user/sven/linux.git, branch v3.10.56

Linux 3.10.56

2014-10-05T21:54:30Z

vm_is_stack: use for_each_thread() rather then buggy while_each_thread()

2014-10-05T21:54:16Z

commit 4449a51a7c281602d3a385044ab928322a122a02 upstream. Aleksei hit the soft lockup during reading /proc/PID/smaps. David investigated the problem and suggested the right fix. while_each_thread() is racy and should die, this patch updates vm_is_stack(). Signed-off-by: Oleg Nesterov Reported-by: Aleksei Besogonov Tested-by: Aleksei Besogonov Suggested-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman

oom_kill: add rcu_read_lock() into find_lock_task_mm()

2014-10-05T21:54:15Z

commit 4d4048be8a93769350efa31d2482a038b7de73d0 upstream. find_lock_task_mm() expects it is called under rcu or tasklist lock, but it seems that at least oom_unkillable_task()->task_in_mem_cgroup() and mem_cgroup_out_of_memory()->oom_badness() can call it lockless. Perhaps we could fix the callers, but this patch simply adds rcu lock into find_lock_task_mm(). This also allows to simplify a bit one of its callers, oom_kill_process(). Signed-off-by: Oleg Nesterov Cc: Sergey Dyasly Cc: Sameer Nanda Cc: "Eric W. Biederman" Cc: Frederic Weisbecker Cc: Mandeep Singh Baines Cc: "Ma, Xindong" Reviewed-by: Michal Hocko Cc: "Tu, Xiaobing" Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman

oom_kill: has_intersects_mems_allowed() needs rcu_read_lock()

2014-10-05T21:54:15Z

commit ad96244179fbd55b40c00f10f399bc04739b8e1f upstream. At least out_of_memory() calls has_intersects_mems_allowed() without even rcu_read_lock(), this is obviously buggy. Add the necessary rcu_read_lock(). This means that we can not simply return from the loop, we need "bool ret" and "break". While at it, swap the names of task_struct's (the argument and the local). This cleans up the code a little bit and avoids the unnecessary initialization. Signed-off-by: Oleg Nesterov Reviewed-by: Sergey Dyasly Tested-by: Sergey Dyasly Reviewed-by: Sameer Nanda Cc: "Eric W. Biederman" Cc: Frederic Weisbecker Cc: Mandeep Singh Baines Cc: "Ma, Xindong" Reviewed-by: Michal Hocko Cc: "Tu, Xiaobing" Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman

oom_kill: change oom_kill.c to use for_each_thread()

2014-10-05T21:54:15Z

commit 1da4db0cd5c8a31d4468ec906b413e75e604b465 upstream. Change oom_kill.c to use for_each_thread() rather than the racy while_each_thread() which can loop forever if we race with exit. Note also that most users were buggy even if while_each_thread() was fine, the task can exit even _before_ rcu_read_lock(). Fortunately the new for_each_thread() only requires the stable task_struct, so this change fixes both problems. Signed-off-by: Oleg Nesterov Reviewed-by: Sergey Dyasly Tested-by: Sergey Dyasly Reviewed-by: Sameer Nanda Cc: "Eric W. Biederman" Cc: Frederic Weisbecker Cc: Mandeep Singh Baines Cc: "Ma, Xindong" Reviewed-by: Michal Hocko Cc: "Tu, Xiaobing" Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman

introduce for_each_thread() to replace the buggy while_each_thread()

2014-10-05T21:54:15Z

commit 0c740d0afc3bff0a097ad03a1c8df92757516f5c upstream. while_each_thread() and next_thread() should die, almost every lockless usage is wrong. 1. Unless g == current, the lockless while_each_thread() is not safe. while_each_thread(g, t) can loop forever if g exits, next_thread() can't reach the unhashed thread in this case. Note that this can happen even if g is the group leader, it can exec. 2. Even if while_each_thread() itself was correct, people often use it wrongly. It was never safe to just take rcu_read_lock() and loop unless you verify that pid_alive(g) == T, even the first next_thread() can point to the already freed/reused memory. This patch adds signal_struct->thread_head and task->thread_node to create the normal rcu-safe list with the stable head. The new for_each_thread(g, t) helper is always safe under rcu_read_lock() as long as this task_struct can't go away. Note: of course it is ugly to have both task_struct->thread_node and the old task_struct->thread_group, we will kill it later, after we change the users of while_each_thread() to use for_each_thread(). Perhaps we can kill it even before we convert all users, we can reimplement next_thread(t) using the new thread_head/thread_node. But we can't do this right now because this will lead to subtle behavioural changes. For example, do/while_each_thread() always sees at least one task, while for_each_thread() can do nothing if the whole thread group has died. Or thread_group_empty(), currently its semantics is not clear unless thread_group_leader(p) and we need to audit the callers before we can change it. So this patch adds the new interface which has to coexist with the old one for some time, hopefully the next changes will be more or less straightforward and the old one will go away soon. Signed-off-by: Oleg Nesterov Reviewed-by: Sergey Dyasly Tested-by: Sergey Dyasly Reviewed-by: Sameer Nanda Acked-by: David Rientjes Cc: "Eric W. Biederman" Cc: Frederic Weisbecker Cc: Mandeep Singh Baines Cc: "Ma, Xindong" Cc: Michal Hocko Cc: "Tu, Xiaobing" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman

kernel/fork.c:copy_process(): unify CLONE_THREAD-or-thread_group_leader code

2014-10-05T21:54:15Z

commit 80628ca06c5d42929de6bc22c0a41589a834d151 upstream. Cleanup and preparation for the next changes. Move the "if (clone_flags & CLONE_THREAD)" code down under "if (likely(p->pid))" and turn it into into the "else" branch. This makes the process/thread initialization more symmetrical and removes one check. Signed-off-by: Oleg Nesterov Cc: "Eric W. Biederman" Cc: Michal Hocko Cc: Pavel Emelyanov Cc: Sergey Dyasly Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Li Zefan Signed-off-by: Greg Kroah-Hartman

arm: multi_v7_defconfig: Enable Zynq UART driver

2014-10-05T21:54:15Z

commit 90de827b9c238f8d8209bc7adc70190575514315 upstream. Signed-off-by: Soren Brinkmann Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman

ext2: Fix fs corruption in ext2_get_xip_mem()

2014-10-05T21:54:15Z

commit 7ba3ec5749ddb61f79f7be17b5fd7720eebc52de upstream. Commit 8e3dffc651cb "Ext2: mark inode dirty after the function dquot_free_block_nodirty is called" unveiled a bug in __ext2_get_block() called from ext2_get_xip_mem(). That function called ext2_get_block() mistakenly asking it to map 0 blocks while 1 was intended. Before the above mentioned commit things worked out fine by luck but after that commit we started returning that we allocated 0 blocks while we in fact allocated 1 block and thus allocation was looping until all blocks in the filesystem were exhausted. Fix the problem by properly asking for one block and also add assertion in ext2_get_blocks() to catch similar problems. Reported-and-tested-by: Andiry Xu Signed-off-by: Jan Kara Cc: Wang Nan Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: check the result of TX buffer mapping

2014-10-05T21:54:15Z

commit d4089a332883ad969700aac5dd4dd5f1c4fee825 upstream. Using dma_mapping_error() to make sure the mapping did not fail. Signed-off-by: Heikki Krogerus Cc: "Petallo, MauriceX R" Signed-off-by: Greg Kroah-Hartman