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-rw-r--r--tools/perf/util/symbol.c574
1 files changed, 574 insertions, 0 deletions
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 <libelf.h>
+#include <gelf.h>
+#include <elf.h>
+
+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);
+}
generated by cgit (git 2.34.1) at 2024-11-11 17:56:26 +0000