perf symbols: Convert dso__load_syms to take 2 symsrc's

To properly handle platforms with an opd section, both a runtime image
(which contains the opd section but possibly lacks symbols) and a symbol
image (which probably lacks an opd section but has symbols).

The next patch ("perf symbol: use both runtime and debug images")
adjusts the callsite in dso__load() to take advantage of being able to
pass both runtime & debug images.

Assumptions made here:

 - The opd section, if it exists in the runtime image, has headers in
   both the runtime image and the debug/syms image.

 - The index of the opd section (again, only if it exists in the runtime
   image) is the same in both the runtime and debug/symbols image.

Both of these are true on RHEL, but it is unclear how accurate they are
in general (on platforms with function descriptors in opd sections).

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Hansen <dave@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matt Hellsley <matthltc@us.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1344637382-22789-16-git-send-email-cody@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Cody P Schafer 2012-08-10 15:23:01 -07:00 committed by Arnaldo Carvalho de Melo
parent d26cd12b46
commit 261360b6e9
4 changed files with 30 additions and 27 deletions

View File

@ -619,7 +619,8 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
return err;
}
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
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;
@ -630,31 +631,27 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
int err = -1;
uint32_t idx;
GElf_Ehdr ehdr;
GElf_Shdr shdr, opdshdr;
GElf_Shdr shdr;
Elf_Data *syms, *opddata = NULL;
GElf_Sym sym;
Elf_Scn *sec, *sec_strndx, *opdsec;
Elf_Scn *sec, *sec_strndx;
Elf *elf;
int nr = 0;
size_t opdidx = 0;
dso->symtab_type = ss->type;
dso->symtab_type = syms_ss->type;
if (!ss->symtab) {
ss->symtab = ss->dynsym;
ss->symshdr = ss->dynshdr;
if (!syms_ss->symtab) {
syms_ss->symtab = syms_ss->dynsym;
syms_ss->symshdr = syms_ss->dynshdr;
}
elf = ss->elf;
ehdr = ss->ehdr;
sec = ss->symtab;
shdr = ss->symshdr;
elf = syms_ss->elf;
ehdr = syms_ss->ehdr;
sec = syms_ss->symtab;
shdr = syms_ss->symshdr;
opdsec = ss->opdsec;
opdshdr = ss->opdshdr;
opdidx = ss->opdidx;
if (opdsec)
opddata = elf_rawdata(opdsec, NULL);
if (runtime_ss->opdsec)
opddata = elf_rawdata(runtime_ss->opdsec, NULL);
syms = elf_getdata(sec, NULL);
if (syms == NULL)
@ -679,13 +676,14 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
nr_syms = shdr.sh_size / shdr.sh_entsize;
memset(&sym, 0, sizeof(sym));
dso->adjust_symbols = ss->adjust_symbols;
dso->adjust_symbols = runtime_ss->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 (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
@ -704,14 +702,16 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
continue;
}
if (opdsec && sym.st_shndx == opdidx) {
u32 offset = sym.st_value - opdshdr.sh_addr;
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(elf, sym.st_value);
sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
sym.st_value);
used_opd = true;
}
sec = elf_getscn(elf, sym.st_shndx);
sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
if (!sec)
goto out_elf_end;
@ -777,7 +777,8 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
goto new_symbol;
}
if (curr_dso->adjust_symbols && sym.st_value) {
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,

View File

@ -280,6 +280,7 @@ int dso__synthesize_plt_symbols(struct dso *dso __used,
}
int dso__load_sym(struct dso *dso, struct map *map __used, struct symsrc *ss,
struct symsrc *runtime_ss __used,
symbol_filter_t filter __used, int kmodule __used)
{
unsigned char *build_id[BUILD_ID_SIZE];

View File

@ -1094,7 +1094,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
continue;
}
ret = dso__load_sym(dso, map, &ss, filter, 0);
ret = dso__load_sym(dso, map, &ss, &ss, filter, 0);
/*
* Some people seem to have debuginfo files _WITHOUT_ debug
@ -1380,7 +1380,7 @@ int dso__load_vmlinux(struct dso *dso, struct map *map,
if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
return -1;
err = dso__load_sym(dso, map, &ss, filter, 0);
err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
symsrc__destroy(&ss);
if (err > 0) {

View File

@ -369,8 +369,9 @@ ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr,
u8 *data, ssize_t size);
int dso__test_data(void);
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
symbol_filter_t filter, int kmodule);
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
struct symsrc *runtime_ss, symbol_filter_t filter,
int kmodule);
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss,
struct map *map, symbol_filter_t filter);