
following conflicting type error when generating kfunc prototypes from
BTF:
In file included from skeleton/pid_iter.bpf.c:5:
/home/dxu/dev/linux/tools/bpf/bpftool/bootstrap/libbpf/include/bpf/bpf_core_read.h:297:14: error: conflicting types for 'bpf_rdonly_cast'
extern void *bpf_rdonly_cast(const void *obj__ign, __u32 btf_id__k) __ksym __weak;
^
./vmlinux.h:135625:14: note: previous declaration is here
extern void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k) __weak __ksym;
This is b/c the kernel defines bpf_rdonly_cast() with non-const arg.
Since const arg is more permissive and thus backwards compatible, we
change the kernel definition as well to avoid conflicting type errors.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/dfd3823f11ffd2d4c838e961d61ec9ae8a646773.1707080349.git.dxu@dxuuu.xyz
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/helpers.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 4db1c658254c..3503949b4c1b 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2484,9 +2484,9 @@ __bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj) return obj; } -__bpf_kfunc void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k) +__bpf_kfunc void *bpf_rdonly_cast(const void *obj__ign, u32 btf_id__k) { - return obj__ign; + return (void *)obj__ign; } __bpf_kfunc void bpf_rcu_read_lock(void) |