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[S390] Add dynamic size check for usercopy functions.

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Use a wrapper for copy_to/from_user to chose the best usercopy method.
The mvcos instruction is better for sizes greater than 256 bytes, if
mvcos is not available a page table walk is better for sizes greater
than 1024 bytes. Also removed the redundant copy_to/from_user_std_small
functions.

Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Gerald Schaefer
2006-12-04 15:40:45 +01:00
committed by Martin Schwidefsky
parent d57de5a367
commit 59f35d53fd
4 changed files with 190 additions and 59 deletions
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27
arch/s390/lib/uaccess_mvcos.c
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@ -27,6 +27,9 @@
#define SLR "slgr"
#endif
extern size_t copy_from_user_std(size_t, const void __user *, void *);
extern size_t copy_to_user_std(size_t, void __user *, const void *);
size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
{
register unsigned long reg0 asm("0") = 0x81UL;
@ -66,6 +69,13 @@ size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
return size;
}
size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x)
{
if (size <= 256)
return copy_from_user_std(size, ptr, x);
return copy_from_user_mvcos(size, ptr, x);
}
size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
{
register unsigned long reg0 asm("0") = 0x810000UL;
@ -95,6 +105,13 @@ size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
return size;
}
size_t copy_to_user_mvcos_check(size_t size, void __user *ptr, const void *x)
{
if (size <= 256)
return copy_to_user_std(size, ptr, x);
return copy_to_user_mvcos(size, ptr, x);
}
size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from)
{
register unsigned long reg0 asm("0") = 0x810081UL;
@ -145,18 +162,16 @@ size_t clear_user_mvcos(size_t size, void __user *to)
return size;
}
extern size_t copy_from_user_std_small(size_t, const void __user *, void *);
extern size_t copy_to_user_std_small(size_t, void __user *, const void *);
extern size_t strnlen_user_std(size_t, const char __user *);
extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
extern int futex_atomic_op(int, int __user *, int, int *);
extern int futex_atomic_cmpxchg(int __user *, int, int);
struct uaccess_ops uaccess_mvcos = {
.copy_from_user = copy_from_user_mvcos,
.copy_from_user_small = copy_from_user_std_small,
.copy_to_user = copy_to_user_mvcos,
.copy_to_user_small = copy_to_user_std_small,
.copy_from_user = copy_from_user_mvcos_check,
.copy_from_user_small = copy_from_user_std,
.copy_to_user = copy_to_user_mvcos_check,
.copy_to_user_small = copy_to_user_std,
.copy_in_user = copy_in_user_mvcos,
.clear_user = clear_user_mvcos,
.strnlen_user = strnlen_user_std,