diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2022-09-04 22:41:16 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-09-07 11:46:34 -0700 |
| commit | cc48755808c646666436745b35629c3f0d05e165 (patch) | |
| tree | 6d751a095f90870c410008319bd51e5e33dc36a7 /include/linux/bpf.h | |
| parent | 6df4ea1ff0ff70798ff1e7eed79f98ccb7b5b0a2 (diff) | |
bpf: Add zero_map_value to zero map value with special fields
We need this helper to skip over special fields (bpf_spin_lock,
bpf_timer, kptrs) while zeroing a map value. Use the same logic as
copy_map_value but memset instead of memcpy.
Currently, the code zeroing map value memory does not have to deal with
special fields, hence this is a prerequisite for introducing such
support.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220904204145.3089-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux/bpf.h')
| -rw-r--r-- | include/linux/bpf.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 6a73e94821c4..48ae05099f36 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -329,6 +329,25 @@ static inline void copy_map_value_long(struct bpf_map *map, void *dst, void *src __copy_map_value(map, dst, src, true); } +static inline void zero_map_value(struct bpf_map *map, void *dst) +{ + u32 curr_off = 0; + int i; + + if (likely(!map->off_arr)) { + memset(dst, 0, map->value_size); + return; + } + + for (i = 0; i < map->off_arr->cnt; i++) { + u32 next_off = map->off_arr->field_off[i]; + + memset(dst + curr_off, 0, next_off - curr_off); + curr_off += map->off_arr->field_sz[i]; + } + memset(dst + curr_off, 0, map->value_size - curr_off); +} + void copy_map_value_locked(struct bpf_map *map, void *dst, void *src, bool lock_src); void bpf_timer_cancel_and_free(void *timer); |