From 6d3db89b12e5c206b8848f0ab35e0632dbbf4bbf Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Mon, 27 Oct 2014 00:59:42 -0700 Subject: AArch64: 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 concatenating instead of string continuation. Also document why this inline-asm works - it depends on the 32bit relocation being resolved at link time. ChangeLog: 2014-11-21 Will Newton Andrew Pinski * sysdeps/aarch64/dl-machine.h (elf_machine_load_address): Refactor inline-asm. Also add comment. --- ChangeLog | 3 +++ sysdeps/aarch64/dl-machine.h | 21 ++++++++++++--------- 2 files changed, 15 insertions(+), 9 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3fd08436cb..076c09df18 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,6 +1,9 @@ 2014-11-21 Will Newton Andrew Pinski + * sysdeps/aarch64/dl-machine.h (elf_machine_load_address): + Refactor inline-asm. Also add comment. + * sysdeps/aarch64/bits/link.h (la_aarch64_gnu_pltenter): Use ElfW macro instead of hardcoded Elf64 types. (la_aarch64_gnu_pltenter): Likewise. diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h index 7f5ce2b671..1294369268 100644 --- a/sysdeps/aarch64/dl-machine.h +++ b/sysdeps/aarch64/dl-machine.h @@ -52,19 +52,22 @@ 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; } -- cgit v1.2.3