From 0ae27b2cc9d1462b9efd65358abcdc884c96833a Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Sun, 19 Feb 2012 07:56:26 -0800
Subject: [PATCH] --- yaml --- r: 297727 b: refs/heads/master c:
 fca460f95e928bae373daa8295877b6905bc62b8 h: refs/heads/master i:   297725:
 4532f4d445d5e0a2a2c35986b925cf9ca7f594ce   297723:
 fc925833aa32b4b5b5a848bfccc7ab116ebd069e   297719:
 1a553e2531f6ed1e09dd7c6113c31d93f7f74e8b   297711:
 bf321e29d19b2b425b5f2ccdf518d336a1080e2d   297695:
 036bbfba8cb05caae17b0918a37854a1dcc4ad1d   297663:
 6dc0bc1e5a6b97e6a542f9efda8dbd0c7e5b9989   297599:
 1331ff4428382f3aadef20443aef2d387fe7b347   297471:
 f7adfc76a702536e3b1394682db1ed1e897adb50 v: v3

---
 [refs]                               |  2 +-
 trunk/arch/x86/include/asm/compat.h  | 13 +++++++++++--
 trunk/arch/x86/include/asm/syscall.h |  5 +++--
 trunk/arch/x86/include/asm/unistd.h  |  7 +++++++
 trunk/arch/x86/kernel/entry_64.S     | 10 ++++++++++
 5 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 65ad62d68b66..c1a96e275995 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9d3897630e14b3d33bcb24a3c0fa9d60a01d3058
+refs/heads/master: fca460f95e928bae373daa8295877b6905bc62b8
diff --git a/trunk/arch/x86/include/asm/compat.h b/trunk/arch/x86/include/asm/compat.h
index 30d737ef2a42..7938b84e4506 100644
--- a/trunk/arch/x86/include/asm/compat.h
+++ b/trunk/arch/x86/include/asm/compat.h
@@ -7,6 +7,7 @@
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <asm/user32.h>
+#include <asm/unistd.h>
 
 #define COMPAT_USER_HZ		100
 #define COMPAT_UTS_MACHINE	"i686\0\0"
@@ -212,9 +213,17 @@ static inline void __user *arch_compat_alloc_user_space(long len)
 	return (void __user *)regs->sp - len;
 }
 
-static inline int is_compat_task(void)
+static inline bool is_compat_task(void)
 {
-	return current_thread_info()->status & TS_COMPAT;
+#ifdef CONFIG_IA32_EMULATION
+	if (current_thread_info()->status & TS_COMPAT)
+		return true;
+#endif
+#ifdef CONFIG_X86_X32_ABI
+	if (task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)
+		return true;
+#endif
+	return false;
 }
 
 #endif /* _ASM_X86_COMPAT_H */
diff --git a/trunk/arch/x86/include/asm/syscall.h b/trunk/arch/x86/include/asm/syscall.h
index d962e5652a73..386b78686c4d 100644
--- a/trunk/arch/x86/include/asm/syscall.h
+++ b/trunk/arch/x86/include/asm/syscall.h
@@ -16,6 +16,7 @@
 #include <linux/sched.h>
 #include <linux/err.h>
 #include <asm/asm-offsets.h>	/* For NR_syscalls */
+#include <asm/unistd.h>
 
 extern const unsigned long sys_call_table[];
 
@@ -26,13 +27,13 @@ extern const unsigned long sys_call_table[];
  */
 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
 {
-	return regs->orig_ax;
+	return regs->orig_ax & __SYSCALL_MASK;
 }
 
 static inline void syscall_rollback(struct task_struct *task,
 				    struct pt_regs *regs)
 {
-	regs->ax = regs->orig_ax;
+	regs->ax = regs->orig_ax & __SYSCALL_MASK;
 }
 
 static inline long syscall_get_error(struct task_struct *task,
diff --git a/trunk/arch/x86/include/asm/unistd.h b/trunk/arch/x86/include/asm/unistd.h
index 7a48a5557470..37cdc9d99bb1 100644
--- a/trunk/arch/x86/include/asm/unistd.h
+++ b/trunk/arch/x86/include/asm/unistd.h
@@ -5,6 +5,13 @@
 #define __X32_SYSCALL_BIT	0x40000000
 
 #ifdef __KERNEL__
+
+# ifdef CONFIG_X86_X32_ABI
+#  define __SYSCALL_MASK (~(__X32_SYSCALL_BIT))
+# else
+#  define __SYSCALL_MASK (~0)
+# endif
+
 # ifdef CONFIG_X86_32
 
 #  include <asm/unistd_32.h>
diff --git a/trunk/arch/x86/kernel/entry_64.S b/trunk/arch/x86/kernel/entry_64.S
index 3fe8239fd8fb..a17b34216971 100644
--- a/trunk/arch/x86/kernel/entry_64.S
+++ b/trunk/arch/x86/kernel/entry_64.S
@@ -482,7 +482,12 @@ GLOBAL(system_call_after_swapgs)
 	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
 	jnz tracesys
 system_call_fastpath:
+#if __SYSCALL_MASK == ~0
 	cmpq $__NR_syscall_max,%rax
+#else
+	andl $__SYSCALL_MASK,%eax
+	cmpl $__NR_syscall_max,%eax
+#endif
 	ja badsys
 	movq %r10,%rcx
 	call *sys_call_table(,%rax,8)  # XXX:	 rip relative
@@ -596,7 +601,12 @@ tracesys:
 	 */
 	LOAD_ARGS ARGOFFSET, 1
 	RESTORE_REST
+#if __SYSCALL_MASK == ~0
 	cmpq $__NR_syscall_max,%rax
+#else
+	andl $__SYSCALL_MASK,%eax
+	cmpl $__NR_syscall_max,%eax
+#endif
 	ja   int_ret_from_sys_call	/* RAX(%rsp) set to -ENOSYS above */
 	movq %r10,%rcx	/* fixup for C */
 	call *sys_call_table(,%rax,8)