Assume mutex locking cannot fail

Locking and unlocking a non-recursive mutex is a simple memory
operation and should not fail on any reasonable platform with correct
usage.  A pthread mutex can return EDEADLK on lock or EPERM on unlock,
or EINVAL if the mutex is uninitialized, but all of these conditions
would reflect serious bugs in the calling code.

Change the k5_mutex_lock and k5_mutex_unlock wrappers to return void
and adjust all call sites.  Propagate this change through
k5_cc_mutex_lock and k5_cc_mutex_unlock as well.

1 files changed, 8 insertions, 18 deletions

diff --git a/src/util/et/error_message.c b/src/util/et/error_message.c
index 01f2c03ca..50ede704d 100644
--- a/src/util/et/error_message.c
+++ b/src/util/et/error_message.c
@@ -75,8 +75,7 @@ void com_err_terminate(void)
 #endif
     k5_key_delete(K5_KEY_COM_ERR);
     k5_mutex_destroy(&com_err_hook_lock);
-    if (k5_mutex_lock(&et_list_lock) != 0)
-        return;
+    k5_mutex_lock(&et_list_lock);
     for (e = et_list; e; e = enext) {
         enext = e->next;
         free(e);
@@ -121,7 +120,6 @@ error_message(long code)
     unsigned int divisor = 100;
     char *cp, *cp1;
     const struct error_table *table;
-    int merr;
 
     l_offset = (unsigned long)code & ((1<<ERRCODE_RANGE)-1);
     offset = l_offset;
@@ -159,9 +157,7 @@ error_message(long code)
 
     if (CALL_INIT_FUNCTION(com_err_initialize))
         return 0;
-    merr = k5_mutex_lock(&et_list_lock);
-    if (merr)
-        goto oops;
+    k5_mutex_lock(&et_list_lock);
     dprintf(("scanning list for %x\n", table_num));
     for (e = et_list; e != NULL; e = e->next) {
         dprintf(("\t%x = %s\n", e->table->base & ERRCODE_MAX,
@@ -276,7 +272,6 @@ errcode_t KRB5_CALLCONV
 add_error_table(const struct error_table *et)
 {
     struct et_list *e;
-    int merr;
 
     if (CALL_INIT_FUNCTION(com_err_initialize))
         return 0;
@@ -287,11 +282,7 @@ add_error_table(const struct error_table *et)
 
     e->table = et;
 
-    merr = k5_mutex_lock(&et_list_lock);
-    if (merr) {
-        free(e);
-        return merr;
-    }
+    k5_mutex_lock(&et_list_lock);
     e->next = et_list;
     et_list = e;
 
@@ -300,20 +291,18 @@ add_error_table(const struct error_table *et)
     if (et->msgs[et->n_msgs] != NULL && et->msgs[et->n_msgs + 1] != NULL)
         bindtextdomain(et->msgs[et->n_msgs], et->msgs[et->n_msgs + 1]);
 
-    return k5_mutex_unlock(&et_list_lock);
+    k5_mutex_unlock(&et_list_lock);
+    return 0;
 }
 
 errcode_t KRB5_CALLCONV
 remove_error_table(const struct error_table *et)
 {
     struct et_list **ep, *e;
-    int merr;
 
     if (CALL_INIT_FUNCTION(com_err_initialize))
         return 0;
-    merr = k5_mutex_lock(&et_list_lock);
-    if (merr)
-        return merr;
+    k5_mutex_lock(&et_list_lock);
 
     /* Remove the entry that matches the error table instance. */
     for (ep = &et_list; *ep; ep = &(*ep)->next) {
@@ -321,7 +310,8 @@ remove_error_table(const struct error_table *et)
             e = *ep;
             *ep = e->next;
             free(e);
-            return k5_mutex_unlock(&et_list_lock);
+            k5_mutex_unlock(&et_list_lock);
+            return 0;
         }
     }
     k5_mutex_unlock(&et_list_lock);