Add unwind info to __libc_start_main so that unwinding continues one
extra level to _start. Similarly add unwind info to backtrace.
Given many targets require this, do this in a general way.
* csu/Makefile: Add -funwind-tables to libc-start.c.
* debug/Makefile: Add -funwind-tables to backtrace.c.
* sysdeps/aarch64/Makefile: Remove CFLAGS-backtrace.c.
* sysdeps/arm/Makefile: Likewise.
* sysdeps/i386/Makefile: Likewise.
* sysdeps/m68k/Makefile: Likewise.
* sysdeps/mips/Makefile: Likewise.
* sysdeps/nios2/Makefile: Likewise.
* sysdeps/sh/Makefile: Likewise.
* sysdeps/sparc/Makefile: Likewise.
When glibc is built with --enable-profile, the ENTRY of
asm functions includes CALL_MCOUNT for profiling.
(matters for binaries static linked against libc_p.a.)
CALL_MCOUNT did not save/restore argument registers
around the _mcount call so it clobbered them.
(it is enough to only save/restore the arguments passed
to a given asm function, but that would be too many asm
changes so it is simpler to always save all argument
registers in this macro.)
float args are not saved: mcount does not clobber the
float regs and currently no asm function takes float
arguments anyway.
[BZ #18707]
* sysdeps/aarch64/Makefile (CFLAGS-mcount.c): Add -mgeneral-regs-only.
* sysdeps/aarch64/sysdep.h (CALL_MCOUNT): Save argument registers.
This patch moves the AArch64 port to the main sysdeps hierarchy. The
move is essentially:
git mv ports/sysdeps/aarch64 sysdeps/aarch64
git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64
The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move. The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.
