diff options
| author | Song Liu <songliubraving@fb.com> | 2022-02-04 21:57:41 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-02-08 05:13:01 +0300 |
| commit | 33c9805860e584b194199cab1a1e81f4e6395408 (patch) | |
| tree | 935536b12d08e7b5c1a1ad132e5b141e72492652 /include | |
| parent | 57631054fae6dcc9c892ae6310b58bbb6f6e5048 (diff) | |
| download | linux-33c9805860e584b194199cab1a1e81f4e6395408.tar.xz | |
bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]
This is the jit binary allocator built on top of bpf_prog_pack.
bpf_prog_pack allocates RO memory, which cannot be used directly by the
JIT engine. Therefore, a temporary rw buffer is allocated for the JIT
engine. Once JIT is done, bpf_jit_binary_pack_finalize is used to copy
the program to the RO memory.
bpf_jit_binary_pack_alloc reserves 16 bytes of extra space for illegal
instructions, which is small than the 128 bytes space reserved by
bpf_jit_binary_alloc. This change is necessary for bpf_jit_binary_hdr
to find the correct header. Also, flag use_bpf_prog_pack is added to
differentiate a program allocated by bpf_jit_binary_pack_alloc.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204185742.271030-9-song@kernel.org
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/linux/filter.h | 21 |
2 files changed, 13 insertions, 9 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ea0d7fd4a410..2fc7e5c5ef41 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -953,6 +953,7 @@ struct bpf_prog_aux { bool sleepable; bool tail_call_reachable; bool xdp_has_frags; + bool use_bpf_prog_pack; struct hlist_node tramp_hlist; /* BTF_KIND_FUNC_PROTO for valid attach_btf_id */ const struct btf_type *attach_func_proto; diff --git a/include/linux/filter.h b/include/linux/filter.h index 5855eb474c62..1cb1af917617 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -890,15 +890,6 @@ static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr) set_memory_x((unsigned long)hdr, hdr->size >> PAGE_SHIFT); } -static inline struct bpf_binary_header * -bpf_jit_binary_hdr(const struct bpf_prog *fp) -{ - unsigned long real_start = (unsigned long)fp->bpf_func; - unsigned long addr = real_start & PAGE_MASK; - - return (void *)addr; -} - int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); static inline int sk_filter(struct sock *sk, struct sk_buff *skb) { @@ -1068,6 +1059,18 @@ void *bpf_jit_alloc_exec(unsigned long size); void bpf_jit_free_exec(void *addr); void bpf_jit_free(struct bpf_prog *fp); +struct bpf_binary_header * +bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **ro_image, + unsigned int alignment, + struct bpf_binary_header **rw_hdr, + u8 **rw_image, + bpf_jit_fill_hole_t bpf_fill_ill_insns); +int bpf_jit_binary_pack_finalize(struct bpf_prog *prog, + struct bpf_binary_header *ro_header, + struct bpf_binary_header *rw_header); +void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header, + struct bpf_binary_header *rw_header); + int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, struct bpf_jit_poke_descriptor *poke); |