Commit cabc4abe authored Aug 13, 2015 by Heiko Carstens Committed by Martin Schwidefsky Aug 19, 2015

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>

parent 92d62891

arch/s390/lib/uaccess.c

+1 −14

Original line number	Diff line number	Diff line
		@@ -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;
		}

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