perf_counter tools: Move symbol resolution classes from report to libperf

Will be used by perf top as well.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090528175504.GC4747@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 421 insertions, 0 deletions

diff --git a/Documentation/perf_counter/util/symbol.c b/Documentation/perf_counter/util/symbol.c
new file mode 100644
index 000000000000..d06de2cfcdc6
--- /dev/null
+++ b/Documentation/perf_counter/util/symbol.c
@@ -0,0 +1,421 @@
+#include "util.h"
+#include "../perf.h"
+#include "symbol.h"
+
+#include <libelf.h>
+#include <gelf.h>
+#include <elf.h>
+
+static struct symbol *symbol__new(uint64_t start, uint64_t len,
+                                  const char *name)
+{
+        struct symbol *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+        if (self != NULL) {
+                self->start = start;
+                self->end   = start + len;
+                strcpy(self->name, name);
+        }
+
+        return self;
+}
+
+static void symbol__delete(struct symbol *self)
+{
+        free(self);
+}
+
+static size_t symbol__fprintf(struct symbol *self, FILE *fp)
+{
+        return fprintf(fp, " %llx-%llx %s\n",
+                       self->start, self->end, self->name);
+}
+
+struct dso *dso__new(const char *name)
+{
+        struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+        if (self != NULL) {
+                strcpy(self->name, name);
+                self->syms = RB_ROOT;
+        }
+
+        return self;
+}
+
+static void dso__delete_symbols(struct dso *self)
+{
+        struct symbol *pos;
+        struct rb_node *next = rb_first(&self->syms);
+
+        while (next) {
+                pos = rb_entry(next, struct symbol, rb_node);
+                next = rb_next(&pos->rb_node);
+                symbol__delete(pos);
+        }
+}
+
+void dso__delete(struct dso *self)
+{
+        dso__delete_symbols(self);
+        free(self);
+}
+
+static void dso__insert_symbol(struct dso *self, struct symbol *sym)
+{
+        struct rb_node **p = &self->syms.rb_node;
+        struct rb_node *parent = NULL;
+        const uint64_t ip = sym->start;
+        struct symbol *s;
+
+        while (*p != NULL) {
+                parent = *p;
+                s = rb_entry(parent, struct symbol, rb_node);
+                if (ip < s->start)
+                        p = &(*p)->rb_left;
+                else
+                        p = &(*p)->rb_right;
+        }
+        rb_link_node(&sym->rb_node, parent, p);
+        rb_insert_color(&sym->rb_node, &self->syms);
+}
+
+struct symbol *dso__find_symbol(struct dso *self, uint64_t ip)
+{
+        struct rb_node *n;
+
+        if (self == NULL)
+                return NULL;
+
+        n = self->syms.rb_node;
+
+        while (n) {
+                struct symbol *s = rb_entry(n, struct symbol, rb_node);
+
+                if (ip < s->start)
+                        n = n->rb_left;
+                else if (ip > s->end)
+                        n = n->rb_right;
+                else
+                        return s;
+        }
+
+        return NULL;
+}
+
+size_t dso__fprintf(struct dso *self, FILE *fp)
+{
+        size_t ret = fprintf(fp, "dso: %s\n", self->name);
+
+        struct rb_node *nd;
+        for (nd = rb_first(&self->syms); nd; nd = rb_next(nd)) {
+                struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
+                ret += symbol__fprintf(pos, fp);
+        }
+
+        return ret;
+}
+
+static int hex(char ch)
+{
+        if ((ch >= '0') && (ch <= '9'))
+                return ch - '0';
+        if ((ch >= 'a') && (ch <= 'f'))
+                return ch - 'a' + 10;
+        if ((ch >= 'A') && (ch <= 'F'))
+                return ch - 'A' + 10;
+        return -1;
+}
+
+/*
+ * While we find nice hex chars, build a long_val.
+ * Return number of chars processed.
+ */
+static int hex2long(char *ptr, unsigned long *long_val)
+{
+        const char *p = ptr;
+        *long_val = 0;
+
+        while (*p) {
+                const int hex_val = hex(*p);
+
+                if (hex_val < 0)
+                        break;
+
+                *long_val = (*long_val << 4) | hex_val;
+                p++;
+        }
+
+        return p - ptr;
+}
+
+int dso__load_kallsyms(struct dso *self)
+{
+        struct rb_node *nd, *prevnd;
+        char *line = NULL;
+        size_t n;
+        FILE *file = fopen("/proc/kallsyms", "r");
+
+        if (file == NULL)
+                goto out_failure;
+
+        while (!feof(file)) {
+                unsigned long start;
+                struct symbol *sym;
+                int line_len, len;
+                char symbol_type;
+
+                line_len = getline(&line, &n, file);
+                if (line_len < 0)
+                        break;
+
+                if (!line)
+                        goto out_failure;
+
+                line[--line_len] = '\0'; /* \n */
+
+                len = hex2long(line, &start);
+
+                len++;
+                if (len + 2 >= line_len)
+                        continue;
+
+                symbol_type = toupper(line[len]);
+                /*
+                 * We're interested only in code ('T'ext)
+                 */
+                if (symbol_type != 'T' && symbol_type != 'W')
+                        continue;
+                /*
+                 * Well fix up the end later, when we have all sorted.
+                 */
+                sym = symbol__new(start, 0xdead, line + len + 2);
+
+                if (sym == NULL)
+                        goto out_delete_line;
+
+                dso__insert_symbol(self, sym);
+        }
+
+        /*
+         * Now that we have all sorted out, just set the ->end of all
+         * symbols
+         */
+        prevnd = rb_first(&self->syms);
+
+        if (prevnd == NULL)
+                goto out_delete_line;
+
+        for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
+                struct symbol *prev = rb_entry(prevnd, struct symbol, rb_node),
+                              *curr = rb_entry(nd, struct symbol, rb_node);
+
+                prev->end = curr->start - 1;
+                prevnd = nd;
+        }
+
+        free(line);
+        fclose(file);
+
+        return 0;
+
+out_delete_line:
+        free(line);
+out_failure:
+        return -1;
+}
+
+/**
+ * elf_symtab__for_each_symbol - iterate thru all the symbols
+ *
+ * @self: struct elf_symtab instance to iterate
+ * @index: uint32_t index
+ * @sym: GElf_Sym iterator
+ */
+#define elf_symtab__for_each_symbol(syms, nr_syms, index, sym) \
+        for (index = 0, gelf_getsym(syms, index, &sym);\
+             index < nr_syms; \
+             index++, gelf_getsym(syms, index, &sym))
+
+static inline uint8_t elf_sym__type(const GElf_Sym *sym)
+{
+        return GELF_ST_TYPE(sym->st_info);
+}
+
+static inline int elf_sym__is_function(const GElf_Sym *sym)
+{
+        return elf_sym__type(sym) == STT_FUNC &&
+               sym->st_name != 0 &&
+               sym->st_shndx != SHN_UNDEF &&
+               sym->st_size != 0;
+}
+
+static inline const char *elf_sym__name(const GElf_Sym *sym,
+                                        const Elf_Data *symstrs)
+{
+        return symstrs->d_buf + sym->st_name;
+}
+
+static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+                                    GElf_Shdr *shp, const char *name,
+                                    size_t *index)
+{
+        Elf_Scn *sec = NULL;
+        size_t cnt = 1;
+
+        while ((sec = elf_nextscn(elf, sec)) != NULL) {
+                char *str;
+
+                gelf_getshdr(sec, shp);
+                str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
+                if (!strcmp(name, str)) {
+                        if (index)
+                                *index = cnt;
+                        break;
+                }
+                ++cnt;
+        }
+
+        return sec;
+}
+
+static int dso__load_sym(struct dso *self, int fd, const char *name)
+{
+        Elf_Data *symstrs;
+        uint32_t nr_syms;
+        int err = -1;
+        uint32_t index;
+        GElf_Ehdr ehdr;
+        GElf_Shdr shdr;
+        Elf_Data *syms;
+        GElf_Sym sym;
+        Elf_Scn *sec;
+        Elf *elf;
+        int nr = 0;
+
+        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+        if (elf == NULL) {
+                fprintf(stderr, "%s: cannot read %s ELF file.\n",
+                        __func__, name);
+                goto out_close;
+        }
+
+        if (gelf_getehdr(elf, &ehdr) == NULL) {
+                fprintf(stderr, "%s: cannot get elf header.\n", __func__);
+                goto out_elf_end;
+        }
+
+        sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
+        if (sec == NULL)
+                sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
+
+        if (sec == NULL)
+                goto out_elf_end;
+
+        syms = elf_getdata(sec, NULL);
+        if (syms == NULL)
+                goto out_elf_end;
+
+        sec = elf_getscn(elf, shdr.sh_link);
+        if (sec == NULL)
+                goto out_elf_end;
+
+        symstrs = elf_getdata(sec, NULL);
+        if (symstrs == NULL)
+                goto out_elf_end;
+
+        nr_syms = shdr.sh_size / shdr.sh_entsize;
+
+        elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
+                struct symbol *f;
+
+                if (!elf_sym__is_function(&sym))
+                        continue;
+
+                sec = elf_getscn(elf, sym.st_shndx);
+                if (!sec)
+                        goto out_elf_end;
+
+                gelf_getshdr(sec, &shdr);
+                sym.st_value -= shdr.sh_addr - shdr.sh_offset;
+
+                f = symbol__new(sym.st_value, sym.st_size,
+                                elf_sym__name(&sym, symstrs));
+                if (!f)
+                        goto out_elf_end;
+
+                dso__insert_symbol(self, f);
+
+                nr++;
+        }
+
+        err = nr;
+out_elf_end:
+        elf_end(elf);
+out_close:
+        return err;
+}
+
+int dso__load(struct dso *self)
+{
+        int size = strlen(self->name) + sizeof("/usr/lib/debug%s.debug");
+        char *name = malloc(size);
+        int variant = 0;
+        int ret = -1;
+        int fd;
+
+        if (!name)
+                return -1;
+
+more:
+        do {
+                switch (variant) {
+                case 0: /* Fedora */
+                        snprintf(name, size, "/usr/lib/debug%s.debug", self->name);
+                        break;
+                case 1: /* Ubuntu */
+                        snprintf(name, size, "/usr/lib/debug%s", self->name);
+                        break;
+                case 2: /* Sane people */
+                        snprintf(name, size, "%s", self->name);
+                        break;
+
+                default:
+                        goto out;
+                }
+                variant++;
+
+                fd = open(name, O_RDONLY);
+        } while (fd < 0);
+
+        ret = dso__load_sym(self, fd, name);
+        close(fd);
+
+        /*
+         * Some people seem to have debuginfo files _WITHOUT_ debug info!?!?
+         */
+        if (!ret)
+                goto more;
+
+out:
+        free(name);
+        return ret;
+}
+
+int dso__load_vmlinux(struct dso *self, const char *vmlinux)
+{
+        int err, fd = open(vmlinux, O_RDONLY);
+
+        if (fd < 0)
+                return -1;
+
+        err = dso__load_sym(self, fd, vmlinux);
+        close(fd);
+
+        return err;
+}
+
+void symbol__init(void)
+{
+        elf_version(EV_CURRENT);
+}