Bug 371525 (unaligned-access)

Summary:	[TRACKER] packages with unaligned accesses
Product:	Quality Assurance	Reporter:	Matt Turner <mattst88>
Component:	Trackers	Assignee:	Gentoo Quality Assurance Team <qa>
Status:	CONFIRMED ---
Severity:	normal	CC:	alpha, arm, bertrand, eike, hppa, ia64, matoro_bugzilla_gentoo, mips, nikoli, ppc64, ppc, sam, sparc
Priority:	Normal	Keywords:	Tracker
Version:	unspecified
Hardware:	All
OS:	Linux
See Also:	https://bugs.gentoo.org/show_bug.cgi?id=915000
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:	634822, 636552, 638066, 642284, 653240, 717908, 920066, 920345, 920956, 923423, 924191, 925109, 13402, 42010, 87218, 99290, 118777, 152487, 154928, 157408, 158550, 163430, 179877, 192491, 195717, 201102, 209501, 209550, 218278, 227391, 230953, 239472, 246483, 250830, 250880, 251603, 260481, 265792, 270867, 278377, 292940, 295682, 304921, 310095, 320871, 348387, 363705, 371527, 371561, 380559, 401615, 454006, 454470, 488226, 498514, 498632, 532088, 558436, 565630, 591312, 638172, 638888, 640618, 642360, 642492, 642756, 643086, 647238, 659460, 663976, 664860, 666448, 673472, 676062, 683018, 686620, 686914, 700190, 700902, 709014, 793398, 797358, 805974, 818400, 829270, 830275, 847853, 867931, 905750, 924180
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.

Comment 3 Larry the Git Cow gentoo-dev

2022-02-21 05:15:44 UTC

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/proj/devmanual.git/commit/?id=f0be5cfbd0fe4f62fe0ee70abef4044247984a7b

commit f0be5cfbd0fe4f62fe0ee70abef4044247984a7b
Author:     Sam James <sam@gentoo.org>
AuthorDate: 2022-01-22 20:48:47 +0000
Commit:     Sam James <sam@gentoo.org>
CommitDate: 2022-02-21 05:15:25 +0000

    archs/sparc: mention SIGBUS/unaligned access and link to tracker bug
    
    Bug: https://bugs.gentoo.org/371525
    Signed-off-by: Sam James <sam@gentoo.org>
    Closes: https://github.com/gentoo/devmanual/pull/266
    Signed-off-by: Sam James <sam@gentoo.org>

 archs/sparc/text.xml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)