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From:   Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
To:     Jarkko Sakkinen <jarkko@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Sean Christopherson <seanjc@google.com>, x86@kernel.org,
        linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jia Zhang <zhang.jia@linux.alibaba.com>
Cc:     Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Subject: [PATCH v2] x86/sgx: Remove redundant if conditions in sgx_encl_create
Date:   Wed, 20 Jan 2021 11:53:28 +0800
Message-Id: <20210120035328.19868-1-tianjia.zhang@linux.alibaba.com>
MIME-Version: 1.0
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In this scenario, there is no case where va_page is NULL, and
the error has been checked. The if condition statement here is
redundant, so remove the condition detection.

Reported-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 arch/x86/kernel/cpu/sgx/ioctl.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 1c6ecf9fbeff..efad2fb61c76 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -66,9 +66,12 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
 	va_page = sgx_encl_grow(encl);
 	if (IS_ERR(va_page))
 		return PTR_ERR(va_page);
-	else if (va_page)
-		list_add(&va_page->list, &encl->va_pages);
-	/* else the tail page of the VA page list had free slots. */
+
+	if (WARN_ONCE(!va_page,
+		      "the tail page of the VA page list had free slots\n"))
+		return -EIO;
+
+	list_add(&va_page->list, &encl->va_pages);
 
 	/* The extra page goes to SECS. */
 	encl_size = secs->size + PAGE_SIZE;
-- 
2.19.1.3.ge56e4f7