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>

1 files changed, 76 insertions, 18 deletions

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index 6265bedcd937..a9ff49a4edea 100644
--- 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++;
 
                 /*