perf tools: Make it possible to read object code from kernel modules

[deliverable/linux.git] / tools / perf / util / symbol-elf.c

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index ed6f443a3e101bcee36a185d3b66832b4bdc16c3..3eaa7b486e2e04badec9f6e4603e8f78da86e50a 100644 (file)
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -599,11 +599,13 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
        if (dso->kernel == DSO_TYPE_USER) {
                GElf_Shdr shdr;
                ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
+                               ehdr.e_type == ET_REL ||
                                elf_section_by_name(elf, &ehdr, &shdr,
                                                     ".gnu.prelink_undo",
                                                     NULL) != NULL);
        } else {
-               ss->adjust_symbols = ehdr.e_type == ET_EXEC;
+               ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
+                                    ehdr.e_type == ET_REL;
        }
 
        ss->name   = strdup(name);
@@ -676,6 +678,14 @@ int dso__load_sym(struct dso *dso, struct map *map,
        bool remap_kernel = false, adjust_kernel_syms = false;
 
        dso->symtab_type = syms_ss->type;
+       dso->rel = syms_ss->ehdr.e_type == ET_REL;
+
+       /*
+        * Modules may already have symbols from kallsyms, but those symbols
+        * have the wrong values for the dso maps, so remove them.
+        */
+       if (kmodule && syms_ss->symtab)
+               symbols__delete(&dso->symbols[map->type]);
 
        if (!syms_ss->symtab) {
                syms_ss->symtab  = syms_ss->dynsym;
@@ -828,11 +838,24 @@ int dso__load_sym(struct dso *dso, struct map *map,
                                        map_groups__insert(kmap->kmaps, map);
                                }
 
+                               /*
+                                * The initial module mapping is based on
+                                * /proc/modules mapped to offset zero.
+                                * Overwrite it to map to the module dso.
+                                */
+                               if (remap_kernel && kmodule) {
+                                       remap_kernel = false;
+                                       map->pgoff = shdr.sh_offset;
+                               }
+
                                curr_map = map;
                                curr_dso = dso;
                                goto new_symbol;
                        }
 
+                       if (!kmap)
+                               goto new_symbol;
+
                        snprintf(dso_name, sizeof(dso_name),
                                 "%s%s", dso->short_name, section_name);