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s390/uaccess: remove uaccess_primary kernel parameter 

get_user() and put_user() are inline functions in the meantime
again. Both will generate the mvcos instruction if compiled
with -march=z10 (or greater).

The kernel parameter "uaccess_primary" can only change the behavior
of out-of-line uaccess functions like copy_from_user() to not use
the mvcos instruction, but not for the above named inlined functions.

Therefore it is quite useless and the parameter can be removed.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2015-08-13 13:44:34 +02:00 committed by Martin Schwidefsky
parent 92d6289105
commit cabc4abe8e
1 changed files with 1 additions and 14 deletions
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15
arch/s390/lib/uaccess.c
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@ -370,22 +370,9 @@ long __strncpy_from_user(char *dst, const char __user *src, long size)
}
EXPORT_SYMBOL(__strncpy_from_user);
/*
* The "old" uaccess variant without mvcos can be enforced with the
* uaccess_primary kernel parameter. This is mainly for debugging purposes.
*/
static int uaccess_primary __initdata;
static int __init parse_uaccess_pt(char *__unused)
{
uaccess_primary = 1;
return 0;
}
early_param("uaccess_primary", parse_uaccess_pt);
static int __init uaccess_init(void)
{
if (!uaccess_primary && test_facility(27))
if (test_facility(27))
static_key_slow_inc(&have_mvcos);
return 0;
}