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>,
Andy Lutomirski <luto@kernel.org>,
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-kernel@vger.kernel.org
Subject: [PATCH v8 04/11] x86/entry/64: Adapt assembly for PIE support
Date: Mon, 8 Jul 2019 10:48:57 -0700 [thread overview]
Message-ID: <20190708174913.123308-5-thgarnie@chromium.org> (raw)
In-Reply-To: <20190708174913.123308-1-thgarnie@chromium.org>
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>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/x86/entry/entry_64.S | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 0ea4831a72a4..9f55a359c896 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1309,7 +1309,8 @@ ENTRY(error_entry)
movl %ecx, %eax /* zero extend */
cmpq %rax, RIP+8(%rsp)
je .Lbstep_iret
- cmpq $.Lgs_change, RIP+8(%rsp)
+ leaq .Lgs_change(%rip), %rcx
+ cmpq %rcx, RIP+8(%rsp)
jne .Lerror_entry_done
/*
@@ -1506,10 +1507,10 @@ ENTRY(nmi)
* resume the outer NMI.
*/
- movq $repeat_nmi, %rdx
+ leaq repeat_nmi(%rip), %rdx
cmpq 8(%rsp), %rdx
ja 1f
- movq $end_repeat_nmi, %rdx
+ leaq end_repeat_nmi(%rip), %rdx
cmpq 8(%rsp), %rdx
ja nested_nmi_out
1:
@@ -1563,7 +1564,8 @@ nested_nmi:
pushq %rdx
pushfq
pushq $__KERNEL_CS
- pushq $repeat_nmi
+ leaq repeat_nmi(%rip), %rdx
+ pushq %rdx
/* Put stack back */
addq $(6*8), %rsp
@@ -1602,7 +1604,11 @@ first_nmi:
addq $8, (%rsp) /* Fix up RSP */
pushfq /* RFLAGS */
pushq $__KERNEL_CS /* CS */
- pushq $1f /* RIP */
+ pushq $0 /* Future return address */
+ pushq %rax /* Save RAX */
+ leaq 1f(%rip), %rax /* RIP */
+ movq %rax, 8(%rsp) /* Put 1f on return address */
+ popq %rax /* Restore RAX */
iretq /* continues at repeat_nmi below */
UNWIND_HINT_IRET_REGS
1:
--
2.22.0.410.gd8fdbe21b5-goog
next prev parent reply other threads:[~2019-07-08 17:50 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-08 17:48 [PATCH v8 00/11] x86: PIE support to extend KASLR randomization Thomas Garnier
2019-07-08 17:48 ` [PATCH v8 01/11] x86/crypto: Adapt assembly for PIE support Thomas Garnier
2019-07-08 17:48 ` [PATCH v8 02/11] x86: Add macro to get symbol address " Thomas Garnier
2019-07-08 17:48 ` [PATCH v8 03/11] x86: relocate_kernel - Adapt assembly " Thomas Garnier
2019-07-08 17:48 ` Thomas Garnier [this message]
2019-07-08 17:48 ` [PATCH v8 05/11] x86: pm-trace " Thomas Garnier
2019-07-08 17:48 ` [PATCH v8 06/11] x86/CPU: " Thomas Garnier
2019-07-08 17:49 ` [PATCH v8 07/11] x86/acpi: " Thomas Garnier
2019-07-08 17:49 ` [PATCH v8 08/11] x86/boot/64: " Thomas Garnier
2019-07-08 17:49 ` [PATCH v8 09/11] x86/power/64: " Thomas Garnier
2019-07-08 17:49 ` [PATCH v8 10/11] x86/paravirt: " Thomas Garnier
2019-07-08 17:49 ` [PATCH v8 11/11] x86/alternatives: " Thomas Garnier
2019-07-30 18:01 ` [PATCH v8 00/11] x86: PIE support to extend KASLR randomization Kees Cook
2019-07-30 19:09 ` Thomas Garnier
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