tile: get rid of zeroing, switch to RAW_COPY_USER

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/tile/Kconfig

@@ -33,6 +33,7 @@ config TILE
 	select USER_STACKTRACE_SUPPORT
 	select USE_PMC if PERF_EVENTS
 	select VIRT_TO_BUS
+	select ARCH_HAS_RAW_COPY_USER
 
 config MMU
 	def_bool y

arch/tile/include/asm/uaccess.h

@@ -313,145 +313,16 @@ extern int __put_user_bad(void)
 		((x) = 0, -EFAULT);					\
 })
 
-/**
- * __copy_to_user() - copy data into user space, with less checking.
- * @to:   Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from kernel space to user space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * An alternate version - __copy_to_user_inatomic() - is designed
- * to be called from atomic context, typically bracketed by calls
- * to pagefault_disable() and pagefault_enable().
- */
-extern unsigned long __must_check __copy_to_user_inatomic(
-	void __user *to, const void *from, unsigned long n);
-
-static inline unsigned long __must_check
-__copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-	might_fault();
-	return __copy_to_user_inatomic(to, from, n);
-}
-
-static inline unsigned long __must_check
-copy_to_user(void __user *to, const void *from, unsigned long n)
-{
-	if (access_ok(VERIFY_WRITE, to, n))
-		n = __copy_to_user(to, from, n);
-	return n;
-}
-
-/**
- * __copy_from_user() - copy data from user space, with less checking.
- * @to:   Destination address, in kernel space.
- * @from: Source address, in user space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to kernel space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * If some data could not be copied, this function will pad the copied
- * data to the requested size using zero bytes.
- *
- * An alternate version - __copy_from_user_inatomic() - is designed
- * to be called from atomic context, typically bracketed by calls
- * to pagefault_disable() and pagefault_enable().  This version
- * does *NOT* pad with zeros.
- */
-extern unsigned long __must_check __copy_from_user_inatomic(
-	void *to, const void __user *from, unsigned long n);
-extern unsigned long __must_check __copy_from_user_zeroing(
-	void *to, const void __user *from, unsigned long n);
-
-static inline unsigned long __must_check
-__copy_from_user(void *to, const void __user *from, unsigned long n)
-{
-       might_fault();
-       return __copy_from_user_zeroing(to, from, n);
-}
-
-static inline unsigned long __must_check
-_copy_from_user(void *to, const void __user *from, unsigned long n)
-{
-	if (access_ok(VERIFY_READ, from, n))
-		n = __copy_from_user(to, from, n);
-	else
-		memset(to, 0, n);
-	return n;
-}
-
-extern void __compiletime_error("usercopy buffer size is too small")
-__bad_copy_user(void);
-
-static inline void copy_user_overflow(int size, unsigned long count)
-{
-	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
-}
-
-static inline unsigned long __must_check copy_from_user(void *to,
-					  const void __user *from,
-					  unsigned long n)
-{
-	int sz = __compiletime_object_size(to);
-
-	if (likely(sz == -1 || sz >= n))
-		n = _copy_from_user(to, from, n);
-	else if (!__builtin_constant_p(n))
-		copy_user_overflow(sz, n);
-	else
-		__bad_copy_user();
-
-	return n;
-}
+extern unsigned long __must_check
+raw_copy_to_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __must_check
+raw_copy_from_user(void *to, const void __user *from, unsigned long n);
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
 
 #ifdef __tilegx__
-/**
- * __copy_in_user() - copy data within user space, with less checking.
- * @to:   Destination address, in user space.
- * @from: Source address, in user space.
- * @n:    Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to user space.  Caller must check
- * the specified blocks with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- */
-extern unsigned long __copy_in_user_inatomic(
+extern unsigned long raw_copy_in_user(
 	void __user *to, const void __user *from, unsigned long n);
-
-static inline unsigned long __must_check
-__copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
-	might_fault();
-	return __copy_in_user_inatomic(to, from, n);
-}
-
-static inline unsigned long __must_check
-copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
-	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
-		n = __copy_in_user(to, from, n);
-	return n;
-}
 #endif
 
 

arch/tile/lib/exports.c

@@ -38,11 +38,10 @@ EXPORT_SYMBOL(__mcount);
 
 /* arch/tile/lib/, various memcpy files */
 EXPORT_SYMBOL(memcpy);
-EXPORT_SYMBOL(__copy_to_user_inatomic);
-EXPORT_SYMBOL(__copy_from_user_inatomic);
-EXPORT_SYMBOL(__copy_from_user_zeroing);
+EXPORT_SYMBOL(raw_copy_to_user);
+EXPORT_SYMBOL(raw_copy_from_user);
 #ifdef __tilegx__
-EXPORT_SYMBOL(__copy_in_user_inatomic);
+EXPORT_SYMBOL(raw_copy_in_user);
 #endif
 
 /* hypervisor glue */

arch/tile/lib/memcpy_32.S

@@ -24,7 +24,6 @@
 
 #define IS_MEMCPY	  0
 #define IS_COPY_FROM_USER  1
-#define IS_COPY_FROM_USER_ZEROING  2
 #define IS_COPY_TO_USER   -1
 
 	.section .text.memcpy_common, "ax"
@@ -42,40 +41,31 @@
 	9
 
 
-/* __copy_from_user_inatomic takes the kernel target address in r0,
+/* raw_copy_from_user takes the kernel target address in r0,
  * the user source in r1, and the bytes to copy in r2.
  * It returns the number of uncopiable bytes (hopefully zero) in r0.
  */
-ENTRY(__copy_from_user_inatomic)
-.type __copy_from_user_inatomic, @function
-	FEEDBACK_ENTER_EXPLICIT(__copy_from_user_inatomic, \
+ENTRY(raw_copy_from_user)
+.type raw_copy_from_user, @function
+	FEEDBACK_ENTER_EXPLICIT(raw_copy_from_user, \
 	  .text.memcpy_common, \
-	  .Lend_memcpy_common - __copy_from_user_inatomic)
+	  .Lend_memcpy_common - raw_copy_from_user)
 	{ movei r29, IS_COPY_FROM_USER; j memcpy_common }
-	.size __copy_from_user_inatomic, . - __copy_from_user_inatomic
+	.size raw_copy_from_user, . - raw_copy_from_user
 
-/* __copy_from_user_zeroing is like __copy_from_user_inatomic, but
- * any uncopiable bytes are zeroed in the target.
- */
-ENTRY(__copy_from_user_zeroing)
-.type __copy_from_user_zeroing, @function
-	FEEDBACK_REENTER(__copy_from_user_inatomic)
-	{ movei r29, IS_COPY_FROM_USER_ZEROING; j memcpy_common }
-	.size __copy_from_user_zeroing, . - __copy_from_user_zeroing
-
-/* __copy_to_user_inatomic takes the user target address in r0,
+/* raw_copy_to_user takes the user target address in r0,
  * the kernel source in r1, and the bytes to copy in r2.
  * It returns the number of uncopiable bytes (hopefully zero) in r0.
  */
-ENTRY(__copy_to_user_inatomic)
-.type __copy_to_user_inatomic, @function
-	FEEDBACK_REENTER(__copy_from_user_inatomic)
+ENTRY(raw_copy_to_user)
+.type raw_copy_to_user, @function
+	FEEDBACK_REENTER(raw_copy_from_user)
 	{ movei r29, IS_COPY_TO_USER; j memcpy_common }
-	.size __copy_to_user_inatomic, . - __copy_to_user_inatomic
+	.size raw_copy_to_user, . - raw_copy_to_user
 
 ENTRY(memcpy)
 .type memcpy, @function
-	FEEDBACK_REENTER(__copy_from_user_inatomic)
+	FEEDBACK_REENTER(raw_copy_from_user)
 	{ movei r29, IS_MEMCPY }
 	.size memcpy, . - memcpy
 	/* Fall through */
@@ -520,12 +510,7 @@ copy_from_user_fixup_loop:
 	{ bnzt r2, copy_from_user_fixup_loop }
 
 .Lcopy_from_user_fixup_zero_remainder:
-	{ bbs r29, 2f }  /* low bit set means IS_COPY_FROM_USER */
-	/* byte-at-a-time loop faulted, so zero the rest. */
-	{ move r3, r2; bz r2, 2f /* should be impossible, but handle it. */ }
-1:      { sb r0, zero; addi r0, r0, 1; addi r3, r3, -1 }
-	{ bnzt r3, 1b }
-2:	move lr, r27
+	move lr, r27
 	{ move r0, r2; jrp lr }
 
 copy_to_user_fixup_loop:

arch/tile/lib/memcpy_user_64.c

@@ -51,7 +51,7 @@
 		__v;						\
 	})
 
-#define USERCOPY_FUNC __copy_to_user_inatomic
+#define USERCOPY_FUNC raw_copy_to_user
 #define ST1(p, v) _ST((p), st1, (v))
 #define ST2(p, v) _ST((p), st2, (v))
 #define ST4(p, v) _ST((p), st4, (v))
@@ -62,7 +62,7 @@
 #define LD8 LD
 #include "memcpy_64.c"
 
-#define USERCOPY_FUNC __copy_from_user_inatomic
+#define USERCOPY_FUNC raw_copy_from_user
 #define ST1 ST
 #define ST2 ST
 #define ST4 ST
@@ -73,7 +73,7 @@
 #define LD8(p) _LD((p), ld)
 #include "memcpy_64.c"
 
-#define USERCOPY_FUNC __copy_in_user_inatomic
+#define USERCOPY_FUNC raw_copy_in_user
 #define ST1(p, v) _ST((p), st1, (v))
 #define ST2(p, v) _ST((p), st2, (v))
 #define ST4(p, v) _ST((p), st4, (v))
@@ -83,12 +83,3 @@
 #define LD4(p) _LD((p), ld4u)
 #define LD8(p) _LD((p), ld)
 #include "memcpy_64.c"
-
-unsigned long __copy_from_user_zeroing(void *to, const void __user *from,
-				       unsigned long n)
-{
-	unsigned long rc = __copy_from_user_inatomic(to, from, n);
-	if (unlikely(rc))
-		memset(to + n - rc, 0, rc);
-	return rc;
-}