![Adrian Hunter](/assets/img/avatar_default.png)
In the absence of vmlinux, perf tools uses kallsyms for symbols. If the user has access, now also map to /proc/kcore. The dso data_type is now set to either DSO_BINARY_TYPE__KCORE or DSO_BINARY_TYPE__GUEST_KCORE as approprite. This patch breaks the "vmlinux symtab matches kallsyms" test. That is fixed in a following patch. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1375875537-4509-8-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1009 lines
23 KiB
C
1009 lines
23 KiB
C
#include <fcntl.h>
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#include <stdio.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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#include <inttypes.h>
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#include "symbol.h"
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#include "debug.h"
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#ifndef NT_GNU_BUILD_ID
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#define NT_GNU_BUILD_ID 3
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#endif
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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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* @syms: struct elf_symtab instance to iterate
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* @idx: uint32_t idx
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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, idx, sym) \
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for (idx = 0, gelf_getsym(syms, idx, &sym);\
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idx < nr_syms; \
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idx++, gelf_getsym(syms, idx, &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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}
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static inline bool elf_sym__is_object(const GElf_Sym *sym)
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{
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return elf_sym__type(sym) == STT_OBJECT &&
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sym->st_name != 0 &&
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sym->st_shndx != SHN_UNDEF;
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}
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static inline int elf_sym__is_label(const GElf_Sym *sym)
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{
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return elf_sym__type(sym) == STT_NOTYPE &&
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sym->st_name != 0 &&
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sym->st_shndx != SHN_UNDEF &&
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sym->st_shndx != SHN_ABS;
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}
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static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
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{
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switch (type) {
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case MAP__FUNCTION:
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return elf_sym__is_function(sym);
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case MAP__VARIABLE:
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return elf_sym__is_object(sym);
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default:
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return false;
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}
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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 inline const char *elf_sec__name(const GElf_Shdr *shdr,
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const Elf_Data *secstrs)
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{
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return secstrs->d_buf + shdr->sh_name;
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}
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static inline int elf_sec__is_text(const GElf_Shdr *shdr,
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const Elf_Data *secstrs)
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{
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return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
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}
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static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
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const Elf_Data *secstrs)
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{
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return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
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}
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static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
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enum map_type type)
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{
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switch (type) {
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case MAP__FUNCTION:
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return elf_sec__is_text(shdr, secstrs);
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case MAP__VARIABLE:
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return elf_sec__is_data(shdr, secstrs);
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default:
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return false;
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}
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}
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static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
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{
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Elf_Scn *sec = NULL;
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GElf_Shdr shdr;
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size_t cnt = 1;
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while ((sec = elf_nextscn(elf, sec)) != NULL) {
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gelf_getshdr(sec, &shdr);
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if ((addr >= shdr.sh_addr) &&
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(addr < (shdr.sh_addr + shdr.sh_size)))
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return cnt;
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++cnt;
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}
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return -1;
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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 *idx)
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{
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Elf_Scn *sec = NULL;
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size_t cnt = 1;
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/* Elf is corrupted/truncated, avoid calling elf_strptr. */
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if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
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return NULL;
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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 (idx)
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*idx = 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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/*
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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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* And always look at the original dso, not at debuginfo packages, that
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* have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
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*/
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int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
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symbol_filter_t filter)
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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, shdr_dynsym;
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Elf_Data *reldata, *syms, *symstrs;
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Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
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size_t dynsym_idx;
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GElf_Ehdr ehdr;
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char sympltname[1024];
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Elf *elf;
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int nr = 0, symidx, err = 0;
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if (!ss->dynsym)
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return 0;
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elf = ss->elf;
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ehdr = ss->ehdr;
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scn_dynsym = ss->dynsym;
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shdr_dynsym = ss->dynshdr;
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dynsym_idx = ss->dynsym_idx;
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if (scn_dynsym == NULL)
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goto out_elf_end;
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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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goto out_elf_end;
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}
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err = -1;
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if (shdr_rel_plt.sh_link != dynsym_idx)
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goto out_elf_end;
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if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
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goto out_elf_end;
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/*
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* Fetch the relocation section to find the idxes 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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goto out_elf_end;
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syms = elf_getdata(scn_dynsym, NULL);
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if (syms == NULL)
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goto out_elf_end;
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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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goto out_elf_end;
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symstrs = elf_getdata(scn_symstrs, NULL);
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if (symstrs == NULL)
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goto out_elf_end;
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if (symstrs->d_size == 0)
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goto out_elf_end;
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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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STB_GLOBAL, sympltname);
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if (!f)
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goto out_elf_end;
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if (filter && filter(map, f))
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symbol__delete(f);
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else {
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symbols__insert(&dso->symbols[map->type], f);
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++nr;
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}
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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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STB_GLOBAL, sympltname);
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if (!f)
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goto out_elf_end;
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if (filter && filter(map, f))
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symbol__delete(f);
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else {
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symbols__insert(&dso->symbols[map->type], f);
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++nr;
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}
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}
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}
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err = 0;
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out_elf_end:
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if (err == 0)
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return nr;
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pr_debug("%s: problems reading %s PLT info.\n",
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__func__, dso->long_name);
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return 0;
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}
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/*
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* Align offset to 4 bytes as needed for note name and descriptor data.
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*/
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#define NOTE_ALIGN(n) (((n) + 3) & -4U)
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static int elf_read_build_id(Elf *elf, void *bf, size_t size)
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{
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int err = -1;
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GElf_Ehdr ehdr;
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GElf_Shdr shdr;
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Elf_Data *data;
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Elf_Scn *sec;
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Elf_Kind ek;
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void *ptr;
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if (size < BUILD_ID_SIZE)
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goto out;
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ek = elf_kind(elf);
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if (ek != ELF_K_ELF)
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goto out;
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if (gelf_getehdr(elf, &ehdr) == NULL) {
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pr_err("%s: cannot get elf header.\n", __func__);
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goto out;
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}
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/*
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* Check following sections for notes:
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* '.note.gnu.build-id'
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* '.notes'
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* '.note' (VDSO specific)
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*/
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do {
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sec = elf_section_by_name(elf, &ehdr, &shdr,
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".note.gnu.build-id", NULL);
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if (sec)
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break;
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sec = elf_section_by_name(elf, &ehdr, &shdr,
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".notes", NULL);
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if (sec)
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break;
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sec = elf_section_by_name(elf, &ehdr, &shdr,
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".note", NULL);
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if (sec)
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break;
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return err;
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} while (0);
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data = elf_getdata(sec, NULL);
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if (data == NULL)
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goto out;
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ptr = data->d_buf;
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while (ptr < (data->d_buf + data->d_size)) {
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GElf_Nhdr *nhdr = ptr;
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size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
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descsz = NOTE_ALIGN(nhdr->n_descsz);
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const char *name;
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ptr += sizeof(*nhdr);
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name = ptr;
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ptr += namesz;
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if (nhdr->n_type == NT_GNU_BUILD_ID &&
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nhdr->n_namesz == sizeof("GNU")) {
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if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
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size_t sz = min(size, descsz);
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memcpy(bf, ptr, sz);
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memset(bf + sz, 0, size - sz);
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err = descsz;
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break;
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}
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}
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ptr += descsz;
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}
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out:
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return err;
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}
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int filename__read_build_id(const char *filename, void *bf, size_t size)
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{
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int fd, err = -1;
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Elf *elf;
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if (size < BUILD_ID_SIZE)
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goto out;
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fd = open(filename, O_RDONLY);
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if (fd < 0)
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goto out;
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elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
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if (elf == NULL) {
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pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
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goto out_close;
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}
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err = elf_read_build_id(elf, bf, size);
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elf_end(elf);
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out_close:
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close(fd);
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out:
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return err;
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}
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int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
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{
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int fd, err = -1;
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if (size < BUILD_ID_SIZE)
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goto out;
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fd = open(filename, O_RDONLY);
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if (fd < 0)
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goto out;
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|
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while (1) {
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char bf[BUFSIZ];
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GElf_Nhdr nhdr;
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size_t namesz, descsz;
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if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
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break;
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namesz = NOTE_ALIGN(nhdr.n_namesz);
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descsz = NOTE_ALIGN(nhdr.n_descsz);
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if (nhdr.n_type == NT_GNU_BUILD_ID &&
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nhdr.n_namesz == sizeof("GNU")) {
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if (read(fd, bf, namesz) != (ssize_t)namesz)
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break;
|
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if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
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size_t sz = min(descsz, size);
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if (read(fd, build_id, sz) == (ssize_t)sz) {
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memset(build_id + sz, 0, size - sz);
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err = 0;
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break;
|
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}
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} else if (read(fd, bf, descsz) != (ssize_t)descsz)
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break;
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} else {
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int n = namesz + descsz;
|
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if (read(fd, bf, n) != n)
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break;
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}
|
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}
|
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close(fd);
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out:
|
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return err;
|
|
}
|
|
|
|
int filename__read_debuglink(const char *filename, char *debuglink,
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|
size_t size)
|
|
{
|
|
int fd, err = -1;
|
|
Elf *elf;
|
|
GElf_Ehdr ehdr;
|
|
GElf_Shdr shdr;
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Elf_Data *data;
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Elf_Scn *sec;
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Elf_Kind ek;
|
|
|
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fd = open(filename, O_RDONLY);
|
|
if (fd < 0)
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|
goto out;
|
|
|
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elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
|
|
if (elf == NULL) {
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|
pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
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|
goto out_close;
|
|
}
|
|
|
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ek = elf_kind(elf);
|
|
if (ek != ELF_K_ELF)
|
|
goto out_close;
|
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) {
|
|
pr_err("%s: cannot get elf header.\n", __func__);
|
|
goto out_close;
|
|
}
|
|
|
|
sec = elf_section_by_name(elf, &ehdr, &shdr,
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|
".gnu_debuglink", NULL);
|
|
if (sec == NULL)
|
|
goto out_close;
|
|
|
|
data = elf_getdata(sec, NULL);
|
|
if (data == NULL)
|
|
goto out_close;
|
|
|
|
/* the start of this section is a zero-terminated string */
|
|
strncpy(debuglink, data->d_buf, size);
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|
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elf_end(elf);
|
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|
|
out_close:
|
|
close(fd);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int dso__swap_init(struct dso *dso, unsigned char eidata)
|
|
{
|
|
static unsigned int const endian = 1;
|
|
|
|
dso->needs_swap = DSO_SWAP__NO;
|
|
|
|
switch (eidata) {
|
|
case ELFDATA2LSB:
|
|
/* We are big endian, DSO is little endian. */
|
|
if (*(unsigned char const *)&endian != 1)
|
|
dso->needs_swap = DSO_SWAP__YES;
|
|
break;
|
|
|
|
case ELFDATA2MSB:
|
|
/* We are little endian, DSO is big endian. */
|
|
if (*(unsigned char const *)&endian != 0)
|
|
dso->needs_swap = DSO_SWAP__YES;
|
|
break;
|
|
|
|
default:
|
|
pr_err("unrecognized DSO data encoding %d\n", eidata);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool symsrc__possibly_runtime(struct symsrc *ss)
|
|
{
|
|
return ss->dynsym || ss->opdsec;
|
|
}
|
|
|
|
bool symsrc__has_symtab(struct symsrc *ss)
|
|
{
|
|
return ss->symtab != NULL;
|
|
}
|
|
|
|
void symsrc__destroy(struct symsrc *ss)
|
|
{
|
|
free(ss->name);
|
|
elf_end(ss->elf);
|
|
close(ss->fd);
|
|
}
|
|
|
|
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
|
|
enum dso_binary_type type)
|
|
{
|
|
int err = -1;
|
|
GElf_Ehdr ehdr;
|
|
Elf *elf;
|
|
int fd;
|
|
|
|
fd = open(name, O_RDONLY);
|
|
if (fd < 0)
|
|
return -1;
|
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
|
|
if (elf == NULL) {
|
|
pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
|
|
goto out_close;
|
|
}
|
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) {
|
|
pr_debug("%s: cannot get elf header.\n", __func__);
|
|
goto out_elf_end;
|
|
}
|
|
|
|
if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
|
|
goto out_elf_end;
|
|
|
|
/* Always reject images with a mismatched build-id: */
|
|
if (dso->has_build_id) {
|
|
u8 build_id[BUILD_ID_SIZE];
|
|
|
|
if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
|
|
goto out_elf_end;
|
|
|
|
if (!dso__build_id_equal(dso, build_id))
|
|
goto out_elf_end;
|
|
}
|
|
|
|
ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
|
|
NULL);
|
|
if (ss->symshdr.sh_type != SHT_SYMTAB)
|
|
ss->symtab = NULL;
|
|
|
|
ss->dynsym_idx = 0;
|
|
ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
|
|
&ss->dynsym_idx);
|
|
if (ss->dynshdr.sh_type != SHT_DYNSYM)
|
|
ss->dynsym = NULL;
|
|
|
|
ss->opdidx = 0;
|
|
ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
|
|
&ss->opdidx);
|
|
if (ss->opdshdr.sh_type != SHT_PROGBITS)
|
|
ss->opdsec = NULL;
|
|
|
|
if (dso->kernel == DSO_TYPE_USER) {
|
|
GElf_Shdr shdr;
|
|
ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
|
|
ehdr.e_type == ET_REL ||
|
|
elf_section_by_name(elf, &ehdr, &shdr,
|
|
".gnu.prelink_undo",
|
|
NULL) != NULL);
|
|
} else {
|
|
ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
|
|
ehdr.e_type == ET_REL;
|
|
}
|
|
|
|
ss->name = strdup(name);
|
|
if (!ss->name)
|
|
goto out_elf_end;
|
|
|
|
ss->elf = elf;
|
|
ss->fd = fd;
|
|
ss->ehdr = ehdr;
|
|
ss->type = type;
|
|
|
|
return 0;
|
|
|
|
out_elf_end:
|
|
elf_end(elf);
|
|
out_close:
|
|
close(fd);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ref_reloc_sym_not_found - has kernel relocation symbol been found.
|
|
* @kmap: kernel maps and relocation reference symbol
|
|
*
|
|
* This function returns %true if we are dealing with the kernel maps and the
|
|
* relocation reference symbol has not yet been found. Otherwise %false is
|
|
* returned.
|
|
*/
|
|
static bool ref_reloc_sym_not_found(struct kmap *kmap)
|
|
{
|
|
return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
|
|
!kmap->ref_reloc_sym->unrelocated_addr;
|
|
}
|
|
|
|
/**
|
|
* ref_reloc - kernel relocation offset.
|
|
* @kmap: kernel maps and relocation reference symbol
|
|
*
|
|
* This function returns the offset of kernel addresses as determined by using
|
|
* the relocation reference symbol i.e. if the kernel has not been relocated
|
|
* then the return value is zero.
|
|
*/
|
|
static u64 ref_reloc(struct kmap *kmap)
|
|
{
|
|
if (kmap && kmap->ref_reloc_sym &&
|
|
kmap->ref_reloc_sym->unrelocated_addr)
|
|
return kmap->ref_reloc_sym->addr -
|
|
kmap->ref_reloc_sym->unrelocated_addr;
|
|
return 0;
|
|
}
|
|
|
|
int dso__load_sym(struct dso *dso, struct map *map,
|
|
struct symsrc *syms_ss, struct symsrc *runtime_ss,
|
|
symbol_filter_t filter, int kmodule)
|
|
{
|
|
struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
|
|
struct map *curr_map = map;
|
|
struct dso *curr_dso = dso;
|
|
Elf_Data *symstrs, *secstrs;
|
|
uint32_t nr_syms;
|
|
int err = -1;
|
|
uint32_t idx;
|
|
GElf_Ehdr ehdr;
|
|
GElf_Shdr shdr;
|
|
Elf_Data *syms, *opddata = NULL;
|
|
GElf_Sym sym;
|
|
Elf_Scn *sec, *sec_strndx;
|
|
Elf *elf;
|
|
int nr = 0;
|
|
bool remap_kernel = false, adjust_kernel_syms = false;
|
|
|
|
dso->symtab_type = syms_ss->type;
|
|
dso->rel = syms_ss->ehdr.e_type == ET_REL;
|
|
|
|
/*
|
|
* Modules may already have symbols from kallsyms, but those symbols
|
|
* have the wrong values for the dso maps, so remove them.
|
|
*/
|
|
if (kmodule && syms_ss->symtab)
|
|
symbols__delete(&dso->symbols[map->type]);
|
|
|
|
if (!syms_ss->symtab) {
|
|
syms_ss->symtab = syms_ss->dynsym;
|
|
syms_ss->symshdr = syms_ss->dynshdr;
|
|
}
|
|
|
|
elf = syms_ss->elf;
|
|
ehdr = syms_ss->ehdr;
|
|
sec = syms_ss->symtab;
|
|
shdr = syms_ss->symshdr;
|
|
|
|
if (runtime_ss->opdsec)
|
|
opddata = elf_rawdata(runtime_ss->opdsec, NULL);
|
|
|
|
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;
|
|
|
|
sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
|
|
if (sec_strndx == NULL)
|
|
goto out_elf_end;
|
|
|
|
secstrs = elf_getdata(sec_strndx, NULL);
|
|
if (secstrs == NULL)
|
|
goto out_elf_end;
|
|
|
|
nr_syms = shdr.sh_size / shdr.sh_entsize;
|
|
|
|
memset(&sym, 0, sizeof(sym));
|
|
|
|
/*
|
|
* The kernel relocation symbol is needed in advance in order to adjust
|
|
* kernel maps correctly.
|
|
*/
|
|
if (ref_reloc_sym_not_found(kmap)) {
|
|
elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
|
|
const char *elf_name = elf_sym__name(&sym, symstrs);
|
|
|
|
if (strcmp(elf_name, kmap->ref_reloc_sym->name))
|
|
continue;
|
|
kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
|
|
break;
|
|
}
|
|
}
|
|
|
|
dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
|
|
/*
|
|
* Initial kernel and module mappings do not map to the dso. For
|
|
* function mappings, flag the fixups.
|
|
*/
|
|
if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
|
|
remap_kernel = true;
|
|
adjust_kernel_syms = dso->adjust_symbols;
|
|
}
|
|
elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
|
|
struct symbol *f;
|
|
const char *elf_name = elf_sym__name(&sym, symstrs);
|
|
char *demangled = NULL;
|
|
int is_label = elf_sym__is_label(&sym);
|
|
const char *section_name;
|
|
bool used_opd = false;
|
|
|
|
if (!is_label && !elf_sym__is_a(&sym, map->type))
|
|
continue;
|
|
|
|
/* Reject ARM ELF "mapping symbols": these aren't unique and
|
|
* don't identify functions, so will confuse the profile
|
|
* output: */
|
|
if (ehdr.e_machine == EM_ARM) {
|
|
if (!strcmp(elf_name, "$a") ||
|
|
!strcmp(elf_name, "$d") ||
|
|
!strcmp(elf_name, "$t"))
|
|
continue;
|
|
}
|
|
|
|
if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
|
|
u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
|
|
u64 *opd = opddata->d_buf + offset;
|
|
sym.st_value = DSO__SWAP(dso, u64, *opd);
|
|
sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
|
|
sym.st_value);
|
|
used_opd = true;
|
|
}
|
|
/*
|
|
* When loading symbols in a data mapping, ABS symbols (which
|
|
* has a value of SHN_ABS in its st_shndx) failed at
|
|
* elf_getscn(). And it marks the loading as a failure so
|
|
* already loaded symbols cannot be fixed up.
|
|
*
|
|
* I'm not sure what should be done. Just ignore them for now.
|
|
* - Namhyung Kim
|
|
*/
|
|
if (sym.st_shndx == SHN_ABS)
|
|
continue;
|
|
|
|
sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
|
|
if (!sec)
|
|
goto out_elf_end;
|
|
|
|
gelf_getshdr(sec, &shdr);
|
|
|
|
if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
|
|
continue;
|
|
|
|
section_name = elf_sec__name(&shdr, secstrs);
|
|
|
|
/* On ARM, symbols for thumb functions have 1 added to
|
|
* the symbol address as a flag - remove it */
|
|
if ((ehdr.e_machine == EM_ARM) &&
|
|
(map->type == MAP__FUNCTION) &&
|
|
(sym.st_value & 1))
|
|
--sym.st_value;
|
|
|
|
if (dso->kernel || kmodule) {
|
|
char dso_name[PATH_MAX];
|
|
|
|
/* Adjust symbol to map to file offset */
|
|
if (adjust_kernel_syms)
|
|
sym.st_value -= shdr.sh_addr - shdr.sh_offset;
|
|
|
|
if (strcmp(section_name,
|
|
(curr_dso->short_name +
|
|
dso->short_name_len)) == 0)
|
|
goto new_symbol;
|
|
|
|
if (strcmp(section_name, ".text") == 0) {
|
|
/*
|
|
* The initial kernel mapping is based on
|
|
* kallsyms and identity maps. Overwrite it to
|
|
* map to the kernel dso.
|
|
*/
|
|
if (remap_kernel && dso->kernel) {
|
|
remap_kernel = false;
|
|
map->start = shdr.sh_addr +
|
|
ref_reloc(kmap);
|
|
map->end = map->start + shdr.sh_size;
|
|
map->pgoff = shdr.sh_offset;
|
|
map->map_ip = map__map_ip;
|
|
map->unmap_ip = map__unmap_ip;
|
|
/* Ensure maps are correctly ordered */
|
|
map_groups__remove(kmap->kmaps, map);
|
|
map_groups__insert(kmap->kmaps, map);
|
|
}
|
|
|
|
/*
|
|
* The initial module mapping is based on
|
|
* /proc/modules mapped to offset zero.
|
|
* Overwrite it to map to the module dso.
|
|
*/
|
|
if (remap_kernel && kmodule) {
|
|
remap_kernel = false;
|
|
map->pgoff = shdr.sh_offset;
|
|
}
|
|
|
|
curr_map = map;
|
|
curr_dso = dso;
|
|
goto new_symbol;
|
|
}
|
|
|
|
if (!kmap)
|
|
goto new_symbol;
|
|
|
|
snprintf(dso_name, sizeof(dso_name),
|
|
"%s%s", dso->short_name, section_name);
|
|
|
|
curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
|
|
if (curr_map == NULL) {
|
|
u64 start = sym.st_value;
|
|
|
|
if (kmodule)
|
|
start += map->start + shdr.sh_offset;
|
|
|
|
curr_dso = dso__new(dso_name);
|
|
if (curr_dso == NULL)
|
|
goto out_elf_end;
|
|
curr_dso->kernel = dso->kernel;
|
|
curr_dso->long_name = dso->long_name;
|
|
curr_dso->long_name_len = dso->long_name_len;
|
|
curr_map = map__new2(start, curr_dso,
|
|
map->type);
|
|
if (curr_map == NULL) {
|
|
dso__delete(curr_dso);
|
|
goto out_elf_end;
|
|
}
|
|
if (adjust_kernel_syms) {
|
|
curr_map->start = shdr.sh_addr +
|
|
ref_reloc(kmap);
|
|
curr_map->end = curr_map->start +
|
|
shdr.sh_size;
|
|
curr_map->pgoff = shdr.sh_offset;
|
|
} else {
|
|
curr_map->map_ip = identity__map_ip;
|
|
curr_map->unmap_ip = identity__map_ip;
|
|
}
|
|
curr_dso->symtab_type = dso->symtab_type;
|
|
map_groups__insert(kmap->kmaps, curr_map);
|
|
dsos__add(&dso->node, curr_dso);
|
|
dso__set_loaded(curr_dso, map->type);
|
|
} else
|
|
curr_dso = curr_map->dso;
|
|
|
|
goto new_symbol;
|
|
}
|
|
|
|
if ((used_opd && runtime_ss->adjust_symbols)
|
|
|| (!used_opd && syms_ss->adjust_symbols)) {
|
|
pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
|
|
"sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
|
|
(u64)sym.st_value, (u64)shdr.sh_addr,
|
|
(u64)shdr.sh_offset);
|
|
sym.st_value -= shdr.sh_addr - shdr.sh_offset;
|
|
}
|
|
/*
|
|
* We need to figure out if the object was created from C++ sources
|
|
* DWARF DW_compile_unit has this, but we don't always have access
|
|
* to it...
|
|
*/
|
|
if (symbol_conf.demangle) {
|
|
demangled = bfd_demangle(NULL, elf_name,
|
|
DMGL_PARAMS | DMGL_ANSI);
|
|
if (demangled != NULL)
|
|
elf_name = demangled;
|
|
}
|
|
new_symbol:
|
|
f = symbol__new(sym.st_value, sym.st_size,
|
|
GELF_ST_BIND(sym.st_info), elf_name);
|
|
free(demangled);
|
|
if (!f)
|
|
goto out_elf_end;
|
|
|
|
if (filter && filter(curr_map, f))
|
|
symbol__delete(f);
|
|
else {
|
|
symbols__insert(&curr_dso->symbols[curr_map->type], f);
|
|
nr++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For misannotated, zeroed, ASM function sizes.
|
|
*/
|
|
if (nr > 0) {
|
|
symbols__fixup_duplicate(&dso->symbols[map->type]);
|
|
symbols__fixup_end(&dso->symbols[map->type]);
|
|
if (kmap) {
|
|
/*
|
|
* We need to fixup this here too because we create new
|
|
* maps here, for things like vsyscall sections.
|
|
*/
|
|
__map_groups__fixup_end(kmap->kmaps, map->type);
|
|
}
|
|
}
|
|
err = nr;
|
|
out_elf_end:
|
|
return err;
|
|
}
|
|
|
|
static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
|
|
{
|
|
GElf_Phdr phdr;
|
|
size_t i, phdrnum;
|
|
int err;
|
|
u64 sz;
|
|
|
|
if (elf_getphdrnum(elf, &phdrnum))
|
|
return -1;
|
|
|
|
for (i = 0; i < phdrnum; i++) {
|
|
if (gelf_getphdr(elf, i, &phdr) == NULL)
|
|
return -1;
|
|
if (phdr.p_type != PT_LOAD)
|
|
continue;
|
|
if (exe) {
|
|
if (!(phdr.p_flags & PF_X))
|
|
continue;
|
|
} else {
|
|
if (!(phdr.p_flags & PF_R))
|
|
continue;
|
|
}
|
|
sz = min(phdr.p_memsz, phdr.p_filesz);
|
|
if (!sz)
|
|
continue;
|
|
err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
|
|
bool *is_64_bit)
|
|
{
|
|
int err;
|
|
Elf *elf;
|
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
|
|
if (elf == NULL)
|
|
return -1;
|
|
|
|
if (is_64_bit)
|
|
*is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
|
|
|
|
err = elf_read_maps(elf, exe, mapfn, data);
|
|
|
|
elf_end(elf);
|
|
return err;
|
|
}
|
|
|
|
void symbol__elf_init(void)
|
|
{
|
|
elf_version(EV_CURRENT);
|
|
}
|