From: Joe Burton <jevburton@xxxxxxxxxx>
The macros BPF_TRACE_MAP_{K,KV} provide a convenient way to invoke
tracing programs. Maps will register themselves with a late_initcall()
then use these macros to invoke tracing programs.
Signed-off-by: Joe Burton <jevburton@xxxxxxxxxx>
---
include/linux/bpf.h | 13 +++++++++++++
kernel/bpf/map_trace.c | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 6f7aeeedca07..73f4524c1c29 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1532,6 +1532,16 @@ struct bpf_map_trace_progs {
struct mutex mutex; /* protects writes to progs, length */
};
+struct bpf_map_trace_ctx__update_elem {
+ __bpf_md_ptr(void *, key);
+ __bpf_md_ptr(void *, value);
+ u64 flags;
+};
+
+struct bpf_map_trace_ctx__delete_elem {
+ __bpf_md_ptr(void *, key);
+};
+
struct bpf_map_trace_reg {
const char *target;
enum bpf_map_trace_type trace_type;
@@ -1560,6 +1570,9 @@ int bpf_map_trace_reg_target(const struct bpf_map_trace_reg *reg_info);
int bpf_map_trace_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
struct bpf_prog *prog);
int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_prog *prog);
+void bpf_trace_map_update_elem(struct bpf_map *map, void *key, void *value,
+ u64 flags);
+void bpf_trace_map_delete_elem(struct bpf_map *map, void *key);
int bpf_iter_new_fd(struct bpf_link *link);
bool bpf_link_is_iter(struct bpf_link *link);
struct bpf_prog *bpf_iter_get_info(struct bpf_iter_meta *meta, bool in_stop);
diff --git a/kernel/bpf/map_trace.c b/kernel/bpf/map_trace.c
index ed0cbc941522..77a55f8cd119 100644
--- a/kernel/bpf/map_trace.c
+++ b/kernel/bpf/map_trace.c
@@ -295,3 +295,43 @@ int bpf_map_trace_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
return err;
}
+static void bpf_map_trace_run_progs(struct bpf_map *map,
+ enum bpf_map_trace_type trace_type,
+ void *ctx)
+{
+ struct bpf_map_trace_prog *prog;
+
+ if (!map->trace_progs)
+ return;
+
+ rcu_read_lock();
+ migrate_disable();
+ list_for_each_entry_rcu(prog,
+ &map->trace_progs->progs[trace_type].list,
+ list) {
+ bpf_prog_run(prog->prog, ctx); /* return code is ignored */
+ }
+ migrate_enable();
+ rcu_read_unlock();
+}
+
+void bpf_trace_map_update_elem(struct bpf_map *map,
+ void *key, void *value, u64 flags)
+{
+ struct bpf_map_trace_ctx__update_elem ctx;
+
+ ctx.key = key;
+ ctx.value = value;
+ ctx.flags = flags;
+ bpf_map_trace_run_progs(map, BPF_MAP_TRACE_UPDATE_ELEM, &ctx);
+}
+
+void bpf_trace_map_delete_elem(struct bpf_map *map,
+ void *key)
+{
+ struct bpf_map_trace_ctx__delete_elem ctx;
+
+ ctx.key = key;
+ bpf_map_trace_run_progs(map, BPF_MAP_TRACE_DELETE_ELEM, &ctx);
+}
+
--
2.33.0.685.g46640cef36-goog
