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17c257e867
One should use tracing_path_mount() instead, so more things get done lazily instead of at every 'perf' tool call startup. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-fci4yll35idd9yuslp67vqc2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
141 lines
3.2 KiB
C
141 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#ifndef _GNU_SOURCE
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# define _GNU_SOURCE
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <linux/string.h>
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#include <errno.h>
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#include <unistd.h>
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#include "fs.h"
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#include "tracing_path.h"
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static char tracing_mnt[PATH_MAX] = "/sys/kernel/debug";
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static char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing";
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char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
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static void __tracing_path_set(const char *tracing, const char *mountpoint)
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{
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snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
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snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
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mountpoint, tracing);
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snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
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mountpoint, tracing, "events");
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}
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static const char *tracing_path_tracefs_mount(void)
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{
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const char *mnt;
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mnt = tracefs__mount();
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if (!mnt)
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return NULL;
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__tracing_path_set("", mnt);
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return mnt;
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}
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static const char *tracing_path_debugfs_mount(void)
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{
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const char *mnt;
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mnt = debugfs__mount();
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if (!mnt)
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return NULL;
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__tracing_path_set("tracing/", mnt);
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return mnt;
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}
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const char *tracing_path_mount(void)
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{
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const char *mnt;
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mnt = tracing_path_tracefs_mount();
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if (mnt)
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return mnt;
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mnt = tracing_path_debugfs_mount();
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return mnt;
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}
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void tracing_path_set(const char *mntpt)
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{
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__tracing_path_set("tracing/", mntpt);
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}
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char *get_tracing_file(const char *name)
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{
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char *file;
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if (asprintf(&file, "%s/%s", tracing_path_mount(), name) < 0)
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return NULL;
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return file;
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}
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void put_tracing_file(char *file)
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{
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free(file);
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}
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int tracing_path__strerror_open_tp(int err, char *buf, size_t size,
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const char *sys, const char *name)
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{
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char sbuf[128];
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char filename[PATH_MAX];
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snprintf(filename, PATH_MAX, "%s/%s", sys, name ?: "*");
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switch (err) {
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case ENOENT:
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/*
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* We will get here if we can't find the tracepoint, but one of
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* debugfs or tracefs is configured, which means you probably
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* want some tracepoint which wasn't compiled in your kernel.
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* - jirka
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*/
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if (debugfs__configured() || tracefs__configured()) {
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/* sdt markers */
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if (!strncmp(filename, "sdt_", 4)) {
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snprintf(buf, size,
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"Error:\tFile %s/%s not found.\n"
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"Hint:\tSDT event cannot be directly recorded on.\n"
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"\tPlease first use 'perf probe %s:%s' before recording it.\n",
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tracing_events_path, filename, sys, name);
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} else {
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snprintf(buf, size,
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"Error:\tFile %s/%s not found.\n"
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"Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
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tracing_events_path, filename);
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}
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break;
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}
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snprintf(buf, size, "%s",
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"Error:\tUnable to find debugfs/tracefs\n"
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"Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
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"Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
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"Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
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break;
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case EACCES: {
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snprintf(buf, size,
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"Error:\tNo permissions to read %s/%s\n"
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"Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
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tracing_events_path, filename, tracing_path_mount());
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}
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break;
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default:
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snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf)));
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break;
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}
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return 0;
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}
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