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#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "debugfs.h"
#include "tracefs.h"
#include "tracing_path.h"
char tracing_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing";
char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
static void __tracing_path_set(const char *tracing, const char *mountpoint)
{
snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
mountpoint, tracing);
snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
mountpoint, tracing, "events");
}
static const char *tracing_path_tracefs_mount(void)
{
const char *mnt;
mnt = tracefs_mount(NULL);
if (!mnt)
return NULL;
__tracing_path_set("", mnt);
return mnt;
}
static const char *tracing_path_debugfs_mount(void)
{
const char *mnt;
mnt = debugfs_mount(NULL);
if (!mnt)
return NULL;
__tracing_path_set("tracing/", mnt);
return mnt;
}
const char *tracing_path_mount(void)
{
const char *mnt;
mnt = tracing_path_tracefs_mount();
if (mnt)
return mnt;
mnt = tracing_path_debugfs_mount();
return mnt;
}
void tracing_path_set(const char *mntpt)
{
__tracing_path_set("tracing/", mntpt);
}
char *get_tracing_file(const char *name)
{
char *file;
if (asprintf(&file, "%s/%s", tracing_path, name) < 0)
return NULL;
return file;
}
void put_tracing_file(char *file)
{
free(file);
}
static int strerror_open(int err, char *buf, size_t size, const char *filename)
{
char sbuf[128];
switch (err) {
case ENOENT:
if (debugfs_configured()) {
snprintf(buf, size,
"Error:\tFile %s/%s not found.\n"
"Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
debugfs_mountpoint, filename);
break;
}
snprintf(buf, size, "%s",
"Error:\tUnable to find debugfs\n"
"Hint:\tWas your kernel compiled with debugfs support?\n"
"Hint:\tIs the debugfs filesystem mounted?\n"
"Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
break;
case EACCES: {
const char *mountpoint = debugfs_mountpoint;
if (!access(debugfs_mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
const char *tracefs_mntpoint = tracefs_find_mountpoint();
if (tracefs_mntpoint)
mountpoint = tracefs_mntpoint;
}
snprintf(buf, size,
"Error:\tNo permissions to read %s/%s\n"
"Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
debugfs_mountpoint, filename, mountpoint);
}
break;
default:
snprintf(buf, size, "%s", strerror_r(err, sbuf, sizeof(sbuf)));
break;
}
return 0;
}
int tracing_path__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
{
char path[PATH_MAX];
snprintf(path, PATH_MAX, "tracing/events/%s/%s", sys, name ?: "*");
return strerror_open(err, buf, size, path);
}
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