user/sven/linux.git/kernel, branch v3.2.47

audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE

2013-06-19T01:17:00Z

commit f000cfdde5de4fc15dead5ccf524359c07eadf2b upstream. audit_log_start() does wait_for_auditd() in a loop until audit_backlog_wait_time passes or audit_skb_queue has a room. If signal_pending() is true this becomes a busy-wait loop, schedule() in TASK_INTERRUPTIBLE won't block. Thanks to Guy for fully investigating and explaining the problem. (akpm: that'll cause the system to lock up on a non-preemptible uniprocessor kernel) (Guy: "Our customer was in fact running a uniprocessor machine, and they reported a system hang.") Signed-off-by: Oleg Nesterov Reported-by: Guy Streeter Cc: Eric Paris Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: adjust context, indentation] Signed-off-by: Ben Hutchings

reboot: rigrate shutdown/reboot to boot cpu

2013-06-19T01:17:00Z

commit cf7df378aa4ff7da3a44769b7ff6e9eef1a9f3db upstream. We recently noticed that reboot of a 1024 cpu machine takes approx 16 minutes of just stopping the cpus. The slowdown was tracked to commit f96972f2dc63 ("kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()"). The current implementation does all the work of hot removing the cpus before halting the system. We are switching to just migrating to the boot cpu and then continuing with shutdown/reboot. This also has the effect of not breaking x86's command line parameter for specifying the reboot cpu. Note, this code was shamelessly copied from arch/x86/kernel/reboot.c with bits removed pertaining to the reboot_cpu command line parameter. Signed-off-by: Robin Holt Tested-by: Shawn Guo Cc: "Srivatsa S. Bhat" Cc: H. Peter Anvin Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Russ Anderson Cc: Robin Holt Cc: Russell King Cc: Guan Xuetao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

CPU hotplug: provide a generic helper to disable/enable CPU hotplug

2013-06-19T01:16:59Z

commit 16e53dbf10a2d7e228709a7286310e629ede5e45 upstream. There are instances in the kernel where we would like to disable CPU hotplug (from sysfs) during some important operation. Today the freezer code depends on this and the code to do it was kinda tailor-made for that. Restructure the code and make it generic enough to be useful for other usecases too. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Robin Holt Cc: H. Peter Anvin Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Russ Anderson Cc: Robin Holt Cc: Russell King Cc: Guan Xuetao Cc: Shawn Guo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

ftrace: Move ftrace_filter_lseek out of CONFIG_DYNAMIC_FTRACE section

2013-06-19T01:16:47Z

commit 7f49ef69db6bbf756c0abca7e9b65b32e999eec8 upstream. As ftrace_filter_lseek is now used with ftrace_pid_fops, it needs to be moved out of the #ifdef CONFIG_DYNAMIC_FTRACE section as the ftrace_pid_fops is defined when DYNAMIC_FTRACE is not. Cc: Namhyung Kim Signed-off-by: Steven Rostedt [bwh: Backported to 3.2: - ftrace_filter_lseek() is static and not declared in ftrace.h - 'whence' parameter was called 'origin'] Signed-off-by: Ben Hutchings

sched/debug: Fix sd->*_idx limit range avoiding overflow

2013-05-30T13:35:09Z

commit fd9b86d37a600488dbd80fe60cca46b822bff1cd upstream. Commit 201c373e8e ("sched/debug: Limit sd->*_idx range on sysctl") was an incomplete bug fix. This patch fixes sd->*_idx limit range to [0 ~ CPU_LOAD_IDX_MAX-1] avoiding array overflow caused by setting sd->*_idx to CPU_LOAD_IDX_MAX on sysctl. Signed-off-by: Libin Cc: Cc: Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/51626610.2040607@huawei.com Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings

sched/debug: Limit sd->*_idx range on sysctl

2013-05-30T13:35:09Z

commit 201c373e8e4823700d3160d5c28e1ab18fd1193e upstream. Various sd->*_idx's are used for refering the rq's load average table when selecting a cpu to run. However they can be set to any number with sysctl knobs so that it can crash the kernel if something bad is given. Fix it by limiting them into the actual range. Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1345104204-8317-1-git-send-email-namhyung@kernel.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: - Adjust filename - s/umode_t/mode_t/] Signed-off-by: Ben Hutchings

usermodehelper: check subprocess_info->path != NULL

2013-05-30T13:35:00Z

commit 264b83c07a84223f0efd0d1db9ccc66d6f88288f upstream. argv_split(empty_or_all_spaces) happily succeeds, it simply returns argc == 0 and argv[0] == NULL. Change call_usermodehelper_exec() to check sub_info->path != NULL to avoid the crash. This is the minimal fix, todo: - perhaps we should change argv_split() to return NULL or change the callers. - kill or justify ->path[0] check - narrow the scope of helper_lock() Signed-off-by: Oleg Nesterov Acked-By: Lucas De Marchi Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

tracing: Fix leaks of filter preds

2013-05-30T13:35:00Z

commit 60705c89460fdc7227f2d153b68b3f34814738a4 upstream. Special preds are created when folding a series of preds that can be done in serial. These are allocated in an ops field of the pred structure. But they were never freed, causing memory leaks. This was discovered using the kmemleak checker: unreferenced object 0xffff8800797fd5e0 (size 32): comm "swapper/0", pid 1, jiffies 4294690605 (age 104.608s) hex dump (first 32 bytes): 00 00 01 00 03 00 05 00 07 00 09 00 0b 00 0d 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmemleak_alloc+0x73/0x98 [] kmemleak_alloc_recursive.constprop.42+0x16/0x18 [] __kmalloc+0xd7/0x125 [] kcalloc.constprop.24+0x2d/0x2f [] fold_pred_tree_cb+0xa9/0xf4 [] walk_pred_tree+0x47/0xcc [] replace_preds.isra.20+0x6f8/0x72f [] create_filter+0x4e/0x8b [] ftrace_test_event_filter+0x5a/0x155 [] do_one_initcall+0xa0/0x137 [] kernel_init_freeable+0x14d/0x1dc [] kernel_init+0xe/0xdb [] ret_from_fork+0x7c/0xb0 [] 0xffffffffffffffff Cc: Tom Zanussi Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings

timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE

2013-05-30T13:34:59Z

commit 42a5cf46cd56f46267d2a9fcf2655f4078cd3042 upstream. An inactive timer's base can refer to a offline cpu's base. In the current code, cpu_base's lock is blindly reinitialized each time a CPU is brought up. If a CPU is brought online during the period that another thread is trying to modify an inactive timer on that CPU with holding its timer base lock, then the lock will be reinitialized under its feet. This leads to following SPIN_BUG(). <0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466 <0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466, .owner_cpu: 1 <4> [] (unwind_backtrace+0x0/0x11c) from [] (do_raw_spin_unlock+0x40/0xcc) <4> [] (do_raw_spin_unlock+0x40/0xcc) from [] (_raw_spin_unlock+0x8/0x30) <4> [] (_raw_spin_unlock+0x8/0x30) from [] (mod_timer+0x294/0x310) <4> [] (mod_timer+0x294/0x310) from [] (queue_delayed_work_on+0x104/0x120) <4> [] (queue_delayed_work_on+0x104/0x120) from [] (sdhci_msm_bus_voting+0x88/0x9c) <4> [] (sdhci_msm_bus_voting+0x88/0x9c) from [] (sdhci_disable+0x40/0x48) <4> [] (sdhci_disable+0x40/0x48) from [] (mmc_release_host+0x4c/0xb0) <4> [] (mmc_release_host+0x4c/0xb0) from [] (mmc_sd_detect+0x90/0xfc) <4> [] (mmc_sd_detect+0x90/0xfc) from [] (mmc_rescan+0x7c/0x2c4) <4> [] (mmc_rescan+0x7c/0x2c4) from [] (process_one_work+0x27c/0x484) <4> [] (process_one_work+0x27c/0x484) from [] (worker_thread+0x210/0x3b0) <4> [] (worker_thread+0x210/0x3b0) from [] (kthread+0x80/0x8c) <4> [] (kthread+0x80/0x8c) from [] (kernel_thread_exit+0x0/0x8) As an example, this particular crash occurred when CPU #3 is executing mod_timer() on an inactive timer whose base is refered to offlined CPU #2. The code locked the timer_base corresponding to CPU #2. Before it could proceed, CPU #2 came online and reinitialized the spinlock corresponding to its base. Thus now CPU #3 held a lock which was reinitialized. When CPU #3 finally ended up unlocking the old cpu_base corresponding to CPU #2, we hit the above SPIN_BUG(). CPU #0 CPU #3 CPU #2 ------ ------- ------- ..... ...... mod_timer() lock_timer_base spin_lock_irqsave(&base->lock) cpu_up(2) ..... ...... init_timers_cpu() .... ..... spin_lock_init(&base->lock) ..... spin_unlock_irqrestore(&base->lock) ...... Allocation of per_cpu timer vector bases is done only once under "tvec_base_done[]" check. In the current code, spinlock_initialization of base->lock isn't under this check. When a CPU is up each time the base lock is reinitialized. Move base spinlock initialization under the check. Signed-off-by: Tirupathi Reddy Link: http://lkml.kernel.org/r/1368520142-4136-1-git-send-email-tirupath@codeaurora.org Signed-off-by: Thomas Gleixner Signed-off-by: Ben Hutchings

tick: Cleanup NOHZ per cpu data on cpu down

2013-05-30T13:34:56Z

commit 4b0c0f294f60abcdd20994a8341a95c8ac5eeb96 upstream. Prarit reported a crash on CPU offline/online. The reason is that on CPU down the NOHZ related per cpu data of the dead cpu is not cleaned up. If at cpu online an interrupt happens before the per cpu tick device is registered the irq_enter() check potentially sees stale data and dereferences a NULL pointer. Cleanup the data after the cpu is dead. Reported-by: Prarit Bhargava Cc: Mike Galbraith Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305031451561.2886@ionos Signed-off-by: Thomas Gleixner Signed-off-by: Ben Hutchings