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-rw-r--r--tools/lib/api/fs/debugfs.c100
-rw-r--r--tools/lib/api/fs/debugfs.h29
-rw-r--r--tools/lib/api/fs/fs.c165
-rw-r--r--tools/lib/api/fs/fs.h14
4 files changed, 308 insertions, 0 deletions
diff --git a/tools/lib/api/fs/debugfs.c b/tools/lib/api/fs/debugfs.c
new file mode 100644
index 00000000000..a74fba6d774
--- /dev/null
+++ b/tools/lib/api/fs/debugfs.c
@@ -0,0 +1,100 @@
+#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 (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;
+}
diff --git a/tools/lib/api/fs/debugfs.h b/tools/lib/api/fs/debugfs.h
new file mode 100644
index 00000000000..f19d3df9609
--- /dev/null
+++ b/tools/lib/api/fs/debugfs.h
@@ -0,0 +1,29 @@
+#ifndef __API_DEBUGFS_H__
+#define __API_DEBUGFS_H__
+
+#define _STR(x) #x
+#define STR(x) _STR(x)
+
+/*
+ * On most systems <limits.h> would have given us this, but not on some systems
+ * (e.g. GNU/Hurd).
+ */
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+#ifndef DEBUGFS_MAGIC
+#define DEBUGFS_MAGIC 0x64626720
+#endif
+
+#ifndef PERF_DEBUGFS_ENVIRONMENT
+#define PERF_DEBUGFS_ENVIRONMENT "PERF_DEBUGFS_DIR"
+#endif
+
+const char *debugfs_find_mountpoint(void);
+int debugfs_valid_mountpoint(const char *debugfs);
+char *debugfs_mount(const char *mountpoint);
+
+extern char debugfs_mountpoint[];
+
+#endif /* __API_DEBUGFS_H__ */
diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c
new file mode 100644
index 00000000000..c1b49c36a95
--- /dev/null
+++ b/tools/lib/api/fs/fs.c
@@ -0,0 +1,165 @@
+/* TODO merge/factor in debugfs.c here */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/vfs.h>
+
+#include "debugfs.h"
+#include "fs.h"
+
+static const char * const sysfs__fs_known_mountpoints[] = {
+ "/sys",
+ 0,
+};
+
+static const char * const procfs__known_mountpoints[] = {
+ "/proc",
+ 0,
+};
+
+struct fs {
+ const char *name;
+ const char * const *mounts;
+ char path[PATH_MAX + 1];
+ bool found;
+ long magic;
+};
+
+enum {
+ FS__SYSFS = 0,
+ FS__PROCFS = 1,
+};
+
+static struct fs fs__entries[] = {
+ [FS__SYSFS] = {
+ .name = "sysfs",
+ .mounts = sysfs__fs_known_mountpoints,
+ .magic = SYSFS_MAGIC,
+ },
+ [FS__PROCFS] = {
+ .name = "proc",
+ .mounts = procfs__known_mountpoints,
+ .magic = PROC_SUPER_MAGIC,
+ },
+};
+
+static bool fs__read_mounts(struct fs *fs)
+{
+ bool found = false;
+ char type[100];
+ FILE *fp;
+
+ fp = fopen("/proc/mounts", "r");
+ if (fp == NULL)
+ return NULL;
+
+ while (!found &&
+ fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
+ fs->path, type) == 2) {
+
+ if (strcmp(type, fs->name) == 0)
+ found = true;
+ }
+
+ fclose(fp);
+ return fs->found = found;
+}
+
+static int fs__valid_mount(const char *fs, long magic)
+{
+ struct statfs st_fs;
+
+ if (statfs(fs, &st_fs) < 0)
+ return -ENOENT;
+ else if (st_fs.f_type != magic)
+ return -ENOENT;
+
+ return 0;
+}
+
+static bool fs__check_mounts(struct fs *fs)
+{
+ const char * const *ptr;
+
+ ptr = fs->mounts;
+ while (*ptr) {
+ if (fs__valid_mount(*ptr, fs->magic) == 0) {
+ fs->found = true;
+ strcpy(fs->path, *ptr);
+ return true;
+ }
+ ptr++;
+ }
+
+ return false;
+}
+
+static void mem_toupper(char *f, size_t len)
+{
+ while (len) {
+ *f = toupper(*f);
+ f++;
+ len--;
+ }
+}
+
+/*
+ * Check for "NAME_PATH" environment variable to override fs location (for
+ * testing). This matches the recommendation in Documentation/sysfs-rules.txt
+ * for SYSFS_PATH.
+ */
+static bool fs__env_override(struct fs *fs)
+{
+ char *override_path;
+ size_t name_len = strlen(fs->name);
+ /* name + "_PATH" + '\0' */
+ char upper_name[name_len + 5 + 1];
+ memcpy(upper_name, fs->name, name_len);
+ mem_toupper(upper_name, name_len);
+ strcpy(&upper_name[name_len], "_PATH");
+
+ override_path = getenv(upper_name);
+ if (!override_path)
+ return false;
+
+ fs->found = true;
+ strncpy(fs->path, override_path, sizeof(fs->path));
+ return true;
+}
+
+static const char *fs__get_mountpoint(struct fs *fs)
+{
+ if (fs__env_override(fs))
+ return fs->path;
+
+ if (fs__check_mounts(fs))
+ return fs->path;
+
+ if (fs__read_mounts(fs))
+ return fs->path;
+
+ return NULL;
+}
+
+static const char *fs__mountpoint(int idx)
+{
+ struct fs *fs = &fs__entries[idx];
+
+ if (fs->found)
+ return (const char *)fs->path;
+
+ return fs__get_mountpoint(fs);
+}
+
+#define FS__MOUNTPOINT(name, idx) \
+const char *name##__mountpoint(void) \
+{ \
+ return fs__mountpoint(idx); \
+}
+
+FS__MOUNTPOINT(sysfs, FS__SYSFS);
+FS__MOUNTPOINT(procfs, FS__PROCFS);
diff --git a/tools/lib/api/fs/fs.h b/tools/lib/api/fs/fs.h
new file mode 100644
index 00000000000..cb7049551f3
--- /dev/null
+++ b/tools/lib/api/fs/fs.h
@@ -0,0 +1,14 @@
+#ifndef __API_FS__
+#define __API_FS__
+
+#ifndef SYSFS_MAGIC
+#define SYSFS_MAGIC 0x62656572
+#endif
+
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC 0x9fa0
+#endif
+
+const char *sysfs__mountpoint(void);
+const char *procfs__mountpoint(void);
+#endif /* __API_FS__ */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 12:54:04 +0000