From 2a36c26fe3b8e2cf39e15e80ba1abc889a75da4f Mon Sep 17 00:00:00 2001
From: Pengcheng Yang <yangpc@wangsu.com>
Date: Sat, 6 May 2023 11:07:19 +0800
Subject: [PATCH] bpftool: Support bpffs mountpoint as pin path for prog
loadall
Currently, when using prog loadall and the pin path is a bpffs mountpoint,
bpffs will be repeatedly mounted to the parent directory of the bpffs
mountpoint path. For example, a `bpftool prog loadall test.o /sys/fs/bpf`
will trigger this.
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/1683342439-3677-1-git-send-email-yangpc@wangsu.com
---
tools/bpf/bpftool/common.c | 9 ++++++---
tools/bpf/bpftool/iter.c | 2 +-
tools/bpf/bpftool/main.h | 2 +-
tools/bpf/bpftool/prog.c | 2 +-
tools/bpf/bpftool/struct_ops.c | 2 +-
5 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 1360c82ae732f..cc6e6aae2447d 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -68,7 +68,7 @@ void p_info(const char *fmt, ...)
va_end(ap);
}
-static bool is_bpffs(char *path)
+static bool is_bpffs(const char *path)
{
struct statfs st_fs;
@@ -244,13 +244,16 @@ int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type)
return fd;
}
-int mount_bpffs_for_pin(const char *name)
+int mount_bpffs_for_pin(const char *name, bool is_dir)
{
char err_str[ERR_MAX_LEN];
char *file;
char *dir;
int err = 0;
+ if (is_dir && is_bpffs(name))
+ return err;
+
file = malloc(strlen(name) + 1);
if (!file) {
p_err("mem alloc failed");
@@ -286,7 +289,7 @@ int do_pin_fd(int fd, const char *name)
{
int err;
- err = mount_bpffs_for_pin(name);
+ err = mount_bpffs_for_pin(name, false);
if (err)
return err;
diff --git a/tools/bpf/bpftool/iter.c b/tools/bpf/bpftool/iter.c
index 9a1d2365a2974..6b0e5202ca7a9 100644
--- a/tools/bpf/bpftool/iter.c
+++ b/tools/bpf/bpftool/iter.c
@@ -76,7 +76,7 @@ static int do_pin(int argc, char **argv)
goto close_obj;
}
- err = mount_bpffs_for_pin(path);
+ err = mount_bpffs_for_pin(path, false);
if (err)
goto close_link;
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index a49534d7eafa9..b8bb08d10dec9 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -142,7 +142,7 @@ const char *get_fd_type_name(enum bpf_obj_type type);
char *get_fdinfo(int fd, const char *key);
int open_obj_pinned(const char *path, bool quiet);
int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type);
-int mount_bpffs_for_pin(const char *name);
+int mount_bpffs_for_pin(const char *name, bool is_dir);
int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(int *, char ***));
int do_pin_fd(int fd, const char *name);
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 91b6075b2db32..1f736dc298242 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1739,7 +1739,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
goto err_close_obj;
}
- err = mount_bpffs_for_pin(pinfile);
+ err = mount_bpffs_for_pin(pinfile, !first_prog_only);
if (err)
goto err_close_obj;
diff --git a/tools/bpf/bpftool/struct_ops.c b/tools/bpf/bpftool/struct_ops.c
index 57c3da70aa31a..3ebc9fe91e0e1 100644
--- a/tools/bpf/bpftool/struct_ops.c
+++ b/tools/bpf/bpftool/struct_ops.c
@@ -509,7 +509,7 @@ static int do_register(int argc, char **argv)
if (argc == 1)
linkdir = GET_ARG();
- if (linkdir && mount_bpffs_for_pin(linkdir)) {
+ if (linkdir && mount_bpffs_for_pin(linkdir, true)) {
p_err("can't mount bpffs for pinning");
return -1;
}
--
2.30.2