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[Xen-devel] [RFC 04/22] x86: Add macro to get symbol address 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 15:33:15 -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 22:34:19 +0000
- List-id: Xen developer discussion <xen-devel.lists.xen.org>
Add a new _ASM_GET_PTR macro to fetch a symbol address. It will be used
to replace "_ASM_MOV $<symbol>, %dst" code construct that are not compatible
with PIE.
Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx>
---
arch/x86/include/asm/asm.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 7a9df3beb89b..bf2842cfb583 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -55,6 +55,19 @@
# define CC_OUT(c) [_cc_ ## c] "=qm"
#endif
+/* Macros to get a global variable address with PIE support on 64-bit */
+#ifdef CONFIG_X86_32
+#define __ASM_GET_PTR_PRE(_src) __ASM_FORM_COMMA(movl $##_src)
+#else
+#ifdef __ASSEMBLY__
+#define __ASM_GET_PTR_PRE(_src) __ASM_FORM_COMMA(leaq (_src)(%rip))
+#else
+#define __ASM_GET_PTR_PRE(_src) __ASM_FORM_COMMA(leaq (_src)(%%rip))
+#endif
+#endif
+#define _ASM_GET_PTR(_src, _dst) \
+ __ASM_GET_PTR_PRE(_src) __ASM_FORM(_dst)
+
/* Exception table entry */
#ifdef __ASSEMBLY__
# define _ASM_EXTABLE_HANDLE(from, to, handler) \
--
2.13.2.932.g7449e964c-goog
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