From 864709302a80f26fa9da3be5b47304f0b8bae192 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 6 Jun 2009 20:33:43 +0200 Subject: perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ Several people have suggested that 'perf' has become a full-fledged tool that should be moved out of Documentation/. Move it to the (new) tools/ directory. Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/util/symbol.c | 574 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 574 insertions(+) create mode 100644 tools/perf/util/symbol.c (limited to 'tools/perf/util/symbol.c') diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c new file mode 100644 index 00000000000..23f4f7b3b83 --- /dev/null +++ b/tools/perf/util/symbol.c @@ -0,0 +1,574 @@ +#include "util.h" +#include "../perf.h" +#include "string.h" +#include "symbol.h" + +#include +#include +#include + +const char *sym_hist_filter; + +static struct symbol *symbol__new(uint64_t start, uint64_t len, + const char *name, unsigned int priv_size, + uint64_t obj_start, int verbose) +{ + size_t namelen = strlen(name) + 1; + struct symbol *self = calloc(1, priv_size + sizeof(*self) + namelen); + + if (!self) + return NULL; + + if (verbose >= 2) + printf("new symbol: %016Lx [%08lx]: %s, hist: %p, obj_start: %p\n", + (__u64)start, len, name, self->hist, (void *)obj_start); + + self->obj_start= obj_start; + self->hist = NULL; + self->hist_sum = 0; + + if (sym_hist_filter && !strcmp(name, sym_hist_filter)) + self->hist = calloc(sizeof(__u64), len); + + if (priv_size) { + memset(self, 0, priv_size); + self = ((void *)self) + priv_size; + } + self->start = start; + self->end = start + len - 1; + memcpy(self->name, name, namelen); + + return self; +} + +static void symbol__delete(struct symbol *self, unsigned int priv_size) +{ + free(((void *)self) - priv_size); +} + +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, unsigned int sym_priv_size) +{ + struct dso *self = malloc(sizeof(*self) + strlen(name) + 1); + + if (self != NULL) { + strcpy(self->name, name); + self->syms = RB_ROOT; + self->sym_priv_size = sym_priv_size; + self->find_symbol = dso__find_symbol; + } + + 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); + rb_erase(&pos->rb_node, &self->syms); + symbol__delete(pos, self->sym_priv_size); + } +} + +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 dso__load_kallsyms(struct dso *self, symbol_filter_t filter, int verbose) +{ + 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)) { + __u64 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 = hex2u64(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, + self->sym_priv_size, 0, verbose); + + if (sym == NULL) + goto out_delete_line; + + if (filter && filter(self, sym)) + symbol__delete(sym, self->sym_priv_size); + else + 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; +} + +#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ + for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ + idx < nr_entries; \ + ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) + +#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ + for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ + idx < nr_entries; \ + ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) + +static int dso__synthesize_plt_symbols(struct dso *self, Elf *elf, + GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym, + GElf_Shdr *shdr_dynsym, + size_t dynsym_idx, int verbose) +{ + uint32_t nr_rel_entries, idx; + GElf_Sym sym; + __u64 plt_offset; + GElf_Shdr shdr_plt; + struct symbol *f; + GElf_Shdr shdr_rel_plt; + Elf_Data *reldata, *syms, *symstrs; + Elf_Scn *scn_plt_rel, *scn_symstrs; + char sympltname[1024]; + int nr = 0, symidx; + + scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt, + ".rela.plt", NULL); + if (scn_plt_rel == NULL) { + scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt, + ".rel.plt", NULL); + if (scn_plt_rel == NULL) + return 0; + } + + if (shdr_rel_plt.sh_link != dynsym_idx) + return 0; + + if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL) + return 0; + + /* + * Fetch the relocation section to find the indexes to the GOT + * and the symbols in the .dynsym they refer to. + */ + reldata = elf_getdata(scn_plt_rel, NULL); + if (reldata == NULL) + return -1; + + syms = elf_getdata(scn_dynsym, NULL); + if (syms == NULL) + return -1; + + scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link); + if (scn_symstrs == NULL) + return -1; + + symstrs = elf_getdata(scn_symstrs, NULL); + if (symstrs == NULL) + return -1; + + nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; + plt_offset = shdr_plt.sh_offset; + + if (shdr_rel_plt.sh_type == SHT_RELA) { + GElf_Rela pos_mem, *pos; + + elf_section__for_each_rela(reldata, pos, pos_mem, idx, + nr_rel_entries) { + symidx = GELF_R_SYM(pos->r_info); + plt_offset += shdr_plt.sh_entsize; + gelf_getsym(syms, symidx, &sym); + snprintf(sympltname, sizeof(sympltname), + "%s@plt", elf_sym__name(&sym, symstrs)); + + f = symbol__new(plt_offset, shdr_plt.sh_entsize, + sympltname, self->sym_priv_size, 0, verbose); + if (!f) + return -1; + + dso__insert_symbol(self, f); + ++nr; + } + } else if (shdr_rel_plt.sh_type == SHT_REL) { + GElf_Rel pos_mem, *pos; + elf_section__for_each_rel(reldata, pos, pos_mem, idx, + nr_rel_entries) { + symidx = GELF_R_SYM(pos->r_info); + plt_offset += shdr_plt.sh_entsize; + gelf_getsym(syms, symidx, &sym); + snprintf(sympltname, sizeof(sympltname), + "%s@plt", elf_sym__name(&sym, symstrs)); + + f = symbol__new(plt_offset, shdr_plt.sh_entsize, + sympltname, self->sym_priv_size, 0, verbose); + if (!f) + return -1; + + dso__insert_symbol(self, f); + ++nr; + } + } else { + /* + * TODO: There are still one more shdr_rel_plt.sh_type + * I have to investigate, but probably should be ignored. + */ + } + + return nr; +} + +static int dso__load_sym(struct dso *self, int fd, const char *name, + symbol_filter_t filter, int verbose) +{ + 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, *sec_dynsym; + Elf *elf; + size_t dynsym_idx; + int nr = 0; + + elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + if (elf == NULL) { + if (verbose) + fprintf(stderr, "%s: cannot read %s ELF file.\n", + __func__, name); + goto out_close; + } + + if (gelf_getehdr(elf, &ehdr) == NULL) { + if (verbose) + fprintf(stderr, "%s: cannot get elf header.\n", __func__); + goto out_elf_end; + } + + /* + * We need to check if we have a .dynsym, so that we can handle the + * .plt, synthesizing its symbols, that aren't on the symtabs (be it + * .dynsym or .symtab) + */ + sec_dynsym = elf_section_by_name(elf, &ehdr, &shdr, + ".dynsym", &dynsym_idx); + if (sec_dynsym != NULL) { + nr = dso__synthesize_plt_symbols(self, elf, &ehdr, + sec_dynsym, &shdr, + dynsym_idx, verbose); + if (nr < 0) + goto out_elf_end; + } + + /* + * But if we have a full .symtab (that is a superset of .dynsym) we + * should add the symbols not in the .dynsyn + */ + sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL); + if (sec == NULL) { + if (sec_dynsym == NULL) + goto out_elf_end; + + sec = sec_dynsym; + gelf_getshdr(sec, &shdr); + } + + 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; + uint64_t obj_start; + + if (!elf_sym__is_function(&sym)) + continue; + + sec = elf_getscn(elf, sym.st_shndx); + if (!sec) + goto out_elf_end; + + gelf_getshdr(sec, &shdr); + obj_start = sym.st_value; + + sym.st_value -= shdr.sh_addr - shdr.sh_offset; + + f = symbol__new(sym.st_value, sym.st_size, + elf_sym__name(&sym, symstrs), + self->sym_priv_size, obj_start, verbose); + if (!f) + goto out_elf_end; + + if (filter && filter(self, f)) + symbol__delete(f, self->sym_priv_size); + else { + dso__insert_symbol(self, f); + nr++; + } + } + + err = nr; +out_elf_end: + elf_end(elf); +out_close: + return err; +} + +int dso__load(struct dso *self, symbol_filter_t filter, int verbose) +{ + 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, filter, verbose); + close(fd); + + /* + * Some people seem to have debuginfo files _WITHOUT_ debug info!?!? + */ + if (!ret) + goto more; + +out: + free(name); + return ret; +} + +static int dso__load_vmlinux(struct dso *self, const char *vmlinux, + symbol_filter_t filter, int verbose) +{ + int err, fd = open(vmlinux, O_RDONLY); + + if (fd < 0) + return -1; + + err = dso__load_sym(self, fd, vmlinux, filter, verbose); + close(fd); + + return err; +} + +int dso__load_kernel(struct dso *self, const char *vmlinux, + symbol_filter_t filter, int verbose) +{ + int err = -1; + + if (vmlinux) + err = dso__load_vmlinux(self, vmlinux, filter, verbose); + + if (err) + err = dso__load_kallsyms(self, filter, verbose); + + return err; +} + +void symbol__init(void) +{ + elf_version(EV_CURRENT); +} -- cgit v1.2.3