Commit 375a4481 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf symbols: Combine handling for SHT_RELA and SHT_REL 



SHT_REL and SHT_RELA are handled the same way. Simplify by combining the
handling.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarIan Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-10-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 45204677

tools/perf/util/symbol-elf.c

+27 −48
Original line number Diff line number Diff line
@@ -323,6 +323,23 @@ static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name) 
	return demangled;

}



struct rel_info {

	bool		is_rela;

	Elf_Data	*reldata;

	GElf_Rela	rela;

	GElf_Rel	rel;

};



static u32 get_rel_symidx(struct rel_info *ri, u32 idx)

{

	if (ri->is_rela) {

		gelf_getrela(ri->reldata, idx, &ri->rela);

		return GELF_R_SYM(ri->rela.r_info);

	}

	gelf_getrel(ri->reldata, idx, &ri->rel);

	return GELF_R_SYM(ri->rel.r_info);

}



static bool get_plt_sizes(struct dso *dso, GElf_Ehdr *ehdr, GElf_Shdr *shdr_plt,

			  u64 *plt_header_size, u64 *plt_entry_size)

{
@@ -353,16 +370,6 @@ static bool get_plt_sizes(struct dso *dso, GElf_Ehdr *ehdr, GElf_Shdr *shdr_plt, 
	}

}



#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \

	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \

	     idx < nr_entries; \

	     ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))



#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \

	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \

	     idx < nr_entries; \

	     ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))



/*

 * We need to check if we have a .dynsym, so that we can handle the

 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
@@ -378,13 +385,14 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) 
	GElf_Shdr shdr_plt;

	struct symbol *f;

	GElf_Shdr shdr_rel_plt, shdr_dynsym;

	Elf_Data *reldata, *syms, *symstrs;

	Elf_Data *syms, *symstrs;

	Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;

	size_t dynsym_idx;

	GElf_Ehdr ehdr;

	char sympltname[1024];

	Elf *elf;

	int nr = 0, symidx, err = -1;

	int nr = 0, err = -1;

	struct rel_info ri = { .is_rela = false };



	elf = ss->elf;

	ehdr = ss->ehdr;
@@ -433,8 +441,8 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) 
	 * Fetch the relocation section to find the idxes to the GOT

	 * and the symbols in the .dynsym they refer to.

	 */

	reldata = elf_getdata(scn_plt_rel, NULL);

	if (reldata == NULL)

	ri.reldata = elf_getdata(scn_plt_rel, NULL);

	if (!ri.reldata)

		goto out_elf_end;



	syms = elf_getdata(scn_dynsym, NULL);
@@ -456,44 +464,15 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) 
	plt_offset = shdr_plt.sh_offset;

	plt_offset += plt_header_size;



	if (shdr_rel_plt.sh_type == SHT_RELA) {

		GElf_Rela pos_mem, *pos;

	ri.is_rela = shdr_rel_plt.sh_type == SHT_RELA;



		elf_section__for_each_rela(reldata, pos, pos_mem, idx,

					   nr_rel_entries) {

	if (shdr_rel_plt.sh_type == SHT_RELA ||

	    shdr_rel_plt.sh_type == SHT_REL) {

		for (idx = 0; idx < nr_rel_entries; idx++) {

			const char *elf_name = NULL;

			char *demangled = NULL;

			symidx = GELF_R_SYM(pos->r_info);

			gelf_getsym(syms, symidx, &sym);



			elf_name = elf_sym__name(&sym, symstrs);

			demangled = demangle_sym(dso, 0, elf_name);

			if (demangled != NULL)

				elf_name = demangled;

			if (*elf_name)

				snprintf(sympltname, sizeof(sympltname), "%s@plt", elf_name);

			else

				snprintf(sympltname, sizeof(sympltname),

					 "offset_%#" PRIx64 "@plt", plt_offset);

			free(demangled);



			f = symbol__new(plt_offset, plt_entry_size,

					STB_GLOBAL, STT_FUNC, sympltname);

			if (!f)

				goto out_elf_end;



			plt_offset += plt_entry_size;

			symbols__insert(&dso->symbols, f);

			++nr;

		}

	} else if (shdr_rel_plt.sh_type == SHT_REL) {

		GElf_Rel pos_mem, *pos;

		elf_section__for_each_rel(reldata, pos, pos_mem, idx,

					  nr_rel_entries) {

			const char *elf_name = NULL;

			char *demangled = NULL;

			symidx = GELF_R_SYM(pos->r_info);

			gelf_getsym(syms, symidx, &sym);

			gelf_getsym(syms, get_rel_symidx(&ri, idx), &sym);



			elf_name = elf_sym__name(&sym, symstrs);

			demangled = demangle_sym(dso, 0, elf_name);