[PATCH bpf-next v2 1/4] bpf: export bpf_map_inc_not_zero
From: Stanislav Fomichev <hidden>
Date: 2019-08-09 16:10:44
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Rename existing bpf_map_inc_not_zero to __bpf_map_inc_not_zero to indicate that it's caller's responsibility to do proper locking. Create and export bpf_map_inc_not_zero wrapper that properly locks map_idr_lock. Will be used in the next commit to hold a map while cloning a socket. Cc: Martin KaFai Lau <redacted> Cc: Yonghong Song <redacted> Signed-off-by: Stanislav Fomichev <redacted> --- include/linux/bpf.h | 2 ++ kernel/bpf/syscall.c | 16 +++++++++++++--- 2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f9a506147c8a..15ae49862b82 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -647,6 +647,8 @@ void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock); struct bpf_map *bpf_map_get_with_uref(u32 ufd); struct bpf_map *__bpf_map_get(struct fd f); struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref); +struct bpf_map * __must_check bpf_map_inc_not_zero(struct bpf_map *map, + bool uref); void bpf_map_put_with_uref(struct bpf_map *map); void bpf_map_put(struct bpf_map *map); int bpf_map_charge_memlock(struct bpf_map *map, u32 pages);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 5d141f16f6fa..cf8052b016e7 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c@@ -683,8 +683,8 @@ struct bpf_map *bpf_map_get_with_uref(u32 ufd) } /* map_idr_lock should have been held */ -static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, - bool uref) +static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, + bool uref) { int refold;
@@ -704,6 +704,16 @@ static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, return map; } +struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, bool uref) +{ + spin_lock_bh(&map_idr_lock); + map = __bpf_map_inc_not_zero(map, uref); + spin_unlock_bh(&map_idr_lock); + + return map; +} +EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); + int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) { return -ENOTSUPP;
@@ -2177,7 +2187,7 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr) spin_lock_bh(&map_idr_lock); map = idr_find(&map_idr, id); if (map) - map = bpf_map_inc_not_zero(map, true); + map = __bpf_map_inc_not_zero(map, true); else map = ERR_PTR(-ENOENT); spin_unlock_bh(&map_idr_lock);
--
2.23.0.rc1.153.gdeed80330f-goog