Bug #59486 Incorrect usage of UNIV_UNLIKELY() in mlog_parse_string()

• Submitted: 13 Jan 2011 20:51
• Modified: 10 Feb 2011 19:56
• Reporter: Alexey Kopytov
• Status: Closed
• Category: MySQL Server: InnoDB storage engine
• Severity: S3 (Non-critical)
• Version: 5.1, 5.5
• OS: Any
• Assigned to: Marko Mäkelä
• CPU Architecture: Any

[13 Jan 2011 20:51] Alexey Kopytov

Description:
This is from innodb_plugin/mtr/mtr0log.c in 5.1:

410	if (UNIV_UNLIKELY(offset >= UNIV_PAGE_SIZE)
411			|| UNIV_UNLIKELY(len + offset) > UNIV_PAGE_SIZE) {
412		recv_sys->found_corrupt_log = TRUE;
413
414		return(NULL);
415	}

When building with gcc, the second condition in if() is expanded into "__builtin_expect(len + offset, FALSE) > UNIV_PAGE_SIZE" which is likely not what it was supposed to be.

The same code is in 5.5.

How to repeat:
Examine the source.

[14 Jan 2011 7:50] Valeriy Kravchuk

Verified by code review in current mysql-5.1 and mysql-5.5 trees.

[25 Jan 2011 10:03] 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/129527

[25 Jan 2011 10:03] 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/129528

[25 Jan 2011 10:18] 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/129531

[25 Jan 2011 10:18] 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/129532

[30 Jan 2011 16:58] Bugs System

Pushed into mysql-5.1 5.1.56 (revid:[e-mail]-20110130164158-1q99a41kb2wvkw3a) (version source revid:[e-mail]-20110130164158-1q99a41kb2wvkw3a) (merge vers: 5.1.56) (pib:24)

[30 Jan 2011 16:59] Bugs System

Pushed into mysql-trunk 5.6.2 (revid:[e-mail]-20110130165639-1pr3opz839b98q5j) (version source revid:[e-mail]-20110130165522-m0o6al0pn5ig9kv3) (merge vers: 5.6.2) (pib:24)

[30 Jan 2011 17:00] Bugs System

Pushed into mysql-5.5 5.5.10 (revid:[e-mail]-20110130165343-he9art47agq1a3gr) (version source revid:[e-mail]-20110130165137-5lvzsq9j29j0hp1s) (merge vers: 5.5.10) (pib:24)