575 lines
12 KiB
C
575 lines
12 KiB
C
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#include "util.h"
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#include "../perf.h"
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#include "string.h"
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#include "symbol.h"
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#include <libelf.h>
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#include <gelf.h>
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#include <elf.h>
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const char *sym_hist_filter;
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static struct symbol *symbol__new(uint64_t start, uint64_t len,
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const char *name, unsigned int priv_size,
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uint64_t obj_start, int verbose)
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{
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size_t namelen = strlen(name) + 1;
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struct symbol *self = calloc(1, priv_size + sizeof(*self) + namelen);
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if (!self)
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return NULL;
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if (verbose >= 2)
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printf("new symbol: %016Lx [%08lx]: %s, hist: %p, obj_start: %p\n",
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(__u64)start, len, name, self->hist, (void *)obj_start);
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self->obj_start= obj_start;
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self->hist = NULL;
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self->hist_sum = 0;
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if (sym_hist_filter && !strcmp(name, sym_hist_filter))
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self->hist = calloc(sizeof(__u64), len);
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if (priv_size) {
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memset(self, 0, priv_size);
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self = ((void *)self) + priv_size;
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}
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self->start = start;
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self->end = start + len - 1;
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memcpy(self->name, name, namelen);
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return self;
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}
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static void symbol__delete(struct symbol *self, unsigned int priv_size)
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{
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free(((void *)self) - priv_size);
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}
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static size_t symbol__fprintf(struct symbol *self, FILE *fp)
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{
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return fprintf(fp, " %llx-%llx %s\n",
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self->start, self->end, self->name);
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}
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struct dso *dso__new(const char *name, unsigned int sym_priv_size)
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{
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struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
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if (self != NULL) {
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strcpy(self->name, name);
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self->syms = RB_ROOT;
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self->sym_priv_size = sym_priv_size;
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self->find_symbol = dso__find_symbol;
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}
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return self;
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}
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static void dso__delete_symbols(struct dso *self)
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{
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struct symbol *pos;
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struct rb_node *next = rb_first(&self->syms);
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while (next) {
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pos = rb_entry(next, struct symbol, rb_node);
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next = rb_next(&pos->rb_node);
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rb_erase(&pos->rb_node, &self->syms);
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symbol__delete(pos, self->sym_priv_size);
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}
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}
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void dso__delete(struct dso *self)
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{
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dso__delete_symbols(self);
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free(self);
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}
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static void dso__insert_symbol(struct dso *self, struct symbol *sym)
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{
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struct rb_node **p = &self->syms.rb_node;
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struct rb_node *parent = NULL;
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const uint64_t ip = sym->start;
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struct symbol *s;
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while (*p != NULL) {
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parent = *p;
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s = rb_entry(parent, struct symbol, rb_node);
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if (ip < s->start)
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p = &(*p)->rb_left;
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else
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p = &(*p)->rb_right;
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}
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rb_link_node(&sym->rb_node, parent, p);
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rb_insert_color(&sym->rb_node, &self->syms);
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}
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struct symbol *dso__find_symbol(struct dso *self, uint64_t ip)
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{
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struct rb_node *n;
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if (self == NULL)
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return NULL;
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n = self->syms.rb_node;
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while (n) {
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struct symbol *s = rb_entry(n, struct symbol, rb_node);
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if (ip < s->start)
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n = n->rb_left;
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else if (ip > s->end)
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n = n->rb_right;
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else
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return s;
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}
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return NULL;
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}
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size_t dso__fprintf(struct dso *self, FILE *fp)
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{
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size_t ret = fprintf(fp, "dso: %s\n", self->name);
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struct rb_node *nd;
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for (nd = rb_first(&self->syms); nd; nd = rb_next(nd)) {
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struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
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ret += symbol__fprintf(pos, fp);
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}
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return ret;
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}
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static int dso__load_kallsyms(struct dso *self, symbol_filter_t filter, int verbose)
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{
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struct rb_node *nd, *prevnd;
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char *line = NULL;
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size_t n;
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FILE *file = fopen("/proc/kallsyms", "r");
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if (file == NULL)
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goto out_failure;
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while (!feof(file)) {
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__u64 start;
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struct symbol *sym;
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int line_len, len;
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char symbol_type;
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line_len = getline(&line, &n, file);
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if (line_len < 0)
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break;
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if (!line)
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goto out_failure;
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line[--line_len] = '\0'; /* \n */
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len = hex2u64(line, &start);
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len++;
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if (len + 2 >= line_len)
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continue;
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symbol_type = toupper(line[len]);
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/*
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* We're interested only in code ('T'ext)
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*/
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if (symbol_type != 'T' && symbol_type != 'W')
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continue;
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/*
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* Well fix up the end later, when we have all sorted.
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*/
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sym = symbol__new(start, 0xdead, line + len + 2,
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self->sym_priv_size, 0, verbose);
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if (sym == NULL)
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goto out_delete_line;
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if (filter && filter(self, sym))
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symbol__delete(sym, self->sym_priv_size);
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else
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dso__insert_symbol(self, sym);
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}
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/*
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* Now that we have all sorted out, just set the ->end of all
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* symbols
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*/
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prevnd = rb_first(&self->syms);
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if (prevnd == NULL)
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goto out_delete_line;
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for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
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struct symbol *prev = rb_entry(prevnd, struct symbol, rb_node),
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*curr = rb_entry(nd, struct symbol, rb_node);
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prev->end = curr->start - 1;
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prevnd = nd;
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}
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free(line);
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fclose(file);
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return 0;
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out_delete_line:
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free(line);
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out_failure:
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return -1;
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}
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/**
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* elf_symtab__for_each_symbol - iterate thru all the symbols
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*
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* @self: struct elf_symtab instance to iterate
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* @index: uint32_t index
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* @sym: GElf_Sym iterator
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*/
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#define elf_symtab__for_each_symbol(syms, nr_syms, index, sym) \
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for (index = 0, gelf_getsym(syms, index, &sym);\
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index < nr_syms; \
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index++, gelf_getsym(syms, index, &sym))
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static inline uint8_t elf_sym__type(const GElf_Sym *sym)
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{
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return GELF_ST_TYPE(sym->st_info);
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}
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static inline int elf_sym__is_function(const GElf_Sym *sym)
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{
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return elf_sym__type(sym) == STT_FUNC &&
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sym->st_name != 0 &&
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sym->st_shndx != SHN_UNDEF &&
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sym->st_size != 0;
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}
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static inline const char *elf_sym__name(const GElf_Sym *sym,
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const Elf_Data *symstrs)
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{
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return symstrs->d_buf + sym->st_name;
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}
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static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
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GElf_Shdr *shp, const char *name,
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size_t *index)
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{
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Elf_Scn *sec = NULL;
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size_t cnt = 1;
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while ((sec = elf_nextscn(elf, sec)) != NULL) {
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char *str;
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gelf_getshdr(sec, shp);
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str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
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if (!strcmp(name, str)) {
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if (index)
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*index = cnt;
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break;
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}
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++cnt;
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}
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return sec;
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}
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#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
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for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
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idx < nr_entries; \
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++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
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#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
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for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
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idx < nr_entries; \
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++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
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static int dso__synthesize_plt_symbols(struct dso *self, Elf *elf,
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GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym,
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GElf_Shdr *shdr_dynsym,
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size_t dynsym_idx, int verbose)
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{
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uint32_t nr_rel_entries, idx;
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GElf_Sym sym;
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__u64 plt_offset;
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GElf_Shdr shdr_plt;
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struct symbol *f;
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GElf_Shdr shdr_rel_plt;
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Elf_Data *reldata, *syms, *symstrs;
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Elf_Scn *scn_plt_rel, *scn_symstrs;
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char sympltname[1024];
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int nr = 0, symidx;
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scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
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".rela.plt", NULL);
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if (scn_plt_rel == NULL) {
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scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
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".rel.plt", NULL);
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if (scn_plt_rel == NULL)
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return 0;
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}
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if (shdr_rel_plt.sh_link != dynsym_idx)
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return 0;
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if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL)
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return 0;
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/*
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* Fetch the relocation section to find the indexes to the GOT
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* and the symbols in the .dynsym they refer to.
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*/
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reldata = elf_getdata(scn_plt_rel, NULL);
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if (reldata == NULL)
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return -1;
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syms = elf_getdata(scn_dynsym, NULL);
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if (syms == NULL)
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return -1;
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scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link);
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if (scn_symstrs == NULL)
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return -1;
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symstrs = elf_getdata(scn_symstrs, NULL);
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if (symstrs == NULL)
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return -1;
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nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
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plt_offset = shdr_plt.sh_offset;
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if (shdr_rel_plt.sh_type == SHT_RELA) {
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GElf_Rela pos_mem, *pos;
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elf_section__for_each_rela(reldata, pos, pos_mem, idx,
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nr_rel_entries) {
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symidx = GELF_R_SYM(pos->r_info);
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plt_offset += shdr_plt.sh_entsize;
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gelf_getsym(syms, symidx, &sym);
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snprintf(sympltname, sizeof(sympltname),
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"%s@plt", elf_sym__name(&sym, symstrs));
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f = symbol__new(plt_offset, shdr_plt.sh_entsize,
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sympltname, self->sym_priv_size, 0, verbose);
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if (!f)
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return -1;
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dso__insert_symbol(self, f);
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++nr;
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}
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} else if (shdr_rel_plt.sh_type == SHT_REL) {
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GElf_Rel pos_mem, *pos;
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elf_section__for_each_rel(reldata, pos, pos_mem, idx,
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nr_rel_entries) {
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symidx = GELF_R_SYM(pos->r_info);
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plt_offset += shdr_plt.sh_entsize;
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gelf_getsym(syms, symidx, &sym);
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snprintf(sympltname, sizeof(sympltname),
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"%s@plt", elf_sym__name(&sym, symstrs));
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f = symbol__new(plt_offset, shdr_plt.sh_entsize,
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sympltname, self->sym_priv_size, 0, verbose);
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if (!f)
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return -1;
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dso__insert_symbol(self, f);
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++nr;
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}
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} else {
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/*
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* TODO: There are still one more shdr_rel_plt.sh_type
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* I have to investigate, but probably should be ignored.
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*/
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}
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return nr;
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}
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static int dso__load_sym(struct dso *self, int fd, const char *name,
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symbol_filter_t filter, int verbose)
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{
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Elf_Data *symstrs;
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uint32_t nr_syms;
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int err = -1;
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uint32_t index;
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GElf_Ehdr ehdr;
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GElf_Shdr shdr;
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Elf_Data *syms;
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GElf_Sym sym;
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Elf_Scn *sec, *sec_dynsym;
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Elf *elf;
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size_t dynsym_idx;
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int nr = 0;
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elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
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if (elf == NULL) {
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if (verbose)
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fprintf(stderr, "%s: cannot read %s ELF file.\n",
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__func__, name);
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goto out_close;
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}
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if (gelf_getehdr(elf, &ehdr) == NULL) {
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if (verbose)
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fprintf(stderr, "%s: cannot get elf header.\n", __func__);
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goto out_elf_end;
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}
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/*
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* We need to check if we have a .dynsym, so that we can handle the
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* .plt, synthesizing its symbols, that aren't on the symtabs (be it
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* .dynsym or .symtab)
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*/
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sec_dynsym = elf_section_by_name(elf, &ehdr, &shdr,
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".dynsym", &dynsym_idx);
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if (sec_dynsym != NULL) {
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nr = dso__synthesize_plt_symbols(self, elf, &ehdr,
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sec_dynsym, &shdr,
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dynsym_idx, verbose);
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if (nr < 0)
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goto out_elf_end;
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}
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/*
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||
|
* 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);
|
||
|
}
|