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From 598187ec16f424b7548e8f049436c0c9c43d7795 Mon Sep 17 00:00:00 2001
From: Andrew Pinski <apinski@cavium.com>
Date: Mon, 27 Oct 2014 00:59:42 -0700
Subject: [PATCH 19/32] Reformat inline-asm in elf_machine_load_address.
This patch reformats the inline-asm in elf_machine_load_address so it is
easier to change only part of the inline-asm. That is using string
concating instead of string continueing.
Also document on why this inline-asm works, it depends on the 32bit
relocation being resolved at link time.
* sysdeps/aarch64/dl-machine.h (elf_machine_load_address):
Refactor inline-asm. Also add comment.
---
sysdeps/aarch64/dl-machine.h | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h
index 6e041b1..121b178 100644
--- a/sysdeps/aarch64/dl-machine.h
+++ b/sysdeps/aarch64/dl-machine.h
@@ -53,19 +53,22 @@ elf_machine_load_address (void)
The choice of symbol is arbitrary. The static address we obtain
by constructing a non GOT reference to the symbol, the dynamic
address of the symbol we compute using adrp/add to compute the
- symbol's address relative to the PC. */
+ symbol's address relative to the PC.
+ This depends on 32bit relocations being resolved at link time
+ and that the static address fits in the 32bits. */
ElfW(Addr) static_addr;
ElfW(Addr) dynamic_addr;
- asm (" \n\
- adrp %1, _dl_start; \n\
- add %1, %1, #:lo12:_dl_start \n\
- ldr %w0, 1f \n\
- b 2f \n\
-1: .word _dl_start \n\
-2: \n\
- " : "=r" (static_addr), "=r" (dynamic_addr));
+ asm (" \n"
+" adrp %1, _dl_start; \n"
+" add %1, %1, #:lo12:_dl_start \n"
+" ldr %w0, 1f \n"
+" b 2f \n"
+"1: \n"
+" .word _dl_start \n"
+"2: \n"
+ : "=r" (static_addr), "=r" (dynamic_addr));
return dynamic_addr - static_addr;
}
--
1.9.3
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