Menu
▾
▴
[linuxsh-dev] uaccess.h changes of 2002
|
From: NIIBE Y. <gn...@m1...> - 2002-03-25 10:01:31
|
With (microscopic) optimization of the functionality of __addr_ok
(which is used to access user space memory from kernel), kernel runs
slightly faster.
Besides, I've re-wrote __clear_user function which has been left as
not-so-good implementation for three years (it's not so important as
its use is so limited).
2002-03-25 NIIBE Yutaka <gn...@m1...>
* include/asm-sh/uaccess.h (__clear_user): Make it external
function. (Was: inline function).
* arch/sh/mm/Makefile: Added the entry for __clear_user.o.
* arch/sh/mm/__clear_user.S: File name change. As it's also used by
SH-3, renamed from __clear_user_page-sh4.S,
(__clear_user): New function.
2002-03-24 NIIBE Yutaka <gn...@m1...>
* include/asm-sh/system.h (mm_segment_t): Move the definition to...
* include/asm-sh/uaccess.h: ... here. And change it to have boolean
is_user_space.
(KERNEL_DS, USER_DS): New value domain: 0 or 1.
(get_fs): Simplified.
(set_fs): Optimized by asm.
(__get_user_check): New implementation.
(__get_user_1, __get_user_2, __get_user_4): New macros.
(strnlen_user): Use __access_ok function.
(strlen_user): Implemented as inline function.
2002-03-23 NIIBE Yutaka <gn...@m1...>
* include/asm-sh/uaccess.h (__range_ok): Removed.
(__access_ok, access_ok): New implementation.
* include/asm-sh/thread_info.h (TIF_USERSPACE): Change to 31,
so that expression can be simple (was: 18).
Index: arch/sh/mm/Makefile
===================================================================
RCS file: /cvsroot/linuxsh/linux/arch/sh/mm/Makefile,v
retrieving revision 1.1.1.1
diff -u -3 -p -r1.1.1.1 Makefile
--- arch/sh/mm/Makefile 15 Oct 2001 20:44:53 -0000 1.1.1.1
+++ arch/sh/mm/Makefile 25 Mar 2002 09:51:56 -0000
@@ -10,8 +10,8 @@
O_TARGET := mm.o
obj-y := init.o fault.o extable.o clear_page.o copy_page.o
-obj-$(CONFIG_CPU_SH3) += cache-sh3.o
-obj-$(CONFIG_CPU_SH4) += cache-sh4.o __clear_user_page-sh4.o __copy_user_page-sh4.o ioremap.o
+obj-$(CONFIG_CPU_SH3) += cache-sh3.o __clear_user.o
+obj-$(CONFIG_CPU_SH4) += cache-sh4.o __clear_user.o __copy_user_page-sh4.o ioremap.o
USE_STANDARD_AS_RULE := true
Index: arch/sh/mm/__clear_user.S
===================================================================
RCS file: arch/sh/mm/__clear_user.S
diff -N arch/sh/mm/__clear_user.S
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ arch/sh/mm/__clear_user.S 25 Mar 2002 09:51:56 -0000
@@ -0,0 +1,138 @@
+/* $Id: __clear_user_page.S,v 1.1.1.1 2001/10/15 20:44:53 mrbrown Exp $
+ *
+ * __clear_user_page implementation of SuperH
+ *
+ * Copyright (C) 2001, 2002 Niibe Yutaka & Kaz Kojima
+ *
+ */
+
+#if defined(__SH4__)
+/*
+ * __clear_user_page
+ * @to: P1 address (with same color)
+ * @orig_to: P1 address
+ *
+ * void __clear_user_page(void *to, void *orig_to)
+ */
+
+/*
+ * r0 --- scratch
+ * r4 --- to
+ * r5 --- orig_to
+ * r6 --- to + 4096
+ */
+#include <linux/linkage.h>
+ENTRY(__clear_user_page)
+ mov.w .L4096,r0
+ mov r4,r6
+ add r0,r6
+ mov #0,r0
+ !
+1: ocbi @r5
+ add #32,r5
+ movca.l r0,@r4
+ mov r4,r1
+ add #32,r4
+ mov.l r0,@-r4
+ mov.l r0,@-r4
+ mov.l r0,@-r4
+ mov.l r0,@-r4
+ mov.l r0,@-r4
+ mov.l r0,@-r4
+ mov.l r0,@-r4
+ add #28,r4
+ cmp/eq r6,r4
+ bf/s 1b
+ ocbwb @r1
+ !
+ rts
+ nop
+.L4096: .word 4096
+#endif
+
+ENTRY(__clear_user)
+ !
+ mov #0, r0
+ mov #0xe0, r1 ! 0xffffffe0
+ !
+ ! r4..r4&~32 -------- not aligned [ Area 0 ]
+ ! r4&~32..(r4+r5)&~32 -------- aligned [ Area 1 ]
+ ! (r4+r5)&~32..r4+r5 -------- not aligned [ Area 2 ]
+ !
+ ! Clear area 0
+ mov r4, r2
+ and r1, r2
+ cmp/eq r4, r2
+ bt/s area1
+ mov r4, r3
+ sub r2, r3
+ mov r4, r2
+ !
+l0: dt r3
+0: mov.b r0, @r2
+ bf/s l0
+ add #1, r2
+ !
+ mov r4, r3
+ add r5, r3
+ and r1, r3
+ !
+ ! Clear area 1
+area1:
+#if defined(__SH4__)
+1: movca.l r0, @r2
+#else
+1: mov.l r0, @r2
+#endif
+ add #4, r2
+2: mov.l r0, @r2
+ add #4, r2
+3: mov.l r0, @r2
+ add #4, r2
+4: mov.l r0, @r2
+ add #4, r2
+5: mov.l r0, @r2
+ add #4, r2
+6: mov.l r0, @r2
+ add #4, r2
+7: mov.l r0, @r2
+ add #4, r2
+8: mov.l r0, @r2
+ add #4, r2
+ cmp/hi r2, r3
+ bt/s 1b
+ nop
+ !
+ ! Clear area 2
+ add r5, r4
+ cmp/eq r4, r2
+ bt/s done
+ sub r2, r4
+l2: dt r4
+9: mov.b r0, @r2
+ bf/s l2
+ add #1, r2
+ !
+done: rts
+ nop ! return 0 as normal return
+
+ ! return the number of bytes remained
+bad_clear_user:
+ mov r4, r0
+ mov r5, r0
+ rts
+ sub r2, r0
+
+.section __ex_table,"a"
+ .align 2
+ .long 0b, bad_clear_user
+ .long 1b, bad_clear_user
+ .long 2b, bad_clear_user
+ .long 3b, bad_clear_user
+ .long 4b, bad_clear_user
+ .long 5b, bad_clear_user
+ .long 6b, bad_clear_user
+ .long 7b, bad_clear_user
+ .long 8b, bad_clear_user
+ .long 9b, bad_clear_user
+.previous
Index: arch/sh/mm/__clear_user_page-sh4.S
===================================================================
RCS file: arch/sh/mm/__clear_user_page-sh4.S
diff -N arch/sh/mm/__clear_user_page-sh4.S
--- arch/sh/mm/__clear_user_page-sh4.S 15 Oct 2001 20:44:53 -0000 1.1.1.1
+++ /dev/null 1 Jan 1970 00:00:00 -0000
@@ -1,49 +0,0 @@
-/* $Id: __clear_user_page-sh4.S,v 1.1.1.1 2001/10/15 20:44:53 mrbrown Exp $
- *
- * __clear_user_page implementation of SuperH
- *
- * Copyright (C) 2001 Niibe Yutaka & Kaz Kojima
- *
- */
-
-/*
- * __clear_user_page
- * @to: P1 address (with same color)
- * @orig_to: P1 address
- *
- * void __clear_user_page(void *to, void *orig_to)
- */
-
-/*
- * r0 --- scratch
- * r4 --- to
- * r5 --- orig_to
- * r6 --- to + 4096
- */
-#include <linux/linkage.h>
-ENTRY(__clear_user_page)
- mov r4,r6
- mov.w .L4096,r0
- add r0,r6
- mov #0,r0
- !
-1: ocbi @r5
- add #32,r5
- movca.l r0,@r4
- mov r4,r1
- add #32,r4
- mov.l r0,@-r4
- mov.l r0,@-r4
- mov.l r0,@-r4
- mov.l r0,@-r4
- mov.l r0,@-r4
- mov.l r0,@-r4
- mov.l r0,@-r4
- add #28,r4
- cmp/eq r6,r4
- bf/s 1b
- ocbwb @r1
- !
- rts
- nop
-.L4096: .word 4096
Index: include/asm-sh/system.h
===================================================================
RCS file: /cvsroot/linuxsh/linux/include/asm-sh/system.h,v
retrieving revision 1.3
diff -u -3 -p -r1.3 system.h
--- include/asm-sh/system.h 22 Mar 2002 12:57:10 -0000 1.3
+++ include/asm-sh/system.h 25 Mar 2002 09:51:56 -0000
@@ -12,10 +12,6 @@
* switch_to() should switch tasks to task nr n, first
*/
-typedef struct {
- unsigned long seg;
-} mm_segment_t;
-
#ifdef CONFIG_SMP
#error no SMP SuperH
#else
Index: include/asm-sh/thread_info.h
===================================================================
RCS file: /cvsroot/linuxsh/linux/include/asm-sh/thread_info.h,v
retrieving revision 1.3
diff -u -3 -p -r1.3 thread_info.h
--- include/asm-sh/thread_info.h 22 Mar 2002 12:57:10 -0000 1.3
+++ include/asm-sh/thread_info.h 25 Mar 2002 09:51:56 -0000
@@ -94,7 +94,7 @@ static inline struct thread_info *curren
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
-#define TIF_USERSPACE 18 /* true if FS sets userspace */
+#define TIF_USERSPACE 31 /* true if FS sets userspace */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
Index: include/asm-sh/uaccess.h
===================================================================
RCS file: /cvsroot/linuxsh/linux/include/asm-sh/uaccess.h,v
retrieving revision 1.4
diff -u -3 -p -r1.4 uaccess.h
--- include/asm-sh/uaccess.h 6 Mar 2002 23:04:52 -0000 1.4
+++ include/asm-sh/uaccess.h 25 Mar 2002 09:51:56 -0000
@@ -2,7 +2,7 @@
*
* User space memory access functions
*
- * Copyright (C) 1999 Niibe Yutaka
+ * Copyright (C) 1999, 2002 Niibe Yutaka
*
* Based on:
* MIPS implementation version 1.15 by
@@ -15,9 +15,21 @@
#include <linux/errno.h>
#include <linux/sched.h>
+/*
+ * NOTE: Macro/functions in this file depends on threads_info.h implementation.
+ * Assumes:
+ * TI_FLAGS == 8
+ * TIF_USERSPACE == 31
+ * USER_ADDR_LIMIT == 0x80000000
+ */
+
#define VERIFY_READ 0
#define VERIFY_WRITE 1
+typedef struct {
+ unsigned int is_user_space;
+} mm_segment_t;
+
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
@@ -28,50 +40,83 @@
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
-#define KERN_ADDR_LIMIT 0xFFFFFFFF
#define USER_ADDR_LIMIT 0x80000000
-#define KERNEL_DS MAKE_MM_SEG(KERN_ADDR_LIMIT)
-#define USER_DS MAKE_MM_SEG(USER_ADDR_LIMIT)
+#define KERNEL_DS MAKE_MM_SEG(0)
+#define USER_DS MAKE_MM_SEG(1)
#define get_ds() (KERNEL_DS)
static inline mm_segment_t get_fs(void)
{
- if (test_thread_flag(TIF_USERSPACE))
- return USER_DS;
- else
- return KERNEL_DS;
+ return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
}
static inline void set_fs(mm_segment_t s)
{
- if (s.seg == USER_ADDR_LIMIT)
+ unsigned long ti, flag;
+ __asm__ __volatile__(
+ "stc r7_bank, %0\n\t"
+ "mov.l @(8,%0), %1\n\t"
+ "shal %1\n\t"
+ "cmp/pl %2\n\t"
+ "rotcr %1\n\t"
+ "mov.l %1, @(8,%0)"
+ : "=&r" (ti), "=&r" (flag)
+ : "r" (s.is_user_space)
+ : "t");
+/****
+ if (s.is_user_space)
set_thread_flag(TIF_USERSPACE);
else
clear_thread_flag(TIF_USERSPACE);
+****/
}
-#define segment_eq(a,b) ((a).seg == (b).seg)
-
-#define __addr_ok(addr) ((unsigned long)(addr) < (get_fs().seg))
+#define segment_eq(a,b) ((a).is_user_space == (b).is_user_space)
/*
- * Uhhuh, this needs 33-bit arithmetic. We have a carry..
+ * __access_ok: Check if address with size is OK or not.
*
- * sum := addr + size; carry? --> flag = true;
- * if (sum >= addr_limit) flag = true;
+ * We do three checks:
+ * (1) is it user space?
+ * (2) addr + size --> carry?
+ * (3) addr + size >= 0x80000000 (USER_ADDR_LIMIT)
+ *
+ * (1) (2) (3) | RESULT
+ * 0 0 0 | ok
+ * 0 0 1 | ok
+ * 0 1 0 | bad
+ * 0 1 1 | bad
+ * 1 0 0 | ok
+ * 1 0 1 | bad
+ * 1 1 0 | bad
+ * 1 1 1 | bad
*/
-#define __range_ok(addr,size) ({ \
- unsigned long flag,sum; \
- __asm__("clrt; addc %3, %1; movt %0; cmp/hi %4, %1; rotcl %0" \
- :"=&r" (flag), "=r" (sum) \
- :"1" (addr), "r" ((int)(size)), "r" (get_fs().seg) \
- :"t"); \
- flag; })
+static int __access_ok(unsigned long addr, unsigned long size)
+{
+ unsigned long flag, tmp;
-#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
-#define __access_ok(addr,size) (__range_ok(addr,size) == 0)
+ __asm__("stc r7_bank, %0\n\t"
+ "mov.l @(8,%0), %0\n\t"
+ "clrt\n\t"
+ "addc %2, %1\n\t"
+ "and %1, %0\n\t"
+ "rotcl %0\n\t"
+ "rotcl %0\n\t"
+ "and #3, %0"
+ : "=&z" (flag), "=r" (tmp)
+ : "r" (addr), "1" (size)
+ : "t");
+
+ return flag == 0;
+}
+
+static inline int access_ok(int type, const void *p, unsigned long size)
+{
+ unsigned long addr = (unsigned long)p;
+ return __access_ok(addr, size);
+}
static inline int verify_area(int type, const void * addr, unsigned long size)
{
@@ -118,20 +163,92 @@ case 4: __get_user_asm("l"); break; \
default: __get_user_unknown(); break; \
} x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
-#define __get_user_check(x,ptr,size) ({ \
-long __gu_err; \
-__typeof__(*(ptr)) __gu_val; \
-long __gu_addr; \
-__asm__("":"=r" (__gu_val)); \
-__gu_addr = (long) (ptr); \
-__asm__("":"=r" (__gu_err)); \
-if (__access_ok(__gu_addr,size)) { \
-switch (size) { \
-case 1: __get_user_asm("b"); break; \
-case 2: __get_user_asm("w"); break; \
-case 4: __get_user_asm("l"); break; \
-default: __get_user_unknown(); break; \
-} } x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
+#define __get_user_check(x,ptr,size) \
+({ __typeof__(*(ptr)) __val; long __err; \
+ switch(size) { \
+ case 1: __err = __get_user_1(__val, ptr); break; \
+ case 2: __err = __get_user_2(__val, ptr); break; \
+ case 4: __err = __get_user_4(__val, ptr); break; \
+ default: __get_user_unknown(); break; \
+ } \
+ (x) = __val; __err; })
+
+#define __get_user_1(x,ptr) ({ \
+long __gu_err; \
+__typeof__(*(ptr)) __gu_val; \
+long __gu_addr = (long) (ptr); \
+__asm__("stc r7_bank, %1\n\t" \
+ "mov.l @(8,%1), %1\n\t" \
+ "and %2, %1\n\t" \
+ "cmp/pz %1\n\t" \
+ "bt/s 1f\n\t" \
+ " mov #0, %0\n\t" \
+ "0:\n" \
+ "mov #-14, %0\n\t" \
+ "bra 2f\n\t" \
+ " mov #0, %1\n" \
+ "1:\n\t" \
+ "mov.b @%2, %1\n\t" \
+ "extu.b %1, %1\n" \
+ "2:\n" \
+ ".section __ex_table,\"a\"\n\t" \
+ ".long 1b, 0b\n\t" \
+ ".previous" \
+ : "=&r" (__gu_err), "=&r" (__gu_val) \
+ : "r" (__gu_addr) \
+ : "t"); \
+x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
+
+#define __get_user_2(x,ptr) ({ \
+long __gu_err; \
+__typeof__(*(ptr)) __gu_val; \
+long __gu_addr = (long) (ptr); \
+__asm__("stc r7_bank, %1\n\t" \
+ "mov.l @(8,%1), %1\n\t" \
+ "and %2, %1\n\t" \
+ "cmp/pz %1\n\t" \
+ "bt/s 1f\n\t" \
+ " mov #0, %0\n\t" \
+ "0:\n" \
+ "mov #-14, %0\n\t" \
+ "bra 2f\n\t" \
+ " mov #0, %1\n" \
+ "1:\n\t" \
+ "mov.w @%2, %1\n\t" \
+ "extu.w %1, %1\n" \
+ "2:\n" \
+ ".section __ex_table,\"a\"\n\t" \
+ ".long 1b, 0b\n\t" \
+ ".previous" \
+ : "=&r" (__gu_err), "=&r" (__gu_val) \
+ : "r" (__gu_addr) \
+ : "t"); \
+x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
+
+#define __get_user_4(x,ptr) ({ \
+long __gu_err; \
+__typeof__(*(ptr)) __gu_val; \
+long __gu_addr = (long) (ptr); \
+__asm__("stc r7_bank, %1\n\t" \
+ "mov.l @(8,%1), %1\n\t" \
+ "and %2, %1\n\t" \
+ "cmp/pz %1\n\t" \
+ "bt/s 1f\n\t" \
+ " mov #0, %0\n\t" \
+ "0:\n" \
+ "mov #-14, %0\n\t" \
+ "bra 2f\n\t" \
+ " mov #0, %1\n" \
+ "1:\n\t" \
+ "mov.l @%2, %1\n\t" \
+ "2:\n" \
+ ".section __ex_table,\"a\"\n\t" \
+ ".long 1b, 0b\n\t" \
+ ".previous" \
+ : "=&r" (__gu_err), "=&r" (__gu_val) \
+ : "r" (__gu_addr) \
+ : "t"); \
+x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
#define __get_user_asm(insn) \
({ \
@@ -325,39 +442,11 @@ __copy_res; })
__copy_user((void *)(to), \
(void *)(from), n)
-/* XXX: Not sure it works well..
- should be such that: 4byte clear and the rest. */
-static __inline__ __kernel_size_t
-__clear_user(void *addr, __kernel_size_t size)
-{
- unsigned long __a;
-
- __asm__ __volatile__(
- "9:\n\t"
- "dt %0\n"
- "1:\n\t"
- "mov.b %4, @%1\n\t"
- "bf/s 9b\n\t"
- " add #1, %1\n"
- "2:\n"
- ".section .fixup,\"ax\"\n"
- "3:\n\t"
- "mov.l 4f, %1\n\t"
- "jmp @%1\n\t"
- " nop\n"
- ".balign 4\n"
- "4: .long 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .balign 4\n"
- " .long 1b,3b\n"
- ".previous"
- : "=r" (size), "=r" (__a)
- : "0" (size), "1" (addr), "r" (0)
- : "memory", "t");
-
- return size;
-}
+/*
+ * Clear the area and return remaining number of bytes
+ * (on failure. Usually it's 0.)
+ */
+extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
#define clear_user(addr,n) ({ \
void * __cl_addr = (addr); \
@@ -413,8 +502,6 @@ if(__access_ok(__sfu_src, __sfu_count))
__sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
} __sfu_res; })
-#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
-
/*
* Return the size of a string (including the ending 0!)
*/
@@ -453,10 +540,18 @@ static __inline__ long __strnlen_user(co
static __inline__ long strnlen_user(const char *s, long n)
{
- if (!__addr_ok(s))
+ if (!access_ok(VERIFY_READ, s, n))
return 0;
else
return __strnlen_user(s, n);
+}
+
+static __inline__ long strlen_user(const char *s)
+{
+ if (!access_ok(VERIFY_READ, s, 0))
+ return 0;
+ else
+ return __strnlen_user(s, ~0UL >> 1);
}
struct exception_table_entry
--
|
