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| author | Joanne Koong <joannelkoong@gmail.com> | 2023-04-20 09:14:11 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-04-27 10:40:36 +0200 |
| commit | 540ccf96ddbc173474c32e595787d5622253be3d (patch) | |
| tree | c0228d85f2f719c4888102dd0605b7b87fb4369e /kernel/bpf/helpers.c | |
| parent | bpf: Add bpf_dynptr_adjust (diff) | |
| download | linux-540ccf96ddbc173474c32e595787d5622253be3d.tar.xz linux-540ccf96ddbc173474c32e595787d5622253be3d.zip | |
bpf: Add bpf_dynptr_is_null and bpf_dynptr_is_rdonly
bpf_dynptr_is_null returns true if the dynptr is null / invalid
(determined by whether ptr->data is NULL), else false if
the dynptr is a valid dynptr.
bpf_dynptr_is_rdonly returns true if the dynptr is read-only,
else false if the dynptr is read-writable. If the dynptr is
null / invalid, false is returned by default.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20230420071414.570108-3-joannelkoong@gmail.com
Diffstat (limited to 'kernel/bpf/helpers.c')
| -rw-r--r-- | kernel/bpf/helpers.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 42e06d1b492d..a683b3e71a28 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1423,7 +1423,7 @@ static const struct bpf_func_proto bpf_kptr_xchg_proto = { #define DYNPTR_SIZE_MASK 0xFFFFFF #define DYNPTR_RDONLY_BIT BIT(31) -static bool bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr) +static bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr) { return ptr->size & DYNPTR_RDONLY_BIT; } @@ -1570,7 +1570,7 @@ BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u32, offset, v enum bpf_dynptr_type type; int err; - if (!dst->data || bpf_dynptr_is_rdonly(dst)) + if (!dst->data || __bpf_dynptr_is_rdonly(dst)) return -EINVAL; err = bpf_dynptr_check_off_len(dst, offset, len); @@ -1626,7 +1626,7 @@ BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u3 if (err) return 0; - if (bpf_dynptr_is_rdonly(ptr)) + if (__bpf_dynptr_is_rdonly(ptr)) return 0; type = bpf_dynptr_get_type(ptr); @@ -2276,7 +2276,7 @@ __bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset __bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr_kern *ptr, u32 offset, void *buffer, u32 buffer__szk) { - if (!ptr->data || bpf_dynptr_is_rdonly(ptr)) + if (!ptr->data || __bpf_dynptr_is_rdonly(ptr)) return NULL; /* bpf_dynptr_slice_rdwr is the same logic as bpf_dynptr_slice. @@ -2322,6 +2322,19 @@ __bpf_kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 en return 0; } +__bpf_kfunc bool bpf_dynptr_is_null(struct bpf_dynptr_kern *ptr) +{ + return !ptr->data; +} + +__bpf_kfunc bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr) +{ + if (!ptr->data) + return false; + + return __bpf_dynptr_is_rdonly(ptr); +} + __bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj) { return obj; @@ -2395,6 +2408,8 @@ BTF_ID_FLAGS(func, bpf_iter_num_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_num_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_num_destroy, KF_ITER_DESTROY) BTF_ID_FLAGS(func, bpf_dynptr_adjust) +BTF_ID_FLAGS(func, bpf_dynptr_is_null) +BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly) BTF_SET8_END(common_btf_ids) static const struct btf_kfunc_id_set common_kfunc_set = { |