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-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-map.rst4
-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-prog.rst4
-rw-r--r--tools/bpf/bpftool/Documentation/bpftool.rst4
-rw-r--r--tools/bpf/bpftool/common.c31
-rw-r--r--tools/bpf/bpftool/main.c8
-rw-r--r--tools/bpf/bpftool/main.h6
-rw-r--r--tools/bpf/bpftool/tracelog.c23
7 files changed, 66 insertions, 14 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 3221be1b9ccc..64b001b4f777 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -128,6 +128,10 @@ OPTIONS
-f, --bpffs
Show file names of pinned maps.
+ -n, --nomount
+ Do not automatically attempt to mount any virtual file system
+ (such as tracefs or BPF virtual file system) when necessary.
+
EXAMPLES
========
**# bpftool map show**
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 53920ffc48dd..58c8369b77dd 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -161,6 +161,10 @@ OPTIONS
-m, --mapcompat
Allow loading maps with unknown map definitions.
+ -n, --nomount
+ Do not automatically attempt to mount any virtual file system
+ (such as tracefs or BPF virtual file system) when necessary.
+
EXAMPLES
========
**# bpftool prog show**
diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst
index 129b7a9c0f9b..e1677e81ed59 100644
--- a/tools/bpf/bpftool/Documentation/bpftool.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool.rst
@@ -60,6 +60,10 @@ OPTIONS
-m, --mapcompat
Allow loading maps with unknown map definitions.
+ -n, --nomount
+ Do not automatically attempt to mount any virtual file system
+ (such as tracefs or BPF virtual file system) when necessary.
+
SEE ALSO
========
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 24582e8a96fb..897483457bf0 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 +177,13 @@ 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);
+ if (block_mount) {
+ p_err("no BPF file system found, not mounting it due to --nomount option");
+ err = -1;
+ goto out_free;
+ }
+
+ 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.c b/tools/bpf/bpftool/main.c
index 9e657e7d5172..f44a1c2c4ea0 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -24,6 +24,7 @@ json_writer_t *json_wtr;
bool pretty_output;
bool json_output;
bool show_pinned;
+bool block_mount;
int bpf_flags;
struct pinned_obj_table prog_table;
struct pinned_obj_table map_table;
@@ -313,6 +314,7 @@ int main(int argc, char **argv)
{ "version", no_argument, NULL, 'V' },
{ "bpffs", no_argument, NULL, 'f' },
{ "mapcompat", no_argument, NULL, 'm' },
+ { "nomount", no_argument, NULL, 'n' },
{ 0 }
};
int opt, ret;
@@ -321,13 +323,14 @@ int main(int argc, char **argv)
pretty_output = false;
json_output = false;
show_pinned = false;
+ block_mount = false;
bin_name = argv[0];
hash_init(prog_table.table);
hash_init(map_table.table);
opterr = 0;
- while ((opt = getopt_long(argc, argv, "Vhpjfm",
+ while ((opt = getopt_long(argc, argv, "Vhpjfmn",
options, NULL)) >= 0) {
switch (opt) {
case 'V':
@@ -354,6 +357,9 @@ int main(int argc, char **argv)
case 'm':
bpf_flags = MAPS_RELAX_COMPAT;
break;
+ case 'n':
+ block_mount = true;
+ break;
default:
p_err("unrecognized option '%s'", argv[optind - 1]);
if (json_output)
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 9487345b04a7..052c91d4dc55 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -44,7 +44,8 @@
#define HELP_SPEC_PROGRAM \
"PROG := { id PROG_ID | pinned FILE | tag PROG_TAG }"
#define HELP_SPEC_OPTIONS \
- "OPTIONS := { {-j|--json} [{-p|--pretty}] | {-f|--bpffs} | {-m|--mapcompat}"
+ "OPTIONS := { {-j|--json} [{-p|--pretty}] | {-f|--bpffs} |\n" \
+ "\t {-m|--mapcompat} | {-n|--nomount} }"
#define HELP_SPEC_MAP \
"MAP := { id MAP_ID | pinned FILE }"
@@ -85,6 +86,7 @@ extern const char *bin_name;
extern json_writer_t *json_wtr;
extern bool json_output;
extern bool show_pinned;
+extern bool block_mount;
extern int bpf_flags;
extern struct pinned_obj_table prog_table;
extern struct pinned_obj_table map_table;
@@ -98,6 +100,8 @@ 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..e80a5c79b38f 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 +88,20 @@ 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;
+
+ if (block_mount)
+ return false;
+
+ 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 +128,13 @@ 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) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-13 06:53:10 +0000