user/sven/linux.git/kernel, branch v4.9.57

rcu: Allow for page faults in NMI handlers

2017-10-18T07:35:38Z

commit 28585a832602747cbfa88ad8934013177a3aae38 upstream. A number of architecture invoke rcu_irq_enter() on exception entry in order to allow RCU read-side critical sections in the exception handler when the exception is from an idle or nohz_full CPU. This works, at least unless the exception happens in an NMI handler. In that case, rcu_nmi_enter() would already have exited the extended quiescent state, which would mean that rcu_irq_enter() would (incorrectly) cause RCU to think that it is again in an extended quiescent state. This will in turn result in lockdep splats in response to later RCU read-side critical sections. This commit therefore causes rcu_irq_enter() and rcu_irq_exit() to take no action if there is an rcu_nmi_enter() in effect, thus avoiding the unscheduled return to RCU quiescent state. This in turn should make the kernel safe for on-demand RCU voyeurism. Link: http://lkml.kernel.org/r/20170922211022.GA18084@linux.vnet.ibm.com Fixes: 0be964be0 ("module: Sanitize RCU usage and locking") Reported-by: Steven Rostedt Signed-off-by: Paul E. McKenney Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs

2017-10-12T09:51:25Z

commit 50e76632339d4655859523a39249dd95ee5e93e7 upstream. Cpusets vs. suspend-resume is _completely_ broken. And it got noticed because it now resulted in non-cpuset usage breaking too. On suspend cpuset_cpu_inactive() doesn't call into cpuset_update_active_cpus() because it doesn't want to move tasks about, there is no need, all tasks are frozen and won't run again until after we've resumed everything. But this means that when we finally do call into cpuset_update_active_cpus() after resuming the last frozen cpu in cpuset_cpu_active(), the top_cpuset will not have any difference with the cpu_active_mask and this it will not in fact do _anything_. So the cpuset configuration will not be restored. This was largely hidden because we would unconditionally create identity domains and mobile users would not in fact use cpusets much. And servers what do use cpusets tend to not suspend-resume much. An addition problem is that we'd not in fact wait for the cpuset work to finish before resuming the tasks, allowing spurious migrations outside of the specified domains. Fix the rebuild by introducing cpuset_force_rebuild() and fix the ordering with cpuset_wait_for_hotplug(). Reported-by: Andy Lutomirski Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Tejun Heo Cc: Thomas Gleixner Fixes: deb7aa308ea2 ("cpuset: reorganize CPU / memory hotplug handling") Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar Signed-off-by: Mike Galbraith Signed-off-by: Greg Kroah-Hartman

ftrace: Fix kmemleak in unregister_ftrace_graph

2017-10-12T09:51:24Z

commit 2b0b8499ae75df91455bbeb7491d45affc384fb0 upstream. The trampoline allocated by function tracer was overwriten by function_graph tracer, and caused a memory leak. The save_global_trampoline should have saved the previous trampoline in register_ftrace_graph() and restored it in unregister_ftrace_graph(). But as it is implemented, save_global_trampoline was only used in unregister_ftrace_graph as default value 0, and it overwrote the previous trampoline's value. Causing the previous allocated trampoline to be lost. kmmeleak backtrace: kmemleak_vmalloc+0x77/0xc0 __vmalloc_node_range+0x1b5/0x2c0 module_alloc+0x7c/0xd0 arch_ftrace_update_trampoline+0xb5/0x290 ftrace_startup+0x78/0x210 register_ftrace_function+0x8b/0xd0 function_trace_init+0x4f/0x80 tracing_set_tracer+0xe6/0x170 tracing_set_trace_write+0x90/0xd0 __vfs_write+0x37/0x170 vfs_write+0xb2/0x1b0 SyS_write+0x55/0xc0 do_syscall_64+0x67/0x180 return_from_SYSCALL_64+0x0/0x6a [ Looking further into this, I found that this was left over from when the function and function graph tracers shared the same ftrace_ops. But in commit 5f151b2401 ("ftrace: Fix function_profiler and function tracer together"), the two were separated, and the save_global_trampoline no longer was necessary (and it may have been broken back then too). -- Steven Rostedt ] Link: http://lkml.kernel.org/r/20170912021454.5976-1-shuwang@redhat.com Fixes: 5f151b2401 ("ftrace: Fix function_profiler and function tracer together") Signed-off-by: Shu Wang Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

bpf: one perf event close won't free bpf program attached by another perf event

2017-10-12T09:51:21Z

[ Upstream commit ec9dd352d591f0c90402ec67a317c1ed4fb2e638 ] This patch fixes a bug exhibited by the following scenario: 1. fd1 = perf_event_open with attr.config = ID1 2. attach bpf program prog1 to fd1 3. fd2 = perf_event_open with attr.config = ID1 4. user program closes fd2 and prog1 is detached from the tracepoint. 5. user program with fd1 does not work properly as tracepoint no output any more. The issue happens at step 4. Multiple perf_event_open can be called successfully, but only one bpf prog pointer in the tp_event. In the current logic, any fd release for the same tp_event will free the tp_event->prog. The fix is to free tp_event->prog only when the closing fd corresponds to the one which registered the program. Signed-off-by: Yonghong Song Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

bpf/verifier: reject BPF_ALU64|BPF_END

2017-10-12T09:51:20Z

[ Upstream commit e67b8a685c7c984e834e3181ef4619cd7025a136 ] Neither ___bpf_prog_run nor the JITs accept it. Also adds a new test case. Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Signed-off-by: Edward Cree Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

timer/sysclt: Restrict timer migration sysctl values to 0 and 1

2017-10-05T07:44:04Z

commit b94bf594cf8ed67cdd0439e70fa939783471597a upstream. timer_migration sysctl acts as a boolean switch, so the allowed values should be restricted to 0 and 1. Add the necessary extra fields to the sysctl table entry to enforce that. [ tglx: Rewrote changelog ] Signed-off-by: Myungho Jung Link: http://lkml.kernel.org/r/1492640690-3550-1-git-send-email-mhjungk@gmail.com Signed-off-by: Thomas Gleixner Cc: Kazuhiro Hayashi Signed-off-by: Greg Kroah-Hartman

seccomp: fix the usage of get/put_seccomp_filter() in seccomp_get_filter()

2017-10-05T07:44:02Z

commit 66a733ea6b611aecf0119514d2dddab5f9d6c01e upstream. As Chris explains, get_seccomp_filter() and put_seccomp_filter() can end up using different filters. Once we drop ->siglock it is possible for task->seccomp.filter to have been replaced by SECCOMP_FILTER_FLAG_TSYNC. Fixes: f8e529ed941b ("seccomp, ptrace: add support for dumping seccomp filters") Reported-by: Chris Salls Signed-off-by: Oleg Nesterov [tycho: add __get_seccomp_filter vs. open coding refcount_inc()] Signed-off-by: Tycho Andersen [kees: tweak commit log] Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

tracing: Erase irqsoff trace with empty write

2017-10-05T07:43:59Z

commit 8dd33bcb7050dd6f8c1432732f930932c9d3a33e upstream. One convenient way to erase trace is "echo > trace". However, this is currently broken if the current tracer is irqsoff tracer. This is because irqsoff tracer use max_buffer as the default trace buffer. Set the max_buffer as the one to be cleared when it's the trace buffer currently in use. Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com Cc: Fixes: 4acd4d00f ("tracing: give easy way to clear trace buffer") Signed-off-by: Bo Yan Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Fix trace_pipe behavior for instance traces

2017-10-05T07:43:59Z

commit 75df6e688ccd517e339a7c422ef7ad73045b18a2 upstream. When reading data from trace_pipe, tracing_wait_pipe() performs a check to see if tracing has been turned off after some data was read. Currently, this check always looks at global trace state, but it should be checking the trace instance where trace_pipe is located at. Because of this bug, cat instances/i1/trace_pipe in the following script will immediately exit instead of waiting for data: cd /sys/kernel/debug/tracing echo 0 > tracing_on mkdir -p instances/i1 echo 1 > instances/i1/tracing_on echo 1 > instances/i1/events/sched/sched_process_exec/enable cat instances/i1/trace_pipe Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com Fixes: 10246fa35d4f ("tracing: give easy way to clear trace buffer") Signed-off-by: Tahsin Erdogan Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

genirq: Make sparse_irq_lock protect what it should protect

2017-10-05T07:43:58Z

commit 12ac1d0f6c3e95732d144ffa65c8b20fbd9aa462 upstream. for_each_active_irq() iterates the sparse irq allocation bitmap. The caller must hold sparse_irq_lock. Several code pathes expect that an active bit in the sparse bitmap also has a valid interrupt descriptor. Unfortunately that's not true. The (de)allocation is a two step process, which holds the sparse_irq_lock only across the queue/remove from the radix tree and the set/clear in the allocation bitmap. If a iteration locks sparse_irq_lock between the two steps, then it might see an active bit but the corresponding irq descriptor is NULL. If that is dereferenced unconditionally, then the kernel oopses. Of course, all iterator sites could be audited and fixed, but.... There is no reason why the sparse_irq_lock needs to be dropped between the two steps, in fact the code becomes simpler when the mutex is held across both and the semantics become more straight forward, so future problems of missing NULL pointer checks in the iteration are avoided and all existing sites are fixed in one go. Expand the lock held sections so both operations are covered and the bitmap and the radixtree are in sync. Fixes: a05a900a51c7 ("genirq: Make sparse_lock a mutex") Reported-and-tested-by: Huang Ying Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman