perf_counter: tools: /usr/lib/debug%s.debug support

Some distros seem to store debuginfo in weird places.

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>

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index 6265bedcd9370a924899753e7c458c695b4c2e2d..a9ff49a4edea37ca9d2fa8a2e45a0671a4a87453 100644 (file)
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -190,7 +190,8 @@ static inline int elf_sym__is_function(const GElf_Sym *sym)
 {
        return elf_sym__type(sym) == STT_FUNC &&
               sym->st_name != 0 &&
-              sym->st_shndx != SHN_UNDEF;
+              sym->st_shndx != SHN_UNDEF &&
+              sym->st_size != 0;
 }
 
 static inline const char *elf_sym__name(const GElf_Sym *sym,
@@ -222,11 +223,11 @@ static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
        return sec;
 }
 
-static int dso__load(struct dso *self)
+static int dso__load_sym(struct dso *self, int fd, char *name)
 {
        Elf_Data *symstrs;
        uint32_t nr_syms;
-       int fd, err = -1;
+       int err = -1;
        uint32_t index;
        GElf_Ehdr ehdr;
        GElf_Shdr shdr;
@@ -234,16 +235,12 @@ static int dso__load(struct dso *self)
        GElf_Sym sym;
        Elf_Scn *sec;
        Elf *elf;
-
-
-       fd = open(self->name, O_RDONLY);
-       if (fd == -1)
-               return -1;
+       int nr = 0;
 
        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
        if (elf == NULL) {
                fprintf(stderr, "%s: cannot read %s ELF file.\n",
-                       __func__, self->name);
+                       __func__, name);
                goto out_close;
        }
 
@@ -292,16 +289,63 @@ static int dso__load(struct dso *self)
                        goto out_elf_end;
 
                dso__insert_symbol(self, f);
+
+               nr++;
        }
 
-       err = 0;
+       err = nr;
 out_elf_end:
        elf_end(elf);
 out_close:
-       close(fd);
        return err;
 }
 
+static int dso__load(struct dso *self)
+{
+       int size = strlen(self->name) + sizeof("/usr/lib/debug%s.debug");
+       char *name = malloc(size);
+       int variant = 0;
+       int ret = -1;
+       int fd;
+
+       if (!name)
+               return -1;
+
+more:
+       do {
+               switch (variant) {
+               case 0: /* Fedora */
+                       snprintf(name, size, "/usr/lib/debug%s.debug", self->name);
+                       break;
+               case 1: /* Ubuntu */
+                       snprintf(name, size, "/usr/lib/debug%s", self->name);
+                       break;
+               case 2: /* Sane people */
+                       snprintf(name, size, "%s", self->name);
+                       break;
+
+               default:
+                       goto out;
+               }
+               variant++;
+
+               fd = open(name, O_RDONLY);
+       } while (fd < 0);
+
+       ret = dso__load_sym(self, fd, name);
+       close(fd);
+
+       /*
+        * Some people seem to have debuginfo files _WITHOUT_ debug info!?!?
+        */
+       if (!ret)
+               goto more;
+
+out:
+       free(name);
+       return ret;
+}
+
 static size_t dso__fprintf(struct dso *self, FILE *fp)
 {
        size_t ret = fprintf(fp, "dso: %s\n", self->name);
@@ -336,11 +380,23 @@ static struct dso *dsos__find(const char *name)
 static struct dso *dsos__findnew(const char *name)
 {
        struct dso *dso = dsos__find(name);
+       int nr;
 
        if (dso == NULL) {
                dso = dso__new(name);
-               if (dso != NULL && dso__load(dso) < 0)
+               if (!dso)
+                       goto out_delete_dso;
+
+               nr = dso__load(dso);
+               if (nr < 0) {
+                       fprintf(stderr, "Failed to open: %s\n", name);
                        goto out_delete_dso;
+               }
+               if (!nr) {
+                       fprintf(stderr,
+               "Failed to find debug symbols for: %s, maybe install a debug package?\n",
+                                       name);
+               }
 
                dsos__add(dso);
        }
@@ -547,9 +603,9 @@ symhist__fprintf(struct symhist *self, uint64_t total_samples, FILE *fp)
        size_t ret;
 
        if (total_samples)
-               ret = fprintf(fp, "%5.2f", (self->count * 100.0) / total_samples);
+               ret = fprintf(fp, "%5.2f%% ", (self->count * 100.0) / total_samples);
        else
-               ret = fprintf(fp, "%12d", self->count);
+               ret = fprintf(fp, "%12d ", self->count);
 
        ret += fprintf(fp, "%14s [%c] ",
                       thread__name(self->thread, bf, sizeof(bf)),
@@ -922,10 +978,12 @@ more:
        }
        default: {
 broken_event:
-               fprintf(stderr, "%p [%p]: skipping unknown header type: %d\n",
-                       (void *)(offset + head),
-                       (void *)(long)(event->header.size),
-                       event->header.type);
+               if (dump_trace)
+                       fprintf(stderr, "%p [%p]: skipping unknown header type: %d\n",
+                                       (void *)(offset + head),
+                                       (void *)(long)(event->header.size),
+                                       event->header.type);
+
                total_unknown++;
 
                /*