On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
> This patch enables perf-record to save bpf_prog_info information as
> headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
> introduced for this data.
>
> Signed-off-by: Song Liu <songliubrav...@fb.com>
> ---
> tools/perf/util/header.c | 143 ++++++++++++++++++++++++++++++++++++++-
> tools/perf/util/header.h | 1 +
> 2 files changed, 143 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 4b88de5e9192..16f5bedb0b7d 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -18,6 +18,7 @@
> #include <sys/utsname.h>
> #include <linux/time64.h>
> #include <dirent.h>
> +#include <bpf/libbpf.h>
>
> #include "evlist.h"
> #include "evsel.h"
> @@ -39,6 +40,7 @@
> #include "tool.h"
> #include "time-utils.h"
> #include "units.h"
> +#include "bpf-event.h"
>
> #include "sane_ctype.h"
>
> @@ -1074,6 +1076,51 @@ static int write_clockid(struct feat_fd *ff,
> sizeof(ff->ph->env.clockid_res_ns));
> }
>
> +static int write_bpf_prog_info(struct feat_fd *ff,
> + struct perf_evlist *evlist __maybe_unused)
> +{
> + struct perf_env *env = &ff->ph->env;
> + struct rb_root *root;
> + struct rb_node *next;
> + u32 count = 0;
> + int ret;
> +
> + down_read(&env->bpf_progs.lock);
> +
> + root = &env->bpf_progs.infos;
> + next = rb_first(root);
> + while (next) {
> + ++count;
> + next = rb_next(next);
> + }
> +
> + ret = do_write(ff, &count, sizeof(count));
> +
> + if (ret < 0)
> + goto out;
> +
> + next = rb_first(root);
> + while (next) {
> + struct bpf_prog_info_node *node;
> + size_t len;
> +
> + node = rb_entry(next, struct bpf_prog_info_node, rb_node);
> + next = rb_next(&node->rb_node);
> + len = sizeof(struct bpf_prog_info_linear) +
> + node->info_linear->data_len;
> +
> + /* before writing to file, translate address to offset */
> + bpf_program__bpil_addr_to_offs(node->info_linear);
> + ret = do_write(ff, node->info_linear, len);
> + bpf_program__bpil_offs_to_addr(node->info_linear);
what's the reason to call this before the error check?
thanks,
jirka
> + if (ret < 0)
> + goto out;
> + }
> +out:
> + up_read(&env->bpf_progs.lock);
> + return ret;
> +}
SNIP
