Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-07-15

The following pull-request contains BPF updates for your *net-next* tree.

We've added 45 non-merge commits during the last 15 day(s) which contain
a total of 52 files changed, 3122 insertions(+), 384 deletions(-).

The main changes are:

1) Introduce bpf timers, from Alexei.

2) Add sockmap support for unix datagram socket, from Cong.

3) Fix potential memleak and UAF in the verifier, from He.

4) Add bpf_get_func_ip helper, from Jiri.

5) Improvements to generic XDP mode, from Kumar.

6) Support for passing xdp_md to XDP programs in bpf_prog_run, from Zvi.
===================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 91 insertions, 13 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6f5e2757bb3c..4ccfae30e681 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3894,6 +3894,42 @@ static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
 	return 0;
 }
 
+static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info)
+{
+	char file[PATH_MAX], buff[4096];
+	FILE *fp;
+	__u32 val;
+	int err;
+
+	snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd);
+	memset(info, 0, sizeof(*info));
+
+	fp = fopen(file, "r");
+	if (!fp) {
+		err = -errno;
+		pr_warn("failed to open %s: %d. No procfs support?\n", file,
+			err);
+		return err;
+	}
+
+	while (fgets(buff, sizeof(buff), fp)) {
+		if (sscanf(buff, "map_type:\t%u", &val) == 1)
+			info->type = val;
+		else if (sscanf(buff, "key_size:\t%u", &val) == 1)
+			info->key_size = val;
+		else if (sscanf(buff, "value_size:\t%u", &val) == 1)
+			info->value_size = val;
+		else if (sscanf(buff, "max_entries:\t%u", &val) == 1)
+			info->max_entries = val;
+		else if (sscanf(buff, "map_flags:\t%i", &val) == 1)
+			info->map_flags = val;
+	}
+
+	fclose(fp);
+
+	return 0;
+}
+
 int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 {
 	struct bpf_map_info info = {};
@@ -3902,6 +3938,8 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 	char *new_name;
 
 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
+	if (err && errno == EINVAL)
+		err = bpf_get_map_info_from_fdinfo(fd, &info);
 	if (err)
 		return libbpf_err(err);
 
@@ -4381,12 +4419,16 @@ static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
 	struct bpf_map_info map_info = {};
 	char msg[STRERR_BUFSIZE];
 	__u32 map_info_len;
+	int err;
 
 	map_info_len = sizeof(map_info);
 
-	if (bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len)) {
-		pr_warn("failed to get map info for map FD %d: %s\n",
-			map_fd, libbpf_strerror_r(errno, msg, sizeof(msg)));
+	err = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len);
+	if (err && errno == EINVAL)
+		err = bpf_get_map_info_from_fdinfo(map_fd, &map_info);
+	if (err) {
+		pr_warn("failed to get map info for map FD %d: %s\n", map_fd,
+			libbpf_strerror_r(errno, msg, sizeof(msg)));
 		return false;
 	}
 
@@ -10304,19 +10346,25 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 	return pfd;
 }
 
-struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
-					    bool retprobe,
-					    const char *func_name)
+struct bpf_program_attach_kprobe_opts {
+	bool retprobe;
+	unsigned long offset;
+};
+
+static struct bpf_link*
+bpf_program__attach_kprobe_opts(struct bpf_program *prog,
+				const char *func_name,
+				struct bpf_program_attach_kprobe_opts *opts)
 {
 	char errmsg[STRERR_BUFSIZE];
 	struct bpf_link *link;
 	int pfd, err;
 
-	pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
-				    0 /* offset */, -1 /* pid */);
+	pfd = perf_event_open_probe(false /* uprobe */, opts->retprobe, func_name,
+				    opts->offset, -1 /* pid */);
 	if (pfd < 0) {
 		pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
-			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+			prog->name, opts->retprobe ? "kretprobe" : "kprobe", func_name,
 			libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
 		return libbpf_err_ptr(pfd);
 	}
@@ -10325,23 +10373,53 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
 	if (err) {
 		close(pfd);
 		pr_warn("prog '%s': failed to attach to %s '%s': %s\n",
-			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+			prog->name, opts->retprobe ? "kretprobe" : "kprobe", func_name,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		return libbpf_err_ptr(err);
 	}
 	return link;
 }
 
+struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
+					    bool retprobe,
+					    const char *func_name)
+{
+	struct bpf_program_attach_kprobe_opts opts = {
+		.retprobe = retprobe,
+	};
+
+	return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
+}
+
 static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
 				      struct bpf_program *prog)
 {
+	struct bpf_program_attach_kprobe_opts opts;
+	unsigned long offset = 0;
+	struct bpf_link *link;
 	const char *func_name;
-	bool retprobe;
+	char *func;
+	int n, err;
 
 	func_name = prog->sec_name + sec->len;
-	retprobe = strcmp(sec->sec, "kretprobe/") == 0;
+	opts.retprobe = strcmp(sec->sec, "kretprobe/") == 0;
+
+	n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%lx", &func, &offset);
+	if (n < 1) {
+		err = -EINVAL;
+		pr_warn("kprobe name is invalid: %s\n", func_name);
+		return libbpf_err_ptr(err);
+	}
+	if (opts.retprobe && offset != 0) {
+		err = -EINVAL;
+		pr_warn("kretprobes do not support offset specification\n");
+		return libbpf_err_ptr(err);
+	}
 
-	return bpf_program__attach_kprobe(prog, retprobe, func_name);
+	opts.offset = offset;
+	link = bpf_program__attach_kprobe_opts(prog, func, &opts);
+	free(func);
+	return link;
 }
 
 struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,