From 19c02415da2345d0dda2b5c4495bc17cc14b18b5 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 26 Sep 2022 11:47:38 -0700 Subject: bpf: use bpf_prog_pack for bpf_dispatcher Allocate bpf_dispatcher with bpf_prog_pack_alloc so that bpf_dispatcher can share pages with bpf programs. arch_prepare_bpf_dispatcher() is updated to provide a RW buffer as working area for arch code to write to. This also fixes CPA W^X warnning like: CPA refuse W^X violation: 8000000000000163 -> 0000000000000163 range: ... Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20220926184739.3512547-2-song@kernel.org Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 3 ++- include/linux/filter.h | 5 +++++ 2 files changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index edd43edb27d6..9ae155c75014 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -946,6 +946,7 @@ struct bpf_dispatcher { struct bpf_dispatcher_prog progs[BPF_DISPATCHER_MAX]; int num_progs; void *image; + void *rw_image; u32 image_off; struct bpf_ksym ksym; }; @@ -964,7 +965,7 @@ int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampolin struct bpf_trampoline *bpf_trampoline_get(u64 key, struct bpf_attach_target_info *tgt_info); void bpf_trampoline_put(struct bpf_trampoline *tr); -int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs); +int arch_prepare_bpf_dispatcher(void *image, void *buf, s64 *funcs, int num_funcs); #define BPF_DISPATCHER_INIT(_name) { \ .mutex = __MUTEX_INITIALIZER(_name.mutex), \ .func = &_name##_func, \ diff --git a/include/linux/filter.h b/include/linux/filter.h index 98e28126c24b..efc42a6e3aed 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1023,6 +1023,8 @@ extern long bpf_jit_limit_max; typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); +void bpf_jit_fill_hole_with_zero(void *area, unsigned int size); + struct bpf_binary_header * bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, unsigned int alignment, @@ -1035,6 +1037,9 @@ void bpf_jit_free(struct bpf_prog *fp); struct bpf_binary_header * bpf_jit_binary_pack_hdr(const struct bpf_prog *fp); +void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns); +void bpf_prog_pack_free(struct bpf_binary_header *hdr); + static inline bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) { return list_empty(&fp->aux->ksym.lnode) || -- cgit v1.2.3