Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   "Hou Wenlong" <houwenlong.hwl@antgroup.com>
To:     linux-kernel@vger.kernel.org
Cc:     "Thomas Garnier" <thgarnie@chromium.org>,
        "Lai Jiangshan" <jiangshan.ljs@antgroup.com>,
        "Kees Cook" <keescook@chromium.org>,
        "Hou Wenlong" <houwenlong.hwl@antgroup.com>,
        "Thomas Gleixner" <tglx@linutronix.de>,
        "Ingo Molnar" <mingo@redhat.com>, "Borislav Petkov" <bp@alien8.de>,
        "Dave Hansen" <dave.hansen@linux.intel.com>, <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH RFC 06/43] x86/CPU: Adapt assembly for PIE support
Date:   Fri, 28 Apr 2023 17:50:46 +0800
Message-Id: <86defd5e8ee1328bbfbe7f6b293bacb4f1b7d23a.1682673543.git.houwenlong.hwl@antgroup.com>
In-Reply-To: <cover.1682673542.git.houwenlong.hwl@antgroup.com>
References: <cover.1682673542.git.houwenlong.hwl@antgroup.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Thomas Garnier <thgarnie@chromium.org>

From: Thomas Garnier <thgarnie@chromium.org>

Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.

Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Cc: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Cc: Kees Cook <keescook@chromium.org>
---
 arch/x86/include/asm/sync_core.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/sync_core.h b/arch/x86/include/asm/sync_core.h
index ab7382f92aff..fa5b1fe1a692 100644
--- a/arch/x86/include/asm/sync_core.h
+++ b/arch/x86/include/asm/sync_core.h
@@ -31,10 +31,12 @@ static inline void iret_to_self(void)
 		"pushfq\n\t"
 		"mov %%cs, %0\n\t"
 		"pushq %q0\n\t"
-		"pushq $1f\n\t"
+		"leaq 1f(%%rip), %q0\n\t"
+		"pushq %q0\n\t"
 		"iretq\n\t"
 		"1:"
-		: "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory");
+		: "=&r" (tmp), ASM_CALL_CONSTRAINT
+		: : "cc", "memory");
 }
 #endif /* CONFIG_X86_32 */
 
-- 
2.31.1