From 85c66be101e1847f0eb46dcb48d5738572129694 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 20 Feb 2013 16:32:30 +0100 Subject: perf tools: Introduce tools/lib/lk library This introduces the tools/lib/lk library, that will gradually have the routines that now are used in tools/perf/ and other tools and that can be shared. Start by carving out debugfs routines for general use. Signed-off-by: Borislav Petkov Cc: Ingo Molnar Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1361374353-30385-5-git-send-email-bp@alien8.de [ committer note: Add tools/lib/lk/ to perf's MANIFEST so that its tarballs continue to build ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/lk/Makefile | 35 +++++++++++++++ tools/lib/lk/debugfs.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++ tools/lib/lk/debugfs.h | 31 +++++++++++++ 3 files changed, 182 insertions(+) create mode 100644 tools/lib/lk/Makefile create mode 100644 tools/lib/lk/debugfs.c create mode 100644 tools/lib/lk/debugfs.h (limited to 'tools/lib/lk') diff --git a/tools/lib/lk/Makefile b/tools/lib/lk/Makefile new file mode 100644 index 0000000..8cf576f --- /dev/null +++ b/tools/lib/lk/Makefile @@ -0,0 +1,35 @@ +include ../../scripts/Makefile.include + +# guard against environment variables +LIB_H= +LIB_OBJS= + +LIB_H += debugfs.h + +LIB_OBJS += $(OUTPUT)debugfs.o + +LIBFILE = liblk.a + +CFLAGS = -ggdb3 -Wall -Wextra -std=gnu99 -Werror $(CFLAGS_OPTIMIZE) -D_FORTIFY_SOURCE=2 $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) -fPIC +EXTLIBS = -lpthread -lrt -lelf -lm +ALL_CFLAGS = $(CFLAGS) $(BASIC_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 +ALL_LDFLAGS = $(LDFLAGS) + +RM = rm -f + +$(LIBFILE): $(LIB_OBJS) + $(QUIET_AR)$(RM) $@ && $(AR) rcs $(OUTPUT)$@ $(LIB_OBJS) + +$(LIB_OBJS): $(LIB_H) + +$(OUTPUT)%.o: %.c + $(QUIET_CC)$(CC) -o $@ -c $(ALL_CFLAGS) $< +$(OUTPUT)%.s: %.c + $(QUIET_CC)$(CC) -S $(ALL_CFLAGS) $< +$(OUTPUT)%.o: %.S + $(QUIET_CC)$(CC) -o $@ -c $(ALL_CFLAGS) $< + +clean: + $(RM) $(LIB_OBJS) $(LIBFILE) + +.PHONY: clean diff --git a/tools/lib/lk/debugfs.c b/tools/lib/lk/debugfs.c new file mode 100644 index 0000000..9cda7a6 --- /dev/null +++ b/tools/lib/lk/debugfs.c @@ -0,0 +1,116 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "debugfs.h" + +char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug"; +char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events"; + +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; +} + +static void debugfs_set_tracing_events_path(const char *mountpoint) +{ + snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s", + mountpoint, "tracing/events"); +} + +/* 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: + debugfs_set_tracing_events_path(debugfs_mountpoint); + return debugfs_mountpoint; +} + +void debugfs_set_path(const char *mountpoint) +{ + snprintf(debugfs_mountpoint, sizeof(debugfs_mountpoint), "%s", mountpoint); + debugfs_set_tracing_events_path(mountpoint); +} diff --git a/tools/lib/lk/debugfs.h b/tools/lib/lk/debugfs.h new file mode 100644 index 0000000..bc5ad2d --- /dev/null +++ b/tools/lib/lk/debugfs.h @@ -0,0 +1,31 @@ +#ifndef __LK_DEBUGFS_H__ +#define __LK_DEBUGFS_H__ + +#define _STR(x) #x +#define STR(x) _STR(x) + +/* + * On most systems 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); +void debugfs_set_path(const char *mountpoint); + +extern char debugfs_mountpoint[]; +extern char tracing_events_path[]; + +#endif /* __LK_DEBUGFS_H__ */ -- cgit v1.1