@@ -26,7 +26,7 @@ MAP COMMANDS
| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
| **bpftool** **map dump** *MAP*
| **bpftool** **map update** *MAP* [**key** *DATA*] **value** *VALUE* [*UPDATE_FLAGS*]
-| **bpftool** **map lookup** *MAP* **key** *DATA*
+| **bpftool** **map lookup** *MAP* [**key** *DATA*]
| **bpftool** **map getnext** *MAP* [**key** *DATA*]
| **bpftool** **map delete** *MAP* **key** *DATA*
| **bpftool** **map pin** *MAP* *FILE*
@@ -75,7 +75,7 @@ DESCRIPTION
the bytes are parsed as decimal values, unless a "0x" prefix
(for hexadecimal) or a "0" prefix (for octal) is provided.
- **bpftool map lookup** *MAP* **key** *DATA*
+ **bpftool map lookup** *MAP* [**key** *DATA*]
Lookup **key** in the map.
**bpftool map getnext** *MAP* [**key** *DATA*]
@@ -835,11 +835,11 @@ static int do_update(int argc, char **argv)
static int do_lookup(int argc, char **argv)
{
+ void *key = NULL, *value = NULL;
struct bpf_map_info info = {};
__u32 len = sizeof(info);
json_writer_t *btf_wtr;
struct btf *btf = NULL;
- void *key, *value;
int err;
int fd;
@@ -850,9 +850,16 @@ static int do_lookup(int argc, char **argv)
if (fd < 0)
return -1;
- key = malloc(info.key_size);
+ if (info.key_size) {
+ key = malloc(info.key_size);
+ if (!key) {
+ p_err("mem alloc failed");
+ err = -1;
+ goto exit_free;
+ }
+ }
value = alloc_value(&info);
- if (!key || !value) {
+ if (!value) {
p_err("mem alloc failed");
err = -1;
goto exit_free;
@@ -1143,7 +1150,7 @@ static int do_help(int argc, char **argv)
" [dev NAME]\n"
" %s %s dump MAP\n"
" %s %s update MAP [key DATA] value VALUE [UPDATE_FLAGS]\n"
- " %s %s lookup MAP key DATA\n"
+ " %s %s lookup MAP [key DATA]\n"
" %s %s getnext MAP [key DATA]\n"
" %s %s delete MAP key DATA\n"
" %s %s pin MAP FILE\n"
Bpftool expects key for 'lookup' operations. For some map types, key should not be specified. Support looking up those map types. Before: bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q bpftool map update pinned /sys/fs/bpf/q value 0 1 2 3 bpftool map lookup pinned /sys/fs/bpf/q Error: did not find key After: bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q bpftool map update pinned /sys/fs/bpf/q value 0 1 2 3 bpftool map lookup pinned /sys/fs/bpf/q key: value: 00 01 02 03 Signed-off-by: Stanislav Fomichev <sdf@google.com> --- tools/bpf/bpftool/Documentation/bpftool-map.rst | 4 ++-- tools/bpf/bpftool/map.c | 15 +++++++++++---- 2 files changed, 13 insertions(+), 6 deletions(-)