diff options
| author | Brenden Blanco <bblanco@plumgrid.com> | 2016-07-19 12:16:46 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-07-19 21:46:31 -0700 |
| commit | 59d3656d5bf504f771fc44fdbc7a9a8590795f22 (patch) | |
| tree | 058ce3d24709783658e7454de289500a1f8d7722 | |
| parent | ddbcb79493d96bd0d98987f4f6602f0f96665518 (diff) | |
bpf: add bpf_prog_add api for bulk prog refcnt
A subsystem may need to store many copies of a bpf program, each
deserving its own reference. Rather than requiring the caller to loop
one by one (with possible mid-loop failure), add a bulk bpf_prog_add
api.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 12 |
2 files changed, 10 insertions, 3 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c13e92b00bf5..75a5ae6bee07 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -224,6 +224,7 @@ void bpf_register_map_type(struct bpf_map_type_list *tl); struct bpf_prog *bpf_prog_get(u32 ufd); struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type); +struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i); struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog); void bpf_prog_put(struct bpf_prog *prog); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 96d938a22050..228f962447a5 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -670,14 +670,20 @@ static struct bpf_prog *____bpf_prog_get(struct fd f) return f.file->private_data; } -struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) +struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i) { - if (atomic_inc_return(&prog->aux->refcnt) > BPF_MAX_REFCNT) { - atomic_dec(&prog->aux->refcnt); + if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) { + atomic_sub(i, &prog->aux->refcnt); return ERR_PTR(-EBUSY); } return prog; } +EXPORT_SYMBOL_GPL(bpf_prog_add); + +struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) +{ + return bpf_prog_add(prog, 1); +} static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type) { |