From 8fdd6c6df7889dc89df3d9fe0f5bbe6733e39f48 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 27 Mar 2006 01:16:26 -0800
Subject: [PATCH] [PATCH] lightweight robust futexes: x86_64
x86_64: add the futex_atomic_cmpxchg_inuser() assembly implementation, and
wire up the new syscalls.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/x86_64/ia32/ia32entry.S | 2 ++
include/asm-x86_64/futex.h | 23 ++++++++++++++++++++++-
include/asm-x86_64/unistd.h | 6 +++++-
3 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 7549a4389fbf..35b2faccdc6c 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -688,6 +688,8 @@ ia32_sys_call_table:
.quad sys_ni_syscall /* pselect6 for now */
.quad sys_ni_syscall /* ppoll for now */
.quad sys_unshare /* 310 */
+ .quad compat_sys_set_robust_list
+ .quad compat_sys_get_robust_list
ia32_syscall_end:
.rept IA32_NR_syscalls-(ia32_syscall_end-ia32_sys_call_table)/8
.quad ni_syscall
diff --git a/include/asm-x86_64/futex.h b/include/asm-x86_64/futex.h
index 4f4cb3410d06..7d9eb1a84546 100644
--- a/include/asm-x86_64/futex.h
+++ b/include/asm-x86_64/futex.h
@@ -97,7 +97,28 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
static inline int
futex_atomic_cmpxchg_inuser(int __user *uaddr, int oldval, int newval)
{
- return -ENOSYS;
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+ return -EFAULT;
+
+ __asm__ __volatile__(
+ "1: " LOCK_PREFIX "cmpxchgl %3, %1 \n"
+
+ "2: .section .fixup, \"ax\" \n"
+ "3: mov %2, %0 \n"
+ " jmp 2b \n"
+ " .previous \n"
+
+ " .section __ex_table, \"a\" \n"
+ " .align 8 \n"
+ " .quad 1b,3b \n"
+ " .previous \n"
+
+ : "=a" (oldval), "=m" (*uaddr)
+ : "i" (-EFAULT), "r" (newval), "0" (oldval)
+ : "memory"
+ );
+
+ return oldval;
}
#endif
diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index da0341c57949..fcc516353087 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -605,8 +605,12 @@ __SYSCALL(__NR_pselect6, sys_ni_syscall) /* for now */
__SYSCALL(__NR_ppoll, sys_ni_syscall) /* for now */
#define __NR_unshare 272
__SYSCALL(__NR_unshare, sys_unshare)
+#define __NR_set_robust_list 273
+__SYSCALL(__NR_set_robust_list, sys_set_robust_list)
+#define __NR_get_robust_list 274
+__SYSCALL(__NR_get_robust_list, sys_get_robust_list)
-#define __NR_syscall_max __NR_unshare
+#define __NR_syscall_max __NR_get_robust_list
#ifndef __NO_STUBS
--
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