[patch 2/4] perf_counter tools: Add infrastructure to support loading of kernel module symbols

Mike Galbraith
2009-07-02T06:07:23Z

perf_counter tools: Add infrastructure to support loading of kernel module symbols.

Add infrastructure for module path discovery and section load addresses.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>

---
tools/perf/Makefile | 2
tools/perf/util/module.c | 502 +++++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/module.h | 53 ++++
3 files changed, 557 insertions(+)

Index: linux-2.6/tools/perf/Makefile
===================================================================
--- linux-2.6.orig/tools/perf/Makefile
+++ linux-2.6/tools/perf/Makefile
@@ -306,6 +306,7 @@ LIB_H += util/strlist.h
LIB_H += util/run-command.h
LIB_H += util/sigchain.h
LIB_H += util/symbol.h
+LIB_H += util/module.h
LIB_H += util/color.h

LIB_OBJS += util/abspath.o
@@ -329,6 +330,7 @@ LIB_OBJS += util/usage.o
LIB_OBJS += util/wrapper.o
LIB_OBJS += util/sigchain.o
LIB_OBJS += util/symbol.o
+LIB_OBJS += util/module.o
LIB_OBJS += util/color.o
LIB_OBJS += util/pager.o
LIB_OBJS += util/header.o
Index: linux-2.6/tools/perf/util/module.h
===================================================================
--- /dev/null
+++ linux-2.6/tools/perf/util/module.h
@@ -0,0 +1,53 @@
+#ifndef _PERF_MODULE_
+#define _PERF_MODULE_ 1
+
+#include <linux/types.h>
+#include "../types.h"
+#include <linux/list.h>
+#include <linux/rbtree.h>
+
+struct section {
+ struct rb_node rb_node;
+ u64 hash;
+ u64 vma;
+ char *name;
+ char *path;
+};
+
+struct sec_dso {
+ struct list_head node;
+ struct rb_root secs;
+ struct section *(*find_section)(struct sec_dso *, const char *name);
+ char name[0];
+};
+
+struct module {
+ struct rb_node rb_node;
+ u64 hash;
+ char *name;
+ char *path;
+ struct sec_dso *sections;
+ int active;
+};
+
+struct mod_dso {
+ struct list_head node;
+ struct rb_root mods;
+ struct module *(*find_module)(struct mod_dso *, const char *name);
+ char name[0];
+};
+
+struct sec_dso *sec_dso__new_dso(const char *name);
+void sec_dso__delete_sections(struct sec_dso *self);
+void sec_dso__delete_self(struct sec_dso *self);
+size_t sec_dso__fprintf(struct sec_dso *self, FILE *fp);
+struct section *sec_dso__find_section(struct sec_dso *self, const char *name);
+
+struct mod_dso *mod_dso__new_dso(const char *name);
+void mod_dso__delete_modules(struct mod_dso *self);
+void mod_dso__delete_self(struct mod_dso *self);
+size_t mod_dso__fprintf(struct mod_dso *self, FILE *fp);
+struct module *mod_dso__find_module(struct mod_dso *self, const char *name);
+int mod_dso__load_modules(struct mod_dso *dso);
+
+#endif /* _PERF_MODULE_ */
Index: linux-2.6/tools/perf/util/module.c
===================================================================
--- /dev/null
+++ linux-2.6/tools/perf/util/module.c
@@ -0,0 +1,502 @@
+#include "util.h"
+#include "../perf.h"
+#include "string.h"
+#include "module.h"
+
+#include <libelf.h>
+#include <gelf.h>
+#include <elf.h>
+#include <dirent.h>
+#include <sys/utsname.h>
+
+static unsigned int crc32(const char *p, unsigned int len)
+{
+ int i;
+ unsigned int crc = 0;
+ while (len--) {
+ crc ^= *p++;
+ for (i = 0; i < 8; i++)
+ crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
+ }
+ return crc;
+}
+
+/* module section methods */
+
+struct sec_dso *sec_dso__new_dso(const char *name)
+{
+ struct sec_dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+ if (self != NULL) {
+ strcpy(self->name, name);
+ self->secs = RB_ROOT;
+ self->find_section = sec_dso__find_section;
+ }
+
+ return self;
+}
+
+static void sec_dso__delete_section(struct section *self)
+{
+ free(((void *)self));
+}
+
+void sec_dso__delete_sections(struct sec_dso *self)
+{
+ struct section *pos;
+ struct rb_node *next = rb_first(&self->secs);
+
+ while (next) {
+ pos = rb_entry(next, struct section, rb_node);
+ next = rb_next(&pos->rb_node);
+ rb_erase(&pos->rb_node, &self->secs);
+ sec_dso__delete_section(pos);
+ }
+}
+
+void sec_dso__delete_self(struct sec_dso *self)
+{
+ sec_dso__delete_sections(self);
+ free(self);
+}
+
+static void sec_dso__insert_section(struct sec_dso *self, struct section *sec)
+{
+ struct rb_node **p = &self->secs.rb_node;
+ struct rb_node *parent = NULL;
+ const u64 hash = sec->hash;
+ struct section *s;
+
+ while (*p != NULL) {
+ parent = *p;
+ s = rb_entry(parent, struct section, rb_node);
+ if (hash < s->hash)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+ rb_link_node(&sec->rb_node, parent, p);
+ rb_insert_color(&sec->rb_node, &self->secs);
+}
+
+struct section *sec_dso__find_section(struct sec_dso *self, const char *name)
+{
+ struct rb_node *n;
+ u64 hash;
+ int len;
+
+ if (self == NULL)
+ return NULL;
+
+ len = strlen(name);
+ hash = crc32(name, len);
+
+ n = self->secs.rb_node;
+
+ while (n) {
+ struct section *s = rb_entry(n, struct section, rb_node);
+
+ if (hash < s->hash)
+ n = n->rb_left;
+ else if (hash > s->hash)
+ n = n->rb_right;
+ else {
+ if (!strcmp(name, s->name))
+ return s;
+ else
+ n = rb_next(&s->rb_node);
+ }
+ }
+
+ return NULL;
+}
+
+static size_t sec_dso__fprintf_section(struct section *self, FILE *fp)
+{
+ return fprintf(fp, "name:%s vma:%llx path:%s\n",
+ self->name, self->vma, self->path);
+}
+
+size_t sec_dso__fprintf(struct sec_dso *self, FILE *fp)
+{
+ size_t ret = fprintf(fp, "dso: %s\n", self->name);
+
+ struct rb_node *nd;
+ for (nd = rb_first(&self->secs); nd; nd = rb_next(nd)) {
+ struct section *pos = rb_entry(nd, struct section, rb_node);
+ ret += sec_dso__fprintf_section(pos, fp);
+ }
+
+ return ret;
+}
+
+static struct section *section__new(const char *name, const char *path)
+{
+ struct section *self = calloc(1, sizeof(*self));
+
+ if (!self)
+ goto out_failure;
+
+ self->name = calloc(1, strlen(name) + 1);
+ if (!self->name)
+ goto out_failure;
+
+ self->path = calloc(1, strlen(path) + 1);
+ if (!self->path)
+ goto out_failure;
+
+ strcpy(self->name, name);
+ strcpy(self->path, path);
+ self->hash = crc32(self->name, strlen(name));
+
+ return self;
+
+out_failure:
+ if (self) {
+ if (self->name)
+ free (self->name);
+ if (self->path)
+ free (self->path);
+ free (self);
+ }
+
+ return NULL;
+}
+
+/* module methods */
+
+struct mod_dso *mod_dso__new_dso(const char *name)
+{
+ struct mod_dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+ if (self != NULL) {
+ strcpy(self->name, name);
+ self->mods = RB_ROOT;
+ self->find_module = mod_dso__find_module;
+ }
+
+ return self;
+}
+
+static void mod_dso__delete_module(struct module *self)
+{
+ free(((void *)self));
+}
+
+void mod_dso__delete_modules(struct mod_dso *self)
+{
+ struct module *pos;
+ struct rb_node *next = rb_first(&self->mods);
+
+ while (next) {
+ pos = rb_entry(next, struct module, rb_node);
+ next = rb_next(&pos->rb_node);
+ rb_erase(&pos->rb_node, &self->mods);
+ mod_dso__delete_module(pos);
+ }
+}
+
+void mod_dso__delete_self(struct mod_dso *self)
+{
+ mod_dso__delete_modules(self);
+ free(self);
+}
+
+static void mod_dso__insert_module(struct mod_dso *self, struct module *mod)
+{
+ struct rb_node **p = &self->mods.rb_node;
+ struct rb_node *parent = NULL;
+ const u64 hash = mod->hash;
+ struct module *m;
+
+ while (*p != NULL) {
+ parent = *p;
+ m = rb_entry(parent, struct module, rb_node);
+ if (hash < m->hash)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+ rb_link_node(&mod->rb_node, parent, p);
+ rb_insert_color(&mod->rb_node, &self->mods);
+}
+
+struct module *mod_dso__find_module(struct mod_dso *self, const char *name)
+{
+ struct rb_node *n;
+ u64 hash;
+ int len;
+
+ if (self == NULL)
+ return NULL;
+
+ len = strlen(name);
+ hash = crc32(name, len);
+
+ n = self->mods.rb_node;
+
+ while (n) {
+ struct module *m = rb_entry(n, struct module, rb_node);
+
+ if (hash < m->hash)
+ n = n->rb_left;
+ else if (hash > m->hash)
+ n = n->rb_right;
+ else {
+ if (!strcmp(name, m->name))
+ return m;
+ else
+ n = rb_next(&m->rb_node);
+ }
+ }
+
+ return NULL;
+}
+
+static size_t mod_dso__fprintf_module(struct module *self, FILE *fp)
+{
+ return fprintf(fp, "name:%s path:%s\n", self->name, self->path);
+}
+
+size_t mod_dso__fprintf(struct mod_dso *self, FILE *fp)
+{
+ size_t ret = fprintf(fp, "dso: %s\n", self->name);
+
+ struct rb_node *nd;
+ for (nd = rb_first(&self->mods); nd; nd = rb_next(nd)) {
+ struct module *pos = rb_entry(nd, struct module, rb_node);
+ ret += mod_dso__fprintf_module(pos, fp);
+ }
+
+ return ret;
+}
+
+static struct module *module__new(const char *name, const char *path)
+{
+ struct module *self = calloc(1, sizeof(*self));
+
+ if (!self)
+ goto out_failure;
+
+ self->name = calloc(1, strlen(name) + 1);
+ if (!self->name)
+ goto out_failure;
+
+ self->path = calloc(1, strlen(path) + 1);
+ if (!self->path)
+ goto out_failure;
+
+ strcpy(self->name, name);
+ strcpy(self->path, path);
+ self->hash = crc32(self->name, strlen(name));
+
+ return self;
+
+out_failure:
+ if (self) {
+ if (self->name)
+ free (self->name);
+ if (self->path)
+ free (self->path);
+ free (self);
+ }
+
+ return NULL;
+}
+
+static int mod_dso__load_sections(struct module *mod)
+{
+ struct dirent *entry;
+ DIR *dir;
+ size_t n;
+ int count = 0, path_len;
+ char *line = NULL;
+ char *dir_path;
+
+ path_len = strlen("/sys/module/");
+ path_len += strlen(mod->name);
+ path_len += strlen("/sections/");
+
+ dir_path = calloc(1, path_len + 1);
+ if (dir_path == NULL)
+ goto out_failure;
+
+ strcat(dir_path, "/sys/module/");
+ strcat(dir_path, mod->name);
+ strcat(dir_path, "/sections/");
+
+ dir = opendir(dir_path);
+ if (dir == NULL)
+ goto out_free;
+
+ while ((entry = readdir(dir))) {
+ struct section *section;
+ FILE *file;
+ char *path, *vma;
+ int line_len;
+
+ if (!strcmp(".", entry->d_name) || !strcmp("..", entry->d_name))
+ continue;
+
+ path = calloc(1, path_len + strlen(entry->d_name) + 1);
+ if (path == NULL)
+ break;
+ strcat(path, dir_path);
+ strcat(path, entry->d_name);
+
+ file = fopen(path, "r");
+ if (file == NULL) {
+ free(path);
+ break;
+ }
+
+ line_len = getline(&line, &n, file);
+ if (line_len < 0) {
+ free(path);
+ fclose(file);
+ break;
+ }
+
+ if (!line) {
+ free(path);
+ fclose(file);
+ break;
+ }
+
+ line[--line_len] = '\0'; /* \n */
+
+ vma = strstr(line, "0x");
+ if (!vma) {
+ free(path);
+ fclose(file);
+ break;
+ }
+ vma += 2;
+
+ section = section__new(entry->d_name, path);
+ if (!section) {
+ fprintf(stderr, "load_sections: allocation error\n");
+ free(path);
+ fclose(file);
+ break;
+ }
+
+ hex2u64(vma, &section->vma);
+ sec_dso__insert_section(mod->sections, section);
+
+ free(path);
+ fclose(file);
+ count++;
+ }
+
+ closedir(dir);
+ free(line);
+ free(dir_path);
+
+ return count;
+
+out_free:
+ free(dir_path);
+
+out_failure:
+ return count;
+}
+
+static int mod_dso__load_module_paths(struct mod_dso *self)
+{
+ struct utsname uts;
+ char *line = NULL;
+ size_t n;
+ FILE *file;
+ int count = 0, len;
+ char *path;
+
+ if(uname(&uts) < 0)
+ goto out_failure;
+
+ len = strlen("/lib/modules/");
+ len += strlen(uts.release);
+ len += strlen("/modules.dep");
+
+ path = calloc(1, len);
+ if (path == NULL)
+ goto out_failure;
+
+ strcat(path, "/lib/modules/");
+ strcat(path, uts.release);
+ strcat(path, "/modules.dep");
+
+ file = fopen(path, "r");
+ free(path);
+ if (file == NULL)
+ goto out_failure;
+
+ while (!feof(file)) {
+ struct module *module;
+ int line_len, len;
+ char *path, *name, *tmp;
+
+ line_len = getline(&line, &n, file);
+ if (line_len < 0)
+ break;
+
+ if (!line)
+ goto out_failure;
+
+ line[--line_len] = '\0'; /* \n */
+
+ path = strtok(line, ":");
+ if (!path)
+ goto out_failure;
+
+ name = strdup(path);
+ name = tmp = strtok(name, "/");
+ while(tmp) {
+ tmp = strtok(NULL, "/");
+ if (tmp)
+ name = tmp;
+ }
+ name = strsep(&name, ".");
+
+ /* Replace '-' with '_' in damn sound modules */
+ for (len = strlen(name); len; len--)
+ if (*(name+len) == '-')
+ *(name+len) = '_';
+
+ module = module__new(name, path);
+ if (!module) {
+ fprintf(stderr, "load_module_paths: allocation error\n");
+ goto out_failure;
+ }
+ mod_dso__insert_module(self, module);
+
+ module->sections = sec_dso__new_dso("sections");
+ if (!module->sections) {
+ fprintf(stderr, "load_module_paths: allocation error\n");
+ goto out_failure;
+ }
+
+ module->active = mod_dso__load_sections(module);
+
+ if (module->active > 0)
+ count++;
+ }
+
+ free(line);
+ fclose(file);
+
+ return count;
+
+out_failure:
+ return -1;
+}
+
+int mod_dso__load_modules(struct mod_dso *dso)
+{
+ int err;
+
+ err = mod_dso__load_module_paths(dso);
+
+ return err;
+}
+