Bug 13134 - Padding/alignment of PAC elements is done wrong on Samba KDCs
Summary: Padding/alignment of PAC elements is done wrong on Samba KDCs
Status: NEW
Alias: None
Product: Samba 4.1 and newer
Classification: Unclassified
Component: AD: LDB/DSDB/SAMDB (show other bugs)
Version: 4.7.0
Hardware: All All
: P5 normal (vote)
Target Milestone: ---
Assignee: Stefan Metzmacher
QA Contact: Samba QA Contact
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-11-14 15:09 UTC by Stefan Metzmacher
Modified: 2019-06-03 10:44 UTC (History)
2 users (show)

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Description Stefan Metzmacher 2017-11-14 15:09:20 UTC
The size of PAC_TYPE_LOGON_INFO and PAC_TYPE_UPN_DNS_INFO elements is supposed
to be padded to an 8 byte boundary...
Comment 1 Amit Kumar 2019-06-03 10:44:33 UTC
(In reply to Stefan Metzmacher from comment #0)
My understanding about alignment:
- I think current processors are bit smart and they can handle the unaligned memory but in some bad situation, the processor takes some extra cycles to fetch the unaligned memory. So it would be good for coder to care about alignment when he writes the code.
- Padding increases the performance of the processor at the penalty of memory.
- For structure, union wastage of memory can be saved by rearranging members in the order of largest size to smallest.

Problems:
- But wont custom struct member alignment cause compatibility issues, for linking external library using different packing alignments?

How?
__attribute__ ((aligned (8)))

Your thoughts