[PATCH 17/23] Add ARM AArch64 sigcode setup function for bsd-user

[Ajeet Singh <itachis6234@gmail.com>]

From: Stacey Son <sson@FreeBSD.org>

signal trampoline function initializes a sequence of instructions
to handle signal returns and exits, and copies this code to the target offset.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Ajeet Singh <itachis@FreeBSD.org>
---
 bsd-user/aarch64/target_arch_sigtramp.h | 48 +++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 bsd-user/aarch64/target_arch_sigtramp.h

diff --git a/bsd-user/aarch64/target_arch_sigtramp.h b/bsd-user/aarch64/target_arch_sigtramp.h
new file mode 100644
index 0000000000..8cdd33b621
--- /dev/null
+++ b/bsd-user/aarch64/target_arch_sigtramp.h
@@ -0,0 +1,48 @@
+/*
+ * ARM AArch64 sigcode for bsd-user
+ *
+ * Copyright (c) 2015 Stacey D. Son <sson at FreeBSD>
+ *
+ * This 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 of the License, or (at your option) any later version.
+ *
+ * This 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 this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TARGET_ARCH_SIGTRAMP_H
+#define TARGET_ARCH_SIGTRAMP_H
+
+/* Compare to ENTRY(sigcode) in arm64/arm64/locore.S */
+static inline abi_long setup_sigtramp(abi_ulong offset, unsigned sigf_uc,
+        unsigned sys_sigreturn)
+{
+    int i;
+    uint32_t sys_exit = TARGET_FREEBSD_NR_exit;
+
+    uint32_t sigtramp_code[] = {
+    /* 1 */ 0x910003e0,                 /* mov x0, sp */
+    /* 2 */ 0x91000000 + (sigf_uc << 10), /* add x0, x0, #SIGF_UC */
+    /* 3 */ 0xd2800000 + (sys_sigreturn << 5) + 0x8, /* mov x8, #SYS_sigreturn */
+    /* 4 */ 0xd4000001,                 /* svc #0 */
+    /* 5 */ 0xd2800028 + (sys_exit << 5) + 0x8, /* mov x8, #SYS_exit */
+    /* 6 */ 0xd4000001,                 /* svc #0 */
+    /* 7 */ 0x17fffffc,                 /* b -4 */
+    /* 8 */ sys_sigreturn,
+    /* 9 */ sys_exit
+    };
+
+    for (i = 0; i < 9; i++) {
+        tswap32s(&sigtramp_code[i]);
+    }
+
+    return memcpy_to_target(offset, sigtramp_code, TARGET_SZSIGCODE);
+}
+#endif /* TARGET_ARCH_SIGTRAMP_H */
-- 
2.34.1