| Message ID | 1416329010-8683-4-git-send-email-will.newton@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 18 November 2014 16:43, Will Newton <will.newton@linaro.org> wrote: > From: Andrew Pinski <apinski@cavium.com> > > 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: > > 2014-11-18 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. OK /Marcus
diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h index 7f5ce2b..1294369 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; }
From: Andrew Pinski <apinski@cavium.com> 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: 2014-11-18 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/dl-machine.h | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)