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 <c...@linux.vnet.ibm.com>
---
tools/perf/util/symbol.c | 45 +++++++++++++++++++++++----------------------
1 file changed, 23 insertions(+), 22 deletions(-)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 83d2276..e740dc1 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1319,7 +1319,8 @@ static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
return -1;
}
-static int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
+static 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;
@@ -1330,26 +1331,22 @@ static 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;
- 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)
@@ -1374,13 +1371,14 @@ static 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)
@@ -1399,14 +1397,16 @@ static 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;
@@ -1472,7 +1472,8 @@ static 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,
@@ -1944,7 +1945,7 @@ restart:
ss.symshdr = ss.dynshdr;
}
- 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
@@ -2249,7 +2250,7 @@ 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) {
--
1.7.11.3
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