Commit 37096003 authored by Al Viro's avatar Al Viro
Browse files

s390: get rid of zeroing, switch to RAW_COPY_USER 



[folded a fix from Martin]
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e70f1d59

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -178,6 +178,7 @@ config S390 
	select ARCH_HAS_SCALED_CPUTIME

	select VIRT_TO_BUS

	select HAVE_NMI

	select ARCH_HAS_RAW_COPY_USER





config SCHED_OMIT_FRAME_POINTER

arch/s390/include/asm/uaccess.h

+9 −111
Original line number Diff line number Diff line
@@ -60,47 +60,14 @@ static inline int __range_ok(unsigned long addr, unsigned long size) 


#define access_ok(type, addr, size) __access_ok(addr, size)



/**

 * __copy_from_user: - Copy a block of 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.

 */

unsigned long __must_check __copy_from_user(void *to, const void __user *from,

					    unsigned long n);

unsigned long __must_check

raw_copy_from_user(void *to, const void __user *from, unsigned long n);



/**

 * __copy_to_user: - Copy a block of 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.

 */

unsigned long __must_check __copy_to_user(void __user *to, const void *from,

					  unsigned long n);

unsigned long __must_check

raw_copy_to_user(void __user *to, const void *from, unsigned long n);



#define __copy_to_user_inatomic __copy_to_user

#define __copy_from_user_inatomic __copy_from_user

#define INLINE_COPY_FROM_USER

#define INLINE_COPY_TO_USER



#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
@@ -189,13 +156,13 @@ static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long s 


static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)

{

	size = __copy_to_user(ptr, x, size);

	size = raw_copy_to_user(ptr, x, size);

	return size ? -EFAULT : 0;

}



static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)

{

	size = __copy_from_user(x, ptr, size);

	size = raw_copy_from_user(x, ptr, size);

	return size ? -EFAULT : 0;

}
@@ -285,77 +252,8 @@ int __get_user_bad(void) __attribute__((noreturn)); 
#define __put_user_unaligned __put_user

#define __get_user_unaligned __get_user



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);

}



/**

 * copy_to_user: - Copy a block of data into user space.

 * @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.

 *

 * Returns number of bytes that could not be copied.

 * On success, this will be zero.

 */

static inline unsigned long __must_check

copy_to_user(void __user *to, const void *from, unsigned long n)

{

	might_fault();

	return __copy_to_user(to, from, n);

}



/**

 * copy_from_user: - Copy a block of data from user space.

 * @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.

 *

 * 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.

 */

static inline unsigned long __must_check

copy_from_user(void *to, const void __user *from, unsigned long n)

{

	unsigned int sz = __compiletime_object_size(to);



	might_fault();

	if (unlikely(sz != -1 && sz < n)) {

		if (!__builtin_constant_p(n))

			copy_user_overflow(sz, n);

		else

			__bad_copy_user();

		return n;

	}

	return __copy_from_user(to, from, n);

}



unsigned long __must_check

__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(to, from, n);

}

raw_copy_in_user(void __user *to, const void __user *from, unsigned long n);



/*

 * Copy a null terminated string from userspace.

arch/s390/lib/uaccess.c

+23 −45
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr 
	tmp1 = -4096UL;

	asm volatile(

		"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"

		"9: jz    7f\n"

		"6: jz    4f\n"

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

		"   slgr  %1,%3\n"

		"   slgr  %2,%3\n"
@@ -35,23 +35,13 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr 
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */

		"   slgr  %4,%1\n"

		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */

		"   jnh   4f\n"

		"   jnh   5f\n"

		"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"

		"10:slgr  %0,%4\n"

		"   algr  %2,%4\n"

		"4: lghi  %4,-1\n"

		"   algr  %4,%0\n"	/* copy remaining size, subtract 1 */

		"   bras  %3,6f\n"	/* memset loop */

		"   xc    0(1,%2),0(%2)\n"

		"5: xc    0(256,%2),0(%2)\n"

		"   la    %2,256(%2)\n"

		"6: aghi  %4,-256\n"

		"   jnm   5b\n"

		"   ex    %4,0(%3)\n"

		"   j     8f\n"

		"7: slgr  %0,%0\n"

		"8:\n"

		EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)

		"7: slgr  %0,%4\n"

		"   j     5f\n"

		"4: slgr  %0,%0\n"

		"5:\n"

		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)

		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)

		: "d" (reg0) : "cc", "memory");

	return size;
@@ -67,49 +57,38 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, 
	asm volatile(

		"   sacf  0\n"

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

		"10:jz    8f\n"

		"7: jz    5f\n"

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

		"   la    %1,256(%1)\n"

		"   la    %2,256(%2)\n"

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

		"11:jnz   1b\n"

		"   j     8f\n"

		"8: jnz   1b\n"

		"   j     5f\n"

		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */

		"   lghi  %3,-4096\n"

		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */

		"   slgr  %4,%1\n"

		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */

		"   jnh   5f\n"

		"   jnh   6f\n"

		"4: mvcp  0(%4,%2),0(%1),%3\n"

		"12:slgr  %0,%4\n"

		"   algr  %2,%4\n"

		"5: lghi  %4,-1\n"

		"   algr  %4,%0\n"	/* copy remaining size, subtract 1 */

		"   bras  %3,7f\n"	/* memset loop */

		"   xc    0(1,%2),0(%2)\n"

		"6: xc    0(256,%2),0(%2)\n"

		"   la    %2,256(%2)\n"

		"7: aghi  %4,-256\n"

		"   jnm   6b\n"

		"   ex    %4,0(%3)\n"

		"   j     9f\n"

		"8: slgr  %0,%0\n"

		"9: sacf  768\n"

		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)

		EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)

		"9: slgr  %0,%4\n"

		"   j     6f\n"

		"5: slgr  %0,%0\n"

		"6: sacf  768\n"

		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)

		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)

		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)

		: : "cc", "memory");

	return size;

}



unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)

unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)

{

	check_object_size(to, n, false);

	if (static_branch_likely(&have_mvcos))

		return copy_from_user_mvcos(to, from, n);

	return copy_from_user_mvcp(to, from, n);

}

EXPORT_SYMBOL(__copy_from_user);

EXPORT_SYMBOL(raw_copy_from_user);



static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,

					       unsigned long size)
@@ -176,14 +155,13 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, 
	return size;

}



unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)

unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)

{

	check_object_size(from, n, true);

	if (static_branch_likely(&have_mvcos))

		return copy_to_user_mvcos(to, from, n);

	return copy_to_user_mvcs(to, from, n);

}

EXPORT_SYMBOL(__copy_to_user);

EXPORT_SYMBOL(raw_copy_to_user);



static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,

					       unsigned long size)
@@ -240,13 +218,13 @@ static inline unsigned long copy_in_user_mvc(void __user *to, const void __user 
	return size;

}



unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)

unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)

{

	if (static_branch_likely(&have_mvcos))

		return copy_in_user_mvcos(to, from, n);

	return copy_in_user_mvc(to, from, n);

}

EXPORT_SYMBOL(__copy_in_user);

EXPORT_SYMBOL(raw_copy_in_user);



static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)

{