sadc: Fix segfault that may happen when appending data to file

Buffers need to be allocated according to activities present in file so
that we can append data to that file.

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>

diff --git a/sadc.c b/sadc.c
index c96d134362d8ad85dfbc329dc62e9fe92d9429a8..edc70859b4e79b820ce3cf5235de7dcea81f3cc0 100644 (file)
--- a/sadc.c
+++ b/sadc.c
@@ -936,20 +936,6 @@ void open_ofile(int *ofd, char ofile[], int restart_mark)
 
                p = get_activity_position(act, file_act[i].id, EXIT_IF_NOT_FOUND);
 
-               /*
-                * Force number of sub-items to that of the file, and reallocate structures.
-                * We don't care for items as their structures will be dynamically allocated.
-                */
-               if (file_act[i].nr2 != act[p]->nr2) {
-                       act[p]->nr2 = file_act[i].nr2;
-                       SREALLOC(act[p]->_buf0, void,
-                                (size_t) act[p]->msize * (size_t) act[p]->nr_ini * (size_t) act[p]->nr2);
-               }
-
-               /* Save activity sequence */
-               id_seq[i] = file_act[i].id;
-               act[p]->options |= AO_COLLECTED;
-
                /*
                 * sar doesn't expect a number of items equal to 0.
                 * Yet @nr_ini may be 0 if no items have been found on current machine.
@@ -958,6 +944,21 @@ void open_ofile(int *ofd, char ofile[], int restart_mark)
                 * the machine.
                 */
                act[p]->nr_ini = file_act[i].nr;
+
+               /*
+                * Force number of sub-items to that of the file, and reallocate structures.
+                * Note: Structures have been allocated in sa_sys_init() only for activities
+                * that are collected. But since activities from file now prevail over them,
+                * we need to reallocate.
+                */
+               act[p]->nr2 = file_act[i].nr2;
+               SREALLOC(act[p]->_buf0, void,
+                        (size_t) act[p]->msize * (size_t) act[p]->nr_ini * (size_t) act[p]->nr2);
+               act[p]->nr_allocated = act[p]->nr_ini;
+
+               /* Save activity sequence */
+               id_seq[i] = file_act[i].id;
+               act[p]->options |= AO_COLLECTED;
        }
 
        return;