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Bug 371525 (unaligned-access) - [TRACKER] packages with unaligned accesses
Summary: [TRACKER] packages with unaligned accesses
Status: CONFIRMED
Alias: unaligned-access
Product: Quality Assurance
Classification: Unclassified
Component: Trackers (show other bugs)
Hardware: All Linux
: Normal normal
Assignee: Gentoo Quality Assurance Team
URL:
Whiteboard:
Keywords: Tracker
Depends on: 634822 636552 638066 638888 640618 642284 700902 717908 829270 847853 201102 295682 348387 371527 371561 454006 498632 532088 558436 591312 638172 642492 643086 659460 663976 664860 666448 673472 676062 686620 686914 700190 709014 805974 818400 830275
Blocks:
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Reported: 2011-06-13 22:01 UTC by Matt Turner
Modified: 2022-06-13 17:18 UTC (History)
12 users (show)

See Also:
Package list:
Runtime testing required: ---


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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(+)