VFP/NEON state is not preserved around signal handlers, causing state corruption between user processes
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-fsl-imx51 (Ubuntu) |
Fix Released
|
High
|
Bryan Wu | ||
Lucid |
Fix Released
|
High
|
Bryan Wu | ||
linux-mvl-dove (Ubuntu) |
Fix Released
|
High
|
Eric Miao | ||
Lucid |
Fix Released
|
High
|
Eric Miao | ||
linux-ti-omap (Ubuntu) |
Fix Released
|
High
|
Amit Kucheria | ||
Lucid |
Fix Released
|
High
|
Amit Kucheria |
Bug Description
NOTE: This issue will apply to all armel kernels except for dove (where the hardware doesn't have NEON support). However, for now imx51 is the only such kernel, so I've raised the bug here.
The issue was discussed on the ARM Linux mailing list; there's a link to the thread and a partial patch here:
http://
State corruption observed in pixman-0.16.x (resulting on various screen rendering artifacts) is believed to be due to this (this is the conclusion Siarhei Siamashka of Nokia — see the above link).
Note that the patch is disupted on the list and hasn't been merged: it may cause issues with userspace code which makes assumptions about the layout and contents of the signal frame... though it could be interesting to see whether it has any effect.
Note: we may revert to CONFIG_NEON=n by default in the iMX51 kernels due to a separate issue. This may mean that the pixman behaviour appears fixed even if it hasn't been fixed: caution should be applied before assuming that this bug has gone away.
(See https:/
Changed in linux-fsl-imx51 (Ubuntu): | |
assignee: | nobody → Bryan Wu (cooloney) |
status: | New → Confirmed |
Changed in linux-mvl-dove (Ubuntu): | |
assignee: | nobody → Eric Miao (eric.y.miao) |
importance: | Undecided → Critical |
Changed in linux-mvl-dove (Ubuntu): | |
importance: | Critical → Medium |
Changed in linux-fsl-imx51 (Ubuntu Lucid): | |
milestone: | lucid-alpha-3 → ubuntu-10.04-beta-1 |
Changed in linux-mvl-dove (Ubuntu Lucid): | |
milestone: | lucid-alpha-3 → ubuntu-10.04-beta-1 |
Changed in linux-ti-omap (Ubuntu Lucid): | |
assignee: | nobody → Amit Kucheria (amitk) |
importance: | Undecided → High |
milestone: | none → ubuntu-10.04-beta-2 |
Changed in linux-ti-omap (Ubuntu Lucid): | |
status: | New → Triaged |
This bug is a potential security hole and should be prioritised as such.