Commit 0cd11518 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

csky: use generic strncpy/strnlen from_user 



Remove the csky implemenation of strncpy/strnlen and instead use the
generic versions.  The csky version is fairly slow because it always does
byte accesses even for aligned data, and it lacks a checks for
user_addr_max().

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent c52801a7

arch/csky/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ config CSKY 
	select GENERIC_IRQ_MULTI_HANDLER

	select GENERIC_SCHED_CLOCK

	select GENERIC_SMP_IDLE_THREAD

	select GENERIC_STRNCPY_FROM_USER

	select GENERIC_STRNLEN_USER

	select GENERIC_TIME_VSYSCALL

	select GENERIC_VDSO_32

	select GENERIC_GETTIMEOFDAY

arch/csky/include/asm/uaccess.h

+0 −6
Original line number Diff line number Diff line
@@ -209,12 +209,6 @@ unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n); 
unsigned long __clear_user(void __user *to, unsigned long n);

#define __clear_user __clear_user



long strncpy_from_user(char *dst, const char *src, long count);

#define strncpy_from_user strncpy_from_user



long strnlen_user(const char *s, long n);

#define strnlen_user strnlen_user



#include <asm/segment.h>

#include <asm-generic/uaccess.h>

arch/csky/lib/usercopy.c

+0 −108
Original line number Diff line number Diff line
@@ -142,114 +142,6 @@ unsigned long raw_copy_to_user(void *to, const void *from, 
}

EXPORT_SYMBOL(raw_copy_to_user);



/*

 * __strncpy_from_user: - Copy a NUL terminated string from userspace,

 * with less checking.

 * @dst:   Destination address, in kernel space.  This buffer must be at

 *         least @count bytes long.

 * @src:   Source address, in user space.

 * @count: Maximum number of bytes to copy, including the trailing NUL.

 *

 * Copies a NUL-terminated string from userspace to kernel space.

 * Caller must check the specified block with access_ok() before calling

 * this function.

 *

 * On success, returns the length of the string (not including the trailing

 * NUL).

 *

 * If access to userspace fails, returns -EFAULT (some data may have been

 * copied).

 *

 * If @count is smaller than the length of the string, copies @count bytes

 * and returns @count.

 */

long strncpy_from_user(char *dst, const char *src, long count)

{

	long res, faultres;

	int tmp;



	if (!access_ok(s, 1))

		return -EFAULT;



	__asm__ __volatile__(

	"       cmpnei  %3, 0           \n"

	"       bf      4f              \n"

	"1:     cmpnei  %1, 0          	\n"

	"       bf      5f              \n"

	"2:     ldb     %4, (%3, 0)     \n"

	"       stb     %4, (%2, 0)     \n"

	"       cmpnei  %4, 0           \n"

	"       bf      3f              \n"

	"       addi    %3,  1          \n"

	"       addi    %2,  1          \n"

	"       subi    %1,  1          \n"

	"       br      1b              \n"

	"3:     subu	%0, %1          \n"

	"       br      5f              \n"

	"4:     mov     %0, %5          \n"

	"       br      5f              \n"

	".section __ex_table, \"a\"     \n"

	".align   2                     \n"

	".long    2b, 4b                \n"

	".previous                      \n"

	"5:                             \n"

	: "=r"(res), "=r"(count), "=r"(dst),

	  "=r"(src), "=r"(tmp), "=r"(faultres)

	: "5"(-EFAULT), "0"(count), "1"(count),

	  "2"(dst), "3"(src)

	: "memory");



	return res;

}

EXPORT_SYMBOL(strncpy_from_user);



/*

 * strnlen_user: - Get the size of a string in user space.

 * @str: The string to measure.

 * @n:   The maximum valid length

 *

 * Get the size of a NUL-terminated string in user space.

 *

 * Returns the size of the string INCLUDING the terminating NUL.

 * On exception, returns 0.

 * If the string is too long, returns a value greater than @n.

 */

long strnlen_user(const char *s, long n)

{

	unsigned long res, tmp;



	if (!access_ok(s, 1))

		return -EFAULT;



	__asm__ __volatile__(

	"       cmpnei  %1, 0           \n"

	"       bf      3f              \n"

	"1:     cmpnei  %0, 0           \n"

	"       bf      3f              \n"

	"2:     ldb     %3, (%1, 0)     \n"

	"       cmpnei  %3, 0           \n"

	"       bf      3f              \n"

	"       subi    %0,  1          \n"

	"       addi    %1,  1          \n"

	"       br      1b              \n"

	"3:     subu    %2, %0          \n"

	"       addi    %2,  1          \n"

	"       br      5f              \n"

	"4:     movi    %0, 0           \n"

	"       br      5f              \n"

	".section __ex_table, \"a\"     \n"

	".align   2                     \n"

	".long    2b, 4b                \n"

	".previous                      \n"

	"5:                             \n"

	: "=r"(n), "=r"(s), "=r"(res), "=r"(tmp)

	: "0"(n), "1"(s), "2"(n)

	: "memory");



	return res;

}

EXPORT_SYMBOL(strnlen_user);



/*

 * __clear_user: - Zero a block of memory in user space, with less checking.

 * @to:   Destination address, in user space.