[PATCH v3 19/21] nptl: nios2: Fix Race conditions in pthread cancellation (BZ#12683)

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

This patch adds the nios2 modifications required for the BZ#12683 fix
by adding the arch-specific cancellation syscall bridge.
---
 .../unix/sysv/linux/nios2/syscall_cancel.S    | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 sysdeps/unix/sysv/linux/nios2/syscall_cancel.S

diff --git a/sysdeps/unix/sysv/linux/nios2/syscall_cancel.S b/sysdeps/unix/sysv/linux/nios2/syscall_cancel.S
new file mode 100644
index 0000000000..cc19c4525e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/nios2/syscall_cancel.S
@@ -0,0 +1,97 @@
+/* Cancellable syscall wrapper.  Linux/nios2 version.
+   Copyright (C) 2019 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>
+
+/* long int __syscall_cancel_arch (int *cancelhandling,
+				   __syscall_arg_t nr,
+				   __syscall_arg_t arg1,
+				   __syscall_arg_t arg2,
+				   __syscall_arg_t arg3,
+				   __syscall_arg_t arg4,
+				   __syscall_arg_t arg5,
+				   __syscall_arg_t arg6)  */
+
+ENTRY (__syscall_cancel_arch)
+#ifdef SHARED
+	addi	sp, sp, -8
+	stw	r22, 0(sp)
+	nextpc	r22
+1:
+	movhi	r8, %hiadj(_gp_got - 1b)
+	addi	r8, r8, %lo(_gp_got - 1b)
+	stw	ra, 4(sp)
+	add	r22, r22, r8
+#else
+	addi	sp, sp, -4
+	cfi_def_cfa_offset (4)
+	stw	ra, 0(sp)
+	cfi_offset (31, -4)
+#endif
+
+	.globl __syscall_cancel_arch_start
+	.type  __syscall_cancel_arch_start,@function
+__syscall_cancel_arch_start:
+	ldw	r3, 0(r4)
+	andi	r3, r3, 4
+	bne	r3, zero, 3f
+	mov	r10, r6
+	mov	r2, r5
+#ifdef SHARED
+# define STACK_ADJ 4
+#else
+# define STACK_ADJ 0
+#endif
+	ldw	r9, (16 + STACK_ADJ)(sp)
+	mov	r5, r7
+	ldw	r8, (12 + STACK_ADJ)(sp)
+	ldw	r7, (8 + STACK_ADJ)(sp)
+	ldw	r6, (4 + STACK_ADJ)(sp)
+	mov	r4, r10
+	trap
+
+	.globl __syscall_cancel_arch_end
+	.type  __syscall_cancel_arch_end,@function
+__syscall_cancel_arch_end:
+	beq	r7, zero, 2f
+	sub	r2, zero, r2
+2:
+#ifdef SHARED
+	ldw	ra, 4(sp)
+	ldw	r22, 0(sp)
+	addi	sp, sp, 8
+#else
+	ldw	ra, (0 + STACK_ADJ)(sp)
+	cfi_remember_state
+	cfi_restore (31)
+	addi	sp, sp, 4
+	cfi_def_cfa_offset (0)
+#endif
+	ret
+
+3:
+#ifdef SHARED
+	ldw	r2, %call(__syscall_do_cancel)(r22)
+	callr	r2
+#else
+	cfi_restore_state
+	call	__syscall_do_cancel
+#endif
+
+END (__syscall_cancel_arch)
+libc_hidden_def (__syscall_cancel_arch)
-- 
2.17.1