summaryrefslogtreecommitdiffstats
path: root/kernel
Commit message (Collapse)AuthorAgeFilesLines
* Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2018-06-033-18/+35
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: - two patches addressing the problem that the scheduler allows under certain conditions user space tasks to be scheduled on CPUs which are not yet fully booted which causes a few subtle and hard to debug issue - add a missing runqueue clock update in the deadline scheduler which triggers a warning under certain circumstances - fix a silly typo in the scheduler header file * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/headers: Fix typo sched/deadline: Fix missing clock update sched/core: Require cpu_active() in select_task_rq(), for user tasks sched/core: Fix rules for running on online && !active CPUs
| * sched/headers: Fix typoDavidlohr Bueso2018-05-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | I cannot spell 'throttling'. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180530224940.17839-1-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/deadline: Fix missing clock updateJuri Lelli2018-05-311-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A missing clock update is causing the following warning: rq->clock_update_flags < RQCF_ACT_SKIP WARNING: CPU: 10 PID: 0 at kernel/sched/sched.h:963 inactive_task_timer+0x5d6/0x720 Call Trace: <IRQ> __hrtimer_run_queues+0x10f/0x530 hrtimer_interrupt+0xe5/0x240 smp_apic_timer_interrupt+0x79/0x2b0 apic_timer_interrupt+0xf/0x20 </IRQ> do_idle+0x203/0x280 cpu_startup_entry+0x6f/0x80 start_secondary+0x1b0/0x200 secondary_startup_64+0xa5/0xb0 hardirqs last enabled at (793919): [<ffffffffa27c5f6e>] cpuidle_enter_state+0x9e/0x360 hardirqs last disabled at (793920): [<ffffffffa2a0096e>] interrupt_entry+0xce/0xe0 softirqs last enabled at (793922): [<ffffffffa20bef78>] irq_enter+0x68/0x70 softirqs last disabled at (793921): [<ffffffffa20bef5d>] irq_enter+0x4d/0x70 This happens because inactive_task_timer() calls sub_running_bw() (if TASK_DEAD and non_contending) that might trigger a schedutil update, which might access the clock. Clock is however currently updated only later in inactive_task_timer() function. Fix the problem by updating the clock right after task_rq_lock(). Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180530160809.9074-1-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Require cpu_active() in select_task_rq(), for user tasksPaul Burton2018-05-311-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | select_task_rq() is used in a few paths to select the CPU upon which a thread should be run - for example it is used by try_to_wake_up() & by fork or exec balancing. As-is it allows use of any online CPU that is present in the task's cpus_allowed mask. This presents a problem because there is a period whilst CPUs are brought online where a CPU is marked online, but is not yet fully initialized - ie. the period where CPUHP_AP_ONLINE_IDLE <= state < CPUHP_ONLINE. Usually we don't run any user tasks during this window, but there are corner cases where this can happen. An example observed is: - Some user task A, running on CPU X, forks to create task B. - sched_fork() calls __set_task_cpu() with cpu=X, setting task B's task_struct::cpu field to X. - CPU X is offlined. - Task A, currently somewhere between the __set_task_cpu() in copy_process() and the call to wake_up_new_task(), is migrated to CPU Y by migrate_tasks() when CPU X is offlined. - CPU X is onlined, but still in the CPUHP_AP_ONLINE_IDLE state. The scheduler is now active on CPU X, but there are no user tasks on the runqueue. - Task A runs on CPU Y & reaches wake_up_new_task(). This calls select_task_rq() with cpu=X, taken from task B's task_struct, and select_task_rq() allows CPU X to be returned. - Task A enqueues task B on CPU X's runqueue, via activate_task() & enqueue_task(). - CPU X now has a user task on its runqueue before it has reached the CPUHP_ONLINE state. In most cases, the user tasks that schedule on the newly onlined CPU have no idea that anything went wrong, but one case observed to be problematic is if the task goes on to invoke the sched_setaffinity syscall. The newly onlined CPU reaches the CPUHP_AP_ONLINE_IDLE state before the CPU that brought it online calls stop_machine_unpark(). This means that for a portion of the window of time between CPUHP_AP_ONLINE_IDLE & CPUHP_ONLINE the newly onlined CPU's struct cpu_stopper has its enabled field set to false. If a user thread is executed on the CPU during this window and it invokes sched_setaffinity with a CPU mask that does not include the CPU it's running on, then when __set_cpus_allowed_ptr() calls stop_one_cpu() intending to invoke migration_cpu_stop() and perform the actual migration away from the CPU it will simply return -ENOENT rather than calling migration_cpu_stop(). We then return from the sched_setaffinity syscall back to the user task that is now running on a CPU which it just asked not to run on, and which is not present in its cpus_allowed mask. This patch resolves the problem by having select_task_rq() enforce that user tasks run on CPUs that are active - the same requirement that select_fallback_rq() already enforces. This should ensure that newly onlined CPUs reach the CPUHP_AP_ACTIVE state before being able to schedule user tasks, and also implies that bringup_wait_for_ap() will have called stop_machine_unpark() which resolves the sched_setaffinity issue above. I haven't yet investigated them, but it may be of interest to review whether any of the actions performed by hotplug states between CPUHP_AP_ONLINE_IDLE & CPUHP_AP_ACTIVE could have similar unintended effects on user tasks that might schedule before they are reached, which might widen the scope of the problem from just affecting the behaviour of sched_setaffinity. Signed-off-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180526154648.11635-2-paul.burton@mips.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Fix rules for running on online && !active CPUsPeter Zijlstra2018-05-311-12/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As already enforced by the WARN() in __set_cpus_allowed_ptr(), the rules for running on an online && !active CPU are stricter than just being a kthread, you need to be a per-cpu kthread. If you're not strictly per-CPU, you have better CPUs to run on and don't need the partially booted one to get your work done. The exception is to allow smpboot threads to bootstrap the CPU itself and get kernel 'services' initialized before we allow userspace on it. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 955dbdf4ce87 ("sched: Allow migrating kthreads into online but inactive CPUs") Link: http://lkml.kernel.org/r/20170725165821.cejhb7v2s3kecems@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge tag 'trace-v4.17-rc4-3' of ↵Linus Torvalds2018-05-293-10/+28
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "While writing selftests for a new feature, I triggered two existing bugs that deal with triggers and instances. - a generic trigger bug where the triggers are not removed from a linked list properly when deleting an instance. - a bug specific to snapshots, where the snapshot is done in the top level buffer, when it is supposed to snapshot the buffer associated to the instance the snapshot trigger exists in" * tag 'trace-v4.17-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Make the snapshot trigger work with instances tracing: Fix crash when freeing instances with event triggers
| * tracing: Make the snapshot trigger work with instancesSteven Rostedt (VMware)2018-05-283-8/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The snapshot trigger currently only affects the main ring buffer, even when it is used by the instances. This can be confusing as the snapshot trigger is listed in the instance. > # cd /sys/kernel/tracing > # mkdir instances/foo > # echo snapshot > instances/foo/events/syscalls/sys_enter_fchownat/trigger > # echo top buffer > trace_marker > # echo foo buffer > instances/foo/trace_marker > # touch /tmp/bar > # chown rostedt /tmp/bar > # cat instances/foo/snapshot # tracer: nop # # # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') > # cat snapshot # tracer: nop # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | bash-1189 [000] .... 111.488323: tracing_mark_write: top buffer Not only did the snapshot occur in the top level buffer, but the instance snapshot buffer should have been allocated, and it is still free. Cc: stable@vger.kernel.org Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * tracing: Fix crash when freeing instances with event triggersSteven Rostedt (VMware)2018-05-271-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a instance has an event trigger enabled when it is freed, it could cause an access of free memory. Here's the case that crashes: # cd /sys/kernel/tracing # mkdir instances/foo # echo snapshot > instances/foo/events/initcall/initcall_start/trigger # rmdir instances/foo Would produce: general protection fault: 0000 [#1] PREEMPT SMP PTI Modules linked in: tun bridge ... CPU: 5 PID: 6203 Comm: rmdir Tainted: G W 4.17.0-rc4-test+ #933 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:clear_event_triggers+0x3b/0x70 RSP: 0018:ffffc90003783de0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 6b6b6b6b6b6b6b2b RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800c7130ba0 RBP: ffffc90003783e00 R08: ffff8801131993f8 R09: 0000000100230016 R10: ffffc90003783d80 R11: 0000000000000000 R12: ffff8800c7130ba0 R13: ffff8800c7130bd8 R14: ffff8800cc093768 R15: 00000000ffffff9c FS: 00007f6f4aa86700(0000) GS:ffff88011eb40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6f4a5aed60 CR3: 00000000cd552001 CR4: 00000000001606e0 Call Trace: event_trace_del_tracer+0x2a/0xc5 instance_rmdir+0x15c/0x200 tracefs_syscall_rmdir+0x52/0x90 vfs_rmdir+0xdb/0x160 do_rmdir+0x16d/0x1c0 __x64_sys_rmdir+0x17/0x20 do_syscall_64+0x55/0x1a0 entry_SYSCALL_64_after_hwframe+0x49/0xbe This was due to the call the clears out the triggers when an instance is being deleted not removing the trigger from the link list. Cc: stable@vger.kernel.org Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2018-05-262-5/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Three fixes for scheduler and kthread code: - allow calling kthread_park() on an already parked thread - restore the sched_pi_setprio() tracepoint behaviour - clarify the unclear string for the scheduling domain debug output" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched, tracing: Fix trace_sched_pi_setprio() for deboosting kthread: Allow kthread_park() on a parked kthread sched/topology: Clarify root domain(s) debug string
| * | kthread: Allow kthread_park() on a parked kthreadPeter Zijlstra2018-05-251-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following commit: 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme() completion issue") added a WARN() in the case where we call kthread_park() on an already parked thread, because the old code wasn't doing the right thing there and it wasn't at all clear that would happen. It turns out, this does in fact happen, so we have to deal with it. Instead of potentially returning early, also wait for the completion. This does however mean we have to use complete_all() and re-initialize the completion on re-use. Reported-by: LKP <lkp@01.org> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kernel test robot <lkp@intel.com> Cc: wfg@linux.intel.com Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 85f1abe0019f ("kthread, sched/wait: Fix kthread_parkme() completion issue") Link: http://lkml.kernel.org/r/20180504091142.GI12235@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/topology: Clarify root domain(s) debug stringJuri Lelli2018-05-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When scheduler debug is enabled, building scheduling domains outputs information about how the domains are laid out and to which root domain each CPU (or sets of CPUs) belongs, e.g.: CPU0 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 } CPU1 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 } [...] span: 0-5 (max cpu_capacity = 1024) The fact that latest line refers to CPUs 0-5 root domain doesn't however look immediately obvious to me: one might wonder why span 0-5 is reported "again". Make it more clear by adding "root domain" to it, as to end with the following: CPU0 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 } CPU1 attaching sched-domain(s): domain-0: span=0-5 level=MC groups: 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 4:{ span=4 }, 5:{ span=5 }, 0:{ span=0 } [...] root domain span: 0-5 (max cpu_capacity = 1024) Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180524152936.17611-1-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-05-251-0/+5
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc fixes from Andrew Morton: "16 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: kasan: fix memory hotplug during boot kasan: free allocated shadow memory on MEM_CANCEL_ONLINE checkpatch: fix macro argument precedence test init/main.c: include <linux/mem_encrypt.h> kernel/sys.c: fix potential Spectre v1 issue mm/memory_hotplug: fix leftover use of struct page during hotplug proc: fix smaps and meminfo alignment mm: do not warn on offline nodes unless the specific node is explicitly requested mm, memory_hotplug: make has_unmovable_pages more robust mm/kasan: don't vfree() nonexistent vm_area MAINTAINERS: change hugetlbfs maintainer and update files ipc/shm: fix shmat() nil address after round-down when remapping Revert "ipc/shm: Fix shmat mmap nil-page protection" idr: fix invalid ptr dereference on item delete ocfs2: revert "ocfs2/o2hb: check len for bio_add_page() to avoid getting incorrect bio" mm: fix nr_rotate_swap leak in swapon() error case
| * | | kernel/sys.c: fix potential Spectre v1 issueGustavo A. R. Silva2018-05-251-0/+5
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | `resource' can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: kernel/sys.c:1474 __do_compat_sys_old_getrlimit() warn: potential spectre issue 'get_current()->signal->rlim' (local cap) kernel/sys.c:1455 __do_sys_old_getrlimit() warn: potential spectre issue 'get_current()->signal->rlim' (local cap) Fix this by sanitizing *resource* before using it to index current->signal->rlim Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Link: http://lkml.kernel.org/r/20180515030038.GA11822@embeddedor.com Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2018-05-251-22/+64
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: "Let's begin the holiday weekend with some networking fixes: 1) Whoops need to restrict cfg80211 wiphy names even more to 64 bytes. From Eric Biggers. 2) Fix flags being ignored when using kernel_connect() with SCTP, from Xin Long. 3) Use after free in DCCP, from Alexey Kodanev. 4) Need to check rhltable_init() return value in ipmr code, from Eric Dumazet. 5) XDP handling fixes in virtio_net from Jason Wang. 6) Missing RTA_TABLE in rtm_ipv4_policy[], from Roopa Prabhu. 7) Need to use IRQ disabling spinlocks in mlx4_qp_lookup(), from Jack Morgenstein. 8) Prevent out-of-bounds speculation using indexes in BPF, from Daniel Borkmann. 9) Fix regression added by AF_PACKET link layer cure, from Willem de Bruijn. 10) Correct ENIC dma mask, from Govindarajulu Varadarajan. 11) Missing config options for PMTU tests, from Stefano Brivio" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (48 commits) ibmvnic: Fix partial success login retries selftests/net: Add missing config options for PMTU tests mlx4_core: allocate ICM memory in page size chunks enic: set DMA mask to 47 bit ppp: remove the PPPIOCDETACH ioctl ipv4: remove warning in ip_recv_error net : sched: cls_api: deal with egdev path only if needed vhost: synchronize IOTLB message with dev cleanup packet: fix reserve calculation net/mlx5: IPSec, Fix a race between concurrent sandbox QP commands net/mlx5e: When RXFCS is set, add FCS data into checksum calculation bpf: properly enforce index mask to prevent out-of-bounds speculation net/mlx4: Fix irq-unsafe spinlock usage net: phy: broadcom: Fix bcm_write_exp() net: phy: broadcom: Fix auxiliary control register reads net: ipv4: add missing RTA_TABLE to rtm_ipv4_policy net/mlx4: fix spelling mistake: "Inrerface" -> "Interface" and rephrase message ibmvnic: Only do H_EOI for mobility events tuntap: correctly set SOCKWQ_ASYNC_NOSPACE virtio-net: fix leaking page for gso packet during mergeable XDP ...
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2018-05-251-22/+64
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf 2018-05-24 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix a bug in the original fix to prevent out of bounds speculation when multiple tail call maps from different branches or calls end up at the same tail call helper invocation, from Daniel. 2) Two selftest fixes, one in reuseport_bpf_numa where test is skipped in case of missing numa support and another one to update kernel config to properly support xdp_meta.sh test, from Anders. ... Would be great if you have a chance to merge net into net-next after that. The verifier fix would be needed later as a dependency in bpf-next for upcomig work there. When you do the merge there's a trivial conflict on BPF side with 849fa50662fb ("bpf/verifier: refine retval R0 state for bpf_get_stack helper"): Resolution is to keep both functions, the do_refine_retval_range() and record_func_map(). ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | bpf: properly enforce index mask to prevent out-of-bounds speculationDaniel Borkmann2018-05-241-22/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While reviewing the verifier code, I recently noticed that the following two program variants in relation to tail calls can be loaded. Variant 1: # bpftool p d x i 15 0: (15) if r1 == 0x0 goto pc+3 1: (18) r2 = map[id:5] 3: (05) goto pc+2 4: (18) r2 = map[id:6] 6: (b7) r3 = 7 7: (35) if r3 >= 0xa0 goto pc+2 8: (54) (u32) r3 &= (u32) 255 9: (85) call bpf_tail_call#12 10: (b7) r0 = 1 11: (95) exit # bpftool m s i 5 5: prog_array flags 0x0 key 4B value 4B max_entries 4 memlock 4096B # bpftool m s i 6 6: prog_array flags 0x0 key 4B value 4B max_entries 160 memlock 4096B Variant 2: # bpftool p d x i 20 0: (15) if r1 == 0x0 goto pc+3 1: (18) r2 = map[id:8] 3: (05) goto pc+2 4: (18) r2 = map[id:7] 6: (b7) r3 = 7 7: (35) if r3 >= 0x4 goto pc+2 8: (54) (u32) r3 &= (u32) 3 9: (85) call bpf_tail_call#12 10: (b7) r0 = 1 11: (95) exit # bpftool m s i 8 8: prog_array flags 0x0 key 4B value 4B max_entries 160 memlock 4096B # bpftool m s i 7 7: prog_array flags 0x0 key 4B value 4B max_entries 4 memlock 4096B In both cases the index masking inserted by the verifier in order to control out of bounds speculation from a CPU via b2157399cc98 ("bpf: prevent out-of-bounds speculation") seems to be incorrect in what it is enforcing. In the 1st variant, the mask is applied from the map with the significantly larger number of entries where we would allow to a certain degree out of bounds speculation for the smaller map, and in the 2nd variant where the mask is applied from the map with the smaller number of entries, we get buggy behavior since we truncate the index of the larger map. The original intent from commit b2157399cc98 is to reject such occasions where two or more different tail call maps are used in the same tail call helper invocation. However, the check on the BPF_MAP_PTR_POISON is never hit since we never poisoned the saved pointer in the first place! We do this explicitly for map lookups but in case of tail calls we basically used the tail call map in insn_aux_data that was processed in the most recent path which the verifier walked. Thus any prior path that stored a pointer in insn_aux_data at the helper location was always overridden. Fix it by moving the map pointer poison logic into a small helper that covers both BPF helpers with the same logic. After that in fixup_bpf_calls() the poison check is then hit for tail calls and the program rejected. Latter only happens in unprivileged case since this is the *only* occasion where a rewrite needs to happen, and where such rewrite is specific to the map (max_entries, index_mask). In the privileged case the rewrite is generic for the insn->imm / insn->code update so multiple maps from different paths can be handled just fine since all the remaining logic happens in the instruction processing itself. This is similar to the case of map lookups: in case there is a collision of maps in fixup_bpf_calls() we must skip the inlined rewrite since this will turn the generic instruction sequence into a non- generic one. Thus the patch_call_imm will simply update the insn->imm location where the bpf_map_lookup_elem() will later take care of the dispatch. Given we need this 'poison' state as a check, the information of whether a map is an unpriv_array gets lost, so enforcing it prior to that needs an additional state. In general this check is needed since there are some complex and tail call intensive BPF programs out there where LLVM tends to generate such code occasionally. We therefore convert the map_ptr rather into map_state to store all this w/o extra memory overhead, and the bit whether one of the maps involved in the collision was from an unpriv_array thus needs to be retained as well there. Fixes: b2157399cc98 ("bpf: prevent out-of-bounds speculation") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | | | Merge branch 'speck-v20' of ↵Linus Torvalds2018-05-213-9/+94
|\ \ \ \ | |/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Merge speculative store buffer bypass fixes from Thomas Gleixner: - rework of the SPEC_CTRL MSR management to accomodate the new fancy SSBD (Speculative Store Bypass Disable) bit handling. - the CPU bug and sysfs infrastructure for the exciting new Speculative Store Bypass 'feature'. - support for disabling SSB via LS_CFG MSR on AMD CPUs including Hyperthread synchronization on ZEN. - PRCTL support for dynamic runtime control of SSB - SECCOMP integration to automatically disable SSB for sandboxed processes with a filter flag for opt-out. - KVM integration to allow guests fiddling with SSBD including the new software MSR VIRT_SPEC_CTRL to handle the LS_CFG based oddities on AMD. - BPF protection against SSB .. this is just the core and x86 side, other architecture support will come separately. * 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits) bpf: Prevent memory disambiguation attack x86/bugs: Rename SSBD_NO to SSB_NO KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG x86/bugs: Rework spec_ctrl base and mask logic x86/bugs: Remove x86_spec_ctrl_set() x86/bugs: Expose x86_spec_ctrl_base directly x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host} x86/speculation: Rework speculative_store_bypass_update() x86/speculation: Add virtualized speculative store bypass disable support x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL x86/speculation: Handle HT correctly on AMD x86/cpufeatures: Add FEATURE_ZEN x86/cpufeatures: Disentangle SSBD enumeration x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP KVM: SVM: Move spec control call after restore of GS x86/cpu: Make alternative_msr_write work for 32-bit code x86/bugs: Fix the parameters alignment and missing void x86/bugs: Make cpu_show_common() static ...
| * | | bpf: Prevent memory disambiguation attackAlexei Starovoitov2018-05-191-3/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Detect code patterns where malicious 'speculative store bypass' can be used and sanitize such patterns. 39: (bf) r3 = r10 40: (07) r3 += -216 41: (79) r8 = *(u64 *)(r7 +0) // slow read 42: (7a) *(u64 *)(r10 -72) = 0 // verifier inserts this instruction 43: (7b) *(u64 *)(r8 +0) = r3 // this store becomes slow due to r8 44: (79) r1 = *(u64 *)(r6 +0) // cpu speculatively executes this load 45: (71) r2 = *(u8 *)(r1 +0) // speculatively arbitrary 'load byte' // is now sanitized Above code after x86 JIT becomes: e5: mov %rbp,%rdx e8: add $0xffffffffffffff28,%rdx ef: mov 0x0(%r13),%r14 f3: movq $0x0,-0x48(%rbp) fb: mov %rdx,0x0(%r14) ff: mov 0x0(%rbx),%rdi 103: movzbq 0x0(%rdi),%rsi Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | seccomp: Move speculation migitation control to arch codeThomas Gleixner2018-05-051-13/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The migitation control is simpler to implement in architecture code as it avoids the extra function call to check the mode. Aside of that having an explicit seccomp enabled mode in the architecture mitigations would require even more workarounds. Move it into architecture code and provide a weak function in the seccomp code. Remove the 'which' argument as this allows the architecture to decide which mitigations are relevant for seccomp. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | seccomp: Add filter flag to opt-out of SSB mitigationKees Cook2018-05-051-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a seccomp user is not interested in Speculative Store Bypass mitigation by default, it can set the new SECCOMP_FILTER_FLAG_SPEC_ALLOW flag when adding filters. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | seccomp: Use PR_SPEC_FORCE_DISABLEThomas Gleixner2018-05-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use PR_SPEC_FORCE_DISABLE in seccomp() because seccomp does not allow to widen restrictions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | seccomp: Enable speculation flaw mitigationsKees Cook2018-05-031-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When speculation flaw mitigations are opt-in (via prctl), using seccomp will automatically opt-in to these protections, since using seccomp indicates at least some level of sandboxing is desired. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | nospec: Allow getting/setting on non-current taskKees Cook2018-05-031-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adjust arch_prctl_get/set_spec_ctrl() to operate on tasks other than current. This is needed both for /proc/$pid/status queries and for seccomp (since thread-syncing can trigger seccomp in non-current threads). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | prctl: Add speculation control prctlsThomas Gleixner2018-05-031-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two new prctls to control aspects of speculation related vulnerabilites and their mitigations to provide finer grained control over performance impacting mitigations. PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature which is selected with arg2 of prctl(2). The return value uses bit 0-2 with the following meaning: Bit Define Description 0 PR_SPEC_PRCTL Mitigation can be controlled per task by PR_SET_SPECULATION_CTRL 1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is disabled 2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is enabled If all bits are 0 the CPU is not affected by the speculation misfeature. If PR_SPEC_PRCTL is set, then the per task control of the mitigation is available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation misfeature will fail. PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which is selected by arg2 of prctl(2) per task. arg3 is used to hand in the control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE. The common return values are: EINVAL prctl is not implemented by the architecture or the unused prctl() arguments are not 0 ENODEV arg2 is selecting a not supported speculation misfeature PR_SET_SPECULATION_CTRL has these additional return values: ERANGE arg3 is incorrect, i.e. it's not either PR_SPEC_ENABLE or PR_SPEC_DISABLE ENXIO prctl control of the selected speculation misfeature is disabled The first supported controlable speculation misfeature is PR_SPEC_STORE_BYPASS. Add the define so this can be shared between architectures. Based on an initial patch from Tim Chen and mostly rewritten. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2018-05-212-34/+84
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Fix refcounting bug for connections in on-packet scheduling mode of IPVS, from Julian Anastasov. 2) Set network header properly in AF_PACKET's packet_snd, from Willem de Bruijn. 3) Fix regressions in 3c59x by converting to generic DMA API. It was relying upon the hack that the PCI DMA interfaces would accept NULL for EISA devices. From Christoph Hellwig. 4) Remove RDMA devices before unregistering netdev in QEDE driver, from Michal Kalderon. 5) Use after free in TUN driver ptr_ring usage, from Jason Wang. 6) Properly check for missing netlink attributes in SMC_PNETID requests, from Eric Biggers. 7) Set DMA mask before performaing any DMA operations in vmxnet3 driver, from Regis Duchesne. 8) Fix mlx5 build with SMP=n, from Saeed Mahameed. 9) Classifier fixes in bcm_sf2 driver from Florian Fainelli. 10) Tuntap use after free during release, from Jason Wang. 11) Don't use stack memory in scatterlists in tls code, from Matt Mullins. 12) Not fully initialized flow key object in ipv4 routing code, from David Ahern. 13) Various packet headroom bug fixes in ip6_gre driver, from Petr Machata. 14) Remove queues from XPS maps using correct index, from Amritha Nambiar. 15) Fix use after free in sock_diag, from Eric Dumazet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (64 commits) net: ip6_gre: fix tunnel metadata device sharing. cxgb4: fix offset in collecting TX rate limit info net: sched: red: avoid hashing NULL child sock_diag: fix use-after-free read in __sk_free sh_eth: Change platform check to CONFIG_ARCH_RENESAS net: dsa: Do not register devlink for unused ports net: Fix a bug in removing queues from XPS map bpf: fix truncated jump targets on heavy expansions bpf: parse and verdict prog attach may race with bpf map update bpf: sockmap update rollback on error can incorrectly dec prog refcnt net: test tailroom before appending to linear skb net: ip6_gre: Fix ip6erspan hlen calculation net: ip6_gre: Split up ip6gre_changelink() net: ip6_gre: Split up ip6gre_newlink() net: ip6_gre: Split up ip6gre_tnl_change() net: ip6_gre: Split up ip6gre_tnl_link_config() net: ip6_gre: Fix headroom request in ip6erspan_tunnel_xmit() net: ip6_gre: Request headroom in __gre6_xmit() selftests/bpf: check return value of fopen in test_verifier.c erspan: fix invalid erspan version. ...
| * | | bpf: fix truncated jump targets on heavy expansionsDaniel Borkmann2018-05-171-25/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recently during testing, I ran into the following panic: [ 207.892422] Internal error: Accessing user space memory outside uaccess.h routines: 96000004 [#1] SMP [ 207.901637] Modules linked in: binfmt_misc [...] [ 207.966530] CPU: 45 PID: 2256 Comm: test_verifier Tainted: G W 4.17.0-rc3+ #7 [ 207.974956] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB18A 03/31/2017 [ 207.982428] pstate: 60400005 (nZCv daif +PAN -UAO) [ 207.987214] pc : bpf_skb_load_helper_8_no_cache+0x34/0xc0 [ 207.992603] lr : 0xffff000000bdb754 [ 207.996080] sp : ffff000013703ca0 [ 207.999384] x29: ffff000013703ca0 x28: 0000000000000001 [ 208.004688] x27: 0000000000000001 x26: 0000000000000000 [ 208.009992] x25: ffff000013703ce0 x24: ffff800fb4afcb00 [ 208.015295] x23: ffff00007d2f5038 x22: ffff00007d2f5000 [ 208.020599] x21: fffffffffeff2a6f x20: 000000000000000a [ 208.025903] x19: ffff000009578000 x18: 0000000000000a03 [ 208.031206] x17: 0000000000000000 x16: 0000000000000000 [ 208.036510] x15: 0000ffff9de83000 x14: 0000000000000000 [ 208.041813] x13: 0000000000000000 x12: 0000000000000000 [ 208.047116] x11: 0000000000000001 x10: ffff0000089e7f18 [ 208.052419] x9 : fffffffffeff2a6f x8 : 0000000000000000 [ 208.057723] x7 : 000000000000000a x6 : 00280c6160000000 [ 208.063026] x5 : 0000000000000018 x4 : 0000000000007db6 [ 208.068329] x3 : 000000000008647a x2 : 19868179b1484500 [ 208.073632] x1 : 0000000000000000 x0 : ffff000009578c08 [ 208.078938] Process test_verifier (pid: 2256, stack limit = 0x0000000049ca7974) [ 208.086235] Call trace: [ 208.088672] bpf_skb_load_helper_8_no_cache+0x34/0xc0 [ 208.093713] 0xffff000000bdb754 [ 208.096845] bpf_test_run+0x78/0xf8 [ 208.100324] bpf_prog_test_run_skb+0x148/0x230 [ 208.104758] sys_bpf+0x314/0x1198 [ 208.108064] el0_svc_naked+0x30/0x34 [ 208.111632] Code: 91302260 f9400001 f9001fa1 d2800001 (29500680) [ 208.117717] ---[ end trace 263cb8a59b5bf29f ]--- The program itself which caused this had a long jump over the whole instruction sequence where all of the inner instructions required heavy expansions into multiple BPF instructions. Additionally, I also had BPF hardening enabled which requires once more rewrites of all constant values in order to blind them. Each time we rewrite insns, bpf_adj_branches() would need to potentially adjust branch targets which cross the patchlet boundary to accommodate for the additional delta. Eventually that lead to the case where the target offset could not fit into insn->off's upper 0x7fff limit anymore where then offset wraps around becoming negative (in s16 universe), or vice versa depending on the jump direction. Therefore it becomes necessary to detect and reject any such occasions in a generic way for native eBPF and cBPF to eBPF migrations. For the latter we can simply check bounds in the bpf_convert_filter()'s BPF_EMIT_JMP helper macro and bail out once we surpass limits. The bpf_patch_insn_single() for native eBPF (and cBPF to eBPF in case of subsequent hardening) is a bit more complex in that we need to detect such truncations before hitting the bpf_prog_realloc(). Thus the latter is split into an extra pass to probe problematic offsets on the original program in order to fail early. With that in place and carefully tested I no longer hit the panic and the rewrites are rejected properly. The above example panic I've seen on bpf-next, though the issue itself is generic in that a guard against this issue in bpf seems more appropriate in this case. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | bpf: parse and verdict prog attach may race with bpf map updateJohn Fastabend2018-05-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the sockmap design BPF programs (SK_SKB_STREAM_PARSER, SK_SKB_STREAM_VERDICT and SK_MSG_VERDICT) are attached to the sockmap map type and when a sock is added to the map the programs are used by the socket. However, sockmap updates from both userspace and BPF programs can happen concurrently with the attach and detach of these programs. To resolve this we use the bpf_prog_inc_not_zero and a READ_ONCE() primitive to ensure the program pointer is not refeched and possibly NULL'd before the refcnt increment. This happens inside a RCU critical section so although the pointer reference in the map object may be NULL (by a concurrent detach operation) the reference from READ_ONCE will not be free'd until after grace period. This ensures the object returned by READ_ONCE() is valid through the RCU criticl section and safe to use as long as we "know" it may be free'd shortly. Daniel spotted a case in the sock update API where instead of using the READ_ONCE() program reference we used the pointer from the original map, stab->bpf_{verdict|parse|txmsg}. The problem with this is the logic checks the object returned from the READ_ONCE() is not NULL and then tries to reference the object again but using the above map pointer, which may have already been NULL'd by a parallel detach operation. If this happened bpf_porg_inc_not_zero could dereference a NULL pointer. Fix this by using variable returned by READ_ONCE() that is checked for NULL. Fixes: 2f857d04601a ("bpf: sockmap, remove STRPARSER map_flags and add multi-map support") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | bpf: sockmap update rollback on error can incorrectly dec prog refcntJohn Fastabend2018-05-181-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the user were to only attach one of the parse or verdict programs then it is possible a subsequent sockmap update could incorrectly decrement the refcnt on the program. This happens because in the rollback logic, after an error, we have to decrement the program reference count when its been incremented. However, we only increment the program reference count if the user has both a verdict and a parse program. The reason for this is because, at least at the moment, both are required for any one to be meaningful. The problem fixed here is in the rollback path we decrement the program refcnt even if only one existing. But we never incremented the refcnt in the first place creating an imbalance. This patch fixes the error path to handle this case. Fixes: 2f857d04601a ("bpf: sockmap, remove STRPARSER map_flags and add multi-map support") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | | | Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2018-05-201-0/+8
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull UP timer fix from Thomas Gleixner: "Work around the for_each_cpu() oddity on UP kernels in the tick broadcast code which causes boot failures because the CPU0 bit is always reported as set independent of the cpumask content" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/broadcast: Use for_each_cpu() specially on UP kernels
| * | | | tick/broadcast: Use for_each_cpu() specially on UP kernelsDexuan Cui2018-05-151-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | for_each_cpu() unintuitively reports CPU0 as set independent of the actual cpumask content on UP kernels. This causes an unexpected PIT interrupt storm on a UP kernel running in an SMP virtual machine on Hyper-V, and as a result, the virtual machine can suffer from a strange random delay of 1~20 minutes during boot-up, and sometimes it can hang forever. Protect if by checking whether the cpumask is empty before entering the for_each_cpu() loop. [ tglx: Use !IS_ENABLED(CONFIG_SMP) instead of #ifdeffery ] Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poulson <jopoulso@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: stable@vger.kernel.org Cc: Rakib Mullick <rakib.mullick@gmail.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KY Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Link: https://lkml.kernel.org/r/KL1P15301MB000678289FE55BA365B3279ABF990@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM Link: https://lkml.kernel.org/r/KL1P15301MB0006FA63BC22BEB64902EAA0BF930@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
* | | | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2018-05-203-7/+4
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixlets from Thomas Gleixner: "Three trivial fixlets for the scheduler: - move print_rt_rq() and print_dl_rq() declarations to the right place - make grub_reclaim() static - fix the bogus documentation reference in Kconfig" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix documentation file path sched/deadline: Make the grub_reclaim() function static sched/debug: Move the print_rt_rq() and print_dl_rq() declarations to kernel/sched/sched.h
| * | | | | sched/deadline: Make the grub_reclaim() function staticMathieu Malaterre2018-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the grub_reclaim() function can be made static, make it so. Silences the following GCC warning (W=1): kernel/sched/deadline.c:1120:5: warning: no previous prototype for ‘grub_reclaim’ [-Wmissing-prototypes] Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180516200902.959-1-malat@debian.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | sched/debug: Move the print_rt_rq() and print_dl_rq() declarations to ↵Mathieu Malaterre2018-05-183-6/+3
| |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel/sched/sched.h In the following commit: 6b55c9654fcc ("sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h") the print_cfs_rq() prototype was added to <kernel/sched/sched.h>, right next to the prototypes for print_cfs_stats(), print_rt_stats() and print_dl_stats(). Finish this previous commit and also move related prototypes for print_rt_rq() and print_dl_rq(). Remove existing extern declarations now that they not needed anymore. Silences the following GCC warning, triggered by W=1: kernel/sched/debug.c:573:6: warning: no previous prototype for ‘print_rt_rq’ [-Wmissing-prototypes] kernel/sched/debug.c:603:6: warning: no previous prototype for ‘print_dl_rq’ [-Wmissing-prototypes] Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180516195348.30426-1-malat@debian.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | locking/percpu-rwsem: Annotate rwsem ownership transfer by setting ↵Waiman Long2018-05-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RWSEM_OWNER_UNKNOWN The filesystem freezing code needs to transfer ownership of a rwsem embedded in a percpu-rwsem from the task that does the freezing to another one that does the thawing by calling percpu_rwsem_release() after freezing and percpu_rwsem_acquire() before thawing. However, the new rwsem debug code runs afoul with this scheme by warning that the task that releases the rwsem isn't the one that acquires it, as reported by Amir Goldstein: DEBUG_LOCKS_WARN_ON(sem->owner != get_current()) WARNING: CPU: 1 PID: 1401 at /home/amir/build/src/linux/kernel/locking/rwsem.c:133 up_write+0x59/0x79 Call Trace: percpu_up_write+0x1f/0x28 thaw_super_locked+0xdf/0x120 do_vfs_ioctl+0x270/0x5f1 ksys_ioctl+0x52/0x71 __x64_sys_ioctl+0x16/0x19 do_syscall_64+0x5d/0x167 entry_SYSCALL_64_after_hwframe+0x49/0xbe To work properly with the rwsem debug code, we need to annotate that the rwsem ownership is unknown during the tranfer period until a brave soul comes forward to acquire the ownership. During that period, optimistic spinning will be disabled. Reported-by: Amir Goldstein <amir73il@gmail.com> Tested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Theodore Y. Ts'o <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-fsdevel@vger.kernel.org Link: http://lkml.kernel.org/r/1526420991-21213-3-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | locking/rwsem: Add a new RWSEM_ANONYMOUSLY_OWNED flagWaiman Long2018-05-163-21/+28
|/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are use cases where a rwsem can be acquired by one task, but released by another task. In thess cases, optimistic spinning may need to be disabled. One example will be the filesystem freeze/thaw code where the task that freezes the filesystem will acquire a write lock on a rwsem and then un-owns it before returning to userspace. Later on, another task will come along, acquire the ownership, thaw the filesystem and release the rwsem. Bit 0 of the owner field was used to designate that it is a reader owned rwsem. It is now repurposed to mean that the owner of the rwsem is not known. If only bit 0 is set, the rwsem is reader owned. If bit 0 and other bits are set, it is writer owned with an unknown owner. One such value for the latter case is (-1L). So we can set owner to 1 for reader-owned, -1 for writer-owned. The owner is unknown in both cases. To handle transfer of rwsem ownership, the higher level code should set the owner field to -1 to indicate a write-locked rwsem with unknown owner. Optimistic spinning will be disabled in this case. Once the higher level code figures who the new owner is, it can then set the owner field accordingly. Tested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Theodore Y. Ts'o <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-fsdevel@vger.kernel.org Link: http://lkml.kernel.org/r/1526420991-21213-2-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-05-137-67/+91
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/pti updates from Thomas Gleixner: "A mixed bag of fixes and updates for the ghosts which are hunting us. The scheduler fixes have been pulled into that branch to avoid conflicts. - A set of fixes to address a khread_parkme() race which caused lost wakeups and loss of state. - A deadlock fix for stop_machine() solved by moving the wakeups outside of the stopper_lock held region. - A set of Spectre V1 array access restrictions. The possible problematic spots were discuvered by Dan Carpenters new checks in smatch. - Removal of an unused file which was forgotten when the rest of that functionality was removed" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Remove unused file perf/x86/cstate: Fix possible Spectre-v1 indexing for pkg_msr perf/x86/msr: Fix possible Spectre-v1 indexing in the MSR driver perf/x86: Fix possible Spectre-v1 indexing for x86_pmu::event_map() perf/x86: Fix possible Spectre-v1 indexing for hw_perf_event cache_* perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[] sched/autogroup: Fix possible Spectre-v1 indexing for sched_prio_to_weight[] sched/core: Fix possible Spectre-v1 indexing for sched_prio_to_weight[] sched/core: Introduce set_special_state() kthread, sched/wait: Fix kthread_parkme() completion issue kthread, sched/wait: Fix kthread_parkme() wait-loop sched/fair: Fix the update of blocked load when newly idle stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock
| * | | | perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[]Peter Zijlstra2018-05-051-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > kernel/events/ring_buffer.c:871 perf_mmap_to_page() warn: potential spectre issue 'rb->aux_pages' Userspace controls @pgoff through the fault address. Sanitize the array index before doing the array dereference. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | sched/autogroup: Fix possible Spectre-v1 indexing for sched_prio_to_weight[]Peter Zijlstra2018-05-051-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > kernel/sched/autogroup.c:230 proc_sched_autogroup_set_nice() warn: potential spectre issue 'sched_prio_to_weight' Userspace controls @nice, sanitize the array index. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | sched/core: Fix possible Spectre-v1 indexing for sched_prio_to_weight[]Peter Zijlstra2018-05-051-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > kernel/sched/core.c:6921 cpu_weight_nice_write_s64() warn: potential spectre issue 'sched_prio_to_weight' Userspace controls @nice, so sanitize the value before using it to index an array. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | sched/core: Introduce set_special_state()Peter Zijlstra2018-05-042-18/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gaurav reported a perceived problem with TASK_PARKED, which turned out to be a broken wait-loop pattern in __kthread_parkme(), but the reported issue can (and does) in fact happen for states that do not do condition based sleeps. When the 'current->state = TASK_RUNNING' store of a previous (concurrent) try_to_wake_up() collides with the setting of a 'special' sleep state, we can loose the sleep state. Normal condition based wait-loops are immune to this problem, but for sleep states that are not condition based are subject to this problem. There already is a fix for TASK_DEAD. Abstract that and also apply it to TASK_STOPPED and TASK_TRACED, both of which are also without condition based wait-loop. Reported-by: Gaurav Kohli <gkohli@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | kthread, sched/wait: Fix kthread_parkme() completion issuePeter Zijlstra2018-05-032-35/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even with the wait-loop fixed, there is a further issue with kthread_parkme(). Upon hotplug, when we do takedown_cpu(), smpboot_park_threads() can return before all those threads are in fact blocked, due to the placement of the complete() in __kthread_parkme(). When that happens, sched_cpu_dying() -> migrate_tasks() can end up migrating such a still runnable task onto another CPU. Normally the task will have hit schedule() and gone to sleep by the time we do kthread_unpark(), which will then do __kthread_bind() to re-bind the task to the correct CPU. However, when we loose the initial TASK_PARKED store to the concurrent wakeup issue described previously, do the complete(), get migrated, it is possible to either: - observe kthread_unpark()'s clearing of SHOULD_PARK and terminate the park and set TASK_RUNNING, or - __kthread_bind()'s wait_task_inactive() to observe the competing TASK_RUNNING store. Either way the WARN() in __kthread_bind() will trigger and fail to correctly set the CPU affinity. Fix this by only issuing the complete() when the kthread has scheduled out. This does away with all the icky 'still running' nonsense. The alternative is to promote TASK_PARKED to a special state, this guarantees wait_task_inactive() cannot observe a 'stale' TASK_RUNNING and we'll end up doing the right thing, but this preserves the whole icky business of potentially migating the still runnable thing. Reported-by: Gaurav Kohli <gkohli@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | kthread, sched/wait: Fix kthread_parkme() wait-loopPeter Zijlstra2018-05-031-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gaurav reported a problem with __kthread_parkme() where a concurrent try_to_wake_up() could result in competing stores to ->state which, when the TASK_PARKED store got lost bad things would happen. The comment near set_current_state() actually mentions this competing store, but only mentions the case against TASK_RUNNING. This same store, with different timing, can happen against a subsequent !RUNNING store. This normally is not a problem, because as per that same comment, the !RUNNING state store is inside a condition based wait-loop: for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); if (!need_sleep) break; schedule(); } __set_current_state(TASK_RUNNING); If we loose the (first) TASK_UNINTERRUPTIBLE store to a previous (concurrent) wakeup, the schedule() will NO-OP and we'll go around the loop once more. The problem here is that the TASK_PARKED store is not inside the KTHREAD_SHOULD_PARK condition wait-loop. There is a genuine issue with sleeps that do not have a condition; this is addressed in a subsequent patch. Reported-by: Gaurav Kohli <gkohli@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | sched/fair: Fix the update of blocked load when newly idleVincent Guittot2018-05-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With commit: 31e77c93e432 ("sched/fair: Update blocked load when newly idle") ... we release the rq->lock when updating blocked load of idle CPUs. This opens a time window during which another CPU can add a task to this CPU's cfs_rq. The check for newly added task of idle_balance() is not in the common path. Move the out label to include this check. Reported-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 31e77c93e432 ("sched/fair: Update blocked load when newly idle") Link: http://lkml.kernel.org/r/20180426103133.GA6953@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlockPeter Zijlstra2018-05-031-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Matt reported the following deadlock: CPU0 CPU1 schedule(.prev=migrate/0) <fault> pick_next_task() ... idle_balance() migrate_swap() active_balance() stop_two_cpus() spin_lock(stopper0->lock) spin_lock(stopper1->lock) ttwu(migrate/0) smp_cond_load_acquire() -- waits for schedule() stop_one_cpu(1) spin_lock(stopper1->lock) -- waits for stopper lock Fix this deadlock by taking the wakeups out from under stopper->lock. This allows the active_balance() to queue the stop work and finish the context switch, which in turn allows the wakeup from migrate_swap() to observe the context and complete the wakeup. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reported-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180420095005.GH4064@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2018-05-131-56/+1
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "Revert the new NUMA aware placement approach which turned out to create more problems than it solved" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "sched/numa: Delay retrying placement for automatic NUMA balance after wake_affine()"
| * | | | | Revert "sched/numa: Delay retrying placement for automatic NUMA balance ↵Mel Gorman2018-05-121-56/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | after wake_affine()" This reverts commit 7347fc87dfe6b7315e74310ee1243dc222c68086. Srikar Dronamra pointed out that while the commit in question did show a performance improvement on ppc64, it did so at the cost of disabling active CPU migration by automatic NUMA balancing which was not the intent. The issue was that a serious flaw in the logic failed to ever active balance if SD_WAKE_AFFINE was disabled on scheduler domains. Even when it's enabled, the logic is still bizarre and against the original intent. Investigation showed that fixing the patch in either the way he suggested, using the correct comparison for jiffies values or introducing a new numa_migrate_deferred variable in task_struct all perform similarly to a revert with a mix of gains and losses depending on the workload, machine and socket count. The original intent of the commit was to handle a problem whereby wake_affine, idle balancing and automatic NUMA balancing disagree on the appropriate placement for a task. This was particularly true for cases where a single task was a massive waker of tasks but where wake_wide logic did not apply. This was particularly noticeable when a futex (a barrier) woke all worker threads and tried pulling the wakees to the waker nodes. In that specific case, it could be handled by tuning MPI or openMP appropriately, but the behavior is not illogical and was worth attempting to fix. However, the approach was wrong. Given that we're at rc4 and a fix is not obvious, it's better to play safe, revert this commit and retry later. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: efault@gmx.de Cc: ggherdovich@suse.cz Cc: hpa@zytor.com Cc: matt@codeblueprint.co.uk Cc: mpe@ellerman.id.au Link: http://lkml.kernel.org/r/20180509163115.6fnnyeg4vdm2ct4v@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-05-111-0/+5
|\ \ \ \ \ \ | |_|_|/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc fixes from Andrew Morton: "13 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: rbtree: include rcu.h scripts/faddr2line: fix error when addr2line output contains discriminator ocfs2: take inode cluster lock before moving reflinked inode from orphan dir mm, oom: fix concurrent munlock and oom reaper unmap, v3 mm: migrate: fix double call of radix_tree_replace_slot() proc/kcore: don't bounds check against address 0 mm: don't show nr_indirectly_reclaimable in /proc/vmstat mm: sections are not offlined during memory hotremove z3fold: fix reclaim lock-ups init: fix false positives in W+X checking lib/find_bit_benchmark.c: avoid soft lockup in test_find_first_bit() KASAN: prohibit KASAN+STRUCTLEAK combination MAINTAINERS: update Shuah's email address
| * | | | | init: fix false positives in W+X checkingJeffrey Hugo2018-05-111-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | load_module() creates W+X mappings via __vmalloc_node_range() (from layout_and_allocate()->move_module()->module_alloc()) by using PAGE_KERNEL_EXEC. These mappings are later cleaned up via "call_rcu_sched(&freeinit->rcu, do_free_init)" from do_init_module(). This is a problem because call_rcu_sched() queues work, which can be run after debug_checkwx() is run, resulting in a race condition. If hit, the race results in a nasty splat about insecure W+X mappings, which results in a poor user experience as these are not the mappings that debug_checkwx() is intended to catch. This issue is observed on multiple arm64 platforms, and has been artificially triggered on an x86 platform. Address the race by flushing the queued work before running the arch-defined mark_rodata_ro() which then calls debug_checkwx(). Link: http://lkml.kernel.org/r/1525103946-29526-1-git-send-email-jhugo@codeaurora.org Fixes: e1a58320a38d ("x86/mm: Warn on W^X mappings") Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org> Reported-by: Timur Tabi <timur@codeaurora.org> Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2018-05-111-5/+14
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Verify lengths of keys provided by the user is AF_KEY, from Kevin Easton. 2) Add device ID for BCM89610 PHY. Thanks to Bhadram Varka. 3) Add Spectre guards to some ATM code, courtesy of Gustavo A. R. Silva. 4) Fix infinite loop in NSH protocol code. To Eric Dumazet we are most grateful for this fix. 5) Line up /proc/net/netlink headers properly. This fix from YU Bo, we do appreciate. 6) Use after free in TLS code. Once again we are blessed by the honorable Eric Dumazet with this fix. 7) Fix regression in TLS code causing stalls on partial TLS records. This fix is bestowed upon us by Andrew Tomt. 8) Deal with too small MTUs properly in LLC code, another great gift from Eric Dumazet. 9) Handle cached route flushing properly wrt. MTU locking in ipv4, to Hangbin Liu we give thanks for this. 10) Fix regression in SO_BINDTODEVIC handling wrt. UDP socket demux. Paolo Abeni, he gave us this. 11) Range check coalescing parameters in mlx4 driver, thank you Moshe Shemesh. 12) Some ipv6 ICMP error handling fixes in rxrpc, from our good brother David Howells. 13) Fix kexec on mlx5 by freeing IRQs in shutdown path. Daniel Juergens, you're the best! 14) Don't send bonding RLB updates to invalid MAC addresses. Debabrata Benerjee saved us! 15) Uh oh, we were leaking in udp_sendmsg and ping_v4_sendmsg. The ship is now water tight, thanks to Andrey Ignatov. 16) IPSEC memory leak in ixgbe from Colin Ian King, man we've got holes everywhere! 17) Fix error path in tcf_proto_create, Jiri Pirko what would we do without you! * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (92 commits) net sched actions: fix refcnt leak in skbmod net: sched: fix error path in tcf_proto_create() when modules are not configured net sched actions: fix invalid pointer dereferencing if skbedit flags missing ixgbe: fix memory leak on ipsec allocation ixgbevf: fix ixgbevf_xmit_frame()'s return type ixgbe: return error on unsupported SFP module when resetting ice: Set rq_last_status when cleaning rq ipv4: fix memory leaks in udp_sendmsg, ping_v4_sendmsg mlxsw: core: Fix an error handling path in 'mlxsw_core_bus_device_register()' bonding: send learning packets for vlans on slave bonding: do not allow rlb updates to invalid mac net/mlx5e: Err if asked to offload TC match on frag being first net/mlx5: E-Switch, Include VF RDMA stats in vport statistics net/mlx5: Free IRQs in shutdown path rxrpc: Trace UDP transmission failure rxrpc: Add a tracepoint to log ICMP/ICMP6 and error messages rxrpc: Fix the min security level for kernel calls rxrpc: Fix error reception on AF_INET6 sockets rxrpc: Fix missing start of call timeout qed: fix spelling mistake: "taskelt" -> "tasklet" ...
| * \ \ \ \ \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2018-05-041-5/+14
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf 2018-05-05 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Sanitize attr->{prog,map}_type from bpf(2) since used as an array index to retrieve prog/map specific ops such that we prevent potential out of bounds value under speculation, from Mark and Daniel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
OpenPOWER on IntegriCloud