Bug #44582 USED_MEM::left not set in alloc_root for debug builds
Submitted: 30 Apr 2009 18:10 Modified: 13 Feb 2014 18:27
Reporter: Mark Callaghan Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:5.0,5.1, 6.0 OS:Any
Assigned to: CPU Architecture:Any
Tags: alloc_root, Contribution, debug

[30 Apr 2009 18:10] Mark Callaghan
Description:
alloc_root does not set USED_MEM::left for the HAVE_purify code. Also a bit more can be done to support valgrind in this code.

This code is missing from the HAVE_purify code in alloc_root:
next->left= Size-ALIGN_SIZE(sizeof(USED_MEM));

I will submit a patch here with possible changes for valgrind

How to repeat:
read the source
[30 Apr 2009 18:11] Mark Callaghan
Patch for my_alloc.c and 5.0.37

Attachment: mad (application/octet-stream, text), 2.76 KiB.

[4 May 2009 6:28] Sveta Smirnova
Thank you for the report.

Verified as described.
[13 Feb 2014 18:27] Paul Dubois
Noted in 5.7.4 changelog.

Code instrumented with Valgrind did not preallocate memory in
alloc_root(), to help find bugs. This behavior is now also enabled if
ASAN (address sanitizer) is used.

(The "used_mem::left" issue was fixed as well.)