struct bpf_struct_ops's cfi_stubs field is used as a readonly pointer but has type void *. Change its type to void const * to allow it to point to readonly global memory. Change the void ** casts of cfi_stubs to void * const * accordingly.
Signed-off-by: Caleb Sander Mateos <[email protected]> --- include/linux/bpf.h | 2 +- kernel/bpf/bpf_struct_ops.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 4e7d72dfbcd4..d74189ea1066 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1977,11 +1977,11 @@ struct bpf_struct_ops { void *kdata, const void *udata); int (*reg)(void *kdata, struct bpf_link *link); void (*unreg)(void *kdata, struct bpf_link *link); int (*update)(void *kdata, void *old_kdata, struct bpf_link *link); int (*validate)(void *kdata); - void *cfi_stubs; + void const *cfi_stubs; struct module *owner; const char *name; struct btf_func_model func_models[BPF_STRUCT_OPS_MAX_NR_MEMBERS]; }; diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index c43346cb3d76..42cfc3e0bc68 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -321,11 +321,11 @@ static bool is_module_member(const struct btf *btf, u32 id) return !strcmp(btf_name_by_offset(btf, t->name_off), "module"); } int bpf_struct_ops_supported(const struct bpf_struct_ops *st_ops, u32 moff) { - void *func_ptr = *(void **)(st_ops->cfi_stubs + moff); + void *func_ptr = *(void * const *)(st_ops->cfi_stubs + moff); return func_ptr ? 0 : -ENOTSUPP; } int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, @@ -444,11 +444,11 @@ int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, mname, st_ops->name); err = -EINVAL; goto errout; } - stub_func_addr = *(void **)(st_ops->cfi_stubs + moff); + stub_func_addr = *(void * const *)(st_ops->cfi_stubs + moff); err = prepare_arg_info(btf, st_ops->name, mname, func_proto, stub_func_addr, arg_info + i); if (err) goto errout; @@ -833,11 +833,11 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, *pksym++ = ksym; trampoline_start = image_off; err = bpf_struct_ops_prepare_trampoline(tlinks, link, &st_ops->func_models[i], - *(void **)(st_ops->cfi_stubs + moff), + *(void * const *)(st_ops->cfi_stubs + moff), &image, &image_off, st_map->image_pages_cnt < MAX_TRAMP_IMAGE_PAGES); if (err) goto reset_unlock; -- 2.45.2
