perf: Don't assume /proc/kallsyms is ordered

perf: Don't assume /proc/kallsyms is ordered

Since we _are_ ordering it by the symbol start, just traverse the
freshly built rbtree setting the prev->end members to curr->start - 1.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: 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: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090526152134.GF4424@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 25 insertions, 19 deletions

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index b19b893d4ff5..e17819001dd5 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -360,17 +360,9 @@ static int load_kallsyms(void)
         char *line = NULL;
         size_t n;
 
-        if (getline(&line, &n, file) < 0 || !line)
-                goto out_delete_dso;
-
-        unsigned long long previous_start;
-        char c, previous_symbf[4096];
-        if (sscanf(line, "%llx %c %s", &previous_start, &c, previous_symbf) != 3)
-                goto out_delete_line;
-
         while (!feof(file)) {
                 unsigned long long start;
-                char symbf[4096];
+                char c, symbf[4096];
 
                 if (getline(&line, &n, file) < 0)
                         break;
@@ -379,21 +371,35 @@ static int load_kallsyms(void)
                         goto out_delete_dso;
 
                 if (sscanf(line, "%llx %c %s", &start, &c, symbf) == 3) {
-                        if (start > previous_start) {
-                                struct symbol *sym = symbol__new(previous_start,
-                                                                 start - previous_start,
-                                                                 previous_symbf);
+                        /*
+                         * Well fix up the end later, when we have all sorted.
+                         */
+                        struct symbol *sym = symbol__new(start, 0xdead, symbf);
 
-                                if (sym == NULL)
-                                        goto out_delete_dso;
+                        if (sym == NULL)
+                                goto out_delete_dso;
 
-                                dso__insert_symbol(kernel_dso, sym);
-                                previous_start = start;
-                                strcpy(previous_symbf, symbf);
-                        }
+                        dso__insert_symbol(kernel_dso, sym);
                 }
         }
 
+        /*
+         * Now that we have all sorted out, just set the ->end of all
+         * symbols
+         */
+        struct rb_node *nd, *prevnd = rb_first(&kernel_dso->syms);
+
+        if (prevnd == NULL)
+                goto out_delete_line;
+
+        for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
+                struct symbol *prev = rb_entry(prevnd, struct symbol, rb_node),
+                              *curr = rb_entry(nd, struct symbol, rb_node);
+
+                prev->end = curr->start - 1;
+                prevnd = nd;
+        }
+
         dsos__add(kernel_dso);
         free(line);
         fclose(file);