mirror of
https://github.com/Fishwaldo/Star64_linux.git
synced 2025-04-21 05:44:01 +00:00
ab85785aa1
Now that we have two mountpoints, one for debugfs and another, for
tracefs, we end up needing to check permissions for both, so, on
a system with default config we were always asking the user to
check the permission of the debugfs mountpoint, even when it was
already sufficient. Fix it.
E.g.:
$ trace -e nanosleep usleep 1
Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit)
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'
$ sudo mount -o remount,mode=755 /sys/kernel/debug
$ trace -e nanosleep usleep 1
Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit)
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
$ sudo mount -o remount,mode=755 /sys/kernel/debug/tracing
$ trace -e nanosleep usleep 1
0.326 ( 0.061 ms): usleep/11961 nanosleep(rqtp: 0x7ffef1081c50) = 0
$
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-0viljeuhc7q84ic8kobsna43@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
129 lines
3 KiB
C
129 lines
3 KiB
C
#define _GNU_SOURCE
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#include <errno.h>
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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 <unistd.h>
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#include <stdbool.h>
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#include <sys/vfs.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/mount.h>
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#include <linux/kernel.h>
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#include "debugfs.h"
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#include "tracefs.h"
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#ifndef DEBUGFS_DEFAULT_PATH
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#define DEBUGFS_DEFAULT_PATH "/sys/kernel/debug"
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#endif
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char debugfs_mountpoint[PATH_MAX + 1] = DEBUGFS_DEFAULT_PATH;
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static const char * const debugfs_known_mountpoints[] = {
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DEBUGFS_DEFAULT_PATH,
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"/debug",
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0,
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};
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static bool debugfs_found;
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bool debugfs_configured(void)
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{
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return debugfs_find_mountpoint() != NULL;
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}
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/* find the path to the mounted debugfs */
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const char *debugfs_find_mountpoint(void)
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{
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const char *ret;
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if (debugfs_found)
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return (const char *)debugfs_mountpoint;
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ret = find_mountpoint("debugfs", (long) DEBUGFS_MAGIC,
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debugfs_mountpoint, PATH_MAX + 1,
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debugfs_known_mountpoints);
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if (ret)
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debugfs_found = true;
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return ret;
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}
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/* mount the debugfs somewhere if it's not mounted */
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char *debugfs_mount(const char *mountpoint)
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{
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/* see if it's already mounted */
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if (debugfs_find_mountpoint())
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goto out;
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/* if not mounted and no argument */
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if (mountpoint == NULL) {
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/* see if environment variable set */
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mountpoint = getenv(PERF_DEBUGFS_ENVIRONMENT);
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/* if no environment variable, use default */
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if (mountpoint == NULL)
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mountpoint = DEBUGFS_DEFAULT_PATH;
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}
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if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0)
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return NULL;
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/* save the mountpoint */
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debugfs_found = true;
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strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
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out:
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return debugfs_mountpoint;
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}
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int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename)
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{
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char sbuf[128];
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switch (err) {
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case ENOENT:
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if (debugfs_found) {
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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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debugfs_mountpoint, filename);
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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\n"
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"Hint:\tWas your kernel compiled with debugfs support?\n"
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"Hint:\tIs the debugfs 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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const char *mountpoint = debugfs_mountpoint;
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if (!access(debugfs_mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
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const char *tracefs_mntpoint = tracefs_find_mountpoint();
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if (tracefs_mntpoint)
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mountpoint = tracefs_mntpoint;
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}
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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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debugfs_mountpoint, filename, mountpoint);
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}
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break;
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default:
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snprintf(buf, size, "%s", strerror_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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int debugfs__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
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{
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char path[PATH_MAX];
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snprintf(path, PATH_MAX, "tracing/events/%s/%s", sys, name ?: "*");
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return debugfs__strerror_open(err, buf, size, path);
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}
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