Commit 261360b6 authored by Cody P Schafer's avatar Cody P Schafer Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarCody 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent d26cd12b

tools/perf/util/symbol-elf.c

+24 −23
Original line number Diff line number Diff line
@@ -619,7 +619,8 @@ out_close: 
	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,

tools/perf/util/symbol-minimal.c

+1 −0
Original line number Diff line number Diff line
@@ -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];

tools/perf/util/symbol.c

+2 −2
Original line number Diff line number Diff line
@@ -1094,7 +1094,7 @@ restart: 
			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) {

tools/perf/util/symbol.h

+3 −2
Original line number Diff line number Diff line
@@ -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);

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