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@xxxxxxxxx>
---
include/linux/bpf.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index a6a0c0025b46..cdc0a8c1b1d1 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);
--
2.34.1
