x86/xen: init %gs very early to avoid page faults with stack protector

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commit 4f277295e5 upstream.

When running as Xen pv guest %gs is initialized some time after
C code is started. Depending on stack protector usage this might be
too late, resulting in page faults.

So setup %gs and MSR_GS_BASE in assembly code already.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Chris Patterson <cjp256@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

...

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Juergen Gross 2018-02-01 13:40:19 +01:00 • committed by Ben Hutchings

parent d5b66d9c52

commit 13fae5bb37

1 changed files with 15 additions and 0 deletions

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arch/x86/xen/xen-head.S

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