From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- tools/bpf/bpftool/token.c | 210 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 tools/bpf/bpftool/token.c (limited to 'tools/bpf/bpftool/token.c') diff --git a/tools/bpf/bpftool/token.c b/tools/bpf/bpftool/token.c new file mode 100644 index 000000000..c08f34b9d --- /dev/null +++ b/tools/bpf/bpftool/token.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* Copyright (C) 2025 Didi Technology Co., Tao Chen */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "json_writer.h" +#include "main.h" + +#define MOUNTS_FILE "/proc/mounts" + +static struct { + const char *header; + const char *key; +} sets[] = { + {"allowed_cmds", "delegate_cmds"}, + {"allowed_maps", "delegate_maps"}, + {"allowed_progs", "delegate_progs"}, + {"allowed_attachs", "delegate_attachs"}, +}; + +static bool has_delegate_options(const char *mnt_ops) +{ + return strstr(mnt_ops, "delegate_cmds") || + strstr(mnt_ops, "delegate_maps") || + strstr(mnt_ops, "delegate_progs") || + strstr(mnt_ops, "delegate_attachs"); +} + +static char *get_delegate_value(char *opts, const char *key) +{ + char *token, *rest, *ret = NULL; + + if (!opts) + return NULL; + + for (token = strtok_r(opts, ",", &rest); token; + token = strtok_r(NULL, ",", &rest)) { + if (strncmp(token, key, strlen(key)) == 0 && + token[strlen(key)] == '=') { + ret = token + strlen(key) + 1; + break; + } + } + + return ret; +} + +static void print_items_per_line(char *input, int items_per_line) +{ + char *str, *rest; + int cnt = 0; + + if (!input) + return; + + for (str = strtok_r(input, ":", &rest); str; + str = strtok_r(NULL, ":", &rest)) { + if (cnt % items_per_line == 0) + printf("\n\t "); + + printf("%-20s", str); + cnt++; + } +} + +#define ITEMS_PER_LINE 4 +static void show_token_info_plain(struct mntent *mntent) +{ + size_t i; + + printf("token_info %s", mntent->mnt_dir); + + for (i = 0; i < ARRAY_SIZE(sets); i++) { + char *opts, *value; + + printf("\n\t%s:", sets[i].header); + opts = strdup(mntent->mnt_opts); + value = get_delegate_value(opts, sets[i].key); + print_items_per_line(value, ITEMS_PER_LINE); + free(opts); + } + + printf("\n"); +} + +static void split_json_array_str(char *input) +{ + char *str, *rest; + + if (!input) { + jsonw_start_array(json_wtr); + jsonw_end_array(json_wtr); + return; + } + + jsonw_start_array(json_wtr); + for (str = strtok_r(input, ":", &rest); str; + str = strtok_r(NULL, ":", &rest)) { + jsonw_string(json_wtr, str); + } + jsonw_end_array(json_wtr); +} + +static void show_token_info_json(struct mntent *mntent) +{ + size_t i; + + jsonw_start_object(json_wtr); + jsonw_string_field(json_wtr, "token_info", mntent->mnt_dir); + + for (i = 0; i < ARRAY_SIZE(sets); i++) { + char *opts, *value; + + jsonw_name(json_wtr, sets[i].header); + opts = strdup(mntent->mnt_opts); + value = get_delegate_value(opts, sets[i].key); + split_json_array_str(value); + free(opts); + } + + jsonw_end_object(json_wtr); +} + +static int __show_token_info(struct mntent *mntent) +{ + if (json_output) + show_token_info_json(mntent); + else + show_token_info_plain(mntent); + + return 0; +} + +static int show_token_info(void) +{ + FILE *fp; + struct mntent *ent; + + fp = setmntent(MOUNTS_FILE, "r"); + if (!fp) { + p_err("Failed to open: %s", MOUNTS_FILE); + return -1; + } + + if (json_output) + jsonw_start_array(json_wtr); + + while ((ent = getmntent(fp)) != NULL) { + if (strncmp(ent->mnt_type, "bpf", 3) == 0) { + if (has_delegate_options(ent->mnt_opts)) + __show_token_info(ent); + } + } + + if (json_output) + jsonw_end_array(json_wtr); + + endmntent(fp); + + return 0; +} + +static int do_show(int argc, char **argv) +{ + if (argc) + return BAD_ARG(); + + return show_token_info(); +} + +static int do_help(int argc, char **argv) +{ + if (json_output) { + jsonw_null(json_wtr); + return 0; + } + + fprintf(stderr, + "Usage: %1$s %2$s { show | list }\n" + " %1$s %2$s help\n" + " " HELP_SPEC_OPTIONS " }\n" + "\n" + "", + bin_name, argv[-2]); + return 0; +} + +static const struct cmd cmds[] = { + { "show", do_show }, + { "list", do_show }, + { "help", do_help }, + { 0 } +}; + +int do_token(int argc, char **argv) +{ + return cmd_select(cmds, argc, argv, do_help); +} -- cgit v1.3.1