From: Linus Torvalds <torvalds@osdl.org>
So here's v3 (which also removes the now stale __put_user_check() macro).
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/i386/kernel/i386_ksyms.c | 5 +
25-akpm/arch/i386/lib/Makefile | 2
25-akpm/arch/i386/lib/putuser.S | 87 ++++++++++++++++++++++++++++++++++
25-akpm/include/asm-i386/uaccess.h | 40 ++++++++++-----
4 files changed, 120 insertions(+), 14 deletions(-)
diff -puN arch/i386/kernel/i386_ksyms.c~out-of-line-x86-put_user-implementation arch/i386/kernel/i386_ksyms.c
--- 25/arch/i386/kernel/i386_ksyms.c~out-of-line-x86-put_user-implementation 2005-02-08 18:28:44.000000000 -0800
+++ 25-akpm/arch/i386/kernel/i386_ksyms.c 2005-02-08 18:28:44.000000000 -0800
@@ -97,6 +97,11 @@ EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);
EXPORT_SYMBOL(__get_user_4);
+EXPORT_SYMBOL(__put_user_1);
+EXPORT_SYMBOL(__put_user_2);
+EXPORT_SYMBOL(__put_user_4);
+EXPORT_SYMBOL(__put_user_8);
+
EXPORT_SYMBOL(strpbrk);
EXPORT_SYMBOL(strstr);
diff -puN arch/i386/lib/Makefile~out-of-line-x86-put_user-implementation arch/i386/lib/Makefile
--- 25/arch/i386/lib/Makefile~out-of-line-x86-put_user-implementation 2005-02-08 18:28:44.000000000 -0800
+++ 25-akpm/arch/i386/lib/Makefile 2005-02-08 18:28:44.000000000 -0800
@@ -3,7 +3,7 @@
#
-lib-y = checksum.o delay.o usercopy.o getuser.o memcpy.o strstr.o \
+lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \
bitops.o
lib-$(CONFIG_X86_USE_3DNOW) += mmx.o
diff -puN /dev/null arch/i386/lib/putuser.S
--- /dev/null 2003-09-15 06:40:47.000000000 -0700
+++ 25-akpm/arch/i386/lib/putuser.S 2005-02-08 18:28:44.000000000 -0800
@@ -0,0 +1,87 @@
+/*
+ * __put_user functions.
+ *
+ * (C) Copyright 2005 Linus Torvalds
+ *
+ * These functions have a non-standard call interface
+ * to make them more efficient, especially as they
+ * return an error value in addition to the "real"
+ * return value.
+ */
+#include <asm/thread_info.h>
+
+
+/*
+ * __put_user_X
+ *
+ * Inputs: %eax[:%edx] contains the data
+ * %ecx contains the address
+ *
+ * Outputs: %eax is error code (0 or -EFAULT)
+ *
+ * These functions should not modify any other registers,
+ * as they get called from within inline assembly.
+ */
+
+#define ENTER pushl %ebx ; GET_THREAD_INFO(%ebx)
+#define EXIT popl %ebx ; ret
+
+.text
+.align 4
+.globl __put_user_1
+__put_user_1:
+ ENTER
+ cmpl TI_addr_limit(%ebx),%ecx
+ jae bad_put_user
+1: movb %al,(%ecx)
+ xorl %eax,%eax
+ EXIT
+
+.align 4
+.globl __put_user_2
+__put_user_2:
+ ENTER
+ movl TI_addr_limit(%ebx),%ebx
+ subl $1,%ebx
+ cmpl %ebx,%ecx
+ jae bad_put_user
+2: movw %ax,(%ecx)
+ xorl %eax,%eax
+ EXIT
+
+.align 4
+.globl __put_user_4
+__put_user_4:
+ ENTER
+ movl TI_addr_limit(%ebx),%ebx
+ subl $3,%ebx
+ cmpl %ebx,%ecx
+ jae bad_put_user
+3: movl %eax,(%ecx)
+ xorl %eax,%eax
+ EXIT
+
+.align 4
+.globl __put_user_8
+__put_user_8:
+ ENTER
+ movl TI_addr_limit(%ebx),%ebx
+ subl $7,%ebx
+ cmpl %ebx,%ecx
+ jae bad_put_user
+4: movl %eax,(%ecx)
+5: movl %edx,4(%ecx)
+ xorl %eax,%eax
+ EXIT
+
+bad_put_user:
+ movl $-14,%eax
+ EXIT
+
+.section __ex_table,"a"
+ .long 1b,bad_put_user
+ .long 2b,bad_put_user
+ .long 3b,bad_put_user
+ .long 4b,bad_put_user
+ .long 5b,bad_put_user
+.previous
diff -puN include/asm-i386/uaccess.h~out-of-line-x86-put_user-implementation include/asm-i386/uaccess.h
--- 25/include/asm-i386/uaccess.h~out-of-line-x86-put_user-implementation 2005-02-08 18:28:44.000000000 -0800
+++ 25-akpm/include/asm-i386/uaccess.h 2005-02-08 18:28:44.000000000 -0800
@@ -185,6 +185,21 @@ extern void __get_user_4(void);
extern void __put_user_bad(void);
+/*
+ * Strange magic calling convention: pointer in %ecx,
+ * value in %eax(:%edx), return value in %eax, no clobbers.
+ */
+extern void __put_user_1(void);
+extern void __put_user_2(void);
+extern void __put_user_4(void);
+extern void __put_user_8(void);
+
+#define __put_user_1(x, ptr) __asm__ __volatile__("call __put_user_1":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_2(x, ptr) __asm__ __volatile__("call __put_user_2":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_4(x, ptr) __asm__ __volatile__("call __put_user_4":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_8(x, ptr) __asm__ __volatile__("call __put_user_8":"=a" (__ret_pu):"A" ((typeof(*(ptr)))(x)), "c" (ptr))
+#define __put_user_X(x, ptr) __asm__ __volatile__("call __put_user_X":"=a" (__ret_pu):"c" (ptr))
+
/**
* put_user: - Write a simple value into user space.
* @x: Value to copy to user space.
@@ -201,9 +216,18 @@ extern void __put_user_bad(void);
*
* Returns zero on success, or -EFAULT on error.
*/
-#define put_user(x,ptr) \
- __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
-
+#define put_user(x,ptr) \
+({ int __ret_pu; \
+ __chk_user_ptr(ptr); \
+ switch(sizeof(*(ptr))) { \
+ case 1: __put_user_1(x, ptr); break; \
+ case 2: __put_user_2(x, ptr); break; \
+ case 4: __put_user_4(x, ptr); break; \
+ case 8: __put_user_8(x, ptr); break; \
+ default:__put_user_X(x, ptr); break; \
+ } \
+ __ret_pu; \
+})
/**
* __get_user: - Get a simple variable from user space, with less checking.
@@ -259,16 +283,6 @@ extern void __put_user_bad(void);
})
-#define __put_user_check(x,ptr,size) \
-({ \
- long __pu_err = -EFAULT; \
- __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
- might_sleep(); \
- if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
- __put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT); \
- __pu_err; \
-})
-
#define __put_user_u64(x, addr, err) \
__asm__ __volatile__( \
"1: movl %%eax,0(%2)\n" \
_