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x86, xsave: keep the XSAVE feature mask as an u64

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The XSAVE feature mask is a 64-bit number; keep it that way, in order
to avoid the mistake done with rdmsr/wrmsr.  Use the xsetbv() function
provided in the previous patch.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
H. Peter Anvin
2008-07-29 17:23:16 -07:00
committed by Ingo Molnar
parent b4a091a62c
commit 6152e4b1c9
3 changed files with 33 additions and 42 deletions
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arch/x86/kernel/i387.c
+5 -7
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@@ -552,18 +552,17 @@ static int restore_i387_xsave(void __user *buf)
(struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
struct xsave_hdr_struct *xsave_hdr =
&current->thread.xstate->xsave.xsave_hdr;
unsigned int lmask, hmask;
u64 mask;
int err;
if (check_for_xstate(fx, buf, &fx_sw_user))
goto fx_only;
lmask = fx_sw_user.xstate_bv;
hmask = fx_sw_user.xstate_bv >> 32;
mask = fx_sw_user.xstate_bv;
err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
xsave_hdr->xstate_bv &= (pcntxt_lmask | (((u64) pcntxt_hmask) << 32));
xsave_hdr->xstate_bv &= pcntxt_mask;
/*
* These bits must be zero.
*/
@@ -573,9 +572,8 @@ static int restore_i387_xsave(void __user *buf)
* Init the state that is not present in the memory layout
* and enabled by the OS.
*/
lmask = ~(pcntxt_lmask & ~lmask);
hmask = ~(pcntxt_hmask & ~hmask);
xsave_hdr->xstate_bv &= (lmask | (((u64) hmask) << 32));
mask = ~(pcntxt_mask & ~mask);
xsave_hdr->xstate_bv &= mask;
return err;
fx_only: