This patch appends new syntax to BPF object section name to support
probing at uprobe event. Now we can use BPF program like this:
SEC(
"target=/lib64/libc.so.6\n"
"libcwrite=__write"
)
int libcwrite(void *ctx)
{
return 1;
}
Where, in section name of a program, before the main config string,
we can use 'key=value' style options. Now the only option key "target"
is for uprobe probing.
Signed-off-by: Wang Nan <wangn...@huawei.com>
Cc: Alexei Starovoitov <a...@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gr...@gmail.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: David Ahern <dsah...@gmail.com>
Cc: He Kuang <heku...@huawei.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Kaixu Xia <xiaka...@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Zefan Li <lize...@huawei.com>
Cc: pi3or...@163.com
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngk...@git.kernel.org
---
tools/perf/util/bpf-loader.c | 86 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 80 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index af549ea..73ff9a9 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -111,6 +111,84 @@ bpf_prog_priv__clear(struct bpf_program *prog
__maybe_unused,
}
static int
+do_config(const char *key, const char *value,
+ struct perf_probe_event *pev)
+{
+ pr_debug("config bpf program: %s=%s\n", key, value);
+ if (strcmp(key, "target") == 0) {
+ pev->uprobes = true;
+ pev->target = strdup(value);
+ return 0;
+ }
+
+ pr_warning("BPF: WARNING: invalid config option in object: %s=%s\n",
+ key, value);
+ pr_warning("\tHint: Currently only valid option is 'target=<file>'\n");
+ return 0;
+}
+
+static const char *
+parse_config_kvpair(const char *config_str, struct perf_probe_event *pev)
+{
+ char *text = strdup(config_str);
+ char *sep, *line;
+ const char *main_str = NULL;
+ int err = 0;
+
+ if (!text) {
+ pr_debug("No enough memory: dup config_str failed\n");
+ return NULL;
+ }
+
+ line = text;
+ while ((sep = strchr(line, '\n'))) {
+ char *equ;
+
+ *sep = '\0';
+ equ = strchr(line, '=');
+ if (!equ) {
+ pr_warning("WARNING: invalid config in BPF object:
%s\n",
+ line);
+ pr_warning("\tShould be 'key=value'.\n");
+ goto nextline;
+ }
+ *equ = '\0';
+
+ err = do_config(line, equ + 1, pev);
+ if (err)
+ break;
+nextline:
+ line = sep + 1;
+ }
+
+ if (!err)
+ main_str = config_str + (line - text);
+ free(text);
+
+ return main_str;
+}
+
+static int
+parse_config(const char *config_str, struct perf_probe_event *pev)
+{
+ const char *main_str;
+ int err;
+
+ main_str = parse_config_kvpair(config_str, pev);
+ if (!main_str)
+ return -EINVAL;
+
+ err = parse_perf_probe_command(main_str, pev);
+ if (err < 0) {
+ pr_debug("bpf: '%s' is not a valid config string\n",
+ config_str);
+ /* parse failed, don't need clear pev. */
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int
config_bpf_program(struct bpf_program *prog)
{
struct perf_probe_event *pev = NULL;
@@ -132,13 +210,9 @@ config_bpf_program(struct bpf_program *prog)
pev = &priv->pev;
pr_debug("bpf: config program '%s'\n", config_str);
- err = parse_perf_probe_command(config_str, pev);
- if (err < 0) {
- pr_debug("bpf: '%s' is not a valid config string\n",
- config_str);
- err = -EINVAL;
+ err = parse_config(config_str, pev);
+ if (err)
goto errout;
- }
if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
pr_debug("bpf: '%s': group for event is set and not '%s'.\n",
--
1.8.3.4
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