From effaa7824da1af4db5cef50c78079d4c4e1717a7 Mon Sep 17 00:00:00 2001
From: Chris Dearman <chris.dearman@imgtec.com>
Date: Wed, 13 Nov 2013 14:15:31 -0800
Subject: [PATCH] [MIPS] Reimplement syscall to invoke the system call directly

Some MIPS kernels do not correctly restart interrupted system calls that
have been invoked using the indirect syscall (NR_syscall).

The simplest workaround is to handle the indirection in userland and then
call the required system call directly.

Change-Id: I8385399621529db9a52b463c96925f6decaaca30
---
 libc/SYSCALLS.TXT                 |  1 -
 libc/arch-mips/bionic/syscall.S   | 57 +++++++++++++++++++++++++++++++
 libc/arch-mips/mips.mk            |  1 +
 libc/arch-mips/syscalls.mk        |  1 -
 libc/arch-mips/syscalls/syscall.S | 23 -------------
 5 files changed, 58 insertions(+), 25 deletions(-)
 create mode 100644 libc/arch-mips/bionic/syscall.S
 delete mode 100644 libc/arch-mips/syscalls/syscall.S

diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 7c1529722..533116e60 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -304,4 +304,3 @@ int     cacheflush:__ARM_NR_cacheflush(long start, long end, long flags)  arm
 
 # MIPS-specific
 int     _flush_cache:cacheflush(char* addr, const int nbytes, const int op) mips
-int     syscall(int number, ...) mips
diff --git a/libc/arch-mips/bionic/syscall.S b/libc/arch-mips/bionic/syscall.S
new file mode 100644
index 000000000..60754e82e
--- /dev/null
+++ b/libc/arch-mips/bionic/syscall.S
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <asm/unistd.h>
+    .text
+    .globl syscall
+    .align 4
+    .ent syscall
+
+syscall:
+    .set noreorder
+    .cpload $t9
+    move    $v0, $a0
+    move    $a0, $a1
+    move    $a1, $a2
+    move    $a2, $a3
+    lw      $a3, 16($sp)
+    lw      $t0, 20($sp)
+    lw      $t1, 24($sp)
+    sw      $t0, 16($sp)
+    sw      $t1, 20($sp)
+    syscall
+    bnez    $a3, 1f
+    move    $a0, $v0
+    j       $ra
+    nop
+1:
+    la      $t9,__set_errno
+    j       $t9
+    nop
+    .set reorder
+    .end syscall
diff --git a/libc/arch-mips/mips.mk b/libc/arch-mips/mips.mk
index 3ebedd01d..c8953576b 100644
--- a/libc/arch-mips/mips.mk
+++ b/libc/arch-mips/mips.mk
@@ -11,6 +11,7 @@ _LIBC_ARCH_COMMON_SRC_FILES := \
     arch-mips/bionic/setjmp.S \
     arch-mips/bionic/__set_tls.c \
     arch-mips/bionic/sigsetjmp.S \
+    arch-mips/bionic/syscall.S \
     arch-mips/bionic/vfork.S \
     arch-mips/string/memcpy.S \
     arch-mips/string/memset.S \
diff --git a/libc/arch-mips/syscalls.mk b/libc/arch-mips/syscalls.mk
index 9be619712..e141a6596 100644
--- a/libc/arch-mips/syscalls.mk
+++ b/libc/arch-mips/syscalls.mk
@@ -175,7 +175,6 @@ syscall_src += arch-mips/syscalls/swapoff.S
 syscall_src += arch-mips/syscalls/swapon.S
 syscall_src += arch-mips/syscalls/symlinkat.S
 syscall_src += arch-mips/syscalls/sync.S
-syscall_src += arch-mips/syscalls/syscall.S
 syscall_src += arch-mips/syscalls/sysinfo.S
 syscall_src += arch-mips/syscalls/tgkill.S
 syscall_src += arch-mips/syscalls/timerfd_create.S
diff --git a/libc/arch-mips/syscalls/syscall.S b/libc/arch-mips/syscalls/syscall.S
deleted file mode 100644
index 2b2b7077e..000000000
--- a/libc/arch-mips/syscalls/syscall.S
+++ /dev/null
@@ -1,23 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <asm/unistd.h>
-    .text
-    .globl syscall
-    .align 4
-    .ent syscall
-
-syscall:
-    .set noreorder
-    .cpload $t9
-    li $v0, __NR_syscall
-    syscall
-    bnez $a3, 1f
-    move $a0, $v0
-    j $ra
-    nop
-1:
-    la $t9,__set_errno
-    j $t9
-    nop
-    .set reorder
-    .end syscall