linux-toradex.git/arch/microblaze/include/asm/uaccess.h, branch tegra

microblaze: Fix /dev/zero corruption from __clear_user()

2011-03-09T07:09:59+00:00

A userland read of more than PAGE_SIZE bytes from /dev/zero results in
(a) not all of the bytes returned being zero, and
(b) memory corruption due to zeroing of bytes beyond the user buffer.

This is caused by improper constraints on the assembly __clear_user function.
The constrints don't indicate to the compiler that the pointer argument is
modified. Since the function is inline, this results in double-incrementing
of the pointer when __clear_user() is invoked through a multi-page read() of
/dev/zero.

Signed-off-by: Steven J. Magnani 
Acked-by: Michal Simek 
CC: stable@kernel.org

microblaze: Fix __copy_to/from_user_inatomic macros

2010-08-02T08:44:03+00:00

__copy_to/from_user_inatomic should call __copy_to/from_user
because there is not necessary to check access because of kernel function.

might_sleep in copy_to/from_user macros is causing problems
in debug sessions too (CONFIG_DEBUG_SPINLOCK_SLEEP).

BUG: sleeping function called from invalid context at
.../arch/microblaze/include/asm/uaccess.h:388
in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper
1 lock held by swapper/1:
 #0:  (&p->cred_guard_mutex){......}, at: [] prepare_bprm_creds+0x2c/0x88
Kernel Stack:
...

Call Trace:
[] microblaze_unwind+0x7c/0x94
[] show_stack+0xf4/0x190
[] dump_stack+0x10/0x30
[] __might_sleep+0x12c/0x160
[] file_read_actor+0x1d8/0x2a8
[] generic_file_aio_read+0x6b4/0xa64
[] do_sync_read+0xac/0x110
[] vfs_read+0xc8/0x160
[] kernel_read+0x38/0x64
[] prepare_binprm+0xfc/0x130
[] do_execve+0x228/0x370
[] microblaze_execve+0x58/0xa4

caused by file_read_actor (mm/filemap.c) which calls
__copy_to_user_inatomic.

Signed-off-by: Michal Simek

microblaze: fix get_user/put_user side-effects

2010-05-13T07:21:14+00:00

The Microblaze implementations of get_user() and (MMU) put_user() evaluate
the address argument more than once. This causes unexpected side-effects for
invocations that include increment operators, i.e. get_user(foo, bar++).

This patch also removes the distinction between MMU and noMMU put_user().

Without the patch:
  $ echo 1234567890 > /proc/sys/kernel/core_pattern
  $ cat /proc/sys/kernel/core_pattern
  12345

Signed-off-by: Steven J. Magnani

microblaze: uaccess: Sync strlen, strnlen, copy_to/from_user

2010-04-01T06:38:23+00:00

Last sync.

Signed-off-by: Michal Simek

microblaze: uaccess: Unify __copy_tofrom_user

2010-04-01T06:38:22+00:00

Move to generic location.

Signed-off-by: Michal Simek

microblaze: uaccess: Move functions to generic location

2010-04-01T06:38:22+00:00

noMMU and MMU use them.

Signed-off-by: Michal Simek

microblaze: uaccess: Fix put_user for noMMU

2010-04-01T06:38:22+00:00

Here is small regression on dhrystone tests and I think
that on all benchmarking tests. It is due to better checking
mechanism in put_user macro

Signed-off-by: Michal Simek

microblaze: uaccess: Fix get_user macro for noMMU

2010-04-01T06:38:22+00:00

Use unified version.

Signed-off-by: Michal Simek

microblaze: uaccess: fix clear_user for noMMU kernel

2010-04-01T06:38:21+00:00

Previous patches fixed only MMU version and this is the first
patch for noMMU kernel

Signed-off-by: Michal Simek

microblaze: uaccess: Fix strncpy_from_user function

2010-04-01T06:38:21+00:00

Generic implementation for noMMU and MMU version

Signed-off-by: Michal Simek