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[Xen-devel] [RFC v3 04/27] x86: Add macro to get symbol address for PIE support



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 c1eadbaf1115..dddcb8a3b777 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)                        \
-- 
2.14.2.920.gcf0c67979c-goog


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