please set /proc/cpu/alignment=4 on Launchpad ARM buildd kernels
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
launchpad-buildd |
Fix Released
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Undecided
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Unassigned |
Bug Description
Bug #1512323 reveals that whereas our buildds use the default /proc/cpu/alignment setting of 2 (fixup), our Ubuntu phones, due to their inheritance from android, are overriding the kernel default and setting this to 4 (raise). This mean that unaligned accesses that work fine on the buildds may fail on the phone.
I consider it a bug that the android chroots are using this non-default setting and am proposing that we fix this. However, I also consider it a bug that the builders use the default setting, because this means that they allow code through (passing build-time test suites, etc.) that will fail on any systems where the end user has also changed their system away from the default.
And because ARM doesn't have support for prctl(PR_
Please change the config of the armhf autobuilders to set /proc/cpu/
description: | updated |
This probably should be changed in canonical-is-puppet for arch=armhf, not in launchpad-buildd, but I couldn't sort out how to reassign the bug successfully. :P