BMC/Intel-BMC/linux.git/kernel, branch v4.18.6

watchdog: Mark watchdog touch functions as notrace

2018-09-05T07:29:55+00:00

commit cb9d7fd51d9fbb329d182423bd7b92d0f8cb0e01 upstream. Some architectures need to use stop_machine() to patch functions for ftrace, and the assumption is that the stopped CPUs do not make function calls to traceable functions when they are in the stopped state. Commit ce4f06dcbb5d ("stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE") added calls to the watchdog touch functions from the stopped CPUs and those functions lack notrace annotations. This leads to crashes when enabling/disabling ftrace on ARM kernels built with the Thumb-2 instruction set. Fix it by adding the necessary notrace annotations. Fixes: ce4f06dcbb5d ("stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE") Signed-off-by: Vincent Whitchurch Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: oleg@redhat.com Cc: tj@kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180821152507.18313-1-vincent.whitchurch@axis.com Signed-off-by: Greg Kroah-Hartman

kprobes: Make list and blacklist root user read only

2018-09-05T07:29:53+00:00

commit f2a3ab36077222437b4826fc76111caa14562b7c upstream. Since the blacklist and list files on debugfs indicates a sensitive address information to reader, it should be restricted to the root user. Suggested-by: Thomas Richter Suggested-by: Ingo Molnar Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: Arnd Bergmann Cc: David Howells Cc: David S . Miller Cc: Heiko Carstens Cc: Jon Medhurst Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tobin C . Harding Cc: Will Deacon Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491890171.9916.5183693615601334087.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

kprobes: Replace %p with other pointer types

2018-09-05T07:29:52+00:00

commit 4458515b2c52831ee622411d2fe3e774d1f5c49a upstream. Replace %p with %pS or just remove it if unneeded. And use WARN_ONCE() if it is a single bug. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: Arnd Bergmann Cc: David Howells Cc: David S . Miller Cc: Heiko Carstens Cc: Jon Medhurst Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Thomas Richter Cc: Tobin C . Harding Cc: Will Deacon Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491899284.9916.5350534544808158621.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

kprobes: Show blacklist addresses as same as kallsyms does

2018-09-05T07:29:52+00:00

commit ffb9bd68ebdb3b8d00ef5a79bbe8167a3281cace upstream. Show kprobes blacklist addresses under same condition of showing kallsyms addresses. Since there are several name conflict for local symbols, kprobe blacklist needs to show each addresses so that user can identify where is on blacklist by comparing with kallsyms. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: Arnd Bergmann Cc: David Howells Cc: David S . Miller Cc: Heiko Carstens Cc: Jon Medhurst Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Thomas Richter Cc: Tobin C . Harding Cc: Will Deacon Cc: acme@kernel.org Cc: akpm@linux-foundation.org Cc: brueckner@linux.vnet.ibm.com Cc: linux-arch@vger.kernel.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/152491893217.9916.14760965896164273464.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

stop_machine: Atomically queue and wake stopper threads

2018-09-05T07:29:44+00:00

commit cfd355145c32bb7ccb65fccbe2d67280dc2119e1 upstream. When cpu_stop_queue_work() releases the lock for the stopper thread that was queued into its wake queue, preemption is enabled, which leads to the following deadlock: CPU0 CPU1 sched_setaffinity(0, ...) __set_cpus_allowed_ptr() stop_one_cpu(0, ...) stop_two_cpus(0, 1, ...) cpu_stop_queue_work(0, ...) cpu_stop_queue_two_works(0, ..., 1, ...) -grabs lock for migration/0- -spins with preemption disabled, waiting for migration/0's lock to be released- -adds work items for migration/0 and queues migration/0 to its wake_q- -releases lock for migration/0 and preemption is enabled- -current thread is preempted, and __set_cpus_allowed_ptr has changed the thread's cpu allowed mask to CPU1 only- -acquires migration/0 and migration/1's locks- -adds work for migration/0 but does not add migration/0 to wake_q, since it is already in a wake_q- -adds work for migration/1 and adds migration/1 to its wake_q- -releases migration/0 and migration/1's locks, wakes migration/1, and enables preemption- -since migration/1 is requested to run, migration/1 begins to run and waits on migration/0, but migration/0 will never be able to run, since the thread that can wake it is affine to CPU1- Disable preemption in cpu_stop_queue_work() before queueing works for stopper threads, and queueing the stopper thread in the wake queue, to ensure that the operation of queueing the works and waking the stopper threads is atomic. Fixes: 0b26351b910f ("stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock") Signed-off-by: Prasad Sodagudi Signed-off-by: Isaac J. Manjarres Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Cc: matt@codeblueprint.co.uk Cc: bigeasy@linutronix.de Cc: gregkh@linuxfoundation.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1533329766-4856-1-git-send-email-isaacm@codeaurora.org Signed-off-by: Greg Kroah-Hartman Co-Developed-by: Isaac J. Manjarres

stop_machine: Reflow cpu_stop_queue_two_works()

2018-09-05T07:29:44+00:00

commit b80a2bfce85e1051056d98d04ecb2d0b55cbbc1c upstream. The code flow in cpu_stop_queue_two_works() is a little arcane; fix this by lifting the preempt_disable() to the top to create more natural nesting wrt the spinlocks and make the wake_up_q() and preempt_enable() unconditional at the end. Furthermore, enable preemption in the -EDEADLK case, such that we spin-wait with preemption enabled. Suggested-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: isaacm@codeaurora.org Cc: matt@codeblueprint.co.uk Cc: psodagud@codeaurora.org Cc: gregkh@linuxfoundation.org Cc: pkondeti@codeaurora.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180730112140.GH2494@hirez.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman

printk/nmi: Prevent deadlock when accessing the main log buffer in NMI

2018-09-05T07:29:42+00:00

commit 03fc7f9c99c1e7ae2925d459e8487f1a6f199f79 upstream. The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") brought back the possible deadlocks in printk() and NMI. The check of logbuf_lock is done only in printk_nmi_enter() to prevent mixed output. But another CPU might take the lock later, enter NMI, and: + Both NMIs might be serialized by yet another lock, for example, the one in nmi_cpu_backtrace(). + The other CPU might get stopped in NMI, see smp_send_stop() in panic(). The only safe solution is to use trylock when storing the message into the main log-buffer. It might cause reordering when some lines go to the main lock buffer directly and others are delayed via the per-CPU buffer. It means that it is not useful in general. This patch replaces the problematic NMI deferred context with NMI direct context. It can be used to mark a code that might produce many messages in NMI and the risk of losing them is more critical than problems with eventual reordering. The context is then used when dumping trace buffers on oops. It was the primary motivation for the original fix. Also the reordering is even smaller issue there because some traces have their own time stamps. Finally, nmi_cpu_backtrace() need not longer be serialized because it will always us the per-CPU buffers again. Fixes: 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20180627142028.11259-1-pmladek@suse.com To: Steven Rostedt Cc: Peter Zijlstra Cc: Tetsuo Handa Cc: Sergey Senozhatsky Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Greg Kroah-Hartman

printk: Create helper function to queue deferred console handling

2018-09-05T07:29:42+00:00

commit a338f84dc196f44b63ba0863d2f34fd9b1613572 upstream. It is just a preparation step. The patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20180627140817.27764-3-pmladek@suse.com To: Steven Rostedt Cc: Peter Zijlstra Cc: Tetsuo Handa Cc: Sergey Senozhatsky Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Greg Kroah-Hartman

printk: Split the code for storing a message into the log buffer

2018-09-05T07:29:42+00:00

commit ba552399954dde1b388f7749fecad5c349216981 upstream. It is just a preparation step. The patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20180627140817.27764-2-pmladek@suse.com To: Steven Rostedt Cc: Peter Zijlstra Cc: Tetsuo Handa Cc: Sergey Senozhatsky Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Greg Kroah-Hartman

cpu/hotplug: Non-SMP machines do not make use of booted_once

2018-08-15T15:37:34+00:00

commit 269777aa530f3438ec1781586cdac0b5fe47b061 upstream. Commit 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") breaks non-SMP builds. [ I suspect the 'bool' fields should just be made to be bitfields and be exposed regardless of configuration, but that's a separate cleanup that I'll leave to the owners of this file for later. - Linus ] Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once") Cc: Dave Hansen Cc: Thomas Gleixner Cc: Tony Luck Signed-off-by: Abel Vesa Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman