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From:   Yejune Deng <yejune.deng@gmail.com>
To:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org,
        hpa@zytor.com, dave.hansen@linux.intel.com, yu-cheng.yu@intel.com,
        tony.luck@intel.com, fenghua.yu@intel.com,
        kan.liang@linux.intel.com, viro@zeniv.linux.org.uk
Cc:     linux-kernel@vger.kernel.org, yejune.deng@gmail.com
Subject: [PATCH] x86/fpu/xstate: calculate the number by sizeof and offsetof
Date:   Wed, 20 Jan 2021 14:44:15 +0800
Message-Id: <20210120064415.16977-1-yejune.deng@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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

Signed-off-by: Yejune Deng <yejune.deng@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