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2017-01-27timers: Omit POSIX timer stuff from task_struct when disabledNicolas Pitre
When CONFIG_POSIX_TIMERS is disabled, it is preferable to remove related structures from struct task_struct and struct signal_struct as they won't contain anything useful and shouldn't be relied upon by mistake. Code still referencing those structures is also disabled here. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-01-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) GTP fixes from Andreas Schultz (missing genl module alias, clear IP DF on transmit). 2) Netfilter needs to reflect the fwmark when sending resets, from Pau Espin Pedrol. 3) nftable dump OOPS fix from Liping Zhang. 4) Fix erroneous setting of VIRTIO_NET_HDR_F_DATA_VALID on transmit, from Rolf Neugebauer. 5) Fix build error of ipt_CLUSTERIP when procfs is disabled, from Arnd Bergmann. 6) Fix regression in handling of NETIF_F_SG in harmonize_features(), from Eric Dumazet. 7) Fix RTNL deadlock wrt. lwtunnel module loading, from David Ahern. 8) tcp_fastopen_create_child() needs to setup tp->max_window, from Alexey Kodanev. 9) Missing kmemdup() failure check in ipv6 segment routing code, from Eric Dumazet. 10) Don't execute unix_bind() under the bindlock, otherwise we deadlock with splice. From WANG Cong. 11) ip6_tnl_parse_tlv_enc_lim() potentially reallocates the skb buffer, therefore callers must reload cached header pointers into that skb. Fix from Eric Dumazet. 12) Fix various bugs in legacy IRQ fallback handling in alx driver, from Tobias Regnery. 13) Do not allow lwtunnel drivers to be unloaded while they are referenced by active instances, from Robert Shearman. 14) Fix truncated PHY LED trigger names, from Geert Uytterhoeven. 15) Fix a few regressions from virtio_net XDP support, from John Fastabend and Jakub Kicinski. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (102 commits) ISDN: eicon: silence misleading array-bounds warning net: phy: micrel: add support for KSZ8795 gtp: fix cross netns recv on gtp socket gtp: clear DF bit on GTP packet tx gtp: add genl family modules alias tcp: don't annotate mark on control socket from tcp_v6_send_response() ravb: unmap descriptors when freeing rings virtio_net: reject XDP programs using header adjustment virtio_net: use dev_kfree_skb for small buffer XDP receive r8152: check rx after napi is enabled r8152: re-schedule napi for tx r8152: avoid start_xmit to schedule napi when napi is disabled r8152: avoid start_xmit to call napi_schedule during autosuspend net: dsa: Bring back device detaching in dsa_slave_suspend() net: phy: leds: Fix truncated LED trigger names net: phy: leds: Break dependency of phy.h on phy_led_triggers.h net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash net-next: ethernet: mediatek: change the compatible string Documentation: devicetree: change the mediatek ethernet compatible string bnxt_en: Fix RTNL lock usage on bnxt_get_port_module_status(). ...
2017-01-27PM / Hibernate: Use rb_entry() instead of container_of()Geliang Tang
To make the code clearer, use rb_entry() instead of container_of() to deal with rbtree. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-26Merge tag 'pm-4.10-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix two regressions introduced recently, one by reverting the problematic commit and one by fixing up the behavior in an overlooked case. Specifics: - Revert the recent change that caused suspend-to-idle to be used as the default suspend method on systems where it is indicated to be efficient by the ACPI tables, as that turned out to be premature and introduced suspend regressions on some systems with missing power management support in device drivers (Rafael Wysocki). - Fix up the intel_pstate driver to take changes of the global limits via sysfs correctly when the performance policy is used which has been broken by a recent change in it (Srinivas Pandruvada)" * tag 'pm-4.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy Revert "PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag"
2017-01-27Merge branches 'pm-sleep' and 'pm-cpufreq'Rafael J. Wysocki
* pm-sleep: Revert "PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag" * pm-cpufreq: cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy
2017-01-26Merge branch 'for-4.10-fixes' into for-4.11Tejun Heo
2017-01-26cgroup: don't online subsystems before cgroup_name/path() are operationalTejun Heo
While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems before the new cgroup is associated with it kernfs_node. This is fine for cgroup proper but cgroup_name/path() depend on the associated kernfs_node and if a subsystem makes the new cgroup_subsys_state visible, which they're allowed to after onlining, it can lead to NULL dereference. The current code performs cgroup creation and subsystem onlining in cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems visible afterwards. There's no reason to online the subsystems early and we can simply drop cgroup_apply_control_enable() call from cgroup_create() so that the subsystems are onlined and made visible at the same time. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") Cc: stable@vger.kernel.org # v4.6+
2017-01-26sysctl: fix proc_doulongvec_ms_jiffies_minmax()Eric Dumazet
We perform the conversion between kernel jiffies and ms only when exporting kernel value to user space. We need to do the opposite operation when value is written by user. Only matters when HZ != 1000 Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-25Merge branches 'doc.2017.01.15b', 'dyntick.2017.01.23a', ↵Paul E. McKenney
'fixes.2017.01.23a', 'srcu.2017.01.25a' and 'torture.2017.01.15b' into HEAD doc.2017.01.15b: Documentation updates dyntick.2017.01.23a: Dyntick tracking consolidation fixes.2017.01.23a: Miscellaneous fixes srcu.2017.01.25a: SRCU rewrite, fixes, and verification torture.2017.01.15b: Torture-test updates
2017-01-25srcu: Reduce probability of SRCU ->unlock_count[] counter overflowPaul E. McKenney
Because there are no memory barriers between the srcu_flip() ->completed increment and the summation of the read-side ->unlock_count[] counters, both the compiler and the CPU can reorder the summation with the ->completed increment. If the updater is preempted long enough during this process, the read-side counters could overflow, resulting in a too-short grace period. This commit therefore adds a memory barrier just after the ->completed increment, ensuring that if the summation misses an increment of ->unlock_count[] from __srcu_read_unlock(), the next __srcu_read_lock() will see the new value of ->completed, thus bounding the number of ->unlock_count[] increments that can be missed to NR_CPUS. The actual overflow computation is more complex due to the possibility of nesting of __srcu_read_lock(). Reported-by: Lance Roy <ldr709@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-01-25srcu: Force full grace-period orderingPaul E. McKenney
If a process invokes synchronize_srcu(), is delayed just the right amount of time, and thus does not sleep when waiting for the grace period to complete, there is no ordering between the end of the grace period and the code following the synchronize_srcu(). Similarly, there can be a lack of ordering between the end of the SRCU grace period and callback invocation. This commit adds the necessary ordering. Reported-by: Lance Roy <ldr709@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: Further smp_mb() adjustment per email with Lance Roy. ]
2017-01-25srcu: Implement more-efficient reader countsLance Roy
SRCU uses two per-cpu counters: a nesting counter to count the number of active critical sections, and a sequence counter to ensure that the nesting counters don't change while they are being added together in srcu_readers_active_idx_check(). This patch instead uses per-cpu lock and unlock counters. Because both counters only increase and srcu_readers_active_idx_check() reads the unlock counter before the lock counter, this achieves the same end without having to increment two different counters in srcu_read_lock(). This also saves a smp_mb() in srcu_readers_active_idx_check(). Possible bug: There is no guarantee that the lock counter won't overflow during srcu_readers_active_idx_check(), as there are no memory barriers around srcu_flip() (see comment in srcu_readers_active_idx_check() for details). However, this problem was already present before this patch. Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Lance Roy <ldr709@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-01-25bpf: add initial bpf tracepointsDaniel Borkmann
This work adds a number of tracepoints to paths that are either considered slow-path or exception-like states, where monitoring or inspecting them would be desirable. For bpf(2) syscall, tracepoints have been placed for main commands when they succeed. In XDP case, tracepoint is for exceptions, that is, f.e. on abnormal BPF program exit such as unknown or XDP_ABORTED return code, or when error occurs during XDP_TX action and the packet could not be forwarded. Both have been split into separate event headers, and can be further extended. Worst case, if they unexpectedly should get into our way in future, they can also removed [1]. Of course, these tracepoints (like any other) can be analyzed by eBPF itself, etc. Example output: # ./perf record -a -e bpf:* sleep 10 # ./perf script sock_example 6197 [005] 283.980322: bpf:bpf_map_create: map type=ARRAY ufd=4 key=4 val=8 max=256 flags=0 sock_example 6197 [005] 283.980721: bpf:bpf_prog_load: prog=a5ea8fa30ea6849c type=SOCKET_FILTER ufd=5 sock_example 6197 [005] 283.988423: bpf:bpf_prog_get_type: prog=a5ea8fa30ea6849c type=SOCKET_FILTER sock_example 6197 [005] 283.988443: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[06 00 00 00] val=[00 00 00 00 00 00 00 00] [...] sock_example 6197 [005] 288.990868: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[01 00 00 00] val=[14 00 00 00 00 00 00 00] swapper 0 [005] 289.338243: bpf:bpf_prog_put_rcu: prog=a5ea8fa30ea6849c type=SOCKET_FILTER [1] https://lwn.net/Articles/705270/ Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25trace: add variant without spacing in trace_print_hex_seqDaniel Borkmann
For upcoming tracepoint support for BPF, we want to dump the program's tag. Format should be similar to __print_hex(), but without spacing. Add a __print_hex_str() variant for exactly that purpose that reuses trace_print_hex_seq(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25Merge branch 'linus' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-24Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge fixes from Andrew Morton: "26 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits) MAINTAINERS: add Dan Streetman to zbud maintainers MAINTAINERS: add Dan Streetman to zswap maintainers mm: do not export ioremap_page_range symbol for external module mn10300: fix build error of missing fpu_save() romfs: use different way to generate fsid for BLOCK or MTD frv: add missing atomic64 operations mm, page_alloc: fix premature OOM when racing with cpuset mems update mm, page_alloc: move cpuset seqcount checking to slowpath mm, page_alloc: fix fast-path race with cpuset update or removal mm, page_alloc: fix check for NULL preferred_zone kernel/panic.c: add missing \n fbdev: color map copying bounds checking frv: add atomic64_add_unless() mm/mempolicy.c: do not put mempolicy before using its nodemask radix-tree: fix private list warnings Documentation/filesystems/proc.txt: add VmPin mm, memcg: do not retry precharge charges proc: add a schedule point in proc_pid_readdir() mm: alloc_contig: re-allow CMA to compact FS pages mm/slub.c: trace free objects at KERN_INFO ...
2017-01-24kernel/panic.c: add missing \nJiri Slaby
When a system panics, the "Rebooting in X seconds.." message is never printed because it lacks a new line. Fix it. Link: http://lkml.kernel.org/r/20170119114751.2724-1-jslaby@suse.cz Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24kernel/watchdog: prevent false hardlockup on overloaded systemDon Zickus
On an overloaded system, it is possible that a change in the watchdog threshold can be delayed long enough to trigger a false positive. This can easily be achieved by having a cpu spinning indefinitely on a task, while another cpu updates watchdog threshold. What happens is while trying to park the watchdog threads, the hrtimers on the other cpus trigger and reprogram themselves with the new slower watchdog threshold. Meanwhile, the nmi watchdog is still programmed with the old faster threshold. Because the one cpu is blocked, it prevents the thread parking on the other cpus from completing, which is needed to shutdown the nmi watchdog and reprogram it correctly. As a result, a false positive from the nmi watchdog is reported. Fix this by setting a park_in_progress flag to block all lockups until the parking is complete. Fix provided by Ulrich Obergfell. [akpm@linux-foundation.org: s/park_in_progress/watchdog_park_in_progress/] Link: http://lkml.kernel.org/r/1481041033-192236-1-git-send-email-dzickus@redhat.com Signed-off-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace fix from Eric Biederman: "This has a single brown bag fix. The possible deadlock with dec_pid_namespaces that I had thought was fixed earlier turned out only to have been moved. So instead of being cleaver this change takes ucounts_lock with irqs disabled. So dec_ucount can be used from any context without fear of deadlock. The items accounted for dec_ucount and inc_ucount are all comparatively heavy weight objects so I don't exepct this will have any measurable performance impact" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Make ucounts lock irq-safe
2017-01-24bpf: enable verifier to better track const alu opsDaniel Borkmann
William reported couple of issues in relation to direct packet access. Typical scheme is to check for data + [off] <= data_end, where [off] can be either immediate or coming from a tracked register that contains an immediate, depending on the branch, we can then access the data. However, in case of calculating [off] for either the mentioned test itself or for access after the test in a more "complex" way, then the verifier will stop tracking the CONST_IMM marked register and will mark it as UNKNOWN_VALUE one. Adding that UNKNOWN_VALUE typed register to a pkt() marked register, the verifier then bails out in check_packet_ptr_add() as it finds the registers imm value below 48. In the first below example, that is due to evaluate_reg_imm_alu() not handling right shifts and thus marking the register as UNKNOWN_VALUE via helper __mark_reg_unknown_value() that resets imm to 0. In the second case the same happens at the time when r4 is set to r4 &= r5, where it transitions to UNKNOWN_VALUE from evaluate_reg_imm_alu(). Later on r4 we shift right by 3 inside evaluate_reg_alu(), where the register's imm turns into 3. That is, for registers with type UNKNOWN_VALUE, imm of 0 means that we don't know what value the register has, and for imm > 0 it means that the value has [imm] upper zero bits. F.e. when shifting an UNKNOWN_VALUE register by 3 to the right, no matter what value it had, we know that the 3 upper most bits must be zero now. This is to make sure that ALU operations with unknown registers don't overflow. Meaning, once we know that we have more than 48 upper zero bits, or, in other words cannot go beyond 0xffff offset with ALU ops, such an addition will track the target register as a new pkt() register with a new id, but 0 offset and 0 range, so for that a new data/data_end test will be required. Is the source register a CONST_IMM one that is to be added to the pkt() register, or the source instruction is an add instruction with immediate value, then it will get added if it stays within max 0xffff bounds. >From there, pkt() type, can be accessed should reg->off + imm be within the access range of pkt(). [...] from 28 to 30: R0=imm1,min_value=1,max_value=1 R1=pkt(id=0,off=0,r=22) R2=pkt_end R3=imm144,min_value=144,max_value=144 R4=imm0,min_value=0,max_value=0 R5=inv48,min_value=2054,max_value=2054 R10=fp 30: (bf) r5 = r3 31: (07) r5 += 23 32: (77) r5 >>= 3 33: (bf) r6 = r1 34: (0f) r6 += r5 cannot add integer value with 0 upper zero bits to ptr_to_packet [...] from 52 to 80: R0=imm1,min_value=1,max_value=1 R1=pkt(id=0,off=0,r=34) R2=pkt_end R3=inv R4=imm272 R5=inv56,min_value=17,max_value=17 R6=pkt(id=0,off=26,r=34) R10=fp 80: (07) r4 += 71 81: (18) r5 = 0xfffffff8 83: (5f) r4 &= r5 84: (77) r4 >>= 3 85: (0f) r1 += r4 cannot add integer value with 3 upper zero bits to ptr_to_packet Thus to get above use-cases working, evaluate_reg_imm_alu() has been extended for further ALU ops. This is fine, because we only operate strictly within realm of CONST_IMM types, so here we don't care about overflows as they will happen in the simulated but also real execution and interaction with pkt() in check_packet_ptr_add() will check actual imm value once added to pkt(), but it's irrelevant before. With regards to 06c1c049721a ("bpf: allow helpers access to variable memory") that works on UNKNOWN_VALUE registers, the verifier becomes now a bit smarter as it can better resolve ALU ops, so we need to adapt two test cases there, as min/max bound tracking only becomes necessary when registers were spilled to stack. So while mask was set before to track upper bound for UNKNOWN_VALUE case, it's now resolved directly as CONST_IMM, and such contructs are only necessary when f.e. registers are spilled. For commit 6b17387307ba ("bpf: recognize 64bit immediate loads as consts") that initially enabled dw load tracking only for nfp jit/ analyzer, I did couple of tests on large, complex programs and we don't increase complexity badly (my tests were in ~3% range on avg). I've added a couple of tests similar to affected code above, and it works fine with verifier now. Reported-by: William Tu <u9012063@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Gianluca Borello <g.borello@gmail.com> Cc: William Tu <u9012063@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-23bpf, lpm: fix kfree of im_node in trie_update_elemDaniel Borkmann
We need to initialize im_node to NULL, otherwise in case of error path it gets passed to kfree() as uninitialized pointer. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24inotify: Convert to using per-namespace limitsNikolay Borisov
This patchset converts inotify to using the newly introduced per-userns sysctl infrastructure. Currently the inotify instances/watches are being accounted in the user_struct structure. This means that in setups where multiple users in unprivileged containers map to the same underlying real user (i.e. pointing to the same user_struct) the inotify limits are going to be shared as well, allowing one user(or application) to exhaust all others limits. Fix this by switching the inotify sysctls to using the per-namespace/per-user limits. This will allow the server admin to set sensible global limits, which can further be tuned inside every individual user namespace. Additionally, in order to preserve the sysctl ABI make the existing inotify instances/watches sysctls modify the values of the initial user namespace. Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2017-01-23bpf: add a longest prefix match trie map implementationDaniel Mack
This trie implements a longest prefix match algorithm that can be used to match IP addresses to a stored set of ranges. Internally, data is stored in an unbalanced trie of nodes that has a maximum height of n, where n is the prefixlen the trie was created with. Tries may be created with prefix lengths that are multiples of 8, in the range from 8 to 2048. The key used for lookup and update operations is a struct bpf_lpm_trie_key, and the value is a uint64_t. The code carries more information about the internal implementation. Signed-off-by: Daniel Mack <daniel@zonque.org> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-23rcu: Adjust FQS offline checks for exact online-CPU detectionPaul E. McKenney
Commit 7ec99de36f40 ("rcu: Provide exact CPU-online tracking for RCU"), as its title suggests, got rid of RCU's remaining CPU-hotplug timing guesswork. This commit therefore removes the one-jiffy kludge that was used to paper over this guesswork. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Check cond_resched_rcu_qs() state less often to reduce GP overheadPaul E. McKenney
Commit 4a81e8328d37 ("rcu: Reduce overhead of cond_resched() checks for RCU") moved quiescent-state generation out of cond_resched() and commit bde6c3aa9930 ("rcu: Provide cond_resched_rcu_qs() to force quiescent states in long loops") introduced cond_resched_rcu_qs(), and commit 5cd37193ce85 ("rcu: Make cond_resched_rcu_qs() apply to normal RCU flavors") introduced the per-CPU rcu_qs_ctr variable, which is frequently polled by the RCU core state machine. This frequent polling can increase grace-period rate, which in turn increases grace-period overhead, which is visible in some benchmarks (for example, the "open1" benchmark in Anton Blanchard's "will it scale" suite). This commit therefore reduces the rate at which rcu_qs_ctr is polled by moving that polling into the force-quiescent-state (FQS) machinery, and by further polling it only after the grace period has been in effect for at least jiffies_till_sched_qs jiffies. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Abstract extended quiescent state determinationPaul E. McKenney
This commit is the fourth step towards full abstraction of all accesses to the ->dynticks counter, implementing previously open-coded checks and comparisons in new rcu_dynticks_in_eqs() and rcu_dynticks_in_eqs_since() functions. This abstraction will ease changes to the ->dynticks counter operation. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Abstract dynticks extended quiescent state enter/exit operationsPaul E. McKenney
This commit is the third step towards full abstraction of all accesses to the ->dynticks counter, implementing the previously open-coded atomic add of 1 and entry checks in a new rcu_dynticks_eqs_enter() function, and the same but with exit checks in a new rcu_dynticks_eqs_exit() function. This abstraction will ease changes to the ->dynticks counter operation. Note that this commit gets rid of the smp_mb__before_atomic() and the smp_mb__after_atomic() calls that were previously present. The reason that this is OK from a memory-ordering perspective is that the atomic operation is now atomic_add_return(), which, as a value-returning atomic, guarantees full ordering. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: Fixed RCU_TRACE() statements added by this commit. ] Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Add lockdep checks to synchronous expedited primitivesPaul E. McKenney
The non-expedited synchronize_*rcu() primitives have lockdep checks, but their expedited counterparts lack these checks. This commit therefore adds these checks to the expedited synchronize_*rcu() primitives. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Eliminate unused expedited_normal counterPaul E. McKenney
Expedited grace periods no longer fall back to normal grace periods in response to lock contention, given that expedited grace periods now use the rcu_node tree so as to avoid contention. This commit therfore removes the expedited_normal counter. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Fix comment in rcu_organize_nocb_kthreads()Paul E. McKenney
It used to be that the rcuo callback-offload kthreads were spawned in rcu_organize_nocb_kthreads(), and the comment before the "for" loop says as much. However, this spawning has long since moved to the CPU-hotplug code, so this commit fixes this comment. Reported-by: Michalis Kokologiannakis <mixaskok@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Make rcu_cpu_starting() use its "cpu" argumentPaul E. McKenney
The rcu_cpu_starting() function uses this_cpu_ptr() to locate the incoming CPU's rcu_data structure. This works for the boot CPU and for all CPUs onlined after rcu_init() executes (during very early boot). Currently, this is the full set of CPUs, so all is well. But if anyone ever parallelizes boot before rcu_init() time, it will fail. This commit therefore substitutes the rcu_cpu_starting() function's this_cpu_pointer() for per_cpu_ptr(), future-proofing the code and (arguably) improving readability. This commit inadvertently fixes a latent bug: If there ever had been more than just the boot CPU online at rcu_init() time, the old code would not initialize the non-boot CPUs, but rather would repeatedly initialize the boot CPU. Reported-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Add comment headers to expedited-grace-period counter functionsPaul E. McKenney
These functions (rcu_exp_gp_seq_start(), rcu_exp_gp_seq_end(), rcu_exp_gp_seq_snap(), and rcu_exp_gp_seq_done() seemed too obvious to comment when written, but not so much when being documented. This commit therefore adds header comments to each of them. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Don't wake rcuc/X kthreads on NOCB CPUsPaul E. McKenney
Chris Friesen notice that rcuc/X kthreads were consuming CPU even on NOCB CPUs. This makes no sense because the only purpose or these kthreads is to invoke normal (non-offloaded) callbacks, of which there will never be any on NOCB CPUs. This problem was due to a bug in cpu_has_callbacks_ready_to_invoke(), which should have been checking ->nxttail[RCU_NEXT_TAIL] for NULL, but which was instead (incorrectly) checking ->nxttail[RCU_DONE_TAIL]. Because ->nxttail[RCU_DONE_TAIL] is never NULL, the only effect is to cause the rcuc/X kthread to execute when it should not do so. This commit therefore checks ->nxttail[RCU_NEXT_TAIL], which is NULL for NOCB CPUs. Reported-by: Chris Friesen <chris.friesen@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Once again use NMI-based stack traces in stall warningsPaul E. McKenney
This commit is for all intents and purposes a revert of bc1dce514e9b ("rcu: Don't use NMIs to dump other CPUs' stacks"). The reason to suppose that this can now safely be reverted is the presence of 42a0bb3f7138 ("printk/nmi: generic solution for safe printk in NMI"), which is said to have made NMI-based stack dumps safe. However, this reversion keeps one nice property of bc1dce514e9b ("rcu: Don't use NMIs to dump other CPUs' stacks"), namely that only those CPUs blocking the grace period are dumped. The new trigger_single_cpu_backtrace() is used to make this happen, as suggested by Josh Poimboeuf. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Remove short-term CPU kickingPaul E. McKenney
Commit 4914950aaa12d ("rcu: Stop treating in-kernel CPU-bound workloads as errors") added a (relatively) short-timeout call to resched_cpu(). This was inspired by as issue that was fixed by b7e7ade34e61 ("sched/core: Fix remote wakeups"). But given that this issue was fixed, it is time for the current commit to remove this call to resched_cpu(). Reported-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Add long-term CPU kickingPaul E. McKenney
This commit prepares for the removal of short-term CPU kicking (in a subsequent commit). It does so by starting to invoke resched_cpu() for each holdout at each force-quiescent-state interval that is more than halfway through the stall-warning interval. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Remove unused but set variableTobias Klauser
Since commit 7ec99de36f40 ("rcu: Provide exact CPU-online tracking for RCU"), the variable mask in rcu_init_percpu_data is set but no longer used. Remove it to fix the following warning when building with 'W=1': kernel/rcu/tree.c: In function ‘rcu_init_percpu_data’: kernel/rcu/tree.c:3765:16: warning: variable ‘mask’ set but not used [-Wunused-but-set-variable] Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Remove unneeded rcu_process_callbacks() declarationsPaul E. McKenney
The declarations of __rcu_process_callbacks() and rcu_process_callbacks() are not needed, as the definition of both of these functions appear before any uses. This commit therefore removes both declarations. Reported-by: "Ahmed, Iftekhar" <ahmedi@oregonstate.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23rcu: Only dump stalled-tasks stacks if there was a real stallByungchul Park
The print_other_cpu_stall() function currently unconditionally invokes rcu_print_detail_task_stall(). This is OK because if there was a stall sufficient to cause print_other_cpu_stall() to be invoked, that stall is very likely to persist through the entire print_other_cpu_stall() execution. However, if the stall did not persist, the variable ndetected will be zero, and that variable is already tested in an "if" statement. Therefore, this commit moves the call to rcu_print_detail_task_stall() under that pre-existing "if" to improve readability, with a very rare reduction in overhead. Signed-off-by: Byungchul Park <byungchul.park@lge.com> [ paulmck: Reworked commit log. ] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23Fix: Disable sys_membarrier when nohz_full is enabledMathieu Desnoyers
Userspace applications should be allowed to expect the membarrier system call with MEMBARRIER_CMD_SHARED command to issue memory barriers on nohz_full CPUs, but synchronize_sched() does not take those into account. Given that we do not want unrelated processes to be able to affect real-time sensitive nohz_full CPUs, simply return ENOSYS when membarrier is invoked on a kernel with enabled nohz_full CPUs. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Steven Rostedt <rostedt@goodmis.org> CC: <stable@vger.kernel.org> [3.10+] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Lai Jiangshan <jiangshanlai@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23lockdep: Make RCU suspicious-access splats use pr_errPaul E. McKenney
This commit switches RCU suspicious-access splats use pr_err() instead of the current INFO printk()s. This change makes it easier to automatically classify splats. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-01-24userns: Make ucounts lock irq-safeNikolay Borisov
The ucounts_lock is being used to protect various ucounts lifecycle management functionalities. However, those services can also be invoked when a pidns is being freed in an RCU callback (e.g. softirq context). This can lead to deadlocks. There were already efforts trying to prevent similar deadlocks in add7c65ca426 ("pid: fix lockdep deadlock warning due to ucount_lock"), however they just moved the context from hardirq to softrq. Fix this issue once and for all by explictly making the lock disable irqs altogether. Dmitry Vyukov <dvyukov@google.com> reported: > I've got the following deadlock report while running syzkaller fuzzer > on eec0d3d065bfcdf9cd5f56dd2a36b94d12d32297 of linux-next (on odroid > device if it matters): > > ================================= > [ INFO: inconsistent lock state ] > 4.10.0-rc3-next-20170112-xc2-dirty #6 Not tainted > --------------------------------- > inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. > swapper/2/0 [HC0[0]:SC1[1]:HE1:SE0] takes: > (ucounts_lock){+.?...}, at: [< inline >] spin_lock > ./include/linux/spinlock.h:302 > (ucounts_lock){+.?...}, at: [<ffff2000081678c8>] > put_ucounts+0x60/0x138 kernel/ucount.c:162 > {SOFTIRQ-ON-W} state was registered at: > [<ffff2000081c82d8>] mark_lock+0x220/0xb60 kernel/locking/lockdep.c:3054 > [< inline >] mark_irqflags kernel/locking/lockdep.c:2941 > [<ffff2000081c97a8>] __lock_acquire+0x388/0x3260 kernel/locking/lockdep.c:3295 > [<ffff2000081cce24>] lock_acquire+0xa4/0x138 kernel/locking/lockdep.c:3753 > [< inline >] __raw_spin_lock ./include/linux/spinlock_api_smp.h:144 > [<ffff200009798128>] _raw_spin_lock+0x90/0xd0 kernel/locking/spinlock.c:151 > [< inline >] spin_lock ./include/linux/spinlock.h:302 > [< inline >] get_ucounts kernel/ucount.c:131 > [<ffff200008167c28>] inc_ucount+0x80/0x6c8 kernel/ucount.c:189 > [< inline >] inc_mnt_namespaces fs/namespace.c:2818 > [<ffff200008481850>] alloc_mnt_ns+0x78/0x3a8 fs/namespace.c:2849 > [<ffff200008487298>] create_mnt_ns+0x28/0x200 fs/namespace.c:2959 > [< inline >] init_mount_tree fs/namespace.c:3199 > [<ffff200009bd6674>] mnt_init+0x258/0x384 fs/namespace.c:3251 > [<ffff200009bd60bc>] vfs_caches_init+0x6c/0x80 fs/dcache.c:3626 > [<ffff200009bb1114>] start_kernel+0x414/0x460 init/main.c:648 > [<ffff200009bb01e8>] __primary_switched+0x6c/0x70 arch/arm64/kernel/head.S:456 > irq event stamp: 2316924 > hardirqs last enabled at (2316924): [< inline >] rcu_do_batch > kernel/rcu/tree.c:2911 > hardirqs last enabled at (2316924): [< inline >] > invoke_rcu_callbacks kernel/rcu/tree.c:3182 > hardirqs last enabled at (2316924): [< inline >] > __rcu_process_callbacks kernel/rcu/tree.c:3149 > hardirqs last enabled at (2316924): [<ffff200008210414>] > rcu_process_callbacks+0x7a4/0xc28 kernel/rcu/tree.c:3166 > hardirqs last disabled at (2316923): [< inline >] rcu_do_batch > kernel/rcu/tree.c:2900 > hardirqs last disabled at (2316923): [< inline >] > invoke_rcu_callbacks kernel/rcu/tree.c:3182 > hardirqs last disabled at (2316923): [< inline >] > __rcu_process_callbacks kernel/rcu/tree.c:3149 > hardirqs last disabled at (2316923): [<ffff20000820fe80>] > rcu_process_callbacks+0x210/0xc28 kernel/rcu/tree.c:3166 > softirqs last enabled at (2316912): [<ffff20000811b4c4>] > _local_bh_enable+0x4c/0x80 kernel/softirq.c:155 > softirqs last disabled at (2316913): [< inline >] > do_softirq_own_stack ./include/linux/interrupt.h:488 > softirqs last disabled at (2316913): [< inline >] > invoke_softirq kernel/softirq.c:371 > softirqs last disabled at (2316913): [<ffff20000811c994>] > irq_exit+0x264/0x308 kernel/softirq.c:405 > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(ucounts_lock); > <Interrupt> > lock(ucounts_lock); > > *** DEADLOCK *** > > 1 lock held by swapper/2/0: > #0: (rcu_callback){......}, at: [< inline >] __rcu_reclaim > kernel/rcu/rcu.h:108 > #0: (rcu_callback){......}, at: [< inline >] rcu_do_batch > kernel/rcu/tree.c:2919 > #0: (rcu_callback){......}, at: [< inline >] > invoke_rcu_callbacks kernel/rcu/tree.c:3182 > #0: (rcu_callback){......}, at: [< inline >] > __rcu_process_callbacks kernel/rcu/tree.c:3149 > #0: (rcu_callback){......}, at: [<ffff200008210390>] > rcu_process_callbacks+0x720/0xc28 kernel/rcu/tree.c:3166 > > stack backtrace: > CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.10.0-rc3-next-20170112-xc2-dirty #6 > Hardware name: Hardkernel ODROID-C2 (DT) > Call trace: > [<ffff20000808fa60>] dump_backtrace+0x0/0x440 arch/arm64/kernel/traps.c:500 > [<ffff20000808fec0>] show_stack+0x20/0x30 arch/arm64/kernel/traps.c:225 > [<ffff2000088a99e0>] dump_stack+0x110/0x168 > [<ffff2000082fa2b4>] print_usage_bug.part.27+0x49c/0x4bc > kernel/locking/lockdep.c:2387 > [< inline >] print_usage_bug kernel/locking/lockdep.c:2357 > [< inline >] valid_state kernel/locking/lockdep.c:2400 > [< inline >] mark_lock_irq kernel/locking/lockdep.c:2617 > [<ffff2000081c89ec>] mark_lock+0x934/0xb60 kernel/locking/lockdep.c:3065 > [< inline >] mark_irqflags kernel/locking/lockdep.c:2923 > [<ffff2000081c9a60>] __lock_acquire+0x640/0x3260 kernel/locking/lockdep.c:3295 > [<ffff2000081cce24>] lock_acquire+0xa4/0x138 kernel/locking/lockdep.c:3753 > [< inline >] __raw_spin_lock ./include/linux/spinlock_api_smp.h:144 > [<ffff200009798128>] _raw_spin_lock+0x90/0xd0 kernel/locking/spinlock.c:151 > [< inline >] spin_lock ./include/linux/spinlock.h:302 > [<ffff2000081678c8>] put_ucounts+0x60/0x138 kernel/ucount.c:162 > [<ffff200008168364>] dec_ucount+0xf4/0x158 kernel/ucount.c:214 > [< inline >] dec_pid_namespaces kernel/pid_namespace.c:89 > [<ffff200008293dc8>] delayed_free_pidns+0x40/0xe0 kernel/pid_namespace.c:156 > [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 > [< inline >] rcu_do_batch kernel/rcu/tree.c:2919 > [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3182 > [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3149 > [<ffff2000082103d8>] rcu_process_callbacks+0x768/0xc28 kernel/rcu/tree.c:3166 > [<ffff2000080821dc>] __do_softirq+0x324/0x6e0 kernel/softirq.c:284 > [< inline >] do_softirq_own_stack ./include/linux/interrupt.h:488 > [< inline >] invoke_softirq kernel/softirq.c:371 > [<ffff20000811c994>] irq_exit+0x264/0x308 kernel/softirq.c:405 > [<ffff2000081ecc28>] __handle_domain_irq+0xc0/0x150 kernel/irq/irqdesc.c:636 > [<ffff200008081c80>] gic_handle_irq+0x68/0xd8 > Exception stack(0xffff8000648e7dd0 to 0xffff8000648e7f00) > 7dc0: ffff8000648d4b3c 0000000000000007 > 7de0: 0000000000000000 1ffff0000c91a967 1ffff0000c91a967 1ffff0000c91a967 > 7e00: ffff20000a4b6b68 0000000000000001 0000000000000007 0000000000000001 > 7e20: 1fffe4000149ae90 ffff200009d35000 0000000000000000 0000000000000002 > 7e40: 0000000000000000 0000000000000000 0000000002624a1a 0000000000000000 > 7e60: 0000000000000000 ffff200009cbcd88 000060006d2ed000 0000000000000140 > 7e80: ffff200009cff000 ffff200009cb6000 ffff200009cc2020 ffff200009d2159d > 7ea0: 0000000000000000 ffff8000648d4380 0000000000000000 ffff8000648e7f00 > 7ec0: ffff20000820a478 ffff8000648e7f00 ffff20000820a47c 0000000010000145 > 7ee0: 0000000000000140 dfff200000000000 ffffffffffffffff ffff20000820a478 > [<ffff2000080837f8>] el1_irq+0xb8/0x130 arch/arm64/kernel/entry.S:486 > [< inline >] arch_local_irq_restore > ./arch/arm64/include/asm/irqflags.h:81 > [<ffff20000820a47c>] rcu_idle_exit+0x64/0xa8 kernel/rcu/tree.c:1030 > [< inline >] cpuidle_idle_call kernel/sched/idle.c:200 > [<ffff2000081bcbfc>] do_idle+0x1dc/0x2d0 kernel/sched/idle.c:243 > [<ffff2000081bd1cc>] cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:345 > [<ffff200008099f8c>] secondary_start_kernel+0x2cc/0x358 > arch/arm64/kernel/smp.c:276 > [<000000000279f1a4>] 0x279f1a4 Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Fixes: add7c65ca426 ("pid: fix lockdep deadlock warning due to ucount_lock") Fixes: f333c700c610 ("pidns: Add a limit on the number of pid namespaces") Cc: stable@vger.kernel.org Link: https://www.spinics.net/lists/kernel/msg2426637.html Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2017-01-23irqdomain: irq_domain_check_msi_remapEric Auger
This new function checks whether all MSI irq domains implement IRQ remapping. This is useful to understand whether VFIO passthrough is safe with respect to interrupts. On ARM typically an MSI controller can sit downstream to the IOMMU without preventing VFIO passthrough. As such any assigned device can write into the MSI doorbell. In case the MSI controller implements IRQ remapping, assigned devices will not be able to trigger interrupts towards the host. On the contrary, the assignment must be emphasized as unsafe with respect to interrupts. Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-23genirq/msi: Set IRQ_DOMAIN_FLAG_MSI on MSI domain creationEric Auger
Now we have a flag value indicating an IRQ domain implements MSI, let's set it on msi_create_irq_domain(). Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-23irqdomain: Add irq domain MSI and MSI_REMAP flagsEric Auger
We introduce two new enum values for the irq domain flag: - IRQ_DOMAIN_FLAG_MSI indicates the irq domain corresponds to an MSI domain - IRQ_DOMAIN_FLAG_MSI_REMAP indicates the irq domain has MSI remapping capabilities. Those values will be useful to check all MSI irq domains have MSI remapping support when assessing the safety of IRQ assignment to a guest. irq_domain_hierarchical_is_msi_remap() allows to check if an irq domain or any parent implements MSI remapping. Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-23seccomp: dump core when using SECCOMP_RET_KILLMike Frysinger
The SECCOMP_RET_KILL mode is documented as immediately killing the process as if a SIGSYS had been sent and not caught (similar to a SIGKILL). However, a SIGSYS is documented as triggering a coredump which does not happen today. This has the advantage of being able to more easily debug a process that fails a seccomp filter. Today, most apps need to recompile and change their filter in order to get detailed info out, or manually run things through strace, or enable detailed kernel auditing. Now we get coredumps that fit into existing system-wide crash reporting setups. From a security pov, this shouldn't be a problem. Unhandled signals can already be sent externally which trigger a coredump independent of the status of the seccomp filter. The act of dumping core itself does not cause change in execution of the program. URL: https://crbug.com/676357 Signed-off-by: Mike Frysinger <vapier@chromium.org> Acked-by: Jorge Lucangeli Obes <jorgelo@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-01-22Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp/hotplug fix from Thomas Gleixner: "Remove an unused variable which is a leftover from the notifier removal" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Remove unused but set variable in _cpu_down()
2017-01-22locking/rwsem: Reinit wake_q after useWaiman Long
In __rwsem_down_write_failed_common(), the same wake_q variable name is defined twice, with the inner wake_q hiding the one in outer scope. We can either use different names for the two wake_q's. Even better, we can use the same wake_q twice, if necessary. To enable the latter change, we need to define a new helper function wake_q_init() to enable reinitalization of wake_q after use. Signed-off-by: Waiman Long <longman@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> 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> Link: http://lkml.kernel.org/r/1485052415-9611-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-20ftrace: Convert graph filter to use hash tablesNamhyung Kim
Use ftrace_hash instead of a static array of a fixed size. This is useful when a graph filter pattern matches to a large number of functions. Now hash lookup is done with preemption disabled to protect from the hash being changed/freed. Link: http://lkml.kernel.org/r/20170120024447.26097-3-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-01-20ftrace: Expose ftrace_hash_empty and ftrace_lookup_ipNamhyung Kim
It will be used when checking graph filter hashes later. Link: http://lkml.kernel.org/r/20170120024447.26097-2-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> [ Moved ftrace_hash dec and functions outside of FUNCTION_GRAPH define ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>