diff options
| author | Andrew Pinski <apinski@cavium.com> | 2014-10-27 00:59:42 -0700 |
|---|---|---|
| committer | Will Newton <will.newton@linaro.org> | 2014-11-21 14:45:11 +0000 |
| commit | 6d3db89b12e5c206b8848f0ab35e0632dbbf4bbf (patch) | |
| tree | 1a218e6d5fe97276df204a1c5703b5064116547c | |
| parent | 01194ba18d594e79e687be570d85ec3b09a5fcb2 (diff) | |
| download | glibc-6d3db89b12e5c206b8848f0ab35e0632dbbf4bbf.tar.gz | |
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 <will.newton@linaro.org>
Andrew Pinski <andrew.pinski@caviumnetworks.com>
* sysdeps/aarch64/dl-machine.h (elf_machine_load_address):
Refactor inline-asm. Also add comment.
| -rw-r--r-- | ChangeLog | 3 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-machine.h | 21 |
2 files changed, 15 insertions, 9 deletions
@@ -1,6 +1,9 @@ 2014-11-21 Will Newton <will.newton@linaro.org> Andrew Pinski <andrew.pinski@caviumnetworks.com> + * 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; } |