On Thu, 3 Jan 2019 10:33:05 -0800, Stanislav Fomichev wrote:
> Bpftool expects both key and value for 'update' operations. For some
> map types, key should not be specified. Support updating 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
> 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
>
> Signed-off-by: Stanislav Fomichev <s...@google.com>
I guess it doesn't hurt to fix update/lookup, but I'd prefer to see new
separate subcommands to be honest :(
bpftool map push/pop/peek
Could you add those as well? I think most users will be more familiar
with the helpers than the fact that the syscall reuses the old commands.
> diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
> index 2037e3dc864b..30b92715248d 100644
> --- a/tools/bpf/bpftool/map.c
> +++ b/tools/bpf/bpftool/map.c
> @@ -781,11 +781,11 @@ static int do_dump(int argc, char **argv)
>
> static int do_update(int argc, char **argv)
> {
> + void *key = NULL, *value = NULL;
nit: it seems tiny bit more readable to init these in the place you'd
otherwise set key to malloc (in an else clause)
> struct bpf_map_info info = {};
> __u32 len = sizeof(info);
> __u32 *value_fd = NULL;
> __u32 flags = BPF_ANY;
> - void *key, *value;
> int fd, err;
>
> if (argc < 2)
> @@ -795,9 +795,16 @@ static int do_update(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);
Would you mind taking care of the value as well? So we are ready if
sets are ever added?
> - if (!key || !value) {
> + if (!value) {
> p_err("mem alloc failed");
> err = -1;
> goto exit_free;
I'd consider this -next material TBH, but not strongly.
