diff options
| -rw-r--r-- | tools/lib/api/Makefile | 2 | ||||
| -rw-r--r-- | tools/lib/api/fs/tracefs.c | 70 | ||||
| -rw-r--r-- | tools/lib/api/fs/tracefs.h | 20 |
3 files changed, 92 insertions, 0 deletions
diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile index 22b2f15d7255..212aa4fd65a0 100644 --- a/tools/lib/api/Makefile +++ b/tools/lib/api/Makefile @@ -9,12 +9,14 @@ LIB_H= LIB_OBJS= LIB_H += fs/debugfs.h +LIB_H += fs/tracefs.h LIB_H += fs/findfs.h LIB_H += fs/fs.h # See comment below about piggybacking... LIB_H += fd/array.h LIB_OBJS += $(OUTPUT)fs/debugfs.o +LIB_OBJS += $(OUTPUT)fs/tracefs.o LIB_OBJS += $(OUTPUT)fs/findfs.o LIB_OBJS += $(OUTPUT)fs/fs.o # XXX piggybacking here, need to introduce libapikfd, or rename this diff --git a/tools/lib/api/fs/tracefs.c b/tools/lib/api/fs/tracefs.c new file mode 100644 index 000000000000..ef40d15821e9 --- /dev/null +++ b/tools/lib/api/fs/tracefs.c @@ -0,0 +1,70 @@ +#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 "tracefs.h" + +#ifndef TRACEFS_DEFAULT_PATH +#define TRACEFS_DEFAULT_PATH "/sys/kernel/tracing" +#endif + +char tracefs_mountpoint[PATH_MAX + 1] = TRACEFS_DEFAULT_PATH; + +static const char * const tracefs_known_mountpoints[] = { + TRACEFS_DEFAULT_PATH, + "/sys/kernel/debug/tracing", + "/tracing", + "/trace", + 0, +}; + +static bool tracefs_found; + +/* find the path to the mounted tracefs */ +const char *tracefs_find_mountpoint(void) +{ + const char *ret; + + if (tracefs_found) + return (const char *)tracefs_mountpoint; + + ret = find_mountpoint("tracefs", (long) TRACEFS_MAGIC, + tracefs_mountpoint, PATH_MAX + 1, + tracefs_known_mountpoints); + + if (ret) + tracefs_found = true; + + return ret; +} + +/* mount the tracefs somewhere if it's not mounted */ +char *tracefs_mount(const char *mountpoint) +{ + /* see if it's already mounted */ + if (tracefs_find_mountpoint()) + goto out; + + /* if not mounted and no argument */ + if (mountpoint == NULL) { + /* see if environment variable set */ + mountpoint = getenv(PERF_TRACEFS_ENVIRONMENT); + /* if no environment variable, use default */ + if (mountpoint == NULL) + mountpoint = TRACEFS_DEFAULT_PATH; + } + + if (mount(NULL, mountpoint, "tracefs", 0, NULL) < 0) + return NULL; + + /* save the mountpoint */ + tracefs_found = true; + strncpy(tracefs_mountpoint, mountpoint, sizeof(tracefs_mountpoint)); +out: + return tracefs_mountpoint; +} diff --git a/tools/lib/api/fs/tracefs.h b/tools/lib/api/fs/tracefs.h new file mode 100644 index 000000000000..e6f7f5183c87 --- /dev/null +++ b/tools/lib/api/fs/tracefs.h @@ -0,0 +1,20 @@ +#ifndef __API_TRACEFS_H__ +#define __API_TRACEFS_H__ + +#include "findfs.h" + +#ifndef TRACEFS_MAGIC +#define TRACEFS_MAGIC 0x74726163 +#endif + +#ifndef PERF_TRACEFS_ENVIRONMENT +#define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR" +#endif + +const char *tracefs_find_mountpoint(void); +int tracefs_valid_mountpoint(const char *debugfs); +char *tracefs_mount(const char *mountpoint); + +extern char tracefs_mountpoint[]; + +#endif /* __API_DEBUGFS_H__ */ |