Star64_linux/tools/lib/api/fs/debugfs.c
Alexey Brodkin db1806edcf perf tools: Fix statfs.f_type data type mismatch build error with uclibc
ARC Linux uses the no legacy syscalls abi and corresponding uClibc headers
statfs defines f_type to be U32 which causes perf build breakage

http://git.uclibc.org/uClibc/tree/libc/sysdeps/linux/common-generic/bits/statfs.h

  ----------->8---------------
    CC       fs/fs.o
  fs/fs.c: In function 'fs__valid_mount':
  fs/fs.c:82:24: error: comparison between signed and unsigned integer
  expressions [-Werror=sign-compare]
    else if (st_fs.f_type != magic)
                          ^
  cc1: all warnings being treated as errors
  ----------->8---------------

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: http://lkml.kernel.org/r/1420888254-17504-2-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-01-16 17:49:29 -03:00

100 lines
2.1 KiB
C

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <sys/vfs.h>
#include <sys/mount.h>
#include <linux/kernel.h>
#include "debugfs.h"
char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug";
static const char * const debugfs_known_mountpoints[] = {
"/sys/kernel/debug",
"/debug",
0,
};
static bool debugfs_found;
/* find the path to the mounted debugfs */
const char *debugfs_find_mountpoint(void)
{
const char * const *ptr;
char type[100];
FILE *fp;
if (debugfs_found)
return (const char *)debugfs_mountpoint;
ptr = debugfs_known_mountpoints;
while (*ptr) {
if (debugfs_valid_mountpoint(*ptr) == 0) {
debugfs_found = true;
strcpy(debugfs_mountpoint, *ptr);
return debugfs_mountpoint;
}
ptr++;
}
/* give up and parse /proc/mounts */
fp = fopen("/proc/mounts", "r");
if (fp == NULL)
return NULL;
while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
debugfs_mountpoint, type) == 2) {
if (strcmp(type, "debugfs") == 0)
break;
}
fclose(fp);
if (strcmp(type, "debugfs") != 0)
return NULL;
debugfs_found = true;
return debugfs_mountpoint;
}
/* verify that a mountpoint is actually a debugfs instance */
int debugfs_valid_mountpoint(const char *debugfs)
{
struct statfs st_fs;
if (statfs(debugfs, &st_fs) < 0)
return -ENOENT;
else if ((long)st_fs.f_type != (long)DEBUGFS_MAGIC)
return -ENOENT;
return 0;
}
/* mount the debugfs somewhere if it's not mounted */
char *debugfs_mount(const char *mountpoint)
{
/* see if it's already mounted */
if (debugfs_find_mountpoint())
goto out;
/* if not mounted and no argument */
if (mountpoint == NULL) {
/* see if environment variable set */
mountpoint = getenv(PERF_DEBUGFS_ENVIRONMENT);
/* if no environment variable, use default */
if (mountpoint == NULL)
mountpoint = "/sys/kernel/debug";
}
if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0)
return NULL;
/* save the mountpoint */
debugfs_found = true;
strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
out:
return debugfs_mountpoint;
}