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: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1246514830.13293.44.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 562 insertions, 0 deletions

diff --git a/tools/perf/util/module.c b/tools/perf/util/module.c
new file mode 100644
index 00000000000..ddabe925d65
--- /dev/null
+++ b/tools/perf/util/module.c
@@ -0,0 +1,509 @@
+#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)
+{
+        struct rb_node *nd;
+        size_t ret;
+
+        ret = fprintf(fp, "dso: %s\n", self->name);
+
+        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)
+{
+        int count = 0, path_len;
+        struct dirent *entry;
+        char *line = NULL;
+        char *dir_path;
+        DIR *dir;
+        size_t n;
+
+        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;
+                char *path, *vma;
+                int line_len;
+                FILE *file;
+
+                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;
+        int count = 0, len;
+        char *line = NULL;
+        FILE *file;
+        char *path;
+        size_t n;
+
+        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)) {
+                char *path, *name, *tmp;
+                struct module *module;
+                int line_len, len;
+
+                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 = strtok(name, "/");
+
+                tmp = name;
+
+                while (tmp) {
+                        tmp = strtok(NULL, "/");
+                        if (tmp)
+                                name = tmp;
+                }
+                name = strsep(&name, ".");
+
+                /* Quirk: replace '-' with '_' in 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;
+}
diff --git a/tools/perf/util/module.h b/tools/perf/util/module.h
new file mode 100644
index 00000000000..8a592ef641c
--- /dev/null
+++ b/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_ */