kernel/lib, branch linux-2.6.39.y

debugobjects: Fix boot crash when kmemleak and debugobjects enabled

2011-07-09T06:15:22Z

commit 161b6ae0e067e421b20bb35caf66bdb405c929ac upstream. Order of initialization look like this: ... debugobjects kmemleak ...(lots of other subsystems)... workqueues (through early initcall) ... debugobjects use schedule_work for batch freeing of its data and kmemleak heavily use debugobjects, so when it comes to freeing and workqueues were not initialized yet, kernel crashes: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] __queue_work+0x29/0x41a [] queue_work_on+0x16/0x1d [] queue_work+0x29/0x55 [] schedule_work+0x13/0x15 [] free_object+0x90/0x95 [] debug_check_no_obj_freed+0x187/0x1d3 [] ? _raw_spin_unlock_irqrestore+0x30/0x4d [] ? free_object_rcu+0x68/0x6d [] kmem_cache_free+0x64/0x12c [] free_object_rcu+0x68/0x6d [] __rcu_process_callbacks+0x1b6/0x2d9 ... because system_wq is NULL. Fix it by checking if workqueues susbystem was initialized before using. Signed-off-by: Marcin Slusarz Cc: Catalin Marinas Cc: Tejun Heo Cc: Dipankar Sarma Cc: Paul E. McKenney Link: http://lkml.kernel.org/r/20110528112342.GA3068@joi.lan Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

rcu: Fix unpaired rcu_irq_enter() from locking selftests

2011-06-03T00:32:09Z

commit ba9f207c9f82115aba4ce04b22e0081af0ae300f upstream. HARDIRQ_ENTER() maps to irq_enter() which calls rcu_irq_enter(). But HARDIRQ_EXIT() maps to __irq_exit() which doesn't call rcu_irq_exit(). So for every locking selftest that simulates hardirq disabled, we create an imbalance in the rcu extended quiescent state internal state. As a result, after the first missing rcu_irq_exit(), subsequent irqs won't exit dyntick-idle mode after leaving the interrupt handler. This means that RCU won't see the affected CPU as being in an extended quiescent state, resulting in long grace-period delays (as in grace periods extending for hours). To fix this, just use __irq_enter() to simulate the hardirq context. This is sufficient for the locking selftests as we don't need to exit any extended quiescent state or perform any check that irqs normally do when they wake up from idle. As a side effect, this patch makes it possible to restore "rcu: Decrease memory-barrier usage based on semi-formal proof", which eventually helped finding this bug. Reported-and-tested-by: Yinghai Lu Signed-off-by: Frederic Weisbecker Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Paul E. McKenney Signed-off-by: Greg Kroah-Hartman

vsprintf: Turn kptr_restrict off by default

2011-05-12T22:18:16Z

kptr_restrict has been triggering bugs in apps such as perf, and it also makes the system less useful by default, so turn it off by default. This is how we generally handle security features that remove functionality, such as firewall code or SELinux - they have to be configured and activated from user-space. Distributions can turn kptr_restrict on again via this line in /etc/sysctrl.conf: kernel.kptr_restrict = 1 ( Also mark the variable __read_mostly while at it, as it's typically modified only once per bootup, or not at all. ) Signed-off-by: Ingo Molnar Acked-by: David S. Miller Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.infradead.org/users/eparis/selinux into for-linus

2011-05-04T01:59:34Z

XZ decompressor: Fix decoding of empty LZMA2 streams

2011-05-02T15:46:12Z

The old code considered valid empty LZMA2 streams to be corrupt. Note that a typical empty .xz file has no LZMA2 data at all, and thus most .xz files having no uncompressed data are handled correctly even without this fix. Signed-off-by: Lasse Collin Signed-off-by: Linus Torvalds

flex_arrays: allow zero length flex arrays

2011-04-28T20:12:54Z

Just like kmalloc will allow one to allocate a 0 length segment of memory flex arrays should do the same thing. It should bomb if you try to use something, but it should at least allow the allocation. This is needed because when SELinux switched to using flex_arrays in 2.6.38 the inability to allocate a 0 length array resulted in SELinux policy load returning -ENOSPC when previously it worked. Based-on-patch-by: Steffen Klassert Signed-off-by: Eric Paris Tested-by: Chris Richards Cc: stable@kernel.org [2.6.38+]

flex_array: flex_array_prealloc takes a number of elements, not an end

2011-04-28T20:12:47Z

Change flex_array_prealloc to take the number of elements for which space should be allocated instead of the last (inclusive) element. Users and documentation are updated accordingly. flex_arrays got introduced before they had users. When folks started using it, they ended up needing a different API than was coded up originally. This swaps over to the API that folks apparently need. Based-on-patch-by: Steffen Klassert Signed-off-by: Eric Paris Tested-by: Chris Richards Acked-by: Dave Hansen Cc: stable@kernel.org [2.6.38+]

kstrtox: simpler code in _kstrtoull()

2011-04-14T23:06:55Z

Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kstrtox: fix compile warnings in test

2011-04-14T23:06:54Z

Fix the following warnings: CC [M] lib/test-kstrtox.o lib/test-kstrtox.c: In function 'test_kstrtou64_ok': lib/test-kstrtox.c:318: warning: this decimal constant is unsigned only in ISO C90 ... Signed-off-by: Alexey Dobriyan Reported-by: Geert Uytterhoeven Acked-by: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6

2011-04-07T18:14:49Z

* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6: Fix common misspellings