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| author | Andrii Nakryiko <andriin@fb.com> | 2020-03-12 17:21:28 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-13 12:49:51 -0700 |
| commit | 98868668367b24487c0b0b3298d7ca98409baf07 (patch) | |
| tree | fd21f9944906d4f3475021869688cbfe25a18db9 /kernel/bpf | |
| parent | 4cd729fa022cb5142e5b65f25589af61c8148cf6 (diff) | |
| download | lwn-98868668367b24487c0b0b3298d7ca98409baf07.tar.gz lwn-98868668367b24487c0b0b3298d7ca98409baf07.zip | |
bpf: Abstract away entire bpf_link clean up procedure
Instead of requiring users to do three steps for cleaning up bpf_link, its
anon_inode file, and unused fd, abstract that away into bpf_link_cleanup()
helper. bpf_link_defunct() is removed, as it shouldn't be needed as an
individual operation anymore.
v1->v2:
- keep bpf_link_cleanup() static for now (Daniel).
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200313002128.2028680-1-andriin@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/syscall.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b2f73ecacced..85567a6ea5f9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2188,9 +2188,17 @@ void bpf_link_init(struct bpf_link *link, const struct bpf_link_ops *ops, link->prog = prog; } -void bpf_link_defunct(struct bpf_link *link) +/* Clean up bpf_link and corresponding anon_inode file and FD. After + * anon_inode is created, bpf_link can't be just kfree()'d due to deferred + * anon_inode's release() call. This helper manages marking bpf_link as + * defunct, releases anon_inode file and puts reserved FD. + */ +static void bpf_link_cleanup(struct bpf_link *link, struct file *link_file, + int link_fd) { link->prog = NULL; + fput(link_file); + put_unused_fd(link_fd); } void bpf_link_inc(struct bpf_link *link) @@ -2383,9 +2391,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog) err = bpf_trampoline_link_prog(prog); if (err) { - bpf_link_defunct(&link->link); - fput(link_file); - put_unused_fd(link_fd); + bpf_link_cleanup(&link->link, link_file, link_fd); goto out_put_prog; } @@ -2498,9 +2504,7 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr) err = bpf_probe_register(link->btp, prog); if (err) { - bpf_link_defunct(&link->link); - fput(link_file); - put_unused_fd(link_fd); + bpf_link_cleanup(&link->link, link_file, link_fd); goto out_put_btp; } |