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| author | Alexei Starovoitov <ast@kernel.org> | 2021-09-29 02:27:18 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-09-29 02:27:19 +0300 |
| commit | 72e1781a5de9e3ee804e24f7ce9a7dd85596fc51 (patch) | |
| tree | 18cfa723e40dbe24928faf0299bf0b90e8df9f43 /include/linux | |
| parent | 09710d82c0a3469eadc32781721ac2336fdf915d (diff) | |
| parent | 102acbacfd9a96d101abd96d1a7a5bf92b7c3e8e (diff) | |
| download | linux-72e1781a5de9e3ee804e24f7ce9a7dd85596fc51.tar.xz | |
Merge branch 'bpf: Build with -Wcast-function-type'
Kees Cook says:
====================
Hi,
In order to keep ahead of cases in the kernel where Control Flow Integrity
(CFI) may trip over function call casts, enabling -Wcast-function-type
is helpful. To that end, replace BPF_CAST_CALL() as it triggers warnings
with this option and is now one of the last places in the kernel in need
of fixing.
Thanks,
-Kees
v2:
- rebase to bpf-next
- add acks
v1: https://lore.kernel.org/lkml/20210927182700.2980499-1-keescook@chromium.org
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bpf.h | 4 | ||||
| -rw-r--r-- | include/linux/filter.h | 7 |
2 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index b6c45a6cbbba..19735d59230a 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -48,6 +48,7 @@ extern struct idr btf_idr; extern spinlock_t btf_idr_lock; extern struct kobject *btf_kobj; +typedef u64 (*bpf_callback_t)(u64, u64, u64, u64, u64); typedef int (*bpf_iter_init_seq_priv_t)(void *private_data, struct bpf_iter_aux_info *aux); typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data); @@ -142,7 +143,8 @@ struct bpf_map_ops { int (*map_set_for_each_callback_args)(struct bpf_verifier_env *env, struct bpf_func_state *caller, struct bpf_func_state *callee); - int (*map_for_each_callback)(struct bpf_map *map, void *callback_fn, + int (*map_for_each_callback)(struct bpf_map *map, + bpf_callback_t callback_fn, void *callback_ctx, u64 flags); /* BTF name and id of struct allocated by map_alloc */ diff --git a/include/linux/filter.h b/include/linux/filter.h index 4a93c12543ee..47f80adbe744 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -360,10 +360,9 @@ static inline bool insn_is_zext(const struct bpf_insn *insn) .off = 0, \ .imm = TGT }) -/* Function call */ +/* Convert function address to BPF immediate */ -#define BPF_CAST_CALL(x) \ - ((u64 (*)(u64, u64, u64, u64, u64))(x)) +#define BPF_CALL_IMM(x) ((void *)(x) - (void *)__bpf_call_base) #define BPF_EMIT_CALL(FUNC) \ ((struct bpf_insn) { \ @@ -371,7 +370,7 @@ static inline bool insn_is_zext(const struct bpf_insn *insn) .dst_reg = 0, \ .src_reg = 0, \ .off = 0, \ - .imm = ((FUNC) - __bpf_call_base) }) + .imm = BPF_CALL_IMM(FUNC) }) /* Raw code statement block */ |