From f71b2f64177a199d5b1d2047e155d45fd98f564a Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Nov 2022 00:39:57 +0530 Subject: bpf: Refactor map->off_arr handling Refactor map->off_arr handling into generic functions that can work on their own without hardcoding map specific code. The btf_fields_offs structure is now returned from btf_parse_field_offs, which can be reused later for types in program BTF. All functions like copy_map_value, zero_map_value call generic underlying functions so that they can also be reused later for copying to values allocated in programs which encode specific fields. Later, some helper functions will also require access to this btf_field_offs structure to be able to skip over special fields at runtime. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20221103191013.1236066-9-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/syscall.c | 73 +++++++--------------------------------------------- 1 file changed, 9 insertions(+), 64 deletions(-) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 53d6dc5cf0e2..85532d301124 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -943,66 +943,6 @@ int map_check_no_btf(const struct bpf_map *map, return -ENOTSUPP; } -static int map_field_offs_cmp(const void *_a, const void *_b, const void *priv) -{ - const u32 a = *(const u32 *)_a; - const u32 b = *(const u32 *)_b; - - if (a < b) - return -1; - else if (a > b) - return 1; - return 0; -} - -static void map_field_offs_swap(void *_a, void *_b, int size, const void *priv) -{ - struct bpf_map *map = (struct bpf_map *)priv; - u32 *off_base = map->field_offs->field_off; - u32 *a = _a, *b = _b; - u8 *sz_a, *sz_b; - - sz_a = map->field_offs->field_sz + (a - off_base); - sz_b = map->field_offs->field_sz + (b - off_base); - - swap(*a, *b); - swap(*sz_a, *sz_b); -} - -static int bpf_map_alloc_off_arr(struct bpf_map *map) -{ - bool has_fields = !IS_ERR_OR_NULL(map->record); - struct btf_field_offs *fo; - struct btf_record *rec; - u32 i, *off; - u8 *sz; - - if (!has_fields) { - map->field_offs = NULL; - return 0; - } - - fo = kzalloc(sizeof(*map->field_offs), GFP_KERNEL | __GFP_NOWARN); - if (!fo) - return -ENOMEM; - map->field_offs = fo; - - rec = map->record; - off = fo->field_off; - sz = fo->field_sz; - for (i = 0; i < rec->cnt; i++) { - *off++ = rec->fields[i].offset; - *sz++ = btf_field_type_size(rec->fields[i].type); - } - fo->cnt = rec->cnt; - - if (fo->cnt == 1) - return 0; - sort_r(fo->field_off, fo->cnt, sizeof(fo->field_off[0]), - map_field_offs_cmp, map_field_offs_swap, map); - return 0; -} - static int map_check_btf(struct bpf_map *map, const struct btf *btf, u32 btf_key_id, u32 btf_value_id) { @@ -1097,6 +1037,7 @@ free_map_tab: static int map_create(union bpf_attr *attr) { int numa_node = bpf_map_attr_numa_node(attr); + struct btf_field_offs *foffs; struct bpf_map *map; int f_flags; int err; @@ -1176,13 +1117,17 @@ static int map_create(union bpf_attr *attr) attr->btf_vmlinux_value_type_id; } - err = bpf_map_alloc_off_arr(map); - if (err) + + foffs = btf_parse_field_offs(map->record); + if (IS_ERR(foffs)) { + err = PTR_ERR(foffs); goto free_map; + } + map->field_offs = foffs; err = security_bpf_map_alloc(map); if (err) - goto free_map_off_arr; + goto free_map_field_offs; err = bpf_map_alloc_id(map); if (err) @@ -1206,7 +1151,7 @@ static int map_create(union bpf_attr *attr) free_map_sec: security_bpf_map_free(map); -free_map_off_arr: +free_map_field_offs: kfree(map->field_offs); free_map: btf_put(map->btf); -- cgit v1.2.3