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Bug 371525 (unaligned-access)

Summary: [TRACKER] packages with unaligned accesses
Product: Gentoo Linux Reporter: Matt Turner <mattst88>
Component: New packagesAssignee: Gentoo Quality Assurance Team <qa>
Status: CONFIRMED ---    
Severity: normal CC: alpha, arm, bertrand, eike, hppa, ia64, mips, nikoli, ppc64, ppc, sam, sparc
Priority: Normal Keywords: Tracker
Version: unspecified   
Hardware: All   
OS: Linux   
Whiteboard:
Package list:
Runtime testing required: ---
Bug Depends on: 634822, 638066, 638888, 640618, 642492, 663976, 686620, 700902, 709014, 717908, 201102, 295682, 348387, 371527, 371561, 454006, 498632, 532088, 558436, 638172, 643086, 659460, 664860, 666448, 673472, 676062, 686914, 700190    
Bug Blocks:    

Description Matt Turner gentoo-dev 2011-06-13 22:01:39 UTC
Unaligned accesses (see: [1]) are bad.

To find the source of unaligned accesses, use sys-apps/prctl and the instructions here [2].

[1] http://en.wikipedia.org/wiki/Segmentation_fault#Bus_error
[2] http://www.gelato.unsw.edu.au/IA64wiki/UnalignedAccesses

No comments here. This is simply a tracker bug.
Comment 1 SpanKY gentoo-dev 2011-07-12 18:46:25 UTC
the kernel on these arches should automatically fixup unaligned access so the code at least works (albeit at a performance penalty).  if they dont, i'd say that's a bad kernel config.

(i dont mind fixing up unaligned programs, but it shouldnt take priority over "real" bugs imo)
Comment 2 Matt Turner gentoo-dev 2011-07-12 19:41:54 UTC
By default (is there some way to change this?) on MIPS and SPARC, unaligned accesses cause SIGBUS. I know other architectures trap unaligned accesses and handle them in the kernel.