library: fix major oops in procps_pids_reap() function

In my zeal to finalize the initial pids implementation
I omitted some quite important parameter checking from
the above function. Thank goodness top was kind to us.

Also, in anticipation of the additions of single stack
read and supporting functions some items were renamed.

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/proc/pids.c b/proc/pids.c
index 854af90b7d401c16a80451ecae798795551eb9de..913bb2b374db3e023a18cb904edeef0c55da7071 100644 (file)
--- a/proc/pids.c
+++ b/proc/pids.c
@@ -956,10 +956,17 @@ PROCPS_EXPORT struct pids_reap *procps_pids_reap (
  #define n_alloc  info->alloc_total
  #define n_inuse  info->inuse_total
     static proc_t task;    // static for initial zeroes + later dynamic free(s)
-    proc_t*(*read_something)(PROCTAB*, proc_t*);
+    proc_t*(*reap_something)(PROCTAB*, proc_t*);
     struct pids_stacks *ext;
     int n_save = n_alloc;
 
+    if (info == NULL)
+        return NULL;
+    if (!info->maxitems && !info->curitems)
+        return NULL;
+    if (which != PROCPS_REAP_TASKS_ONLY && which != PROCPS_REAP_THREADS_TOO)
+        return NULL;
+
     if (!info->anchor) {
         if ((!(info->anchor = calloc(sizeof(void *), MEMORY_INCR)))
         || (!(info->reaped.stacks = calloc(sizeof(void *), MEMORY_INCR)))
@@ -975,7 +982,7 @@ PROCPS_EXPORT struct pids_reap *procps_pids_reap (
     if (!oldproc_open(info, 0))
         return NULL;
     toggle_history(info);
-    read_something = which ? readeither : readproc;
+    reap_something = which ? readeither : readproc;
 
     for (n_inuse = 0; ; n_inuse++) {
         if (n_inuse == n_alloc) {
@@ -985,7 +992,7 @@ PROCPS_EXPORT struct pids_reap *procps_pids_reap (
                 return NULL;
             memcpy(info->anchor + n_inuse, ext->stacks, sizeof(void *) * MEMORY_INCR);
         }
-        if (NULL == read_something(info->PT, &task))
+        if (NULL == reap_something(info->PT, &task))
             break;
         if (!tally_proc(info, &info->reaped.counts, &task))
             return NULL;
@@ -1131,6 +1138,7 @@ PROCPS_EXPORT int procps_pids_stacks_dealloc (
         struct pids_stacks **these)
 {
     struct stacks_extent *ext;
+    int rc;
 
     if (info == NULL || these == NULL)
         return -EINVAL;
@@ -1138,7 +1146,7 @@ PROCPS_EXPORT int procps_pids_stacks_dealloc (
         return -EINVAL;
 
     ext = (struct stacks_extent *)(*these);
-    int rc = free_extent(info, ext);
+    rc = free_extent(info, ext);
     *these = NULL;
     return rc;
 } // end: procps_pids_stacks_dealloc