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2017-12-15bpf: guarantee r1 to be ctx in case of bpf_helper_changes_pkt_dataDaniel Borkmann
Some JITs don't cache skb context on stack in prologue, so when LD_ABS/IND is used and helper calls yield bpf_helper_changes_pkt_data() as true, then they temporarily save/restore skb pointer. However, the assumption that skb always has to be in r1 is a bit of a gamble. Right now it turned out to be true for all helpers listed in bpf_helper_changes_pkt_data(), but lets enforce that from verifier side, so that we make this a guarantee and bail out if the func proto is misconfigured in future helpers. In case of BPF helper calls from cBPF, bpf_helper_changes_pkt_data() is completely unrelevant here (since cBPF is context read-only) and therefore always false. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-15sched/rt: Do not pull from current CPU if only one CPU to pullSteven Rostedt
Daniel Wagner reported a crash on the BeagleBone Black SoC. This is a single CPU architecture, and does not have a functional arch_send_call_function_single_ipi() implementation which can crash the kernel if that is called. As it only has one CPU, it shouldn't be called, but if the kernel is compiled for SMP, the push/pull RT scheduling logic now calls it for irq_work if the one CPU is overloaded, it can use that function to call itself and crash the kernel. Ideally, we should disable the SCHED_FEAT(RT_PUSH_IPI) if the system only has a single CPU. But SCHED_FEAT is a constant if sched debugging is turned off. Another fix can also be used, and this should also help with normal SMP machines. That is, do not initiate the pull code if there's only one RT overloaded CPU, and that CPU happens to be the current CPU that is scheduling in a lower priority task. Even on a system with many CPUs, if there's many RT tasks waiting to run on a single CPU, and that CPU schedules in another RT task of lower priority, it will initiate the PULL logic in case there's a higher priority RT task on another CPU that is waiting to run. But if there is no other CPU with waiting RT tasks, it will initiate the RT pull logic on itself (as it still has RT tasks waiting to run). This is a wasted effort. Not only does this help with SMP code where the current CPU is the only one with RT overloaded tasks, it should also solve the issue that Daniel encountered, because it will prevent the PULL logic from executing, as there's only one CPU on the system, and the check added here will cause it to exit the RT pull code. Reported-by: Daniel Wagner <wagi@monom.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-rt-users <linux-rt-users@vger.kernel.org> Cc: stable@vger.kernel.org Fixes: 4bdced5c9 ("sched/rt: Simplify the IPI based RT balancing logic") Link: http://lkml.kernel.org/r/20171202130454.4cbbfe8d@vmware.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15cgroup: use strlcpy() instead of strscpy() to avoid spurious warningArnd Bergmann
As long as cft->name is guaranteed to be NUL-terminated, using strlcpy() would work just as well and avoid that warning, so the change below could be folded into that commit. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-15posix-timer: Properly check sigevent->sigev_notifyThomas Gleixner
timer_create() specifies via sigevent->sigev_notify the signal delivery for the new timer. The valid modes are SIGEV_NONE, SIGEV_SIGNAL, SIGEV_THREAD and (SIGEV_SIGNAL | SIGEV_THREAD_ID). The sanity check in good_sigevent() is only checking the valid combination for the SIGEV_THREAD_ID bit, i.e. SIGEV_SIGNAL, but if SIGEV_THREAD_ID is not set it accepts any random value. This has no real effects on the posix timer and signal delivery code, but it affects show_timer() which handles the output of /proc/$PID/timers. That function uses a string array to pretty print sigev_notify. The access to that array has no bound checks, so random sigev_notify cause access beyond the array bounds. Add proper checks for the valid notify modes and remove the SIGEV_THREAD_ID masking from various code pathes as SIGEV_NONE can never be set in combination with SIGEV_THREAD_ID. Reported-by: Eric Biggers <ebiggers3@gmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: stable@vger.kernel.org
2017-12-14Merge tag 'trace-v4.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Various fix-ups: - comment fixes - build fix - better memory alloction (don't use NR_CPUS) - configuration fix - build warning fix - enhanced callback parameter (to simplify users of trace hooks) - give up on stack tracing when RCU isn't watching (it's a lost cause)" * tag 'trace-v4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Have stack trace not record if RCU is not watching tracing: Pass export pointer as argument to ->write() ring-buffer: Remove unused function __rb_data_page_index() tracing: make PREEMPTIRQ_EVENTS depend on TRACING tracing: Allocate mask_str buffer dynamically tracing: always define trace_{irq,preempt}_{enable_disable} tracing: Fix code comments in trace.c
2017-12-14tracing: Have stack trace not record if RCU is not watchingSteven Rostedt (VMware)
The stack tracer records a stack dump whenever it sees a stack usage that is more than what it ever saw before. This can happen at any function that is being traced. If it happens when the CPU is going idle (or other strange locations), RCU may not be watching, and in this case, the recording of the stack trace will trigger a warning. There's been lots of efforts to make hacks to allow stack tracing to proceed even if RCU is not watching, but this only causes more issues to appear. Simply do not trace a stack if RCU is not watching. It probably isn't a bad stack anyway. Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-14arch: define weak abort()Sudip Mukherjee
gcc toggle -fisolate-erroneous-paths-dereference (default at -O2 onwards) isolates faulty code paths such as null pointer access, divide by zero etc. If gcc port doesnt implement __builtin_trap, an abort() is generated which causes kernel link error. In this case, gcc is generating abort due to 'divide by zero' in lib/mpi/mpih-div.c. Currently 'frv' and 'arc' are failing. Previously other arch was also broken like m32r was fixed by commit d22e3d69ee1a ("m32r: fix build failure"). Let's define this weak function which is common for all arch and fix the problem permanently. We can even remove the arch specific 'abort' after this is done. Link: http://lkml.kernel.org/r/1513118956-8718-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-14kernel: make groups_sort calling a responsibility group_info allocatorsThiago Rafael Becker
In testing, we found that nfsd threads may call set_groups in parallel for the same entry cached in auth.unix.gid, racing in the call of groups_sort, corrupting the groups for that entry and leading to permission denials for the client. This patch: - Make groups_sort globally visible. - Move the call to groups_sort to the modifiers of group_info - Remove the call to groups_sort from set_groups Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: NeilBrown <neilb@suse.com> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-14kcov: fix comparison callback signatureDmitry Vyukov
Fix a silly copy-paste bug. We truncated u32 args to u16. Link: http://lkml.kernel.org/r/20171207101134.107168-1-dvyukov@google.com Fixes: ded97d2c2b2c ("kcov: support comparison operands collection") Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: syzkaller@googlegroups.com Cc: Alexander Potapenko <glider@google.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-14fix typo in assignment of fs default overflow gidWolffhardt Schwabe
The patch remains without practical effect since both macros carry identical values. Still, it might become a problem in the future if (for whatever reason) the default overflow uid and gid differ. The DEFAULT_FS_OVERFLOWGID macro was previously unused. Signed-off-by: Wolffhardt Schwabe <wolffhardt.schwabe@fau.de> Signed-off-by: Anatoliy Cherepantsev <anatoliy.cherepantsev@fau.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2017-12-13bpf/tracing: fix kernel/events/core.c compilation errorYonghong Song
Commit f371b304f12e ("bpf/tracing: allow user space to query prog array on the same tp") introduced a perf ioctl command to query prog array attached to the same perf tracepoint. The commit introduced a compilation error under certain config conditions, e.g., (1). CONFIG_BPF_SYSCALL is not defined, or (2). CONFIG_TRACING is defined but neither CONFIG_UPROBE_EVENTS nor CONFIG_KPROBE_EVENTS is defined. Error message: kernel/events/core.o: In function `perf_ioctl': core.c:(.text+0x98c4): undefined reference to `bpf_event_query_prog_array' This patch fixed this error by guarding the real definition under CONFIG_BPF_EVENTS and provided static inline dummy function if CONFIG_BPF_EVENTS was not defined. It renamed the function from bpf_event_query_prog_array to perf_event_query_prog_array and moved the definition from linux/bpf.h to linux/trace_events.h so the definition is in proximity to other prog_array related functions. Fixes: f371b304f12e ("bpf/tracing: allow user space to query prog array on the same tp") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-12bpf: add schedule points to map alloc/freeEric Dumazet
While using large percpu maps, htab_map_alloc() can hold cpu for hundreds of ms. This patch adds cond_resched() calls to percpu alloc/free call sites, all running in process context. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12bpf: fix corruption on concurrent perf_event_output callsDaniel Borkmann
When tracing and networking programs are both attached in the system and both use event-output helpers that eventually call into perf_event_output(), then we could end up in a situation where the tracing attached program runs in user context while a cls_bpf program is triggered on that same CPU out of softirq context. Since both rely on the same per-cpu perf_sample_data, we could potentially corrupt it. This can only ever happen in a combination of the two types; all tracing programs use a bpf_prog_active counter to bail out in case a program is already running on that CPU out of a different context. XDP and cls_bpf programs by themselves don't have this issue as they run in the same context only. Therefore, split both perf_sample_data so they cannot be accessed from each other. Fixes: 20b9d7ac4852 ("bpf: avoid excessive stack usage for perf_sample_data") Reported-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Song Liu <songliubraving@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12bpf: add a bpf_override_function helperJosef Bacik
Error injection is sloppy and very ad-hoc. BPF could fill this niche perfectly with it's kprobe functionality. We could make sure errors are only triggered in specific call chains that we care about with very specific situations. Accomplish this with the bpf_override_funciton helper. This will modify the probe'd callers return value to the specified value and set the PC to an override function that simply returns, bypassing the originally probed function. This gives us a nice clean way to implement systematic error injection for all of our code paths. Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12add infrastructure for tagging functions as error injectableJosef Bacik
Using BPF we can override kprob'ed functions and return arbitrary values. Obviously this can be a bit unsafe, so make this feature opt-in for functions. Simply tag a function with KPROBE_ERROR_INJECT_SYMBOL in order to give BPF access to that function for error injection purposes. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12bpf/tracing: allow user space to query prog array on the same tpYonghong Song
Commit e87c6bc3852b ("bpf: permit multiple bpf attachments for a single perf event") added support to attach multiple bpf programs to a single perf event. Although this provides flexibility, users may want to know what other bpf programs attached to the same tp interface. Besides getting visibility for the underlying bpf system, such information may also help consolidate multiple bpf programs, understand potential performance issues due to a large array, and debug (e.g., one bpf program which overwrites return code may impact subsequent program results). Commit 2541517c32be ("tracing, perf: Implement BPF programs attached to kprobes") utilized the existing perf ioctl interface and added the command PERF_EVENT_IOC_SET_BPF to attach a bpf program to a tracepoint. This patch adds a new ioctl command, given a perf event fd, to query the bpf program array attached to the same perf tracepoint event. The new uapi ioctl command: PERF_EVENT_IOC_QUERY_BPF The new uapi/linux/perf_event.h structure: struct perf_event_query_bpf { __u32 ids_len; __u32 prog_cnt; __u32 ids[0]; }; User space provides buffer "ids" for kernel to copy to. When returning from the kernel, the number of available programs in the array is set in "prog_cnt". The usage: struct perf_event_query_bpf *query = malloc(sizeof(*query) + sizeof(u32) * ids_len); query.ids_len = ids_len; err = ioctl(pmu_efd, PERF_EVENT_IOC_QUERY_BPF, query); if (err == 0) { /* query.prog_cnt is the number of available progs, * number of progs in ids: (ids_len == 0) ? 0 : query.prog_cnt */ } else if (errno == ENOSPC) { /* query.ids_len number of progs copied, * query.prog_cnt is the number of available progs */ } else { /* other errors */ } Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12cgroup: avoid copying strings longer than the buffersMa Shimiao
cgroup root name and file name have max length limit, we should avoid copying longer name than that to the name. tj: minor update to $SUBJ. Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-12locking/lockdep: Remove the cross-release locking checksIngo Molnar
This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y), while it found a number of old bugs initially, was also causing too many false positives that caused people to disable lockdep - which is arguably a worse overall outcome. If we disable cross-release by default but keep the code upstream then in practice the most likely outcome is that we'll allow the situation to degrade gradually, by allowing entropy to introduce more and more false positives, until it overwhelms maintenance capacity. Another bad side effect was that people were trying to work around the false positives by uglifying/complicating unrelated code. There's a marked difference between annotating locking operations and uglifying good code just due to bad lock debugging code ... This gradual decrease in quality happened to a number of debugging facilities in the kernel, and lockdep is pretty complex already, so we cannot risk this outcome. Either cross-release checking can be done right with no false positives, or it should not be included in the upstream kernel. ( Note that it might make sense to maintain it out of tree and go through the false positives every now and then and see whether new bugs were introduced. ) Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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>
2017-12-12locking/core: Remove break_lock field when CONFIG_GENERIC_LOCKBREAK=yWill Deacon
When CONFIG_GENERIC_LOCKBEAK=y, locking structures grow an extra int ->break_lock field which is used to implement raw_spin_is_contended() by setting the field to 1 when waiting on a lock and clearing it to zero when holding a lock. However, there are a few problems with this approach: - There is a write-write race between a CPU successfully taking the lock (and subsequently writing break_lock = 0) and a waiter waiting on the lock (and subsequently writing break_lock = 1). This could result in a contended lock being reported as uncontended and vice-versa. - On machines with store buffers, nothing guarantees that the writes to break_lock are visible to other CPUs at any particular time. - READ_ONCE/WRITE_ONCE are not used, so the field is potentially susceptible to harmful compiler optimisations, Consequently, the usefulness of this field is unclear and we'd be better off removing it and allowing architectures to implement raw_spin_is_contended() by providing a definition of arch_spin_is_contended(), as they can when CONFIG_GENERIC_LOCKBREAK=n. Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1511894539-7988-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-12locking/core: Fix deadlock during boot on systems with GENERIC_LOCKBREAKWill Deacon
Commit: a8a217c22116 ("locking/core: Remove {read,spin,write}_can_lock()") removed the definition of raw_spin_can_lock(), causing the GENERIC_LOCKBREAK spin_lock() routines to poll the ->break_lock field when waiting on a lock. This has been reported to cause a deadlock during boot on s390, because the ->break_lock field is also set by the waiters, and can potentially remain set indefinitely if no other CPUs come in to take the lock after it has been released. This patch removes the explicit spinning on ->break_lock from the waiters, instead relying on the outer trylock() operation to determine when the lock is available. Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Tested-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: a8a217c22116 ("locking/core: Remove {read,spin,write}_can_lock()") Link: http://lkml.kernel.org/r/1511894539-7988-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-11Merge branch 'for-4.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - Prateek posted a couple patches to fix a deadlock involving cpuset and workqueue. It unfortunately caused a different deadlock and the recent workqueue hotplug simplification removed the original deadlock, so Prateek's two patches are reverted for now. - The new stat code was missing u64_stats initialization. Fixed. - Doc and other misc changes * 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: add warning about RT not being supported on cgroup2 Revert "cgroup/cpuset: remove circular dependency deadlock" Revert "cpuset: Make cpuset hotplug synchronous" cgroup: properly init u64_stats debug cgroup: use task_css_set instead of rcu_dereference cpuset: Make cpuset hotplug synchronous cgroup/cpuset: remove circular dependency deadlock
2017-12-11Merge branch 'for-4.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: - Lai's hotplug simplifications inadvertently fix a possible deadlock involving cpuset and workqueue - CPU isolation fix which was reverted due to the changes in the housekeeping code resurrected - A trivial unused include removal * 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove unneeded kallsyms include workqueue/hotplug: remove the workaround in rebind_workers() workqueue/hotplug: simplify workqueue_offline_cpu() workqueue: respect isolated cpus when queueing an unbound work main: kernel_start: move housekeeping_init() before workqueue_init_early()
2017-12-11Merge branches 'cond_resched.2017.12.04a', 'dyntick.2017.11.28a', ↵Paul E. McKenney
'fixes.2017.12.11a', 'srbd.2017.12.05a' and 'torture.2017.12.11a' into HEAD cond_resched.2017.12.04a: Convert cond_resched_rcu_qs() to cond_resched() dyntick.2017.11.28a: Make RCU dynticks handle interrupts from NMI fixes.2017.12.11a: Miscellaneous fixes srbd.2017.12.05a: Remove now-redundant smp_read_barrier_depends() torture.2017.12.11a: Torture-testing update
2017-12-11torture: Save a line in stutter_wait(): while -> forPaul E. McKenney
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11torture: Eliminate torture_runnable and perf_runnablePaul E. McKenney
The purpose of torture_runnable is to allow rcutorture and locktorture to be started and stopped via sysfs when they are built into the kernel (as in not compiled as loadable modules). However, the 0444 permissions for both instances of torture_runnable prevent this use case from ever being put into practice. Given that there have been no complaints about this deficiency, it is reasonable to conclude that no one actually makes use of this sysfs capability. The perf_runnable module parameter for rcuperf is in the same situation. This commit therefore removes both torture_runnable instances as well as perf_runnable. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11torture: Make stutter less vulnerable to compilers and racesPaul E. McKenney
The stutter_wait() function repeatedly fetched stutter_pause_test, and should really just fetch it once on each pass. The races should be harmless, but why have the races? Also, the whole point of the value "2" for stutter_pause_test is to get everyone to start at very nearly the same time, but the value "2" was the first jiffy of the stutter rather than the last jiffy of the stutter. This commit rearranges the code to be more sensible. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11locking/locktorture: Fix num reader/writer corner casesDavidlohr Bueso
Things can explode for locktorture if the user does combinations of nwriters_stress=0 nreaders_stress=0. Fix this by not assuming we always want to torture writer threads. Reported-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Tested-by: Jeremy Linton <jeremy.linton@arm.com>
2017-12-11locking/locktorture: Fix rwsem reader_delayDavidlohr Bueso
We should account for nreader threads, not writers in this callback. Could even trigger a div by 0 if the user explicitly disables writers. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11rcutorture: Preempt RCU-preempt readers more vigorouslyPaul E. McKenney
This commit attempts to make a very rare rcutorture failure happen more often by increasing the fraction of RCU-preempt read-side critical sections that are preempted. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11torture: Reduce #ifdefs for preempt_schedule()Paul E. McKenney
This commit adds a torture_preempt_schedule() that is nothingness in !PREEMPT builds and is preempt_schedule() otherwise. Then torture_preempt_schedule() is used to eliminate several ugly #ifdefs, both in rcutorture and in locktorture. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11rcu: Remove have_rcu_nocb_mask from tree_plugin.hRakib Mullick
Currently have_rcu_nocb_mask is used to avoid double allocation of rcu_nocb_mask during boot up. Due to different representation of cpumask_var_t on different kernel config CPUMASK=y(or n) it was okay. But now we have a helper cpumask_available(), which can be utilized to check whether rcu_nocb_mask has been allocated or not without using a variable. Removing the variable also reduces vmlinux size. Unpatched version: text data bss dec hex filename 13050393 7852470 14543408 35446271 21cddff vmlinux Patched version: text data bss dec hex filename 13050390 7852438 14543408 35446236 21cdddc vmlinux Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11rcu: Add comment giving debug strategy for double call_rcu()Paul E. McKenney
The following statement has for some reason proven non-intuitive: WARN_ON_ONCE(rcu_segcblist_empty(&rdp->cblist) != (count == 0)); This commit therefore adds a comment that states that this warning usually triggers in response to a double call_rcu(), which is sort of like a double free. The comment also suggests building with CONFIG_DEBUG_OBJECTS_RCU_HEAD=y to track down the double call_rcu(). Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-12-11workqueue: remove unneeded kallsyms includeSergey Senozhatsky
The filw was converted from print_symbol() to %pf some time ago (044c782ce3a901fb "workqueue: fix checkpatch issues"). kallsyms does not seem to be needed anymore. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-11sched/core: Fix kernel-doc warnings after code movementRandy Dunlap
Fix the following kernel-doc warnings after code restructuring: ../kernel/sched/core.c:5113: warning: No description found for parameter 't' ../kernel/sched/core.c:5113: warning: Excess function parameter 'interval' description in 'sched_rr_get_interval' get rid of set_fs()") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: abca5fc535a3e ("sched_rr_get_interval(): move compat to native, Link: http://lkml.kernel.org/r/995c6ded-b32e-bbe4-d9f5-4d42d121aff1@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-10futex: futex_wake_op, fix sign_extend32 sign bitsJiri Slaby
sign_extend32 counts the sign bit parameter from 0, not from 1. So we have to use "11" for 12th bit, not "12". This mistake means we have not allowed negative op and cmp args since commit 30d6e0a4190d ("futex: Remove duplicated code and fix undefined behaviour") till now. Fixes: 30d6e0a4190d ("futex: Remove duplicated code and fix undefined behaviour") Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflict was two parallel additions of include files to sch_generic.c, no biggie. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) CAN fixes from Martin Kelly (cancel URBs properly in all the CAN usb drivers). 2) Revert returning -EEXIST from __dev_alloc_name() as this propagates to userspace and broke some apps. From Johannes Berg. 3) Fix conn memory leaks and crashes in TIPC, from Jon Malloc and Cong Wang. 4) Gianfar MAC can't do EEE so don't advertise it by default, from Claudiu Manoil. 5) Relax strict netlink attribute validation, but emit a warning. From David Ahern. 6) Fix regression in checksum offload of thunderx driver, from Florian Westphal. 7) Fix UAPI bpf issues on s390, from Hendrik Brueckner. 8) New card support in iwlwifi, from Ihab Zhaika. 9) BBR congestion control bug fixes from Neal Cardwell. 10) Fix port stats in nfp driver, from Pieter Jansen van Vuuren. 11) Fix leaks in qualcomm rmnet, from Subash Abhinov Kasiviswanathan. 12) Fix DMA API handling in sh_eth driver, from Thomas Petazzoni. 13) Fix spurious netpoll warnings in bnxt_en, from Calvin Owens. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits) net: mvpp2: fix the RSS table entry offset tcp: evaluate packet losses upon RTT change tcp: fix off-by-one bug in RACK tcp: always evaluate losses in RACK upon undo tcp: correctly test congestion state in RACK bnxt_en: Fix sources of spurious netpoll warnings tcp_bbr: reset long-term bandwidth sampling on loss recovery undo tcp_bbr: reset full pipe detection on loss recovery undo tcp_bbr: record "full bw reached" decision in new full_bw_reached bit sfc: pass valid pointers from efx_enqueue_unwind gianfar: Disable EEE autoneg by default tcp: invalidate rate samples during SACK reneging can: peak/pcie_fd: fix potential bug in restarting tx queue can: usb_8dev: cancel urb on -EPIPE and -EPROTO can: kvaser_usb: cancel urb on -EPIPE and -EPROTO can: esd_usb2: cancel urb on -EPIPE and -EPROTO can: ems_usb: cancel urb on -EPIPE and -EPROTO can: mcba_usb: cancel urb on -EPROTO usbnet: fix alignment for frames with no ethernet header tcp: use current time in tcp_rcv_space_adjust() ...
2017-12-08sched/autogroup: move sched.h includeSergey Senozhatsky
Move local "sched.h" include to the bottom. sched.h defines several macros that are getting redefined in ARCH-specific code, for instance, finish_arch_post_lock_switch() and prepare_arch_switch(), so we need ARCH-specific definitions to come in first. Link: http://lkml.kernel.org/r/20171208082422.5021-1-sergey.senozhatsky@gmail.com To: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: linux-pm@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: linux-mm@kvack.org Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-12-08sched/autogroup: remove unneeded kallsyms includeSergey Senozhatsky
Autogroup does not seem to use any of kallsyms functions/defines. Link: http://lkml.kernel.org/r/20171208025616.16267-2-sergey.senozhatsky@gmail.com To: Andrew Morton <akpm@linux-foundation.org> To: Michal Hocko <mhocko@suse.com> To: Rafael Wysocki <rjw@rjwysocki.net> To: Len Brown <len.brown@intel.com> To: Bjorn Helgaas <bhelgaas@google.com> To: Vlastimil Babka <vbabka@suse.cz> To: Tejun Heo <tj@kernel.org> To: Lai Jiangshan <jiangshanlai@gmail.com> To: Thomas Gleixner <tglx@linutronix.de> To: Fengguang Wu <fengguang.wu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: linux-pm@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-12-08sched/fair: Remove unused 'curr' parameter from wakeup_granCheng Jian
The first parameter of wakeup_gran(), 'curr', is unnecessary now. Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: huawei.libin@huawei.com Cc: xiexiuqi@huawei.com Link: http://lkml.kernel.org/r/1512653443-179848-1-git-send-email-cj.chengjian@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-07rcu: Export init_rcu_head() and destroy_rcu_head() to GPL modulesPaul E. McKenney
Use of init_rcu_head() and destroy_rcu_head() from modules results in the following build-time error with CONFIG_DEBUG_OBJECTS_RCU_HEAD=y: ERROR: "init_rcu_head" [drivers/scsi/scsi_mod.ko] undefined! ERROR: "destroy_rcu_head" [drivers/scsi/scsi_mod.ko] undefined! This commit therefore adds EXPORT_SYMBOL_GPL() for each to allow them to be used by GPL-licensed kernel modules. Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-12-07livepatch: force transition to finishMiroslav Benes
If a task sleeps in a set of patched functions uninterruptedly, it could block the whole transition indefinitely. Thus it may be useful to clear its TIF_PATCH_PENDING to allow the process to finish. Admin can do that now by writing to force sysfs attribute in livepatch sysfs directory. TIF_PATCH_PENDING is then cleared for all tasks and the transition can finish successfully. Important note! Administrator should not use this feature without a clearance from a patch distributor. It must be checked that by doing so the consistency model guarantees are not violated. Removal (rmmod) of patch modules is permanently disabled when the feature is used. It cannot be guaranteed there is no task sleeping in such module. Signed-off-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-12-06Merge tag 'for_linus-4.15-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb Pull kgdb fixes from Jason Wessel: - Fix long standing problem with kdb kallsyms_symbol_next() return value - Add new co-maintainer Daniel Thompson * tag 'for_linus-4.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb: kgdb/kdb/debug_core: Add co-maintainer Daniel Thompson kdb: Fix handling of kallsyms_symbol_next() return value
2017-12-06Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug fix from Ingo Molnar: "A single fix moving the smp-call queue flush step to the intended point in the state machine" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp/hotplug: Move step CPUHP_AP_SMPCFD_DYING to the correct place
2017-12-06Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "This includes a fix for the add_wait_queue() queue ordering brown paperbag bug, plus PELT accounting fixes for cgroups scheduling artifacts" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Update and fix the runnable propagation rule sched/wait: Fix add_wait_queue() behavioral change
2017-12-06Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This includes perf namespace support kernel side fixes, plus an accumulated set of perf tooling fixes - including UAPI header synchronization that should make the perf build less noisy" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) tooling/headers: Synchronize updated s390 and x86 UAPI headers tools headers: Syncronize mman.h ABI header tools headers: Synchronize prctl.h ABI header tools headers: Synchronize KVM arch ABI headers tools headers: Synchronize drm/i915_drm.h tools headers uapi: Synchronize drm/drm.h tools headers: Synchronize perf_event.h header tools headers: Synchronize kernel ABI headers wrt SPDX tags tools/headers: Synchronize kernel x86 UAPI headers perf intel-pt: Bring instruction decoder files into line with the kernel perf test: Fix test 21 for s390x perf bench numa: Fixup discontiguous/sparse numa nodes perf top: Use signal interface for SIGWINCH handler perf top: Fix window dimensions change handling perf: Fix header.size for namespace events perf top: Ignore kptr_restrict when not sampling the kernel perf record: Ignore kptr_restrict when not sampling the kernel perf report: Ignore kptr_restrict when not sampling the kernel perf evlist: Add helper to check if attr.exclude_kernel is set in all evsels perf test shell: Fix test case probe libc's inet_pton on s390x ...
2017-12-06Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull lockdep fix from Ingo Molnar: "Fix a possible NULL dereference for the (rare) case when a task doesn't have ->xhlocks space allocated due to kmalloc() OOM-ing" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/lockdep: Fix possible NULL deref
2017-12-06Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Ingo Molnar: "Two fixes: use bool type consistently, plus a irq_matrix_available() bugfix" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqdesc: Use bool return type instead of int genirq/matrix: Fix the precedence fix for real
2017-12-06kdb: Fix handling of kallsyms_symbol_next() return valueDaniel Thompson
kallsyms_symbol_next() returns a boolean (true on success). Currently kdb_read() tests the return value with an inequality that unconditionally evaluates to true. This is fixed in the obvious way and, since the conditional branch is supposed to be unreachable, we also add a WARN_ON(). Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2017-12-06Merge branch 'linus' into perf/urgent, to synchronize UAPI headersIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>