This patch introduces a new bpftool command: perf attach,
which used to attaching/pinning tracepoints programs.
bpftool perf attach PROG TP_NAME FILE
It will attach bpf program PROG to tracepoint TP_NAME and
pin tracepoint program as FILE, FILE must be located in
bpffs mount.
For example,
$ bpftool prog load mtd-mchp23k256.o /sys/fs/bpf/test_prog
$ bpftool prog
510: raw_tracepoint_writable name mtd_mchp23k256 tag 2e13281b1f781bf3 gpl
loaded_at 2022-08-24T02:50:06+0000 uid 0
xlated 960B not jited memlock 4096B map_ids 439,437,440
btf_id 740
$ bpftool perf attach id 510 spi_transfer_writeable /sys/fs/bpf/test_perf
$ bpftool link show
74: raw_tracepoint prog 510
tp 'spi_transfer_writeable'
The implementation a BPF based backend for mchp23k256 mtd mockup
device.
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
---
v1 -> v2: switch to extend perf command instead add new one
v1: https://patchwork.kernel.org/project/netdevbpf/patch/20220816151725.153343-1-weiyongjun1@xxxxxxxxxx/
---
.../bpftool/Documentation/bpftool-perf.rst | 11 ++-
tools/bpf/bpftool/perf.c | 67 ++++++++++++++++++-
2 files changed, 76 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-perf.rst b/tools/bpf/bpftool/Documentation/bpftool-perf.rst
index 5fea633a82f1..085c8dcfb9aa 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-perf.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-perf.rst
@@ -19,12 +19,13 @@ SYNOPSIS
*OPTIONS* := { |COMMON_OPTIONS| }
*COMMANDS* :=
- { **show** | **list** | **help** }
+ { **show** | **list** | **help** | **attach** }
PERF COMMANDS
=============
| **bpftool** **perf** { **show** | **list** }
+| **bpftool** **perf** **attach** *PROG* *TP_NAME* *FILE*
| **bpftool** **perf help**
DESCRIPTION
@@ -39,6 +40,14 @@ DESCRIPTION
or a kernel virtual address.
The attachment point for u[ret]probe is the file name and the file offset.
+ **bpftool perf attach PROG TP_NAME FILE**
+ Attach bpf program *PROG* to tracepoint *TP_NAME* and pin
+ program *PROG* as *FILE*.
+
+ Note: *FILE* must be located in *bpffs* mount. It must not
+ contain a dot character ('.'), which is reserved for future
+ extensions of *bpffs*.
+
**bpftool perf help**
Print short help message.
diff --git a/tools/bpf/bpftool/perf.c b/tools/bpf/bpftool/perf.c
index 226ec2c39052..9149ba960784 100644
--- a/tools/bpf/bpftool/perf.c
+++ b/tools/bpf/bpftool/perf.c
@@ -233,8 +233,9 @@ static int do_show(int argc, char **argv)
static int do_help(int argc, char **argv)
{
fprintf(stderr,
- "Usage: %1$s %2$s { show | list }\n"
+ "Usage: %1$s %2$s { show | list | attach }\n"
" %1$s %2$s help }\n"
+ " %1$s %2$s attach PROG TP_NAME FILE\n"
"\n"
" " HELP_SPEC_OPTIONS " }\n"
"",
@@ -243,10 +244,74 @@ static int do_help(int argc, char **argv)
return 0;
}
+static enum bpf_prog_type get_prog_type(int progfd)
+{
+ struct bpf_prog_info info = {};
+ __u32 len = sizeof(info);
+
+ if (bpf_obj_get_info_by_fd(progfd, &info, &len))
+ return BPF_PROG_TYPE_UNSPEC;
+
+ return info.type;
+}
+
+static int do_attach(int argc, char **argv)
+{
+ enum bpf_prog_type prog_type;
+ char *tp_name, *path;
+ int err, progfd, pfd;
+
+ if (!REQ_ARGS(4))
+ return -EINVAL;
+
+ progfd = prog_parse_fd(&argc, &argv);
+ if (progfd < 0)
+ return progfd;
+
+ if (!REQ_ARGS(2)) {
+ err = -EINVAL;
+ goto out_close;
+ }
+
+ tp_name = GET_ARG();
+ path = GET_ARG();
+
+ prog_type = get_prog_type(progfd);
+ switch (prog_type) {
+ case BPF_PROG_TYPE_RAW_TRACEPOINT:
+ case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
+ pfd = bpf_raw_tracepoint_open(tp_name, progfd);
+ if (pfd < 0) {
+ printf("failed to attach to raw tracepoint '%s'\n",
+ tp_name);
+ err = pfd;
+ goto out_close;
+ }
+ break;
+ default:
+ printf("invalid program type %s\n",
+ libbpf_bpf_prog_type_str(prog_type));
+ err = -EINVAL;
+ goto out_close;
+ }
+
+ err = do_pin_fd(pfd, path);
+ if (err) {
+ close(pfd);
+ goto out_close;
+ }
+
+ return 0;
+
+out_close:
+ return err;
+}
+
static const struct cmd cmds[] = {
{ "show", do_show },
{ "list", do_show },
{ "help", do_help },
+ { "attach", do_attach },
{ 0 }
};
--
2.34.1
