[PATCH v1 04/27] x86: Add macro to get symbol address for PIE support
From: Thomas Garnier via Virtualization <hidden>
Date: 2017-10-11 20:30:04
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> --- 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 b0dc91f4bedc..6de365b8e3fd 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h@@ -57,6 +57,19 @@ # 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) \
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2.15.0.rc0.271.g36b669edcc-goog