linux.git/arch/s390/lib/uaccess_std.c, branch master

s390/uaccess: always run the kernel in home space

2013-10-24T15:16:57+00:00

Simplify the uaccess code by removing the user_mode=home option.
The kernel will now always run in the home space mode.

Signed-off-by: Martin Schwidefsky

s390/uaccess: fix strncpy_from_user string length check

2013-02-28T08:37:11+00:00

The "standard" and page table walk variants of strncpy_from_user() first
check the length of the to be copied string in userspace.
The string is then copied to kernel space and the length returned to the
caller.
However userspace can modify the string at any time while the kernel
checks for the length of the string or copies the string. In result the
returned length of the string is not necessarily correct.
Fix this by copying in a loop which mimics the mvcos variant of
strncpy_from_user(), which handles this correctly.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/uaccess: fix strncpy_from_user/strnlen_user zero maxlen case

2013-02-28T08:37:08+00:00

If the maximum length specified for the to be accessed string for
strncpy_from_user() and strnlen_user() is zero the following incorrect
values would be returned or incorrect memory accesses would happen:

strnlen_user_std() and strnlen_user_pt() incorrectly return "1"
strncpy_from_user_pt() would incorrectly access "dst[maxlen - 1]"
strncpy_from_user_mvcos() would incorrectly return "-EFAULT"

Fix all these oddities by adding early checks.

Reviewed-by: Gerald Schaefer 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/comments: unify copyright messages and remove file names

2012-07-20T09:15:04+00:00

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens

s390/headers: replace s390x with CONFIG_64BIT where possible

2012-05-24T08:10:10+00:00

Replace __s390x__ with CONFIG_64BIT in all places that are not exported
to userspace or guarded with #ifdef __KERNEL__.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

futex: Sanitize futex ops argument types

2011-03-11T11:23:31+00:00

Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic
prototypes to use u32 types for the futex as this is the data type the
futex core code uses all over the place.

Signed-off-by: Michel Lespinasse 
Cc: Darren Hart 
Cc: Peter Zijlstra 
Cc: Matt Turner 
Cc: Russell King 
Cc: David Howells 
Cc: Tony Luck 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: "James E.J. Bottomley" 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Paul Mundt 
Cc: "David S. Miller" 
Cc: Chris Metcalf 
Cc: Linus Torvalds 
LKML-Reference: <20110311025058.GD26122@google.com>
Signed-off-by: Thomas Gleixner

futex: Sanitize cmpxchg_futex_value_locked API

2011-03-11T11:23:08+00:00

The cmpxchg_futex_value_locked API was funny in that it returned either
the original, user-exposed futex value OR an error code such as -EFAULT.
This was confusing at best, and could be a source of livelocks in places
that retry the cmpxchg_futex_value_locked after trying to fix the issue
by running fault_in_user_writeable().
    
This change makes the cmpxchg_futex_value_locked API more similar to the
get_futex_value_locked one, returning an error code and updating the
original value through a reference argument.
    
Signed-off-by: Michel Lespinasse 
Acked-by: Chris Metcalf   [tile]
Acked-by: Tony Luck   [ia64]
Acked-by: Thomas Gleixner 
Tested-by: Michal Simek   [microblaze]
Acked-by: David Howells  [frv]
Cc: Darren Hart 
Cc: Peter Zijlstra 
Cc: Matt Turner 
Cc: Russell King 
Cc: Ralf Baechle 
Cc: "James E.J. Bottomley" 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Paul Mundt 
Cc: "David S. Miller" 
Cc: Linus Torvalds 
LKML-Reference: <20110311024851.GC26122@google.com>
Signed-off-by: Thomas Gleixner

[S390] missing sacf in uaccess

2011-01-31T10:30:20+00:00

The uaccess functions copy_in_user_std and clear_user_std fail to
switch back from secondary space mode to primary space mode with sacf
in case of an unresolvable page fault. We need to make sure that the
switch back to primary mode is done in all cases, otherwise the code
following the uaccess inline assembly will crash.

Reported-by: Alexander Graf 
Signed-off-by: Martin Schwidefsky

[S390] Add EX_TABLE for addressing exception in usercopy functions.

2009-10-06T08:35:10+00:00

This patch adds an EX_TABLE entry to mvc{p|s|os} usercopy functions that
may be called with KERNEL_DS. In combination with collaborative memory
management, kernel pages marked as unused may trigger an adressing exception
in the usercopy functions. This fixes an unhandled addressing exception bug
where strncpy_from_user() is used with len > strnlen and KERNEL_DS, crossing
a page boundary to an unused page.

Signed-off-by: Gerald Schaefer 
Signed-off-by: Martin Schwidefsky

[S390] Fix futex_atomic_cmpxchg_std inline assembly.

2008-02-19T14:29:35+00:00

Add missing exception table entry so that the kernel can handle
proctection exceptions as well on the cs instruction. Currently only
specification exceptions are handled correctly.
The missing entry allows user space to crash the kernel.

Cc: stable 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky