[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Xen-devel] [RFC 05/22] xen: Adapt assembly for PIE support
- To: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>, "David S . Miller" <davem@xxxxxxxxxxxxx>, Thomas Gleixner <tglx@xxxxxxxxxxxxx>, Ingo Molnar <mingo@xxxxxxxxxx>, "H . Peter Anvin" <hpa@xxxxxxxxx>, Peter Zijlstra <peterz@xxxxxxxxxxxxx>, Josh Poimboeuf <jpoimboe@xxxxxxxxxx>, Thomas Garnier <thgarnie@xxxxxxxxxx>, Arnd Bergmann <arnd@xxxxxxxx>, Matthias Kaehlcke <mka@xxxxxxxxxxxx>, Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>, Juergen Gross <jgross@xxxxxxxx>, Paolo Bonzini <pbonzini@xxxxxxxxxx>, Radim Krčmář <rkrcmar@xxxxxxxxxx>, Joerg Roedel <joro@xxxxxxxxxx>, Andy Lutomirski <luto@xxxxxxxxxx>, Borislav Petkov <bp@xxxxxxxxx>, "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>, Brian Gerst <brgerst@xxxxxxxxx>, Borislav Petkov <bp@xxxxxxx>, Christian Borntraeger <borntraeger@xxxxxxxxxx>, "Rafael J . Wysocki" <rjw@xxxxxxxxxxxxx>, Len Brown <len.brown@xxxxxxxxx>, Pavel Machek <pavel@xxxxxx>, Tejun Heo <tj@xxxxxxxxxx>, Christoph Lameter <cl@xxxxxxxxx>, Kees Cook <keescook@xxxxxxxxxxxx>, Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>, Chris Metcalf <cmetcalf@xxxxxxxxxxxx>, "Paul E . McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Christopher Li <sparse@xxxxxxxxxxx>, Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>, Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>, Daniel Borkmann <daniel@xxxxxxxxxxxxx>, Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx>, Peter Foley <pefoley2@xxxxxxxxxxx>, Steven Rostedt <rostedt@xxxxxxxxxxx>, Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>, Catalin Marinas <catalin.marinas@xxxxxxx>, Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>, Michal Hocko <mhocko@xxxxxxxx>, Rob Landley <rob@xxxxxxxxxxx>, Jiri Kosina <jkosina@xxxxxxx>, "H . J . Lu" <hjl.tools@xxxxxxxxx>, Paul Bolle <pebolle@xxxxxxxxxx>, Baoquan He <bhe@xxxxxxxxxx>, Daniel Micay <danielmicay@xxxxxxxxx>
- From: Thomas Garnier <thgarnie@xxxxxxxxxx>
- Date: Tue, 18 Jul 2017 15:33:16 -0700
- Cc: linux-arch@xxxxxxxxxxxxxxx, kvm@xxxxxxxxxxxxxxx, linux-pm@xxxxxxxxxxxxxxx, x86@xxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-sparse@xxxxxxxxxxxxxxx, linux-crypto@xxxxxxxxxxxxxxx, kernel-hardening@xxxxxxxxxxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxxx
- Delivery-date: Tue, 18 Jul 2017 22:34:22 +0000
- List-id: Xen developer discussion <xen-devel.lists.xen.org>
Change the assembly code to use the new _ASM_GET_PTR macro which get a
symbol reference while being PIE compatible. Modify the RELOC macro that
was using an assignment generating a non-relative reference.
Position Independent Executable (PIE) support will allow to extended the
KASLR randomization range below the -2G memory limit.
Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx>
---
arch/x86/xen/xen-asm.h | 3 ++-
arch/x86/xen/xen-head.S | 9 +++++----
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/x86/xen/xen-asm.h b/arch/x86/xen/xen-asm.h
index 465276467a47..3b1c8a2e77d8 100644
--- a/arch/x86/xen/xen-asm.h
+++ b/arch/x86/xen/xen-asm.h
@@ -2,8 +2,9 @@
#define _XEN_XEN_ASM_H
#include <linux/linkage.h>
+#include <asm/asm.h>
-#define RELOC(x, v) .globl x##_reloc; x##_reloc=v
+#define RELOC(x, v) .globl x##_reloc; x##_reloc: _ASM_PTR v
#define ENDPATCH(x) .globl x##_end; x##_end=.
/* Pseudo-flag used for virtual NMI, which we don't implement yet */
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 72a8e6adebe6..ab2462396bd8 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -23,14 +23,15 @@ ENTRY(startup_xen)
/* Clear .bss */
xor %eax,%eax
- mov $__bss_start, %_ASM_DI
- mov $__bss_stop, %_ASM_CX
+ _ASM_GET_PTR(__bss_start, %_ASM_DI)
+ _ASM_GET_PTR(__bss_stop, %_ASM_CX)
sub %_ASM_DI, %_ASM_CX
shr $__ASM_SEL(2, 3), %_ASM_CX
rep __ASM_SIZE(stos)
- mov %_ASM_SI, xen_start_info
- mov $init_thread_union+THREAD_SIZE, %_ASM_SP
+ _ASM_GET_PTR(xen_start_info, %_ASM_AX)
+ mov %_ASM_SI, (%_ASM_AX)
+ _ASM_GET_PTR(init_thread_union+THREAD_SIZE, %_ASM_SP)
jmp xen_start_kernel
--
2.13.2.932.g7449e964c-goog
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel
|