x86, xsave: clear the user buffer before doing fxsave/xsave
commited405958057ca6a8c4c9178a7a3b1167fabb45f5
authorSuresh Siddha <suresh.b.siddha@intel.com>
Wed, 13 Aug 2008 18:38:14 +0000 (13 11:38 -0700)
committerIngo Molnar <mingo@elte.hu>
Thu, 14 Aug 2008 08:56:06 +0000 (14 10:56 +0200)
tree7255d950f6c1b7c58bd96307b9aaa871c2eba9f4
parentee2b92a8201a40021ecd1aee6f0625dc03bacc54
x86, xsave: clear the user buffer before doing fxsave/xsave

fxsave/xsave instructions will not touch all the bytes in the
fxsave/xsave frame. Clear the user buffer before doing fxsave/xsave
directly to user buffer during the sigcontext setup.

This is essentially needed in the context of xsave(for example,
some of the fields in the xsave header are not touched by the xsave
and defined as must be zero).

This will also present uniform and clean context to the user (from
which user can safely do fxrstor/xrstor).

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/xsave.c