linux/tools/lib
Anquan Wu bf3f003785 libbpf: Fix the name of a reused map
BPF map name is limited to BPF_OBJ_NAME_LEN.
A map name is defined as being longer than BPF_OBJ_NAME_LEN,
it will be truncated to BPF_OBJ_NAME_LEN when a userspace program
calls libbpf to create the map. A pinned map also generates a path
in the /sys. If the previous program wanted to reuse the map,
it can not get bpf_map by name, because the name of the map is only
partially the same as the name which get from pinned path.

The syscall information below show that map name "process_pinned_map"
is truncated to "process_pinned_".

    bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/process_pinned_map",
    bpf_fd=0, file_flags=0}, 144) = -1 ENOENT (No such file or directory)

    bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4,
    value_size=4,max_entries=1024, map_flags=0, inner_map_fd=0,
    map_name="process_pinned_",map_ifindex=0, btf_fd=3, btf_key_type_id=6,
    btf_value_type_id=10,btf_vmlinux_value_type_id=0}, 72) = 4

This patch check that if the name of pinned map are the same as the
actual name for the first (BPF_OBJ_NAME_LEN - 1),
bpf map still uses the name which is included in bpf object.

Fixes: 26736eb9a4 ("tools: libbpf: allow map reuse")
Signed-off-by: Anquan Wu <leiqi96@hotmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/OSZP286MB1725CEA1C95C5CB8E7CCC53FB8869@OSZP286MB1725.JPNP286.PROD.OUTLOOK.COM
2022-07-13 22:18:37 -07:00
..
api Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
bpf libbpf: Fix the name of a reused map 2022-07-13 22:18:37 -07:00
perf libperf evsel: Open shouldn't leak fd on failure 2022-06-19 10:41:43 -03:00
subcmd libsubcmd: Fix OPTION_GROUP sorting 2022-04-22 12:32:01 +02:00
symbol libsymbols kallsyms: Move hex2u64 out of header 2020-05-05 16:35:32 -03:00
thermal tools/lib/thermal: remove unneeded semicolon 2022-05-19 12:11:52 +02:00
traceevent libtraceevent: Add __rel_loc relative location attribute support 2021-12-06 15:37:22 -05:00
argv_split.c
bitmap.c bitmap: Fix return values to be unsigned 2022-06-03 06:52:58 -07:00
ctype.c
find_bit.c tools: sync tools/bitmap with mother linux 2022-01-15 08:47:31 -08:00
hweight.c
list_sort.c tools lib: Adopt list_sort() from the kernel sources 2021-10-20 10:30:59 -03:00
rbtree.c tools/: replace HTTP links with HTTPS ones 2020-08-07 11:33:21 -07:00
slab.c tools: Move gfp.h and slab.h from radix-tree to lib 2022-02-20 08:44:37 +02:00
str_error_r.c
string.c tools lib: Adopt memchr_inv() from kernel 2020-11-27 08:34:52 -03:00
vsprintf.c
zalloc.c