From: Steven Rostedt <rostedt@goodmis.org>
To: linux-trace-devel@vger.kernel.org
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Subject: [PATCH v3 4/7] libtracefs: Implement tracefs_get_kprobes()
Date: Thu, 1 Jul 2021 23:10:19 -0400 [thread overview]
Message-ID: <20210702031022.154146-5-rostedt@goodmis.org> (raw)
In-Reply-To: <20210702031022.154146-1-rostedt@goodmis.org>
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Add the function tracefs_get_kprobes() that returns a list of kprobes that
are registered. The list contains strings that are of the format
"group/event" (i.e. "kprobes/open"). The last element in the list is a
NULL pointer. In the case that there are no kprobes, the list will return
a single entry of a NULL pointer.
NULL is returned in the case of error (mainly a memory issue, or bad
parsing).
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/tracefs.h | 1 +
src/tracefs-kprobes.c | 66 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/include/tracefs.h b/include/tracefs.h
index 64164c8c2b20..5f59c480d572 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -219,4 +219,5 @@ int tracefs_kprobe_raw(const char *system, const char *event,
const char *addr, const char *format);
int tracefs_kretprobe_raw(const char *system, const char *event,
const char *addr, const char *format);
+char **tracefs_get_kprobes(void);
#endif /* _TRACE_FS_H */
diff --git a/src/tracefs-kprobes.c b/src/tracefs-kprobes.c
index 9bd9b2df9287..8df3227d687f 100644
--- a/src/tracefs-kprobes.c
+++ b/src/tracefs-kprobes.c
@@ -105,3 +105,69 @@ int tracefs_kretprobe_raw(const char *system, const char *event,
{
return insert_kprobe("r", system, event, addr, format);
}
+
+/**
+ * tracefs_get_kprobes - return a list kprobes (by group/event name)
+ *
+ * Returns a list of strings that contain the kprobes that exist
+ * in the kprobe_events files. The strings returned are in the
+ * "group/event" format.
+ * The list must be freed with tracefs_list_free().
+ * If there are no kprobes, a list is still returned, but it contains
+ * only a NULL pointer.
+ * On error, NULL is returned.
+ */
+char **tracefs_get_kprobes(void)
+{
+ char **list = NULL;
+ char *content;
+ char *saveptr;
+ char *event;
+ char *p;
+ int cnt = 0;
+
+ content = tracefs_instance_file_read(NULL, KPROBE_EVENTS, NULL);
+ if (!content)
+ return NULL;
+
+ p = strtok_r(content, ":", &saveptr);
+
+ while (p) {
+ char **tmp;
+
+ /* Failed parsing always return a failure */
+ p = strtok_r(NULL, " ", &saveptr);
+ if (!p)
+ break;
+
+ event = strdup(p);
+ if (!event)
+ goto fail;
+
+ tmp = realloc(list, sizeof(*list) * (cnt + 2));
+ if (!tmp)
+ goto fail;
+
+ list = tmp;
+ list[cnt++] = event;
+ list[cnt] = NULL;
+
+ p = strtok_r(NULL, "\n", &saveptr);
+ /* Could be end of content */
+ if (!p)
+ break;
+
+ /* p is NULL on end of content */
+ p = strtok_r(NULL, ":", &saveptr);
+ }
+
+ if (!list)
+ list = calloc(1, sizeof(*list));
+ out:
+ free(content);
+ return list;
+ fail:
+ free(list);
+ list = NULL;
+ goto out;
+}
--
2.30.2
next prev parent reply other threads:[~2021-07-02 3:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-02 3:10 [PATCH v3 0/7] libtracefs: Facilitate adding and removing kprobes Steven Rostedt
2021-07-02 3:10 ` [PATCH v3 1/7] libtracefs: Implement tracefs_instances() Steven Rostedt
2021-07-02 3:10 ` [PATCH v3 2/7] libtracefs: Implement tracefs_kprobe_raw() Steven Rostedt
2021-07-02 3:10 ` [PATCH v3 3/7] libtracefs: Implement tracefs_kretprobe_raw() Steven Rostedt
2021-07-02 3:10 ` Steven Rostedt [this message]
2021-07-02 3:10 ` [PATCH v3 5/7] libtracefs: Implement tracefs_kprobe_clear_all() to remove all kprobes Steven Rostedt
2021-07-02 3:10 ` [PATCH v3 6/7] libtracefs: Implement tracefs_kprobe_clear_probe() Steven Rostedt
2021-07-02 3:10 ` [PATCH v3 7/7] libtracefs: Add man pages for kprobe functions Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210702031022.154146-5-rostedt@goodmis.org \
--to=rostedt@goodmis.org \
--cc=linux-trace-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).