WIP eu-stacktrace: perf_copy_event_simple bugfixes

A bunch of oops when writing this code.

diff --git a/src/stacktrace.c b/src/stacktrace.c
index d60d4de005a87258ebe11007050ca51dbd440fcb..ed325af40049363042650d7209ae236b7882e9a3 100644 (file)
--- a/src/stacktrace.c
+++ b/src/stacktrace.c
@@ -349,8 +349,9 @@ perf_reader_begin ()
   attr.sample_freq = 1000;
   attr.sample_type = EUS_PERF_SAMPLE_TYPE;
   attr.disabled = 1;
+  attr.exclude_kernel = 1; /* TODO: Probably don't care about this for our initial usecase. */
   /* TODO attr.mmap, attr.mmap2 */
-  /* TODO? attr.exclude_kernel = 1;
+  /* TODO?
      attr.exclude_hv = 1; */
   /* TODO? attr.precise_ip = 0;
      attr.wakeup_events = 1; */
@@ -422,6 +423,7 @@ perf_event_read_simple (PerfReader *reader,
   uint64_t data_tail = header->data_tail;
   void *base = ((uint8_t *) header) + reader->page_size;
   int ret = DWARF_CB_OK;
+
   struct perf_event_header *ehdr;
   size_t ehdr_size;
 
@@ -442,7 +444,7 @@ perf_event_read_simple (PerfReader *reader,
          if (*copy_size < ehdr_size)
            {
              free(*copy_mem);
-             copy_mem = malloc(ehdr_size);
+             *copy_mem = malloc(ehdr_size);
              if (!*copy_mem)
                {
                  *copy_size = 0;
@@ -453,7 +455,7 @@ perf_event_read_simple (PerfReader *reader,
            }
 
          memcpy(*copy_mem, copy_start, len_first);
-         memcpy(*copy_mem, copy_start, len_secnd);
+         memcpy(*copy_mem + len_first, copy_start, len_secnd);
          ehdr = *copy_mem; 
        }
 
@@ -508,20 +510,23 @@ perf_reader_getframes (PerfReader *reader,
          break;
        }
       for (int i = 0; i < nfds; i++)
-       if (fds[i].revents <= 0)
-         continue;
-       else if (fds[i].revents & POLLIN)
-         {
-           int ok = perf_event_read_simple (reader,
-                                            reader->perf_headers[i],
-                                            &copy_mem, &copy_size,
-                                            callback, arg);
-           if (ok != DWARF_CB_OK)
-             {
-               rc = 1;
-               break;
-             }
-         }
+       {
+         if (fds[i].revents <= 0)
+           continue;
+         ready --;
+         if (fds[i].revents & POLLIN)
+           {
+             int ok = perf_event_read_simple (reader,
+                                              reader->perf_headers[i],
+                                              &copy_mem, &copy_size,
+                                              callback, arg);
+             if (ok != DWARF_CB_OK)
+               {
+                 rc = 1;
+                 break;
+               }
+           }
+       }
     }
   fprintf(stderr, "total %d samples\n", reader->n_samples);
 
@@ -1155,8 +1160,8 @@ perf_unwind_cb (void *arg)
 {
   struct unwind_info *ui = (struct unwind_info *)arg;
   PerfSample *sample = (PerfSample *)(ui->last_frame);
-  /* TODO handle sample */
-  fprintf(stderr, "DEBUG got pid=%d tid=%d ip=%lx\n", sample->pid, sample->tid, sample->ip);
+  /* TODO also report cpu, handle sample */
+  fprintf(stderr, "DEBUG got time=%lx pid=%d tid=%d ip=%lx\n", sample->time, sample->pid, sample->tid, sample->ip);
   return DWARF_CB_OK;
 }