library: optional parms protection missing, <PIDS> api

When those items were made dynamic at 'new' time, some
other functions, previously assured of their presence,
failed to verify a 'reset' had acually been requested.

This commit just corrects that oversight and avoids an
attempt to 'assign_results' when no items are present.

Reference(s):
. when items/numitems became optional
commit 9ebadc1438a6665a98a9f0782523b0f9a2a6248f

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

diff --git a/proc/pids.c b/proc/pids.c
index 7726ff90c24c0a08d8ddaaf69028186fabf9ae6f..1bb5df4de7097a665aa6426d0627587972f0f980 100644 (file)
--- a/proc/pids.c
+++ b/proc/pids.c
@@ -876,8 +876,8 @@ static void itemize_stacks_all (
 
 
 static inline int items_check_failed (
-        int numitems,
-        enum pids_item *items)
+        enum pids_item *items,
+        int numitems)
 {
     int i;
 
@@ -1137,7 +1137,7 @@ PROCPS_EXPORT int procps_pids_new (
     /* if we're without items or numitems, a later call to
        procps_pids_reset() will become mandatory */
     if (items && numitems) {
-        if (items_check_failed(numitems, items)) {
+        if (items_check_failed(items, numitems)) {
             free(p);
             return -EINVAL;
         }
@@ -1242,15 +1242,23 @@ PROCPS_EXPORT struct pids_stack *fatal_proc_unmounted (
     static proc_t self;
     struct stacks_extent *ext;
 
-    // this is very likely the *only* newlib function where the
-    // context (procps_pidsinfo) of NULL will ever be permitted
+    /* this is very likely the *only* newlib function where the
+       context (procps_pidsinfo) of NULL will ever be permitted */
     look_up_our_self(&self);
     if (!return_self)
         return NULL;
 
-    if (info == NULL
-    || !(ext = stacks_alloc(info, 1))
-    || !extent_cut(info, ext))
+    if (info == NULL)
+        return NULL;
+
+    /* with items & numitems technically optional at 'new' time, it's
+       expected 'reset' will have been called -- but just in case ... */
+    if (!info->curitems)
+        return NULL;
+
+    if (!(ext = stacks_alloc(info, 1)))
+        return NULL;
+    if (!extent_cut(info, ext))
         return NULL;
 
     ext->next = info->otherexts;
@@ -1273,6 +1281,10 @@ PROCPS_EXPORT struct pids_stack *procps_pids_get (
         return NULL;
     if (which != PROCPS_FETCH_TASKS_ONLY && which != PROCPS_FETCH_THREADS_TOO)
         return NULL;
+    /* with items & numitems technically optional at 'new' time, it's
+       expected 'reset' will have been called -- but just in case ... */
+    if (!info->curitems)
+        return NULL;
 
 fresh_start:
     if (!info->get_ext) {
@@ -1318,10 +1330,12 @@ PROCPS_EXPORT struct pids_fetch *procps_pids_reap (
 
     if (info == NULL)
         return NULL;
-    if (!info->curitems)
-        return NULL;
     if (which != PROCPS_FETCH_TASKS_ONLY && which != PROCPS_FETCH_THREADS_TOO)
         return NULL;
+    /* with items & numitems technically optional at 'new' time, it's
+       expected 'reset' will have been called -- but just in case ... */
+    if (!info->curitems)
+        return NULL;
 
     if (!oldproc_open(&info->PT, info->oldflags))
         return NULL;
@@ -1342,7 +1356,7 @@ PROCPS_EXPORT int procps_pids_reset (
 {
     if (info == NULL || newitems == NULL)
         return -EINVAL;
-    if (items_check_failed(newnumitems, newitems))
+    if (items_check_failed(newitems, newnumitems))
         return -EINVAL;
 
     /* shame on this caller, they didn't change anything. and unless they have
@@ -1398,6 +1412,10 @@ PROCPS_EXPORT struct pids_fetch *procps_pids_select (
         return NULL;
     if (which != PROCPS_SELECT_PID && which != PROCPS_SELECT_UID)
         return NULL;
+    /* with items & numitems technically optional at 'new' time, it's
+       expected 'reset' will have been called -- but just in case ... */
+    if (!info->curitems)
+        return NULL;
 
     // this zero delimiter is really only needed with PROCPS_SELECT_PID
     memcpy(ids, these, sizeof(unsigned) * numthese);