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From:   Thomas Garnier <thgarnie@chromium.org>
To:     kernel-hardening@lists.openwall.com
Cc:     kristen@linux.intel.com, keescook@chromium.org,
        Thomas Garnier <thgarnie@chromium.org>,
        Pavel Machek <pavel@ucw.cz>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v10 09/11] x86/power/64: Adapt assembly for PIE support
Date:   Wed,  4 Dec 2019 16:09:46 -0800
Message-Id: <20191205000957.112719-10-thgarnie@chromium.org>
In-Reply-To: <20191205000957.112719-1-thgarnie@chromium.org>
References: <20191205000957.112719-1-thgarnie@chromium.org>
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Sender: linux-kernel-owner@vger.kernel.org
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Change the assembly code to use only relative references of symbols for the
kernel to be PIE compatible.

Position Independent Executable (PIE) support will allow to extend the
KASLR randomization range below 0xffffffff80000000.

Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/power/hibernate_asm_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
index 7918b8415f13..977b8ae85045 100644
--- a/arch/x86/power/hibernate_asm_64.S
+++ b/arch/x86/power/hibernate_asm_64.S
@@ -23,7 +23,7 @@
 #include <asm/frame.h>
 
 SYM_FUNC_START(swsusp_arch_suspend)
-	movq	$saved_context, %rax
+	leaq	saved_context(%rip), %rax
 	movq	%rsp, pt_regs_sp(%rax)
 	movq	%rbp, pt_regs_bp(%rax)
 	movq	%rsi, pt_regs_si(%rax)
@@ -116,7 +116,7 @@ SYM_FUNC_START(restore_registers)
 	movq	%rax, %cr4;  # turn PGE back on
 
 	/* We don't restore %rax, it must be 0 anyway */
-	movq	$saved_context, %rax
+	leaq	saved_context(%rip), %rax
 	movq	pt_regs_sp(%rax), %rsp
 	movq	pt_regs_bp(%rax), %rbp
 	movq	pt_regs_si(%rax), %rsi
-- 
2.24.0.393.g34dc348eaf-goog