glibc/sysdeps/arm/arm-unwind-resume.S
Florian Weimer 6b7efa3d87 Implement _Unwind_Resume in libc on top of <unwind-link.h>
Temporarily move the arm _Unwind_Resume implementation to the file
used by libpthread.  It will be ported to <unwind-link.h> along with
the rest of nptl.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-03-01 16:00:03 +01:00

47 lines
1.5 KiB
ArmAsm

/* _Unwind_Resume wrapper for ARM EABI.
Copyright (C) 2015-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
/* This is equivalent to the following C implementation:
void
_Unwind_Resume (struct _Unwind_Exception *exc)
{
__unwind_link_get_resume () (exc);
}
We do it in assembly just to ensure that we get an unmolested tail
call to the libgcc function, which is necessary for the ARM unwinder. */
ENTRY (_Unwind_Resume)
/* We need to save and restore LR (for our own return address)
and R0 (for the argument to _Unwind_Resume) around the call. */
push {r0, lr}
cfi_adjust_cfa_offset (8)
cfi_rel_offset (r0, 0)
cfi_rel_offset (lr, 4)
bl __unwind_link_get_resume
mov r3, r0
pop {r0, lr}
cfi_adjust_cfa_offset (-8)
cfi_restore (r4)
cfi_restore (lr)
bx r3
END (_Unwind_Resume)