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authorBrenden Blanco <bblanco@plumgrid.com>2016-07-19 12:16:46 -0700
committerDavid S. Miller <davem@davemloft.net>2016-07-19 21:46:31 -0700
commit59d3656d5bf504f771fc44fdbc7a9a8590795f22 (patch)
tree058ce3d24709783658e7454de289500a1f8d7722 /kernel/bpf
parentddbcb79493d96bd0d98987f4f6602f0f96665518 (diff)
downloadlinux-59d3656d5bf504f771fc44fdbc7a9a8590795f22.tar.bz2
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>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/syscall.c12
1 files changed, 9 insertions, 3 deletions
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)
{