Bug#569797: misaligned signal stack on sparc
Package: linux-image-2.6.32-2-sparc64-smp
Version: 2.6.32-8
Severity: serious
On my sid sparc box I can reproducibly cause a shell getting
in a state where the kernel soft-locks and one cpu is only
occupied py this process. kill -KILL does not work, sync does
not work, restarting the computer needs reboot -n -f and so on.
I think this is due to some misalignment of signal stacks, as
described in
http://marc.info/?l=linux-sparc&m=126576299426902&w=2
(at least the hanging cpu hangs in the area this patch touches and
the process seems to be hanging in some fault handler occouring in
a fault handler occouring in some signal stuff as far as I can tell,
my sparc assembler skills are quite limited).
Note that the patch given in the mail has still a typo described in
http://marc.info/?l=linux-sparc&m=126592005119857&w=2
See also
http://marc.info/?l=linux-sparc&m=126592110921290&w=2
(Though I do not know if this fix for the patch is needed for 32 bit
sparc kernels Debian afaik no longer has or for 32 bit user space,
but I guess adding both is safest in any case).
Hochachtungsvoll,
Bernhard R. Link
This bug also effects (at least) 2.6.32-3 and 2.6.32-5, but I have no
idea how to tell this the bts as the binary package name changed.
Reply to: