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2017-05-22genirq/msi: Populate the domain name if provided by the irqchipMarc Zyngier
In order to ease debug, let's populate the domain name upfront, before any MSI gets requested. This allows the domain to appear in the irq_domain_mapping, and the user to easily find the expected data. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/20170512115538.10767-4-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22irqdomain: Let irq_domain_mapping display ACPI fwnode attributesMarc Zyngier
If the system is using ACPI, there is no of_node to display. But ACPI can use a struct irqchip_fwid as a domain identifier, and it can be used to display the name contained in that structure. The output on such a system will look like this: pMSI 0 0 0 irqchip@00000000e1180000 MSI 37 0 0 irqchip@00000000e1180000 GICv2m 37 0 0 irqchip@00000000e1180000 GICv2 448 448 0 irqchip@ffff000008003000 Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/20170512115538.10767-3-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22irqdomain: Let irq_domain_mapping display hierarchical domainsMarc Zyngier
Hierarchical domains seem to be hard to grasp, and a number of aspiring kernel hackers find them utterly discombobulating. In order to ease their pain, let's make them appear in /sys/kernel/debug/irq_domain_mapping, such as the following: 96 0x81808 MSI 0x (null) RADIX MSI 96+ 0x00063 GICv2m 0xffff8003ee116980 RADIX GICv2m 96+ 0x00063 GICv2 0xffff00000916bfd8 LINEAR GICv2 [output compressed to fit in a commit log] This shows that IRQ96 is implemented by a stack of three domains, the + sign indicating the stacking. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/20170512115538.10767-2-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22kthread: Fix use-after-free if kthread fork failsVegard Nossum
If a kthread forks (e.g. usermodehelper since commit 1da5c46fa965) but fails in copy_process() between calling dup_task_struct() and setting p->set_child_tid, then the value of p->set_child_tid will be inherited from the parent and get prematurely freed by free_kthread_struct(). kthread() - worker_thread() - process_one_work() | - call_usermodehelper_exec_work() | - kernel_thread() | - _do_fork() | - copy_process() | - dup_task_struct() | - arch_dup_task_struct() | - tsk->set_child_tid = current->set_child_tid // implied | - ... | - goto bad_fork_* | - ... | - free_task(tsk) | - free_kthread_struct(tsk) | - kfree(tsk->set_child_tid) - ... - schedule() - __schedule() - wq_worker_sleeping() - kthread_data(task)->flags // UAF The problem started showing up with commit 1da5c46fa965 since it reused ->set_child_tid for the kthread worker data. A better long-term solution might be to get rid of the ->set_child_tid abuse. The comment in set_kthread_struct() also looks slightly wrong. Debugged-by: Jamie Iles <jamie.iles@oracle.com> Fixes: 1da5c46fa965 ("kthread: Make struct kthread kmalloc'ed") Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jamie Iles <jamie.iles@oracle.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170509073959.17858-1-vegard.nossum@oracle.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22PCI/MSI: Ignore affinity if pre/post vector count is more than min_vecsMichael Hernandez
min_vecs is the minimum amount of vectors needed to operate in MSI-X mode which may just include the vectors that don't need affinity. Disabling affinity settings causes the qla2xxx driver scsi_add_host() to fail when blk_mq is enabled as the blk_mq_pci_map_queues() expects affinity masks on each vector. Fixes: dfef358bd1be ("PCI/MSI: Don't apply affinity if there aren't enough vectors left") Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com> Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org # v4.10+
2017-05-22futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()Peter Zijlstra
Markus reported that the glibc/nptl/tst-robustpi8 test was failing after commit: cfafcd117da0 ("futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()") The following trace shows the problem: ld-linux-x86-64-2161 [019] .... 410.760971: SyS_futex: 00007ffbeb76b028: 80000875 op=FUTEX_LOCK_PI ld-linux-x86-64-2161 [019] ...1 410.760972: lock_pi_update_atomic: 00007ffbeb76b028: curval=80000875 uval=80000875 newval=80000875 ret=0 ld-linux-x86-64-2165 [011] .... 410.760978: SyS_futex: 00007ffbeb76b028: 80000875 op=FUTEX_UNLOCK_PI ld-linux-x86-64-2165 [011] d..1 410.760979: do_futex: 00007ffbeb76b028: curval=80000875 uval=80000875 newval=80000871 ret=0 ld-linux-x86-64-2165 [011] .... 410.760980: SyS_futex: 00007ffbeb76b028: 80000871 ret=0000 ld-linux-x86-64-2161 [019] .... 410.760980: SyS_futex: 00007ffbeb76b028: 80000871 ret=ETIMEDOUT Task 2165 does an UNLOCK_PI, assigning the lock to the waiter task 2161 which then returns with -ETIMEDOUT. That wrecks the lock state, because now the owner isn't aware it acquired the lock and removes the pending robust list entry. If 2161 is killed, the robust list will not clear out this futex and the subsequent acquire on this futex will then (correctly) result in -ESRCH which is unexpected by glibc, triggers an internal assertion and dies. Task 2161 Task 2165 rt_mutex_wait_proxy_lock() timeout(); /* T2161 is still queued in the waiter list */ return -ETIMEDOUT; futex_unlock_pi() spin_lock(hb->lock); rtmutex_unlock() remove_rtmutex_waiter(T2161); mark_lock_available(); /* Make the next waiter owner of the user space side */ futex_uval = 2161; spin_unlock(hb->lock); spin_lock(hb->lock); rt_mutex_cleanup_proxy_lock() if (rtmutex_owner() !== current) ... return FAIL; .... return -ETIMEOUT; This means that rt_mutex_cleanup_proxy_lock() needs to call try_to_take_rt_mutex() so it can take over the rtmutex correctly which was assigned by the waker. If the rtmutex is owned by some other task then this call is harmless and just confirmes that the waiter is not able to acquire it. While there, fix what looks like a merge error which resulted in rt_mutex_cleanup_proxy_lock() having two calls to fixup_rt_mutex_waiters() and rt_mutex_wait_proxy_lock() not having any. Both should have one, since both potentially touch the waiter list. Fixes: 38d589f2fd08 ("futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()") Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Bug-Spotted-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Link: http://lkml.kernel.org/r/20170519154850.mlomgdsd26drq5j6@hirez.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: "Mostly netfilter bug fixes in here, but we have some bits elsewhere as well. 1) Don't do SNAT replies for non-NATed connections in IPVS, from Julian Anastasov. 2) Don't delete conntrack helpers while they are still in use, from Liping Zhang. 3) Fix zero padding in xtables's xt_data_to_user(), from Willem de Bruijn. 4) Add proper RCU protection to nf_tables_dump_set() because we cannot guarantee that we hold the NFNL_SUBSYS_NFTABLES lock. From Liping Zhang. 5) Initialize rcv_mss in tcp_disconnect(), from Wei Wang. 6) smsc95xx devices can't handle IPV6 checksums fully, so don't advertise support for offloading them. From Nisar Sayed. 7) Fix out-of-bounds access in __ip6_append_data(), from Eric Dumazet. 8) Make atl2_probe() propagate the error code properly on failures, from Alexey Khoroshilov. 9) arp_target[] in bond_check_params() is used uninitialized. This got changes from a global static to a local variable, which is how this mistake happened. Fix from Jarod Wilson. 10) Fix fallout from unnecessary NULL check removal in cls_matchall, from Jiri Pirko. This is definitely brown paper bag territory..." * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits) net: sched: cls_matchall: fix null pointer dereference vsock: use new wait API for vsock_stream_sendmsg() bonding: fix randomly populated arp target array net: Make IP alignment calulations clearer. bonding: fix accounting of active ports in 3ad net: atheros: atl2: don't return zero on failure path in atl2_probe() ipv6: fix out of bound writes in __ip6_append_data() bridge: start hello_timer when enabling KERNEL_STP in br_stp_start smsc95xx: Support only IPv4 TCP/UDP csum offload arp: always override existing neigh entries with gratuitous ARP arp: postpone addr_type calculation to as late as possible arp: decompose is_garp logic into a separate function arp: fixed error in a comment tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 netfilter: xtables: fix build failure from COMPAT_XT_ALIGN outside CONFIG_COMPAT ebtables: arpreply: Add the standard target sanity check netfilter: nf_tables: revisit chain/object refcounting from elements netfilter: nf_tables: missing sanitization in data from userspace netfilter: nf_tables: can't assume lock is acquired when dumping set elems netfilter: synproxy: fix conntrackd interaction ...
2017-05-22Merge branches 'pm-sleep' and 'powercap'Rafael J. Wysocki
* pm-sleep: PM / hibernate: Declare variables as static RTC: rtc-cmos: Fix wakeup from suspend-to-idle PM / wakeup: Fix up wakeup_source_report_event() * powercap: PowerCap: Fix an error code in powercap_register_zone()
2017-05-22Merge branches 'intel_pstate', 'pm-cpufreq' and 'pm-cpufreq-sched'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Document the current behavior and user interface * pm-cpufreq: cpufreq: dbx500: add a Kconfig symbol * pm-cpufreq-sched: cpufreq: schedutil: use now as reference when aggregating shared policy requests
2017-05-22net: Make IP alignment calulations clearer.David S. Miller
The assignmnet: ip_align = strict ? 2 : NET_IP_ALIGN; in compare_pkt_ptr_alignment() trips up Coverity because we can only get to this code when strict is true, therefore ip_align will always be 2 regardless of NET_IP_ALIGN's value. So just assign directly to '2' and explain the situation in the comment above. Reported-by: "Gustavo A. R. Silva" <garsilva@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-21Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "A single scheduler fix: Prevent idle task from ever being preempted. That makes sure that synchronize_rcu_tasks() which is ignoring idle task does not pretend that no task is stuck in preempted state. If that happens and idle was preempted on a ftrace trampoline the machine crashes due to inconsistent state" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Call __schedule() from do_idle() without enabling preemption
2017-05-21Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A set of small fixes for the irq subsystem: - Cure a data ordering problem with chained interrupts - Three small fixlets for the mbigen irq chip" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Fix chained interrupt data ordering irqchip/mbigen: Fix the clear register offset calculation irqchip/mbigen: Fix potential NULL dereferencing irqchip/mbigen: Fix memory mapping code
2017-05-21osf_wait4: switch to kernel_wait4()Al Viro
... and sanitize copying rusage to userland Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21waitid(): switch copyout of siginfo to unsafe_put_user()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21wait_task_zombie: consolidate info logicsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21kill wait_noreap_copyout()Al Viro
folds into callers Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21lift getrusage() from wait_noreap_copyout()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21waitid(2): leave copyout of siginfo to syscall itselfAl Viro
have kernel_waitid() collect the information needed for siginfo into a small structure (waitid_info) passed to it; deal with copyout in sys_waitid()/compat_sys_waitid(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21kernel_wait4()/kernel_waitid(): delay copying status to userlandAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21wait4(2)/waitid(2): separate copying rusage to userlandAl Viro
New helpers: kernel_waitid() and kernel_wait4(). sys_waitid(), sys_wait4() and their compat variants switched to those. Copying struct rusage to userland is left to syscall itself. For compat_sys_wait4() that eliminates the use of set_fs() completely. For compat_sys_waitid() it's still needed (for siginfo handling); that will change shortly. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-21move compat wait4 and waitid next to native variantsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-20Merge tag 'trace-v4.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Fix a bug caused by not cleaning up the new instance unique triggers when deleting an instance. It also creates a selftest that triggers that bug. - Fix the delayed optimization happening after kprobes boot up self tests being removed by freeing of init memory. - Comment kprobes on why the delay optimization is not a problem for removal of modules, to keep other developers from searching that riddle. - Fix another case of rcu not watching in stack trace tracing. * tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Make sure RCU is watching before calling a stack trace kprobes: Document how optimized kprobes are removed from module unload selftests/ftrace: Add test to remove instance with active event triggers selftests/ftrace: Fix bashisms ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub ftrace/instances: Clear function triggers when removing instances ftrace: Simplify glob handling in unregister_ftrace_function_probe_func() tracing/kprobes: Enforce kprobes teardown after testing tracing: Move postpone selftests to core from early_initcall
2017-05-20Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A small collection of fixes that should go into this cycle. - a pull request from Christoph for NVMe, which ended up being manually applied to avoid pulling in newer bits in master. Mostly fibre channel fixes from James, but also a few fixes from Jon and Vijay - a pull request from Konrad, with just a single fix for xen-blkback from Gustavo. - a fuseblk bdi fix from Jan, fixing a regression in this series with the dynamic backing devices. - a blktrace fix from Shaohua, replacing sscanf() with kstrtoull(). - a request leak fix for drbd from Lars, fixing a regression in the last series with the kref changes. This will go to stable as well" * 'for-linus' of git://git.kernel.dk/linux-block: nvmet: release the sq ref on rdma read errors nvmet-fc: remove target cpu scheduling flag nvme-fc: stop queues on error detection nvme-fc: require target or discovery role for fc-nvme targets nvme-fc: correct port role bits nvme: unmap CMB and remove sysfs file in reset path blktrace: fix integer parse fuseblk: Fix warning in super_setup_bdi_name() block: xen-blkback: add null check to avoid null pointer dereference drbd: fix request leak introduced by locking/atomic, kref: Kill kref_sub()
2017-05-19blktrace: fix integer parseShaohua Li
sscanf is a very poor way to parse integer. For example, I input "discard" for act_mask, it gets 0xd and completely messes up. Using correct API to do integer parse. This patch also makes attributes accept any base of integer. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-19printk: Use the main logbuf in NMI when logbuf_lock is availablePetr Mladek
The commit 42a0bb3f71383b457a7d ("printk/nmi: generic solution for safe printk in NMI") caused that printk stores messages into a temporary buffer in NMI context. The buffer is per-CPU and therefore the size is rather limited. It works quite well for NMI backtraces. But there are longer logs that might get printed in NMI context, for example, lockdep warnings, ftrace_dump_on_oops. The temporary buffer is used to avoid deadlocks caused by logbuf_lock. Also it is needed to avoid races with the other temporary buffer that is used when PRINTK_SAFE_CONTEXT is entered. But the main buffer can be used in NMI if the lock is available and we did not interrupt PRINTK_SAFE_CONTEXT. The lock is checked using raw_spin_is_locked(). It might cause false negatives when the lock is taken on another CPU and this CPU is in the safe context from other reasons. Note that the safe context is used also to get console semaphore or when calling console drivers. For this reason, we do the check in printk_nmi_enter(). It makes the handling consistent for the entire NMI handler and avoids reshuffling of the messages. The patch also defines special printk context that allows to use printk_deferred() in NMI. Note that we could not flush the messages to the consoles because console drivers might use many other internal locks. The newly created vprintk_deferred() disables the preemption only around the irq work handling. It is needed there to keep the consistency between the two per-CPU variables. But there is no reason to disable preemption around vprintk_emit(). Finally, the patch puts back explicit serialization of the NMI backtraces from different CPUs. It was removed by the commit a9edc88093287183ac934b ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). It was not needed because the flushing of the temporary per-CPU buffers was serialized. Link: http://lkml.kernel.org/r/1493912763-24873-1-git-send-email-pmladek@suse.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rack+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: x86@kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-05-18tracing: Make sure RCU is watching before calling a stack traceSteven Rostedt (VMware)
As stack tracing now requires "rcu watching", force RCU to be watching when recording a stack trace. Link: http://lkml.kernel.org/r/20170512172449.879684501@goodmis.org Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Don't allow negative TCP reordering values, from Soheil Hassas Yeganeh. 2) Don't overflow while parsing ipv6 header options, from Craig Gallek. 3) Handle more cleanly the case where an individual route entry during a dump will not fit into the allocated netlink SKB, from David Ahern. 4) Add missing CONFIG_INET dependency for mlx5e, from Arnd Bergmann. 5) Allow neighbour updates to converge more quickly via gratuitous ARPs, from Ihar Hrachyshka. 6) Fix compile error from CONFIG_INET is disabled, from Eric Dumazet. 7) Fix use after free in x25 protocol init, from Lin Zhang. 8) Valid VLAN pvid ranges passed into br_validate(), from Tobias Jungel. 9) NULL out address lists in child sockets in SCTP, this is similar to the fix we made for inet connection sockets last week. From Eric Dumazet. 10) Fix NULL deref in mlxsw driver, from Ido Schimmel. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits) mlxsw: spectrum: Avoid possible NULL pointer dereference sh_eth: Do not print an error message for probe deferral sh_eth: Use platform device for printing before register_netdev() mlxsw: spectrum_router: Fix rif counter freeing routine mlxsw: spectrum_dpipe: Fix incorrect entry index cxgb4: update latest firmware version supported qmi_wwan: add another Lenovo EM74xx device ID sctp: do not inherit ipv6_{mc|ac|fl}_list from parent udp: make *udp*_queue_rcv_skb() functions static bridge: netlink: check vlan_default_pvid range net: ethernet: faraday: To support device tree usage. net: x25: fix one potential use-after-free issue bpf: adjust verifier heuristics ipv6: Check ip6_find_1stfragopt() return value properly. selftests/bpf: fix broken build due to types.h bnxt_en: Check status of firmware DCBX agent before setting DCB_CAP_DCBX_HOST. bnxt_en: Call bnxt_dcb_init() after getting firmware DCBX configuration. net: fix compile error in skb_orphan_partial() ipv6: Prevent overrun when parsing v6 header options neighbour: update neigh timestamps iff update is effective ...
2017-05-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull pid namespace fixes from Eric Biederman: "These are two bugs that turn out to have simple fixes that were reported during the merge window. Both of these issues have existed for a while and it just happens that they both were reported at almost the same time" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: pid_ns: Fix race between setns'ed fork() and zap_pid_ns_processes() pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes
2017-05-18Merge remote-tracking branch 'mauro-exp/docbook3' into death-to-docbookJonathan Corbet
Mauro says: This patch series convert the remaining DocBooks to ReST. The first version was originally send as 3 patch series: [PATCH 00/36] Convert DocBook documents to ReST [PATCH 0/5] Convert more books to ReST [PATCH 00/13] Get rid of DocBook The lsm book was added as if it were a text file under Documentation. The plan is to merge it with another file under Documentation/security, after both this series and a security Documentation patch series gets merged. It also adjusts some Sphinx-pedantic errors/warnings on some kernel-doc markups. I also added some patches here to add PDF output for all existing ReST books.
2017-05-18doc: ReSTify credentials.txtKees Cook
This updates the credentials API documentation to ReST markup and moves it under the security subsection of kernel API documentation. Cc: David Howells <dhowells@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-17bpf: adjust verifier heuristicsDaniel Borkmann
Current limits with regards to processing program paths do not really reflect today's needs anymore due to programs becoming more complex and verifier smarter, keeping track of more data such as const ALU operations, alignment tracking, spilling of PTR_TO_MAP_VALUE_ADJ registers, and other features allowing for smarter matching of what LLVM generates. This also comes with the side-effect that we result in fewer opportunities to prune search states and thus often need to do more work to prove safety than in the past due to different register states and stack layout where we mismatch. Generally, it's quite hard to determine what caused a sudden increase in complexity, it could be caused by something as trivial as a single branch somewhere at the beginning of the program where LLVM assigned a stack slot that is marked differently throughout other branches and thus causing a mismatch, where verifier then needs to prove safety for the whole rest of the program. Subsequently, programs with even less than half the insn size limit can get rejected. We noticed that while some programs load fine under pre 4.11, they get rejected due to hitting limits on more recent kernels. We saw that in the vast majority of cases (90+%) pruning failed due to register mismatches. In case of stack mismatches, majority of cases failed due to different stack slot types (invalid, spill, misc) rather than differences in spilled registers. This patch makes pruning more aggressive by also adding markers that sit at conditional jumps as well. Currently, we only mark jump targets for pruning. For example in direct packet access, these are usually error paths where we bail out. We found that adding these markers, it can reduce number of processed insns by up to 30%. Another option is to ignore reg->id in probing PTR_TO_MAP_VALUE_OR_NULL registers, which can help pruning slightly as well by up to 7% observed complexity reduction as stand-alone. Meaning, if a previous path with register type PTR_TO_MAP_VALUE_OR_NULL for map X was found to be safe, then in the current state a PTR_TO_MAP_VALUE_OR_NULL register for the same map X must be safe as well. Last but not least the patch also adds a scheduling point and bumps the current limit for instructions to be processed to a more adequate value. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-17kprobes: Document how optimized kprobes are removed from module unloadSteven Rostedt (VMware)
Thomas discovered a bug where the kprobe trace tests had a race condition where the kprobe_optimizer called from a delayed work queue that does the optimizing and "unoptimizing" of a kprobe, can try to modify the text after it has been freed by the init code. The kprobe trace selftest is a special case, and Thomas and myself investigated to see if there's a chance that this could also be a bug with module unloading, as the code is not obvious to how it handles this. After adding lots of printks, I figured it out. Thomas suggested that this should be commented so that others will not have to go through this exercise again. Link: http://lkml.kernel.org/r/20170516145835.3827d3aa@gandalf.local.home Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stubSteven Rostedt (VMware)
No need to add ugly #ifdefs in the code. Having a standard stub file is much prettier. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17ftrace/instances: Clear function triggers when removing instancesNaveen N. Rao
If instance directories are deleted while there are registered function triggers: # cd /sys/kernel/debug/tracing/instances # mkdir test # echo "schedule:enable_event:sched:sched_switch" > test/set_ftrace_filter # rmdir test Unable to handle kernel paging request for data at address 0x00000008 Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000021edde8 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc kvm iptable_filter fuse binfmt_misc pseries_rng rng_core vmx_crypto ib_iser rdma_cm iw_cm ib_cm ib_core libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c multipath virtio_net virtio_blk virtio_pci crc32c_vpmsum virtio_ring virtio CPU: 8 PID: 8694 Comm: rmdir Not tainted 4.11.0-nnr+ #113 task: c0000000bab52800 task.stack: c0000000baba0000 NIP: c0000000021edde8 LR: c0000000021f0590 CTR: c000000002119620 REGS: c0000000baba3870 TRAP: 0300 Not tainted (4.11.0-nnr+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22002422 XER: 20000000 CFAR: 00007fffabb725a8 DAR: 0000000000000008 DSISR: 40000000 SOFTE: 0 GPR00: c00000000220f750 c0000000baba3af0 c000000003157e00 0000000000000000 GPR04: 0000000000000040 00000000000000eb 0000000000000040 0000000000000000 GPR08: 0000000000000000 0000000000000113 0000000000000000 c00000000305db98 GPR12: c000000002119620 c00000000fd42c00 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c0000000bab52e90 0000000000000000 GPR24: 0000000000000000 00000000000000eb 0000000000000040 c0000000baba3bb0 GPR28: c00000009cb06eb0 c0000000bab52800 c00000009cb06eb0 c0000000baba3bb0 NIP [c0000000021edde8] ring_buffer_lock_reserve+0x8/0x4e0 LR [c0000000021f0590] trace_event_buffer_lock_reserve+0xe0/0x1a0 Call Trace: [c0000000baba3af0] [c0000000021f96c8] trace_event_buffer_commit+0x1b8/0x280 (unreliable) [c0000000baba3b60] [c00000000220f750] trace_event_buffer_reserve+0x80/0xd0 [c0000000baba3b90] [c0000000021196b8] trace_event_raw_event_sched_switch+0x98/0x180 [c0000000baba3c10] [c0000000029d9980] __schedule+0x6e0/0xab0 [c0000000baba3ce0] [c000000002122230] do_task_dead+0x70/0xc0 [c0000000baba3d10] [c0000000020ea9c8] do_exit+0x828/0xd00 [c0000000baba3dd0] [c0000000020eaf70] do_group_exit+0x60/0x100 [c0000000baba3e10] [c0000000020eb034] SyS_exit_group+0x24/0x30 [c0000000baba3e30] [c00000000200bcec] system_call+0x38/0x54 Instruction dump: 60000000 60420000 7d244b78 7f63db78 4bffaa09 393efff8 793e0020 39200000 4bfffecc 60420000 3c4c00f7 3842a020 <81230008> 2f890000 409e02f0 a14d0008 ---[ end trace b917b8985d0e650b ]--- Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000021edde8 Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc0000000021edde8 Faulting instruction address: 0xc0000000021edde8 To address this, let's clear all registered function probes before deleting the ftrace instance. Link: http://lkml.kernel.org/r/c5f1ca624043690bd94642bb6bffd3f2fc504035.1494956770.git.naveen.n.rao@linux.vnet.ibm.com Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17ftrace: Simplify glob handling in unregister_ftrace_function_probe_func()Naveen N. Rao
Handle a NULL glob properly and simplify the check. Link: http://lkml.kernel.org/r/5df74d4ffb4721db6d5a22fa08ca031d62ead493.1494956770.git.naveen.n.rao@linux.vnet.ibm.com Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17tracing/kprobes: Enforce kprobes teardown after testingThomas Gleixner
Enabling the tracer selftest triggers occasionally the warning in text_poke(), which warns when the to be modified page is not marked reserved. The reason is that the tracer selftest installs kprobes on functions marked __init for testing. These probes are removed after the tests, but that removal schedules the delayed kprobes_optimizer work, which will do the actual text poke. If the work is executed after the init text is freed, then the warning triggers. The bug can be reproduced reliably when the work delay is increased. Flush the optimizer work and wait for the optimizing/unoptimizing lists to become empty before returning from the kprobes tracer selftest. That ensures that all operations which were queued due to the probes removal have completed. Link: http://lkml.kernel.org/r/20170516094802.76a468bb@gandalf.local.home Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Fixes: 6274de498 ("kprobes: Support delayed unoptimizing") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17tracing: Move postpone selftests to core from early_initcallSteven Rostedt
I hit the following lockdep splat when booting with ftrace selftests enabled, as well as CONFIG_PREEMPT and LOCKDEP. Testing dynamic ftrace ops #1: (1 0 1 0 0) (1 1 2 0 0) (2 1 3 0 169) (2 2 4 0 50066) ------------[ cut here ]------------ WARNING: CPU: 0 PID: 13 at kernel/rcu/srcutree.c:202 check_init_srcu_struct+0x60/0x70 Modules linked in: CPU: 0 PID: 13 Comm: rcu_tasks_kthre Not tainted 4.12.0-rc1-test+ #587 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 task: ffff880119628040 task.stack: ffffc900006a4000 RIP: 0010:check_init_srcu_struct+0x60/0x70 RSP: 0000:ffffc900006a7d98 EFLAGS: 00010246 RAX: 0000000000000246 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff880119628040 RSI: 00000000ffffffff RDI: ffffffff81e5fb40 RBP: ffffc900006a7e20 R08: 00000023b403c000 R09: 0000000000000001 R10: ffffc900006a7e40 R11: 0000000000000000 R12: ffffffff81e5fb40 R13: 0000000000000286 R14: ffff880119628040 R15: ffffc900006a7e98 FS: 0000000000000000(0000) GS:ffff88011ea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88011edff000 CR3: 0000000001e0f000 CR4: 00000000001406f0 Call Trace: ? __synchronize_srcu+0x6e/0x140 ? lock_acquire+0xdc/0x1d0 ? ktime_get_mono_fast_ns+0x5d/0xb0 synchronize_srcu+0x6f/0x110 ? synchronize_srcu+0x6f/0x110 rcu_tasks_kthread+0x20a/0x540 kthread+0x114/0x150 ? __rcu_read_unlock+0x70/0x70 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x2e/0x40 Code: f6 83 70 06 00 00 03 49 89 c5 74 0d be 01 00 00 00 48 89 df e8 42 fa ff ff 4c 89 ee 4c 89 e7 e8 b7 42 75 00 5b 41 5c 41 5d 5d c3 <0f> ff eb aa 66 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 ---[ end trace 5c3f4206ce50f6ac ]--- What happens is that the selftests include a creating of a dynamically allocated ftrace_ops, which requires the use of synchronize_rcu_tasks() which uses srcu, and triggers the above warning. It appears that synchronize_rcu_tasks() is not set up at early_initcall(), but it is at core_initcall(). By moving the tests down to that location works out properly. Link: http://lkml.kernel.org/r/20170517111435.7388c033@gandalf.local.home Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17cgroup: Prevent kill_css() from being called more than onceWaiman Long
The kill_css() function may be called more than once under the condition that the css was killed but not physically removed yet followed by the removal of the cgroup that is hosting the css. This patch prevents any harmm from being done when that happens. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org # v4.5+
2017-05-17nohz: Fix collision between tick and other hrtimers, againFrederic Weisbecker
This restores commit: 24b91e360ef5: ("nohz: Fix collision between tick and other hrtimers") ... which got reverted by commit: 558e8e27e73f: ('Revert "nohz: Fix collision between tick and other hrtimers"') ... due to a regression where CPUs spuriously stopped ticking. The bug happened when a tick fired too early past its expected expiration: on IRQ exit the tick was scheduled again to the same deadline but skipped reprogramming because ts->next_tick still kept in cache the deadline. This has been fixed now with resetting ts->next_tick from the tick itself. Extra care has also been taken to prevent from obsolete values throughout CPU hotplug operations. When the tick is stopped and an interrupt occurs afterward, we check on that interrupt exit if the next tick needs to be rescheduled. If it doesn't need any update, we don't want to do anything. In order to check if the tick needs an update, we compare it against the clockevent device deadline. Now that's a problem because the clockevent device is at a lower level than the tick itself if it is implemented on top of hrtimer. Every hrtimer share this clockevent device. So comparing the next tick deadline against the clockevent device deadline is wrong because the device may be programmed for another hrtimer whose deadline collides with the tick. As a result we may end up not reprogramming the tick accidentally. In a worst case scenario under full dynticks mode, the tick stops firing as it is supposed to every 1hz, leaving /proc/stat stalled: Task in a full dynticks CPU ---------------------------- * hrtimer A is queued 2 seconds ahead * the tick is stopped, scheduled 1 second ahead * tick fires 1 second later * on tick exit, nohz schedules the tick 1 second ahead but sees the clockevent device is already programmed to that deadline, fooled by hrtimer A, the tick isn't rescheduled. * hrtimer A is cancelled before its deadline * tick never fires again until an interrupt happens... In order to fix this, store the next tick deadline to the tick_sched local structure and reuse that value later to check whether we need to reprogram the clock after an interrupt. On the other hand, ts->sleep_length still wants to know about the next clock event and not just the tick, so we want to improve the related comment to avoid confusion. Reported-and-tested-by: Tim Wright <tim@binbash.co.uk> Reported-and-tested-by: Pavel Machek <pavel@ucw.cz> Reported-by: James Hartsock <hartsjc@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1492783255-5051-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-17nohz: Add hrtimer sanity checkFrederic Weisbecker
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-16genirq: Fix chained interrupt data orderingThomas Gleixner
irq_set_chained_handler_and_data() sets up the chained interrupt and then stores the handler data. That's racy against an immediate interrupt which gets handled before the store of the handler data happened. The handler will dereference a NULL pointer and crash. Cure it by storing handler data before installing the chained handler. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2017-05-16irq: update genericirq book locationMauro Carvalho Chehab
This book got converted from DocBook. Update its references to point to the current location. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-05-16mutex, futex: adjust kernel-doc markups to generate ReSTMauro Carvalho Chehab
There are a few issues on some kernel-doc markups that was causing troubles with kernel-doc output on ReST format: ./kernel/futex.c:492: WARNING: Inline emphasis start-string without end-string. ./kernel/futex.c:1264: WARNING: Block quote ends without a blank line; unexpected unindent. ./kernel/futex.c:1721: WARNING: Block quote ends without a blank line; unexpected unindent. ./kernel/futex.c:2338: WARNING: Block quote ends without a blank line; unexpected unindent. ./kernel/futex.c:2426: WARNING: Block quote ends without a blank line; unexpected unindent. ./kernel/futex.c:2899: WARNING: Block quote ends without a blank line; unexpected unindent. ./kernel/futex.c:2972: WARNING: Block quote ends without a blank line; unexpected unindent. Fix them. No functional changes. Acked-by: Darren Hart (VMware) <dvhart@infradead.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Track alignment in BPF verifier so that legitimate programs won't be rejected on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS architectures. 2) Make tail calls work properly in arm64 BPF JIT, from Deniel Borkmann. 3) Make the configuration and semantics Generic XDP make more sense and don't allow both generic XDP and a driver specific instance to be active at the same time. Also from Daniel. 4) Don't crash on resume in xen-netfront, from Vitaly Kuznetsov. 5) Fix use-after-free in VRF driver, from Gao Feng. 6) Use netdev_alloc_skb_ip_align() to avoid unaligned IP headers in qca_spi driver, from Stefan Wahren. 7) Always run cleanup routines in BPF samples when we get SIGTERM, from Andy Gospodarek. 8) The mdio phy code should bring PHYs out of reset using the shared GPIO lines before invoking bus->reset(). From Florian Fainelli. 9) Some USB descriptor access endian fixes in various drivers from Johan Hovold. 10) Handle PAUSE advertisements properly in mlx5 driver, from Gal Pressman. 11) Fix reversed test in mlx5e_setup_tc(), from Saeed Mahameed. 12) Cure netdev leak in AF_PACKET when using timestamping via control messages. From Douglas Caetano dos Santos. 13) netcp doesn't support HWTSTAMP_FILTER_ALl, reject it. From Miroslav Lichvar. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits) ldmvsw: stop the clean timer at beginning of remove ldmvsw: unregistering netdev before disable hardware net: netcp: fix check of requested timestamping filter ipv6: avoid dad-failures for addresses with NODAD qed: Fix uninitialized data in aRFS infrastructure mdio: mux: fix device_node_continue.cocci warnings net/packet: fix missing net_device reference release net/mlx4_core: Use min3 to select number of MSI-X vectors macvlan: Fix performance issues with vlan tagged packets net: stmmac: use correct pointer when printing normal descriptor ring net/mlx5: Use underlay QPN from the root name space net/mlx5e: IPoIB, Only support regular RQ for now net/mlx5e: Fix setup TC ndo net/mlx5e: Fix ethtool pause support and advertise reporting net/mlx5e: Use the correct pause values for ethtool advertising vmxnet3: ensure that adapter is in proper state during force_close sfc: revert changes to NIC revision numbers net: ch9200: add missing USB-descriptor endianness conversions net: irda: irda-usb: fix firmware name on big-endian hosts net: dsa: mv88e6xxx: add default case to switch ...
2017-05-15sched/fair: Fix O(nr_cgroups) in load balance pathTejun Heo
Currently, rq->leaf_cfs_rq_list is a traversal ordered list of all live cfs_rqs which have ever been active on the CPU; unfortunately, this makes update_blocked_averages() O(# total cgroups) which isn't scalable at all. This shows up as a small CPU consumption and scheduling latency increase in the load balancing path in systems with CPU controller enabled across most cgroups. In an edge case where temporary cgroups were leaking, this caused the kernel to consume good several tens of percents of CPU cycles running update_blocked_averages(), each run taking multiple millisecs. This patch fixes the issue by taking empty and fully decayed cfs_rqs off the rq->leaf_cfs_rq_list. Signed-off-by: Tejun Heo <tj@kernel.org> [ Added cfs_rq_is_decayed() ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Cc: Chris Mason <clm@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170426004350.GB3222@wtj.duckdns.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-15sched/fair: Use task_groups instead of leaf_cfs_rq_list to walk all cfs_rqsPeter Zijlstra
In order to allow leaf_cfs_rq_list to remove entries switch the bandwidth hotplug code over to the task_groups list. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170504133122.a6qjlj3hlblbjxux@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-15sched/topology: Rename sched_group_cpus()Peter Zijlstra
There's a discrepancy in naming between the sched_domain and sched_group cpumask accessor. Since we're doing changes, fix it. $ git grep sched_group_cpus | wc -l 28 $ git grep sched_domain_span | wc -l 38 Suggests changing sched_group_cpus() into sched_group_span(): for i in `git grep -l sched_group_cpus` do sed -ie 's/sched_group_cpus/sched_group_span/g' $i done Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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>
2017-05-15sched/topology: Rename sched_group_mask()Peter Zijlstra
Since sched_group_mask() is now an independent cpumask (it no longer masks sched_group_cpus()), rename the thing. Suggested-by: Lauro Ramos Venancio <lvenanci@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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>
2017-05-15sched/topology: Simplify sched_group_mask() usagePeter Zijlstra
While writing the comments, it occurred to me that: sg_cpus & sg_mask == sg_mask at least conceptually; the !overlap case sets the all 1s mask. If we correct that we can simplify things and directly use sg_mask. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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>
2017-05-15sched/topology: Rewrite get_group()Peter Zijlstra
We want to attain: sg_cpus() & sg_mask() == sg_mask() for this to be so we must initialize sg_mask() to sg_cpus() for the !overlap case (its currently cpumask_setall()). Since the code makes my head hurt bad, rewrite it into a simpler form, inspired by the now fixed overlap code. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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>