bk commit into 4.1 tree (kroki:1.2462) BUG#16372

[kroki]

Below is the list of changes that have just been committed into a local
4.1 repository of tomash. When tomash does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet
  1.2462 06/04/27 14:54:36 kroki@stripped +1 -0
  Bug#16372: Server crashes when test 'conc_sys' is running
  
  Concurrent read and update of privilege structures (like simultaneous
  run of SHOW GRANTS and ADD USER) could result in server crash.
  
  Ensure that proper locking of ACL structures is done.

  sql/sql_acl.cc
    1.175 06/04/27 14:54:31 kroki@stripped +31 -6
    Ensure that access to ACL data is protected by acl_cache->lock mutex.
    Use system_charset_info for host names consistently.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	kroki
# Host:	moonlight.intranet
# Root:	/home/tomash/src/mysql_ab/mysql-4.1-bug16372

--- 1.174/sql/sql_acl.cc	2006-03-06 13:02:54 +03:00
+++ 1.175/sql/sql_acl.cc	2006-04-27 14:54:31 +04:00
@@ -894,6 +894,8 @@
 			    USER_RESOURCES  *mqh,
 			    ulong privileges)
 {
+  safe_mutex_assert_owner(&acl_cache->lock);
+
   for (uint i=0 ; i < acl_users.elements ; i++)
   {
     ACL_USER *acl_user=dynamic_element(&acl_users,i,ACL_USER*);
@@ -942,6 +944,9 @@
 			    ulong privileges)
 {
   ACL_USER acl_user;
+
+  safe_mutex_assert_owner(&acl_cache->lock);
+
   acl_user.user=*user ? strdup_root(&mem,user) : 0;
   update_hostname(&acl_user.host, *host ? strdup_root(&mem, host): 0);
   acl_user.access=privileges;
@@ -973,6 +978,8 @@
 static void acl_update_db(const char *user, const char *host, const char *db,
 			  ulong privileges)
 {
+  safe_mutex_assert_owner(&acl_cache->lock);
+
   for (uint i=0 ; i < acl_dbs.elements ; i++)
   {
     ACL_DB *acl_db=dynamic_element(&acl_dbs,i,ACL_DB*);
@@ -1358,6 +1365,9 @@
 {
   DBUG_ENTER("find_acl_user");
   DBUG_PRINT("enter",("host: '%s'  user: '%s'",host,user));
+
+  safe_mutex_assert_owner(&acl_cache->lock);
+
   for (uint i=0 ; i < acl_users.elements ; i++)
   {
     ACL_USER *acl_user=dynamic_element(&acl_users,i,ACL_USER*);
@@ -1370,7 +1380,7 @@
     if (!acl_user->user && !user[0] ||
 	acl_user->user && !strcmp(user,acl_user->user))
     {
-      if (exact ? !my_strcasecmp(&my_charset_latin1, host,
+      if (exact ? !my_strcasecmp(system_charset_info, host,
                                  acl_user->host.hostname ?
 				 acl_user->host.hostname : "") :
           compare_hostname(&acl_user->host,host,host))
@@ -2445,6 +2455,7 @@
     create_new_users= test_if_create_new_users(thd);
   int result=0;
   rw_wrlock(&LOCK_grant);
+  pthread_mutex_lock(&acl_cache->lock);
   MEM_ROOT *old_root= thd->mem_root;
   thd->mem_root= &memex;
 
@@ -2460,10 +2471,8 @@
       continue;
     }
     /* Create user if needed */
-    pthread_mutex_lock(&acl_cache->lock);
     error=replace_user_table(thd, tables[0].table, *Str,
 			     0, revoke_grant, create_new_users);
-    pthread_mutex_unlock(&acl_cache->lock);
     if (error)
     {
       result= -1;				// Remember error
@@ -2552,6 +2561,7 @@
   }
   grant_option=TRUE;
   thd->mem_root= old_root;
+  pthread_mutex_unlock(&acl_cache->lock);
   rw_unlock(&LOCK_grant);
   if (!result)
     send_ok(thd);
@@ -3203,6 +3213,9 @@
     DBUG_RETURN(-1);
   }
 
+  rw_rdlock(&LOCK_grant);
+  VOID(pthread_mutex_lock(&acl_cache->lock));
+
   for (counter=0 ; counter < acl_users.elements ; counter++)
   {
     const char *user,*host;
@@ -3217,6 +3230,9 @@
   }
   if (counter == acl_users.elements)
   {
+    VOID(pthread_mutex_unlock(&acl_cache->lock));
+    rw_unlock(&LOCK_grant);
+
     my_error(ER_NONEXISTING_GRANT, MYF(0),
              lex_user->user.str, lex_user->host.str);
     DBUG_RETURN(-1);
@@ -3230,10 +3246,12 @@
 	  lex_user->host.str,NullS);
   field_list.push_back(field);
   if (protocol->send_fields(&field_list,1))
-    DBUG_RETURN(-1);
+  {
+    VOID(pthread_mutex_unlock(&acl_cache->lock));
+    rw_unlock(&LOCK_grant);
 
-  rw_wrlock(&LOCK_grant);
-  VOID(pthread_mutex_lock(&acl_cache->lock));
+    DBUG_RETURN(-1);
+  }
 
   /* Add first global access grants */
   {
@@ -3540,10 +3558,15 @@
 void get_mqh(const char *user, const char *host, USER_CONN *uc)
 {
   ACL_USER *acl_user;
+
+  pthread_mutex_lock(&acl_cache->lock);
+
   if (initialized && (acl_user= find_acl_user(host,user, FALSE)))
     uc->user_resources= acl_user->user_resource;
   else
     bzero((char*) &uc->user_resources, sizeof(uc->user_resources));
+
+  pthread_mutex_unlock(&acl_cache->lock);
 }
 
 int open_grant_tables(THD *thd, TABLE_LIST *tables)
@@ -3601,6 +3624,8 @@
 {
   ACL_USER *acl_user= 0;
   uint counter;
+
+  safe_mutex_assert_owner(&acl_cache->lock);
 
   for (counter= 0 ; counter < acl_users.elements ; counter++)
   {