summaryrefslogtreecommitdiff
path: root/libc/sysdeps/linux/aarch64/__longjmp.S
diff options
context:
space:
mode:
authorWaldemar Brodkorb <wbx@uclibc-ng.org>2016-10-04 06:51:35 +0200
committerWaldemar Brodkorb <wbx@openadk.org>2017-02-01 17:48:38 +0100
commitdba942c80dc2cfa5768a856fff98e22a755fdd27 (patch)
tree371e775cb6dfec085945f6834aeb9d3b6de36fbe /libc/sysdeps/linux/aarch64/__longjmp.S
parent9b457baf8d46329f7d7ee2aa084022bb0df88551 (diff)
add experimental aarch64 support
Ported over from GNU C Library and runtime tested in Qemu.
Diffstat (limited to 'libc/sysdeps/linux/aarch64/__longjmp.S')
-rw-r--r--libc/sysdeps/linux/aarch64/__longjmp.S107
1 files changed, 107 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/aarch64/__longjmp.S b/libc/sysdeps/linux/aarch64/__longjmp.S
new file mode 100644
index 000000000..e4d11b165
--- /dev/null
+++ b/libc/sysdeps/linux/aarch64/__longjmp.S
@@ -0,0 +1,107 @@
+/* Copyright (C) 1997-2016 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>
+#include <jmpbuf-offsets.h>
+
+/* __longjmp(jmpbuf, val) */
+
+ENTRY (__longjmp)
+ cfi_def_cfa(x0, 0)
+ cfi_offset(x19, JB_X19<<3)
+ cfi_offset(x20, JB_X20<<3)
+ cfi_offset(x21, JB_X21<<3)
+ cfi_offset(x22, JB_X22<<3)
+ cfi_offset(x23, JB_X23<<3)
+ cfi_offset(x24, JB_X24<<3)
+ cfi_offset(x25, JB_X25<<3)
+ cfi_offset(x26, JB_X26<<3)
+ cfi_offset(x27, JB_X27<<3)
+ cfi_offset(x28, JB_X28<<3)
+ cfi_offset(x29, JB_X29<<3)
+ cfi_offset(x30, JB_LR<<3)
+
+ cfi_offset( d8, JB_D8<<3)
+ cfi_offset( d9, JB_D9<<3)
+ cfi_offset(d10, JB_D10<<3)
+ cfi_offset(d11, JB_D11<<3)
+ cfi_offset(d12, JB_D12<<3)
+ cfi_offset(d13, JB_D13<<3)
+ cfi_offset(d14, JB_D14<<3)
+ cfi_offset(d15, JB_D15<<3)
+
+ ldp x19, x20, [x0, #JB_X19<<3]
+ ldp x21, x22, [x0, #JB_X21<<3]
+ ldp x23, x24, [x0, #JB_X23<<3]
+ ldp x25, x26, [x0, #JB_X25<<3]
+ ldp x27, x28, [x0, #JB_X27<<3]
+ ldp x29, x30, [x0, #JB_X29<<3]
+
+ /* longjmp probe takes 3 arguments, address of jump buffer as
+ first argument (8@x0), return value as second argument (-4@x1),
+ and target address (8@x30), respectively. */
+ //LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30)
+ ldp d8, d9, [x0, #JB_D8<<3]
+ ldp d10, d11, [x0, #JB_D10<<3]
+ ldp d12, d13, [x0, #JB_D12<<3]
+ ldp d14, d15, [x0, #JB_D14<<3]
+
+ /* Originally this was implemented with a series of
+ .cfi_restore() directives.
+
+ The theory was that cfi_restore should revert to previous
+ frame value is the same as the current value. In practice
+ this doesn't work, even after cfi_restore() gdb continues
+ to try to recover a previous frame value offset from x0,
+ which gets stuffed after a few more instructions. The
+ cfi_same_value() mechanism appears to work fine. */
+
+ cfi_same_value(x19)
+ cfi_same_value(x20)
+ cfi_same_value(x21)
+ cfi_same_value(x22)
+ cfi_same_value(x23)
+ cfi_same_value(x24)
+ cfi_same_value(x25)
+ cfi_same_value(x26)
+ cfi_same_value(x27)
+ cfi_same_value(x28)
+ cfi_same_value(x29)
+ cfi_same_value(x30)
+ cfi_same_value(d8)
+ cfi_same_value(d9)
+ cfi_same_value(d10)
+ cfi_same_value(d11)
+ cfi_same_value(d12)
+ cfi_same_value(d13)
+ cfi_same_value(d14)
+ cfi_same_value(d15)
+ ldr x5, [x0, #JB_SP<<3]
+ mov sp, x5
+
+ /* longjmp_target probe takes 3 arguments, address of jump buffer
+ as first argument (8@x0), return value as second argument (-4@x1),
+ and target address (8@x30), respectively. */
+ //LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30)
+ cmp x1, #0
+ mov x0, #1
+ csel x0, x1, x0, ne
+ /* Use br instead of ret because ret is guaranteed to mispredict */
+ br x30
+END (__longjmp)
+libc_hidden_def(__longjmp)