1 files changed, 117 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/sigrestorer.S b/ports/sysdeps/unix/sysv/linux/arm/sigrestorer.S
new file mode 100644
index 0000000000..63d83b8a65
--- /dev/null
+++ b/ports/sysdeps/unix/sysv/linux/arm/sigrestorer.S
@@ -0,0 +1,117 @@
+/* Copyright (C) 1999-2012 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+/* If no SA_RESTORER function was specified by the application we use
+   one of these.  This avoids the need for the kernel to synthesise a return
+   instruction on the stack, which would involve expensive cache flushes.
+
+   Nowadays (2.6 series, and somewhat earlier) the kernel uses a high page
+   for signal trampolines, so the cache flushes are not an issue.  But since
+   we do not have a vDSO, continue to use these so that we can provide
+   unwind information.
+
+   Start the unwind tables at least one instruction before the signal
+   trampoline, because the unwinder will assume we are returning after
+   a call site.
+
+   Because the signal frame layout changed in 2.6.18, we provide two
+   copies of these functions with different unwind information.  */
+
+/* Used in ENTRY.  */
+#undef cfi_startproc
+#define cfi_startproc \
+	.cfi_startproc simple; \
+	.cfi_signal_frame
+
+/* The CFA is not computed / used correctly here; this is neither trivial to
+   do, nor is it needed.  */
+#define CFI \
+	cfi_def_cfa (sp, 0); \
+	cfi_offset (r0, OFFSET + 0 * 4); \
+	cfi_offset (r1, OFFSET + 1 * 4); \
+	cfi_offset (r2, OFFSET + 2 * 4); \
+	cfi_offset (r3, OFFSET + 3 * 4); \
+	cfi_offset (r4, OFFSET + 4 * 4); \
+	cfi_offset (r5, OFFSET + 5 * 4); \
+	cfi_offset (r6, OFFSET + 6 * 4); \
+	cfi_offset (r7, OFFSET + 7 * 4); \
+	cfi_offset (r8, OFFSET + 8 * 4); \
+	cfi_offset (r9, OFFSET + 9 * 4); \
+	cfi_offset (r10, OFFSET + 10 * 4); \
+	cfi_offset (r11, OFFSET + 11 * 4); \
+	cfi_offset (r12, OFFSET + 12 * 4); \
+	cfi_offset (r13, OFFSET + 13 * 4); \
+	cfi_offset (r14, OFFSET + 14 * 4); \
+	cfi_offset (r15, OFFSET + 15 * 4)
+
+#ifndef __ASSUME_SIGFRAME_V2
+#define OFFSET 12
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_sa_restorer_v1)
+	CFI
+	mov	r7, $SYS_ify(sigreturn)
+	swi	0x0
+	.fnend
+END(__default_sa_restorer_v1)
+#undef OFFSET
+#endif /* __ASSUME_SIGFRAME_V2 */
+
+#define OFFSET 32
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_sa_restorer_v2)
+	CFI
+	mov	r7, $SYS_ify(sigreturn)
+	swi	0x0
+	.fnend
+END(__default_sa_restorer_v2)
+#undef OFFSET
+
+#ifndef __ASSUME_SIGFRAME_V2
+#define OFFSET 168
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_rt_sa_restorer_v1)
+	CFI
+	mov	r7, $SYS_ify(rt_sigreturn)
+	swi	0x0
+	.fnend
+END(__default_rt_sa_restorer_v1)
+#undef OFFSET
+#endif /* __ASSUME_SIGFRAME_V2 */
+
+#define OFFSET 160
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_rt_sa_restorer_v2)
+	CFI
+	mov	r7, $SYS_ify(rt_sigreturn)
+	swi	0x0
+	.fnend
+END(__default_rt_sa_restorer_v2)
+#undef OFFSET