Bug #43303 Conditional jump valgrind warning for backup_backupdir
Submitted: 2 Mar 2009 10:21 Modified: 27 Mar 2009 0:02
Reporter: Rafal Somla Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Backup Severity:S3 (Non-critical)
Version: OS:Any
Assigned to: Chuck Bell CPU Architecture:Any
Tags: pushbuild failure, unitialized value, valgrind

[2 Mar 2009 10:21] Rafal Somla 
Description:
When running backup_backupdir with valgrind it reports the following problems:

> ==2705== Conditional jump or move depends on uninitialised value(s)
> ==2705==    at 0x8263362: String::c_ptr() (sql_string.h:98)
> ==2705==    by 0x833E556: sys_check_backupdir(THD*, set_var*) (set_var.cc:2953)
> ==2705==    by 0x833E011: sys_var_str::check(THD*, set_var*) (set_var.cc:993)
> ==2705==    by 0x833F94A: set_var::check(THD*) (set_var.cc:4000)
> ==2705==    by 0x8340C53: sql_set_variables(THD*, List<set_var_base>*) (set_var.cc:3907)
> ==2705==    by 0x832F2FF: mysql_execute_command(THD*) (sql_parse.cc:3487)
> ==2705==    by 0x8333AB6: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5812)
> ==2705==    by 0x8334A8F: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1057)
> ==2705==    by 0x8335DAA: do_command(THD*) (sql_parse.cc:739)
> ==2705==    by 0x83229A6: handle_one_connection (sql_connect.cc:1146)
> ==2705==    by 0x404F0BC: start_thread (in /lib/tls/libpthread-2.3.6.so)
> ==2705==    by 0x42829ED: clone (in /lib/tls/libc-2.3.6.so)
> ==2705== 
> ==2705== Conditional jump or move depends on uninitialised value(s)
> ==2705==    at 0x891E9D5: dirname_length (mf_dirname.c:33)
> ==2705==    by 0x891EA54: dirname_part (mf_dirname.c:73)
> ==2705==    by 0x833E593: sys_check_backupdir(THD*, set_var*) (set_var.cc:2957)
> ==2705==    by 0x833E011: sys_var_str::check(THD*, set_var*) (set_var.cc:993)
> ==2705==    by 0x833F94A: set_var::check(THD*) (set_var.cc:4000)
> ==2705==    by 0x8340C53: sql_set_variables(THD*, List<set_var_base>*) (set_var.cc:3907)
> ==2705==    by 0x832F2FF: mysql_execute_command(THD*) (sql_parse.cc:3487)
> ==2705==    by 0x8333AB6: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5812)
> ==2705==    by 0x8334A8F: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1057)
> ==2705==    by 0x8335DAA: do_command(THD*) (sql_parse.cc:739)
> ==2705==    by 0x83229A6: handle_one_connection (sql_connect.cc:1146)
> ==2705==    by 0x404F0BC: start_thread (in /lib/tls/libpthread-2.3.6.so)
> ==2705==    by 0x42829ED: clone (in /lib/tls/libc-2.3.6.so)
> ==2705== 
> ==2705== Conditional jump or move depends on uninitialised value(s)
> ==2705==    at 0x8263362: String::c_ptr() (sql_string.h:98)
> ==2705==    by 0x833F139: sys_update_backupdir(THD*, set_var*) (set_var.cc:3006)
> ==2705==    by 0x8344766: sys_var_str::update(THD*, set_var*) (set_var.h:278)
> ==2705==    by 0x83379D9: set_var::update(THD*) (set_var.cc:4049)
> ==2705==    by 0x8340CDC: sql_set_variables(THD*, List<set_var_base>*) (set_var.cc:3914)
> ==2705==    by 0x832F2FF: mysql_execute_command(THD*) (sql_parse.cc:3487)
> ==2705==    by 0x8333AB6: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5812)
> ==2705==    by 0x8334A8F: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1057)
> ==2705==    by 0x8335DAA: do_command(THD*) (sql_parse.cc:739)
> ==2705==    by 0x83229A6: handle_one_connection (sql_connect.cc:1146)
> ==2705==    by 0x404F0BC: start_thread (in /lib/tls/libpthread-2.3.6.so)
> ==2705==    by 0x42829ED: clone (in /lib/tls/libc-2.3.6.so)

These are in the code handling the @@backupdir variable.

How to repeat:
Run "./mtr backup_backupdir --valgrind" and see server's error log.
[6 Mar 2009 20:44] Chuck Bell 
Working to fix valgrind errors in PB.
[6 Mar 2009 21:24] Bugs System 
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/68561

2787 Chuck Bell	2009-03-06
      BUG#43303 : Conditional jump valgrind warning for backup_backupdir
      
      This warning was being issued because the end of the string 
      for Ptr[] was not being marked. The safe call ensures this
      happens and therefore avoids the valgrind warning.
      modified:
        sql/set_var.cc
[9 Mar 2009 10:21] Jørgen Løland 
Good to push
[9 Mar 2009 11:36] Ingo Strüwing 
Approved.
[26 Mar 2009 12:35] Bugs System 
Pushed into 6.0.11-alpha (revid:alik@sun.com-20090326121822-pt84kzxxayzho4mn) (version source revid:charles.bell@sun.com-20090309134019-vr480npdp30f2gvh) (merge vers: 6.0.11-alpha) (pib:6)
[27 Mar 2009 0:02] Paul DuBois 
Noted in 6.0.11 changelog.

Assigning a value to the backupdir system variable resulted in
Valgrind errors.