[PATCH 12/27] [AARCH64] Add ILP32 support to elf_machine_load_address.

Yury Norov
2016-06-21T05:47:21Z

From: Andrew Pinski <apinski@cavium.com>

This adds ILP32 support to elf_machine_load_address.
Since elf_machine_load_address depends on the static address being
found without relocations, we need to use 16bit relocation which gets
resolved at link time for ILP32. This is just like how the 32bit
relocation gets resolved at link time for LP64.

* sysdeps/aarch64/dl-machine.h (elf_machine_load_address): Add support
for ILP32.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
---
sysdeps/aarch64/dl-machine.h | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h
index 7a49852..771b0c6 100644
--- a/sysdeps/aarch64/dl-machine.h
+++ b/sysdeps/aarch64/dl-machine.h
@@ -54,19 +54,33 @@ elf_machine_load_address (void)
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.
- This depends on 32bit relocations being resolved at link time
- and that the static address fits in the 32bits. */
+ This depends on 32/16bit relocations being resolved at link time
+ and that the static address fits in the 32/16 bits. */

ElfW(Addr) static_addr;
ElfW(Addr) dynamic_addr;

asm (" \n"
" adrp %1, _dl_start; \n"
+#ifdef __LP64__
" add %1, %1, #:lo12:_dl_start \n"
+#else
+" add %w1, %w1, #:lo12:_dl_start \n"
+#endif
" ldr %w0, 1f \n"
" b 2f \n"
"1: \n"
+#ifdef __LP64__
" .word _dl_start \n"
+#else
+# ifdef __AARCH64EB__
+" .short 0 \n"
+# endif
+" .short _dl_start \n"
+# ifndef __AARCH64EB__
+" .short 0 \n"
+# endif
+#endif
"2: \n"
: "=r" (static_addr), "=r" (dynamic_addr));
return dynamic_addr - static_addr;
--
2.7.4