linux-toradex.git/arch/s390/lib/uaccess_pt.c, branch v3.0.7

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] Use do_exception() in pagetable walk usercopy functions.

2009-12-07T11:51:34+00:00

The pagetable walk usercopy functions have used a modified copy of the
do_exception() function for fault handling. This lead to inconsistencies
with recent changes to do_exception(), e.g. performance counters. This
patch changes the pagetable walk usercopy code to call do_exception()
directly, eliminating the redundancy. A new parameter is added to
do_exception() to specify the fault address.

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

Move FAULT_FLAG_xyz into handle_mm_fault() callers

2009-06-21T20:08:22+00:00

This allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault().  All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.

Signed-off-by: Linus Torvalds

[S390] Dont check for pfn_valid() in uaccess_pt.c

2009-03-18T12:28:13+00:00

pfn_valid() actually checks for a valid struct page and not for a
valid pfn. Using xip mappings w/o struct pages, this will result in
-EFAULT returned by the (page table walk) user copy functions,
even though there is valid memory. Those user copy functions don't
need a struct page, so this patch just removes the pfn_valid() check.

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

[S390] uaccess: Always access the correct address space.

2008-04-17T05:47:06+00:00

The current uaccess page table walk code assumes at a few places that
any access is a user space access. This is not correct if somebody
has issued a set_fs(KERNEL_DS) in advance.
Add code which checks which address space we are in and with this make
sure we access the correct address space. This way we get also rid of
the dirty
if (!currrent-mm)
	return -EFAULT;
hack in futex_atomic_cmpxchg_pt.

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

[S390] futex: let futex_atomic_cmpxchg_pt survive early functional tests.

2008-03-20T16:33:46+00:00

a0c1e9073ef7428a14309cba010633a6cd6719ea "futex: runtime enable pi and
robust functionality" introduces a test wether futex in atomic stuff
works or not.
It does that by writing to address 0 of the kernel address space. This
will crash on older machines where addressing mode switching is enabled
but where the mvcos instruction is not available. Page table walking is
done by hand and therefore the code tries to access current->mm which
is NULL.
Therefore add an extra check, so we survive the early test.

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

[S390] 4level-fixup cleanup

2007-10-22T10:52:49+00:00

Get independent from asm-generic/4level-fixup.h

Signed-off-by: Martin Schwidefsky

[S390] Introduce follow_table in uaccess_pt.c

2007-10-22T10:52:49+00:00

Define and use follow_table inline in uaccess_pt.c to simplify
the code.

Signed-off-by: Martin Schwidefsky

pid namespaces: define is_global_init() and is_container_init()

2007-10-19T18:53:37+00:00

is_init() is an ambiguous name for the pid==1 check.  Split it into
is_global_init() and is_container_init().

A cgroup init has it's tsk->pid == 1.

A global init also has it's tsk->pid == 1 and it's active pid namespace
is the init_pid_ns.  But rather than check the active pid namespace,
compare the task structure with 'init_pid_ns.child_reaper', which is
initialized during boot to the /sbin/init process and never changes.

Changelog:

	2.6.22-rc4-mm2-pidns1:
	- Use 'init_pid_ns.child_reaper' to determine if a given task is the
	  global init (/sbin/init) process. This would improve performance
	  and remove dependence on the task_pid().

	2.6.21-mm2-pidns2:

	- [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc,
	  ppc,avr32}/traps.c for the _exception() call to is_global_init().
	  This way, we kill only the cgroup if the cgroup's init has a
	  bug rather than force a kernel panic.

[akpm@linux-foundation.org: fix comment]
[sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c]
[bunk@stusta.de: kernel/pid.c: remove unused exports]
[sukadev@us.ibm.com: Fix capability.c to work with threaded init]
Signed-off-by: Serge E. Hallyn 
Signed-off-by: Sukadev Bhattiprolu 
Acked-by: Pavel Emelianov 
Cc: Eric W. Biederman 
Cc: Cedric Le Goater 
Cc: Dave Hansen 
Cc: Herbert Poetzel 
Cc: Kirill Korotaev 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds