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: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian 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: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 6e4a22acefba029b8327f0481fb2b4344e6f292a..e274f646ac328d06bb5c133d03748daa170e86c5 100644 (file)
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -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);