[PATCH] x86/fpu/xstate: calculate the number by sizeof and offsetof

[Yejune Deng]

In fpstate_sanitize_xstate(), use memset and offsetof instead of '= 0',
and use sizeof instead of a constant.

Signed-off-by: Yejune Deng <yejune.d...@gmail.com>
---
 arch/x86/kernel/fpu/xstate.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 5d8047441a0a..2e75630c86e9 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -161,20 +161,16 @@ void fpstate_sanitize_xstate(struct fpu *fpu)
         * FP is in init state
         */
        if (!(xfeatures & XFEATURE_MASK_FP)) {
+               memset(fx, 0, offsetof(struct fxregs_state, mxcsr));
+               memset(fx->st_space, 0, sizeof(fx->st_space));
                fx->cwd = 0x37f;
-               fx->swd = 0;
-               fx->twd = 0;
-               fx->fop = 0;
-               fx->rip = 0;
-               fx->rdp = 0;
-               memset(&fx->st_space[0], 0, 128);
        }
 
        /*
         * SSE is in init state
         */
        if (!(xfeatures & XFEATURE_MASK_SSE))
-               memset(&fx->xmm_space[0], 0, 256);
+               memset(fx->xmm_space, 0, sizeof(fx->xmm_space));
 
        /*
         * First two features are FPU and SSE, which above we handled
-- 
2.29.0