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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>,
        Len Brown <len.brown@intel.com>,
        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 v9 07/11] x86/acpi: Adapt assembly for PIE support
Date:   Tue, 30 Jul 2019 12:12:51 -0700
Message-Id: <20190730191303.206365-8-thgarnie@chromium.org>
In-Reply-To: <20190730191303.206365-1-thgarnie@chromium.org>
References: <20190730191303.206365-1-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/kernel/acpi/wakeup_64.S | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index b0715c3ac18d..3ec6c1b74ad4 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -15,7 +15,7 @@
 	 * Hooray, we are in Long 64-bit mode (but still running in low memory)
 	 */
 ENTRY(wakeup_long64)
-	movq	saved_magic, %rax
+	movq	saved_magic(%rip), %rax
 	movq	$0x123456789abcdef0, %rdx
 	cmpq	%rdx, %rax
 	jne	bogus_64_magic
@@ -26,14 +26,14 @@ ENTRY(wakeup_long64)
 	movw	%ax, %es
 	movw	%ax, %fs
 	movw	%ax, %gs
-	movq	saved_rsp, %rsp
+	movq	saved_rsp(%rip), %rsp
 
-	movq	saved_rbx, %rbx
-	movq	saved_rdi, %rdi
-	movq	saved_rsi, %rsi
-	movq	saved_rbp, %rbp
+	movq	saved_rbx(%rip), %rbx
+	movq	saved_rdi(%rip), %rdi
+	movq	saved_rsi(%rip), %rsi
+	movq	saved_rbp(%rip), %rbp
 
-	movq	saved_rip, %rax
+	movq	saved_rip(%rip), %rax
 	jmp	*%rax
 ENDPROC(wakeup_long64)
 
@@ -46,7 +46,7 @@ ENTRY(do_suspend_lowlevel)
 	xorl	%eax, %eax
 	call	save_processor_state
 
-	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)
@@ -65,13 +65,14 @@ ENTRY(do_suspend_lowlevel)
 	pushfq
 	popq	pt_regs_flags(%rax)
 
-	movq	$.Lresume_point, saved_rip(%rip)
+	leaq	.Lresume_point(%rip), %rax
+	movq	%rax, saved_rip(%rip)
 
-	movq	%rsp, saved_rsp
-	movq	%rbp, saved_rbp
-	movq	%rbx, saved_rbx
-	movq	%rdi, saved_rdi
-	movq	%rsi, saved_rsi
+	movq	%rsp, saved_rsp(%rip)
+	movq	%rbp, saved_rbp(%rip)
+	movq	%rbx, saved_rbx(%rip)
+	movq	%rdi, saved_rdi(%rip)
+	movq	%rsi, saved_rsi(%rip)
 
 	addq	$8, %rsp
 	movl	$3, %edi
@@ -83,7 +84,7 @@ ENTRY(do_suspend_lowlevel)
 	.align 4
 .Lresume_point:
 	/* We don't restore %rax, it must be 0 anyway */
-	movq	$saved_context, %rax
+	leaq	saved_context(%rip), %rax
 	movq	saved_context_cr4(%rax), %rbx
 	movq	%rbx, %cr4
 	movq	saved_context_cr3(%rax), %rbx
-- 
2.22.0.770.g0f2c4a37fd-goog