parisc: Implement __get/put_kernel_nofault()
Remove CONFIG_SET_FS from parisc, so we need to add
__get_kernel_nofault() and __put_kernel_nofault(), define
HAVE_GET_KERNEL_NOFAULT and remove set_fs(), get_fs(), load_sr2(),
thread_info->addr_limit, KERNEL_DS and USER_DS.
The nice side-effect of this patch is that we now can directly access
userspace via sr3 without the need to use a temporary sr2 which is
either copied from sr3 or set to zero (for kernel space).
Signed-off-by: Helge Deller <deller@gmx.de>
Suggested-by: Arnd Bergmann <arnd@kernel.org>
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index cfb4ca7..192ad9e 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -11,14 +11,6 @@
#include <linux/bug.h>
#include <linux/string.h>
-#define KERNEL_DS ((mm_segment_t){0})
-#define USER_DS ((mm_segment_t){1})
-
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-
-#define get_fs() (current_thread_info()->addr_limit)
-#define set_fs(x) (current_thread_info()->addr_limit = (x))
-
/*
* Note that since kernel addresses are in a separate address space on
* parisc, we don't need to do anything for access_ok().
@@ -33,11 +25,11 @@
#define get_user __get_user
#if !defined(CONFIG_64BIT)
-#define LDD_USER(val, ptr) __get_user_asm64(val, ptr)
-#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
+#define LDD_USER(sr, val, ptr) __get_user_asm64(sr, val, ptr)
+#define STD_USER(sr, x, ptr) __put_user_asm64(sr, x, ptr)
#else
-#define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr)
-#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
+#define LDD_USER(sr, val, ptr) __get_user_asm(sr, val, "ldd", ptr)
+#define STD_USER(sr, x, ptr) __put_user_asm(sr, "std", x, ptr)
#endif
/*
@@ -67,28 +59,15 @@ struct exception_table_entry {
#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\
ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1)
-/*
- * load_sr2() preloads the space register %%sr2 - based on the value of
- * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
- * is 0), or with the current value of %%sr3 to access user space (USER_DS)
- * memory. The following __get_user_asm() and __put_user_asm() functions have
- * %%sr2 hard-coded to access the requested memory.
- */
-#define load_sr2() \
- __asm__(" or,= %0,%%r0,%%r0\n\t" \
- " mfsp %%sr3,%0\n\t" \
- " mtsp %0,%%sr2\n\t" \
- : : "r"(get_fs()) : )
-
-#define __get_user_internal(val, ptr) \
+#define __get_user_internal(sr, val, ptr) \
({ \
register long __gu_err __asm__ ("r8") = 0; \
\
switch (sizeof(*(ptr))) { \
- case 1: __get_user_asm(val, "ldb", ptr); break; \
- case 2: __get_user_asm(val, "ldh", ptr); break; \
- case 4: __get_user_asm(val, "ldw", ptr); break; \
- case 8: LDD_USER(val, ptr); break; \
+ case 1: __get_user_asm(sr, val, "ldb", ptr); break; \
+ case 2: __get_user_asm(sr, val, "ldh", ptr); break; \
+ case 4: __get_user_asm(sr, val, "ldw", ptr); break; \
+ case 8: LDD_USER(sr, val, ptr); break; \
default: BUILD_BUG(); \
} \
\
@@ -97,15 +76,14 @@ struct exception_table_entry {
#define __get_user(val, ptr) \
({ \
- load_sr2(); \
- __get_user_internal(val, ptr); \
+ __get_user_internal("%%sr3,", val, ptr); \
})
-#define __get_user_asm(val, ldx, ptr) \
+#define __get_user_asm(sr, val, ldx, ptr) \
{ \
register long __gu_val; \
\
- __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \
+ __asm__("1: " ldx " 0(" sr "%2),%0\n" \
"9:\n" \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
: "=r"(__gu_val), "=r"(__gu_err) \
@@ -114,9 +92,22 @@ struct exception_table_entry {
(val) = (__force __typeof__(*(ptr))) __gu_val; \
}
+#define HAVE_GET_KERNEL_NOFAULT
+#define __get_kernel_nofault(dst, src, type, err_label) \
+{ \
+ type __z; \
+ long __err; \
+ __err = __get_user_internal("%%sr0,", __z, (type *)(src)); \
+ if (unlikely(__err)) \
+ goto err_label; \
+ else \
+ *(type *)(dst) = __z; \
+}
+
+
#if !defined(CONFIG_64BIT)
-#define __get_user_asm64(val, ptr) \
+#define __get_user_asm64(sr, val, ptr) \
{ \
union { \
unsigned long long l; \
@@ -124,8 +115,8 @@ struct exception_table_entry {
} __gu_tmp; \
\
__asm__(" copy %%r0,%R0\n" \
- "1: ldw 0(%%sr2,%2),%0\n" \
- "2: ldw 4(%%sr2,%2),%R0\n" \
+ "1: ldw 0(" sr "%2),%0\n" \
+ "2: ldw 4(" sr "%2),%R0\n" \
"9:\n" \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
@@ -138,16 +129,16 @@ struct exception_table_entry {
#endif /* !defined(CONFIG_64BIT) */
-#define __put_user_internal(x, ptr) \
+#define __put_user_internal(sr, x, ptr) \
({ \
register long __pu_err __asm__ ("r8") = 0; \
__typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
\
switch (sizeof(*(ptr))) { \
- case 1: __put_user_asm("stb", __x, ptr); break; \
- case 2: __put_user_asm("sth", __x, ptr); break; \
- case 4: __put_user_asm("stw", __x, ptr); break; \
- case 8: STD_USER(__x, ptr); break; \
+ case 1: __put_user_asm(sr, "stb", __x, ptr); break; \
+ case 2: __put_user_asm(sr, "sth", __x, ptr); break; \
+ case 4: __put_user_asm(sr, "stw", __x, ptr); break; \
+ case 8: STD_USER(sr, __x, ptr); break; \
default: BUILD_BUG(); \
} \
\
@@ -156,10 +147,20 @@ struct exception_table_entry {
#define __put_user(x, ptr) \
({ \
- load_sr2(); \
- __put_user_internal(x, ptr); \
+ __put_user_internal("%%sr3,", x, ptr); \
})
+#define __put_kernel_nofault(dst, src, type, err_label) \
+{ \
+ type __z = *(type *)(src); \
+ long __err; \
+ __err = __put_user_internal("%%sr0,", __z, (type *)(dst)); \
+ if (unlikely(__err)) \
+ goto err_label; \
+}
+
+
+
/*
* The "__put_user/kernel_asm()" macros tell gcc they read from memory
@@ -170,26 +171,26 @@ struct exception_table_entry {
* r8 is already listed as err.
*/
-#define __put_user_asm(stx, x, ptr) \
- __asm__ __volatile__ ( \
- "1: " stx " %2,0(%%sr2,%1)\n" \
- "9:\n" \
- ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
- : "=r"(__pu_err) \
+#define __put_user_asm(sr, stx, x, ptr) \
+ __asm__ __volatile__ ( \
+ "1: " stx " %2,0(" sr "%1)\n" \
+ "9:\n" \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
+ : "=r"(__pu_err) \
: "r"(ptr), "r"(x), "0"(__pu_err))
#if !defined(CONFIG_64BIT)
-#define __put_user_asm64(__val, ptr) do { \
- __asm__ __volatile__ ( \
- "1: stw %2,0(%%sr2,%1)\n" \
- "2: stw %R2,4(%%sr2,%1)\n" \
- "9:\n" \
- ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
- ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
- : "=r"(__pu_err) \
- : "r"(ptr), "r"(__val), "0"(__pu_err)); \
+#define __put_user_asm64(sr, __val, ptr) do { \
+ __asm__ __volatile__ ( \
+ "1: stw %2,0(" sr "%1)\n" \
+ "2: stw %R2,4(" sr "%1)\n" \
+ "9:\n" \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
+ : "=r"(__pu_err) \
+ : "r"(ptr), "r"(__val), "0"(__pu_err)); \
} while (0)
#endif /* !defined(CONFIG_64BIT) */
@@ -200,12 +201,11 @@ struct exception_table_entry {
*/
extern long strncpy_from_user(char *, const char __user *, long);
-extern unsigned lclear_user(void __user *, unsigned long);
+extern __must_check unsigned lclear_user(void __user *, unsigned long);
extern __must_check long strnlen_user(const char __user *src, long n);
/*
* Complex access routines -- macros
*/
-#define user_addr_max() (~0UL)
#define clear_user lclear_user
#define __clear_user lclear_user