perf report: Fix ELF symbol parsing

[ Impact: fix DSO symbol output in perf report ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 22 insertions, 52 deletions

diff --git a/Documentation/perf_counter/Makefile b/Documentation/perf_counter/Makefile
index 412dea15d0b7..10c13a6f2bc9 100644
--- a/Documentation/perf_counter/Makefile
+++ b/Documentation/perf_counter/Makefile
@@ -159,7 +159,7 @@ uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
 
 # CFLAGS and LDFLAGS are for the users to override from the command line.
 
-CFLAGS = -g -O2 -Wall
+CFLAGS = -ggdb3 -Wall
 LDFLAGS = -lpthread -lrt -lelf
 ALL_CFLAGS = $(CFLAGS)
 ALL_LDFLAGS = $(LDFLAGS)
diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index 9e59d6071ef3..697f960495fc 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -55,34 +55,6 @@ typedef union event_union {
         struct comm_event comm;
 } event_t;
 
-struct section {
-        struct list_head node;
-        uint64_t         start;
-        uint64_t         end;
-        uint64_t         offset;
-        char             name[0];
-};
-
-struct section *section__new(uint64_t start, uint64_t size,
-                                    uint64_t offset, char *name)
-{
-        struct section *self = malloc(sizeof(*self) + strlen(name) + 1);
-
-        if (self != NULL) {
-                self->start  = start;
-                self->end    = start + size;
-                self->offset = offset;
-                strcpy(self->name, name);
-        }
-
-        return self;
-}
-
-static void section__delete(struct section *self)
-{
-        free(self);
-}
-
 struct symbol {
         struct rb_node rb_node;
         uint64_t       start;
@@ -116,7 +88,6 @@ static size_t symbol__fprintf(struct symbol *self, FILE *fp)
 
 struct dso {
         struct list_head node;
-        struct list_head sections;
         struct rb_root   syms;
         char             name[0];
 };
@@ -127,21 +98,12 @@ static struct dso *dso__new(const char *name)
 
         if (self != NULL) {
                 strcpy(self->name, name);
-                INIT_LIST_HEAD(&self->sections);
                 self->syms = RB_ROOT;
         }
 
         return self;
 }
 
-static void dso__delete_sections(struct dso *self)
-{
-        struct section *pos, *n;
-
-        list_for_each_entry_safe(pos, n, &self->sections, node)
-                section__delete(pos);
-}
-
 static void dso__delete_symbols(struct dso *self)
 {
         struct symbol *pos;
@@ -156,7 +118,6 @@ static void dso__delete_symbols(struct dso *self)
 
 static void dso__delete(struct dso *self)
 {
-        dso__delete_sections(self);
         dso__delete_symbols(self);
         free(self);
 }
@@ -282,9 +243,6 @@ static int dso__load(struct dso *self)
         if (sec == NULL)
                 goto out_elf_end;
 
-        if (gelf_getshdr(sec, &shdr) == NULL)
-                goto out_elf_end;
-
         Elf_Data *syms = elf_getdata(sec, NULL);
         if (syms == NULL)
                 goto out_elf_end;
@@ -302,11 +260,21 @@ static int dso__load(struct dso *self)
         GElf_Sym sym;
         uint32_t index;
         elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
+                struct symbol *f;
+
                 if (!elf_sym__is_function(&sym))
                         continue;
-                struct symbol *f = symbol__new(sym.st_value, sym.st_size,
-                                               elf_sym__name(&sym, symstrs));
-                if (f == NULL)
+
+                sec = elf_getscn(elf, sym.st_shndx);
+                if (!sec)
+                        goto out_elf_end;
+
+                gelf_getshdr(sec, &shdr);
+                sym.st_value -= shdr.sh_addr - shdr.sh_offset;
+
+                f = symbol__new(sym.st_value, sym.st_size,
+                                elf_sym__name(&sym, symstrs));
+                if (!f)
                         goto out_elf_end;
 
                 dso__insert_symbol(self, f);
@@ -498,7 +466,7 @@ static size_t symhist__fprintf(struct symhist *self, FILE *fp)
                 ret += fprintf(fp, "%s", self->sym ? self->sym->name: "<unknown>");
         else
                 ret += fprintf(fp, "%s: %s",
-                               self->dso ? self->dso->name : "<unknown",
+                               self->dso ? self->dso->name : "<unknown>",
                                self->sym ? self->sym->name : "<unknown>");
         return ret + fprintf(fp, ": %u\n", self->count);
 }
@@ -714,6 +682,7 @@ more:
                 int show = 0;
                 struct dso *dso = NULL;
                 struct thread *thread = threads__findnew(event->ip.pid);
+                uint64_t ip = event->ip.ip;
 
                 if (thread == NULL) {
                         fprintf(stderr, "problem processing %d event, bailing out\n",
@@ -728,19 +697,20 @@ more:
                 } else if (event->header.misc & PERF_EVENT_MISC_USER) {
                         show = SHOW_USER;
                         level = '.';
-                        struct map *map = thread__find_map(thread, event->ip.ip);
-                        if (map != NULL)
+                        struct map *map = thread__find_map(thread, ip);
+                        if (map != NULL) {
                                 dso = map->dso;
+                                ip -= map->start + map->pgoff;
+                        }
                 } else {
                         show = SHOW_HV;
                         level = 'H';
                 }
 
                 if (show & show_mask) {
-                        struct symbol *sym = dso__find_symbol(dso, event->ip.ip);
+                        struct symbol *sym = dso__find_symbol(dso, ip);
 
-                        if (thread__symbol_incnew(thread, sym, event->ip.ip,
-                                                  dso, level)) {
+                        if (thread__symbol_incnew(thread, sym, ip, dso, level)) {
                                 fprintf(stderr, "problem incrementing symbol count, bailing out\n");
                                 goto done;
                         }