diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-prog.rst | 13 | ||||
| -rw-r--r-- | tools/bpf/bpftool/bash-completion/bpftool | 5 | ||||
| -rw-r--r-- | tools/bpf/bpftool/main.h | 1 | ||||
| -rw-r--r-- | tools/bpf/bpftool/prog.c | 4 | ||||
| -rw-r--r-- | tools/bpf/bpftool/tracelog.c | 157 |
5 files changed, 176 insertions, 4 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index ab36e920e552..5524b6dccd85 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -26,8 +26,9 @@ MAP COMMANDS | **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes**}] | **bpftool** **prog pin** *PROG* *FILE* | **bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] -| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] -| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*] +| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] +| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*] +| **bpftool** **prog tracelog** | **bpftool** **prog help** | | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } @@ -117,6 +118,14 @@ DESCRIPTION parameter, with the exception of *flow_dissector* which is detached from the current networking name space. + **bpftool prog tracelog** + Dump the trace pipe of the system to the console (stdout). + Hit <Ctrl+C> to stop printing. BPF programs can write to this + trace pipe at runtime with the **bpf_trace_printk()** helper. + This should be used only for debugging purposes. For + streaming data from BPF programs to user space, one can use + perf events (see also **bpftool-map**\ (8)). + **bpftool prog help** Print short help message. diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 9a60080f085f..44c189ba072a 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -398,10 +398,13 @@ _bpftool() ;; esac ;; + tracelog) + return 0 + ;; *) [[ $prev == $object ]] && \ COMPREPLY=( $( compgen -W 'dump help pin attach detach load \ - show list' -- "$cur" ) ) + show list tracelog' -- "$cur" ) ) ;; esac ;; diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 2761981669c8..0be0dd8f467f 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -167,6 +167,7 @@ int do_event_pipe(int argc, char **argv); int do_cgroup(int argc, char **arg); int do_perf(int argc, char **arg); int do_net(int argc, char **arg); +int do_tracelog(int argc, char **arg); int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what); int prog_parse_fd(int *argc, char ***argv); diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 56db61c5a91f..54c8dbf05c9c 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1140,6 +1140,7 @@ static int do_help(int argc, char **argv) " [pinmaps MAP_DIR]\n" " %s %s attach PROG ATTACH_TYPE [MAP]\n" " %s %s detach PROG ATTACH_TYPE [MAP]\n" + " %s %s tracelog\n" " %s %s help\n" "\n" " " HELP_SPEC_MAP "\n" @@ -1158,7 +1159,7 @@ static int do_help(int argc, char **argv) "", bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], - bin_name, argv[-2], bin_name, argv[-2]); + bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]); return 0; } @@ -1173,6 +1174,7 @@ static const struct cmd cmds[] = { { "loadall", do_loadall }, { "attach", do_attach }, { "detach", do_detach }, + { "tracelog", do_tracelog }, { 0 } }; diff --git a/tools/bpf/bpftool/tracelog.c b/tools/bpf/bpftool/tracelog.c new file mode 100644 index 000000000000..1fa8e513f590 --- /dev/null +++ b/tools/bpf/bpftool/tracelog.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* Copyright (c) 2015-2017 Daniel Borkmann */ +/* Copyright (c) 2018 Netronome Systems, Inc. */ + +#include <errno.h> +#include <limits.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <linux/magic.h> +#include <sys/fcntl.h> +#include <sys/vfs.h> + +#include "main.h" + +#ifndef TRACEFS_MAGIC +# define TRACEFS_MAGIC 0x74726163 +#endif + +#define _textify(x) #x +#define textify(x) _textify(x) + +FILE *trace_pipe_fd; +char *buff; + +static int validate_tracefs_mnt(const char *mnt, unsigned long magic) +{ + struct statfs st_fs; + + if (statfs(mnt, &st_fs) < 0) + return -ENOENT; + if ((unsigned long)st_fs.f_type != magic) + return -ENOENT; + + return 0; +} + +static bool +find_tracefs_mnt_single(unsigned long magic, char *mnt, const char *mntpt) +{ + size_t src_len; + + if (validate_tracefs_mnt(mntpt, magic)) + return false; + + src_len = strlen(mntpt); + if (src_len + 1 >= PATH_MAX) { + p_err("tracefs mount point name too long"); + return false; + } + + strcpy(mnt, mntpt); + return true; +} + +static bool find_tracefs_pipe(char *mnt) +{ + static const char * const known_mnts[] = { + "/sys/kernel/debug/tracing", + "/sys/kernel/tracing", + "/tracing", + "/trace", + }; + const char *pipe_name = "/trace_pipe"; + const char *fstype = "tracefs"; + char type[100], format[32]; + const char * const *ptr; + bool found = false; + FILE *fp; + + for (ptr = known_mnts; ptr < known_mnts + ARRAY_SIZE(known_mnts); ptr++) + if (find_tracefs_mnt_single(TRACEFS_MAGIC, mnt, *ptr)) + goto exit_found; + + fp = fopen("/proc/mounts", "r"); + if (!fp) + return false; + + /* Allow room for NULL terminating byte and pipe file name */ + snprintf(format, sizeof(format), "%%*s %%%zds %%99s %%*s %%*d %%*d\\n", + PATH_MAX - strlen(pipe_name) - 1); + while (fscanf(fp, format, mnt, type) == 2) + if (strcmp(type, fstype) == 0) { + found = true; + break; + } + fclose(fp); + + /* The string from fscanf() might be truncated, check mnt is valid */ + if (!found || validate_tracefs_mnt(mnt, TRACEFS_MAGIC)) + return false; + +exit_found: + strcat(mnt, pipe_name); + return true; +} + +static void exit_tracelog(int signum) +{ + fclose(trace_pipe_fd); + free(buff); + + if (json_output) { + jsonw_end_array(json_wtr); + jsonw_destroy(&json_wtr); + } + + exit(0); +} + +int do_tracelog(int argc, char **argv) +{ + const struct sigaction act = { + .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?"); + return -1; + } + + trace_pipe_fd = fopen(trace_pipe, "r"); + if (!trace_pipe_fd) { + p_err("could not open trace pipe: %s", strerror(errno)); + return -1; + } + + sigaction(SIGHUP, &act, NULL); + sigaction(SIGINT, &act, NULL); + sigaction(SIGTERM, &act, NULL); + while (1) { + ssize_t ret; + + ret = getline(&buff, &buff_len, trace_pipe_fd); + if (ret <= 0) { + p_err("failed to read content from trace pipe: %s", + strerror(errno)); + break; + } + if (json_output) + jsonw_string(json_wtr, buff); + else + printf("%s", buff); + } + + fclose(trace_pipe_fd); + free(buff); + return -1; +} |