Merge branch 'asm-generic-uaccess-7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic into asm-generic

These two functions appear to be unnecessarily different between
architectures, and the asm-generic version is a bit questionable,
even for NOMMU architectures.

Clean this up to just use the generic library version for anything
that uses the generic version today. I've expanded on the patch
descriptions a little, as suggested by Christoph Hellwig, but I
suspect a more detailed review would uncover additional problems
with the custom versions that are getting removed.

I ended up adding patches for csky and microblaze as they had the
same implementation that I removed elsewhere, these are now gone
as well.

* 'asm-generic-uaccess-7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: reverse GENERIC_{STRNCPY_FROM,STRNLEN}_USER symbols
  asm-generic: remove extra strn{cpy_from,len}_user declarations
  asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user
  s390: use generic strncpy/strnlen from_user
  microblaze: use generic strncpy/strnlen from_user
  csky: use generic strncpy/strnlen from_user
  arc: use generic strncpy/strnlen from_user
  hexagon: use generic strncpy/strnlen from_user
  h8300: remove stale strncpy_from_user
  asm-generic/uaccess.h: remove __strncpy_from_user/__strnlen_user

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: arndb

arch/alpha/Kconfig

@@ -29,8 +29,6 @@ config ALPHA
 	select AUDIT_ARCH
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA

arch/arc/include/asm/uaccess.h

@@ -655,88 +655,16 @@ static inline unsigned long __arc_clear_user(void __user *to, unsigned long n)
 	return res;
 }
 
-static inline long
-__arc_strncpy_from_user(char *dst, const char __user *src, long count)
-{
-	long res = 0;
-	char val;
-
-	if (count == 0)
-		return 0;
-
-	__asm__ __volatile__(
-	"	mov	lp_count, %5		\n"
-	"	lp	3f			\n"
-	"1:	ldb.ab  %3, [%2, 1]		\n"
-	"	breq.d	%3, 0, 3f               \n"
-	"	stb.ab  %3, [%1, 1]		\n"
-	"	add	%0, %0, 1	# Num of NON NULL bytes copied	\n"
-	"3:								\n"
-	"	.section .fixup, \"ax\"		\n"
-	"	.align 4			\n"
-	"4:	mov %0, %4		# sets @res as -EFAULT	\n"
-	"	j   3b				\n"
-	"	.previous			\n"
-	"	.section __ex_table, \"a\"	\n"
-	"	.align 4			\n"
-	"	.word   1b, 4b			\n"
-	"	.previous			\n"
-	: "+r"(res), "+r"(dst), "+r"(src), "=r"(val)
-	: "g"(-EFAULT), "r"(count)
-	: "lp_count", "memory");
-
-	return res;
-}
-
-static inline long __arc_strnlen_user(const char __user *s, long n)
-{
-	long res, tmp1, cnt;
-	char val;
-
-	__asm__ __volatile__(
-	"	mov %2, %1			\n"
-	"1:	ldb.ab  %3, [%0, 1]		\n"
-	"	breq.d  %3, 0, 2f		\n"
-	"	sub.f   %2, %2, 1		\n"
-	"	bnz 1b				\n"
-	"	sub %2, %2, 1			\n"
-	"2:	sub %0, %1, %2			\n"
-	"3:	;nop				\n"
-	"	.section .fixup, \"ax\"		\n"
-	"	.align 4			\n"
-	"4:	mov %0, 0			\n"
-	"	j   3b				\n"
-	"	.previous			\n"
-	"	.section __ex_table, \"a\"	\n"
-	"	.align 4			\n"
-	"	.word 1b, 4b			\n"
-	"	.previous			\n"
-	: "=r"(res), "=r"(tmp1), "=r"(cnt), "=r"(val)
-	: "0"(s), "1"(n)
-	: "memory");
-
-	return res;
-}
-
 #ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
 
 #define INLINE_COPY_TO_USER
 #define INLINE_COPY_FROM_USER
 
 #define __clear_user(d, n)		__arc_clear_user(d, n)
-#define __strncpy_from_user(d, s, n)	__arc_strncpy_from_user(d, s, n)
-#define __strnlen_user(s, n)		__arc_strnlen_user(s, n)
 #else
 extern unsigned long arc_clear_user_noinline(void __user *to,
 		unsigned long n);
-extern long arc_strncpy_from_user_noinline (char *dst, const char __user *src,
-		long count);
-extern long arc_strnlen_user_noinline(const char __user *src, long n);
-
 #define __clear_user(d, n)		arc_clear_user_noinline(d, n)
-#define __strncpy_from_user(d, s, n)	arc_strncpy_from_user_noinline(d, s, n)
-#define __strnlen_user(s, n)		arc_strnlen_user_noinline(s, n)
-
 #endif
 
 #include <asm/segment.h>

arch/arc/mm/extable.c

@@ -32,16 +32,4 @@ unsigned long arc_clear_user_noinline(void __user *to,
 }
 EXPORT_SYMBOL(arc_clear_user_noinline);
 
-long arc_strncpy_from_user_noinline(char *dst, const char __user *src,
-		long count)
-{
-	return __arc_strncpy_from_user(dst, src, count);
-}
-EXPORT_SYMBOL(arc_strncpy_from_user_noinline);
-
-long arc_strnlen_user_noinline(const char __user *src, long n)
-{
-	return __arc_strnlen_user(src, n);
-}
-EXPORT_SYMBOL(arc_strnlen_user_noinline);
 #endif

arch/arm/Kconfig

@@ -63,8 +63,6 @@ config ARM
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT

arch/arm64/Kconfig

@@ -130,8 +130,6 @@ config ARM64
 	select GENERIC_PTDUMP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_STRNCPY_FROM_USER
-	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_VDSO_TIME_NS

arch/csky/include/asm/uaccess.h

@@ -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

@@ -142,108 +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;
-
-	__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;
-
-	__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.

arch/h8300/kernel/h8300_ksyms.c

@@ -19,7 +19,6 @@ asmlinkage long __mulsi3(long, long);
 asmlinkage long __udivsi3(long, long);
 asmlinkage void *memcpy(void *, const void *, size_t);
 asmlinkage void *memset(void *, int, size_t);
-asmlinkage long strncpy_from_user(void *to, void *from, size_t n);
 
 	/* gcc lib functions */
 EXPORT_SYMBOL(__ucmpdi2);
@@ -34,4 +33,3 @@ EXPORT_SYMBOL(__mulsi3);
 EXPORT_SYMBOL(__udivsi3);
 EXPORT_SYMBOL(memcpy);
 EXPORT_SYMBOL(memset);
-EXPORT_SYMBOL(strncpy_from_user);

arch/h8300/lib/Makefile

@@ -3,7 +3,7 @@
 # Makefile for H8/300-specific library files..
 #
 
-lib-y  = memcpy.o memset.o abs.o strncpy.o \
+lib-y  = memcpy.o memset.o abs.o \
 	 mulsi3.o udivsi3.o muldi3.o moddivsi3.o \
 	 ashldi3.o lshrdi3.o ashrdi3.o ucmpdi2.o \
 	 delay.o