linux.git/include/asm-mips/uaccess.h, branch v2.6.22

[MIPS] Export __copy_user_inatomic.

2007-03-07T00:07:17+00:00

Signed-off-by: Ralf Baechle

[MIPS] Fixup copy_from_user_inatomic

2007-02-20T01:26:42+00:00

From the 01408c4939479ec46c15aa7ef6e2406be50eeeca log message:

The problem is that when we write to a file, the copy from userspace to
pagecache is first done with preemption disabled, so if the source
address is not immediately available the copy fails *and* *zeros* *the*
*destination*.

This is a problem because a concurrent read (which admittedly is an odd
thing to do) might see zeros rather that was there before the write, or
what was there after, or some mixture of the two (any of these being a
reasonable thing to see).

If the copy did fail, it will immediately be retried with preemption
re-enabled so any transient problem with accessing the source won't
cause an error.

The first copying does not need to zero any uncopied bytes, and doing
so causes the problem.  It uses copy_from_user_atomic rather than
copy_from_user so the simple expedient is to change copy_from_user_atomic
to *not* zero out bytes on failure.

< --- end cite --- >

This patch finally implements at least a not so pretty solution by
duplicating the relevant part of __copy_user.

Signed-off-by: Ralf Baechle

[MIPS] Remove stray instruction from __get_user_asm_ll32.

2007-02-13T22:40:51+00:00

This did result in double clearing of the error return value on success
only but should make a meassurable overhead for sigreturn.

Signed-off-by: Ralf Baechle

[MIPS] 32-bit: Fix warning about cast for fetching pointer from userspace.

2007-02-13T22:40:51+00:00

Signed-off-by: Ralf Baechle

Revert "[MIPS] Fix warning in get_user when fetching pointer object from userspace."

2007-02-13T22:40:50+00:00

This reverts commit 4ed3a77f38c023658784804cb39a7ce18063dc88.

[MIPS] Fix warning in get_user when fetching pointer object from userspace.

2007-02-10T22:38:44+00:00

Signed-off-by: Ralf Baechle

[MIPS] Comment fix

2007-02-06T16:53:24+00:00

Signed-off-by: Chris Dearman 
Signed-off-by: Ralf Baechle

Don't include linux/config.h from anywhere else in include/

2006-04-26T11:56:16+00:00

Signed-off-by: David Woodhouse

[MIPS] Fixes for uaccess.h with gcc >= 4.0.1

2006-02-21T16:58:22+00:00

    
It seems current get_user() incorrectly sign-extend an unsigned int
value on 64bit kernel.  I think this is because '(__typeof__(val))'
cast in final assignment.  I suppose the cast should be
'(__typeof__(*(addr))'.
    
Signed-off-by: Atsushi Nemoto 
Signed-off-by: Ralf Baechle

[MIPS] More uaccess.h fixes with gcc >= 4.0.1.

2006-02-14T19:13:24+00:00

    
From Richard Sandiford :
    
This patch caused a miscompilation of the restore_gp_regs() block
in restore_sigcontext().  This was in a 32-bit kernel compiled with
GCC CVS head.
    
restore_gp_regs() copies 64-bit user fields into 32-bit variables,
and in this combination, the new __get_user_asm_ll32() clobbers too
many registers.  It says:
    
/*
 * Get a long long 64 using 32 bit registers.
 */
{									\
	__asm__ __volatile__(						\
	"1:	lw	%1, (%3)				\n"	\
	"2:	lw	%D1, 4(%3)				\n"	\
	"	move	%0, $0					\n"	\
	"3:	.section	.fixup,\"ax\"			\n"	\
	"4:	li	%0, %4					\n"	\
	"	move	%1, $0					\n"	\
	"	move	%D1, $0					\n"	\
	"	j	3b					\n"	\
	"	.previous					\n"	\
	"	.section	__ex_table,\"a\"		\n"	\
	"	" __UA_ADDR "	1b, 4b				\n"	\
	"	" __UA_ADDR "	2b, 4b				\n"	\
	"	.previous					\n"	\
	: "=r" (__gu_err), "=&r" (val)					\
	: "0" (0), "r" (addr), "i" (-EFAULT));				\
}

and this requires val (%1) to be a 64-bit value.  In the case I saw,
gcc was using $3 for the 32-bit val, and wasn't expecting $4 to be
clobbered.

Signed-off-by: Ralf Baechle