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-rw-r--r--tools/bpf/bpftool/common.c25
-rw-r--r--tools/bpf/bpftool/main.h2
-rw-r--r--tools/bpf/bpftool/tracelog.c20
3 files changed, 35 insertions, 12 deletions
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 24582e8a96fb..1bad6602a282 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -76,7 +76,8 @@ void set_max_rlimit(void)
setrlimit(RLIMIT_MEMLOCK, &rinf);
}
-static int mnt_bpffs(const char *target, char *buff, size_t bufflen)
+static int
+mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
{
bool bind_done = false;
@@ -98,15 +99,29 @@ static int mnt_bpffs(const char *target, char *buff, size_t bufflen)
bind_done = true;
}
- if (mount("bpf", target, "bpf", 0, "mode=0700")) {
- snprintf(buff, bufflen, "mount -t bpf bpf %s failed: %s",
- target, strerror(errno));
+ if (mount(type, target, type, 0, "mode=0700")) {
+ snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
+ type, type, target, strerror(errno));
return -1;
}
return 0;
}
+int mount_tracefs(const char *target)
+{
+ char err_str[ERR_MAX_LEN];
+ int err;
+
+ err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
+ if (err) {
+ err_str[ERR_MAX_LEN - 1] = '\0';
+ p_err("can't mount tracefs: %s", err_str);
+ }
+
+ return err;
+}
+
int open_obj_pinned(char *path, bool quiet)
{
int fd;
@@ -162,7 +177,7 @@ int mount_bpffs_for_pin(const char *name)
/* nothing to do if already mounted */
goto out_free;
- err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
+ err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
if (err) {
err_str[ERR_MAX_LEN - 1] = '\0';
p_err("can't mount BPF file system to pin the object (%s): %s",
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 9487345b04a7..9e4499c926fa 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -98,6 +98,8 @@ void usage(void) __noreturn;
void set_max_rlimit(void);
+int mount_tracefs(const char *target);
+
struct pinned_obj_table {
DECLARE_HASHTABLE(table, 16);
};
diff --git a/tools/bpf/bpftool/tracelog.c b/tools/bpf/bpftool/tracelog.c
index 1fa8e513f590..2dc36dfa0896 100644
--- a/tools/bpf/bpftool/tracelog.c
+++ b/tools/bpf/bpftool/tracelog.c
@@ -54,7 +54,7 @@ find_tracefs_mnt_single(unsigned long magic, char *mnt, const char *mntpt)
return true;
}
-static bool find_tracefs_pipe(char *mnt)
+static bool get_tracefs_pipe(char *mnt)
{
static const char * const known_mnts[] = {
"/sys/kernel/debug/tracing",
@@ -88,7 +88,17 @@ static bool find_tracefs_pipe(char *mnt)
fclose(fp);
/* The string from fscanf() might be truncated, check mnt is valid */
- if (!found || validate_tracefs_mnt(mnt, TRACEFS_MAGIC))
+ if (found && validate_tracefs_mnt(mnt, TRACEFS_MAGIC))
+ goto exit_found;
+
+ p_info("could not find tracefs, attempting to mount it now");
+ /* Most of the time, tracefs is automatically mounted by debugfs at
+ * /sys/kernel/debug/tracing when we try to access it. If we could not
+ * find it, it is likely that debugfs is not mounted. Let's give one
+ * attempt at mounting just tracefs at /sys/kernel/tracing.
+ */
+ strcpy(mnt, known_mnts[1]);
+ if (mount_tracefs(mnt))
return false;
exit_found:
@@ -115,17 +125,13 @@ int do_tracelog(int argc, char **argv)
.sa_handler = exit_tracelog
};
char trace_pipe[PATH_MAX];
- bool found_trace_pipe;
size_t buff_len = 0;
if (json_output)
jsonw_start_array(json_wtr);
- found_trace_pipe = find_tracefs_pipe(trace_pipe);
- if (!found_trace_pipe) {
- p_err("could not find trace pipe, tracefs not mounted?");
+ if (!get_tracefs_pipe(trace_pipe))
return -1;
- }
trace_pipe_fd = fopen(trace_pipe, "r");
if (!trace_pipe_fd) {