From: Hou Tao <houtao1@xxxxxxxxxx>
Introduce map flag BPF_F_DYNPTR_IN_KEY to support dynptr in map key. Add
the corresponding helper bpf_map_has_dynptr_key() to check whether or
not the dynptr-key is supported.
For map with dynptr key support, it needs to use map_extra to specify
the maximum length of these dynptrs. The implementation of the map will
check whether map_extra is smaller than the limitation imposed by memory
allocation during map creation. It may also use map_extra to optimizate
the memory allocation for dynptr.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
include/linux/bpf.h | 5 +++++
include/uapi/linux/bpf.h | 3 +++
kernel/bpf/syscall.c | 1 +
tools/include/uapi/linux/bpf.h | 3 +++
4 files changed, 12 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 19d8ca8ac960..f61bf427e14e 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -308,6 +308,11 @@ struct bpf_map {
s64 __percpu *elem_count;
};
+static inline bool bpf_map_has_dynptr_key(const struct bpf_map *map)
+{
+ return map->map_flags & BPF_F_DYNPTR_IN_KEY;
+}
+
static inline const char *btf_field_type_name(enum btf_field_type type)
{
switch (type) {
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c6cd7c7aeeee..07f7df308a01 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1409,6 +1409,9 @@ enum {
/* Do not translate kernel bpf_arena pointers to user pointers */
BPF_F_NO_USER_CONV = (1U << 18),
+
+/* Create a map with bpf_dynptr in key */
+ BPF_F_DYNPTR_IN_KEY = (1U << 19),
};
/* Flags for BPF_PROG_QUERY. */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index a8f1808a1ca5..bffd803c5977 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1232,6 +1232,7 @@ static int map_create(union bpf_attr *attr)
if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
attr->map_type != BPF_MAP_TYPE_ARENA &&
+ !(attr->map_flags & BPF_F_DYNPTR_IN_KEY) &&
attr->map_extra != 0)
return -EINVAL;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 1fb3cb2636e6..14f223282bfa 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1409,6 +1409,9 @@ enum {
/* Do not translate kernel bpf_arena pointers to user pointers */
BPF_F_NO_USER_CONV = (1U << 18),
+
+/* Create a map with bpf_dynptr in key */
+ BPF_F_DYNPTR_IN_KEY = (1U << 19),
};
/* Flags for BPF_PROG_QUERY. */
--
2.44.0
