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* bpf: add missing map_flags to bpf_map_show_fdinfoDaniel Borkmann2016-03-251-2/+4
| | | | | | | | | | | | | Add map_flags attribute to bpf_map_show_fdinfo(), so that tools like tc can check for them when loading objects from a pinned entry, e.g. if user intent wrt allocation (BPF_F_NO_PREALLOC) is different to the pinned object, it can bail out. Follow-up to 6c9059817432 ("bpf: pre-allocate hash map elements"), so that tc can still support this with v4.6. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge tag 'trace-v4.6' of ↵Linus Torvalds2016-03-2411-111/+222
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Nothing major this round. Mostly small clean ups and fixes. Some visible changes: - A new flag was added to distinguish traces done in NMI context. - Preempt tracer now shows functions where preemption is disabled but interrupts are still enabled. Other notes: - Updates were done to function tracing to allow better performance with perf. - Infrastructure code has been added to allow for a new histogram feature for recording live trace event histograms that can be configured by simple user commands. The feature itself was just finished, but needs a round in linux-next before being pulled. This only includes some infrastructure changes that will be needed" * tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits) tracing: Record and show NMI state tracing: Fix trace_printk() to print when not using bprintk() tracing: Remove redundant reset per-CPU buff in irqsoff tracer x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c tracing: Fix crash from reading trace_pipe with sendfile tracing: Have preempt(irqs)off trace preempt disabled functions tracing: Fix return while holding a lock in register_tracer() ftrace: Use kasprintf() in ftrace_profile_tracefs() ftrace: Update dynamic ftrace calls only if necessary ftrace: Make ftrace_hash_rec_enable return update bool tracing: Fix typoes in code comment and printk in trace_nop.c tracing, writeback: Replace cgroup path to cgroup ino tracing: Use flags instead of bool in trigger structure tracing: Add an unreg_all() callback to trigger commands tracing: Add needs_rec flag to event triggers tracing: Add a per-event-trigger 'paused' field tracing: Add get_syscall_name() tracing: Add event record param to trigger_ops.func() tracing: Make event trigger functions available tracing: Make ftrace_event_field checking functions available ...
| * tracing: Record and show NMI statePeter Zijlstra2016-03-223-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | The latency tracer format has a nice column to indicate IRQ state, but this is not able to tell us about NMI state. When tracing perf interrupt handlers (which often run in NMI context) it is very useful to see how the events nest. Link: http://lkml.kernel.org/r/20160318153022.105068893@infradead.org Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix trace_printk() to print when not using bprintk()Steven Rostedt (Red Hat)2016-03-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace_printk() code will allocate extra buffers if the compile detects that a trace_printk() is used. To do this, the format of the trace_printk() is saved to the __trace_printk_fmt section, and if that section is bigger than zero, the buffers are allocated (along with a message that this has happened). If trace_printk() uses a format that is not a constant, and thus something not guaranteed to be around when the print happens, the compiler optimizes the fmt out, as it is not used, and the __trace_printk_fmt section is not filled. This means the kernel will not allocate the special buffers needed for the trace_printk() and the trace_printk() will not write anything to the tracing buffer. Adding a "__used" to the variable in the __trace_printk_fmt section will keep it around, even though it is set to NULL. This will keep the string from being printed in the debugfs/tracing/printk_formats section as it is not needed. Reported-by: Vlastimil Babka <vbabka@suse.cz> Fixes: 07d777fe8c398 "tracing: Add percpu buffers for trace_printk()" Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Remove redundant reset per-CPU buff in irqsoff tracerDmitry Safonov2016-03-181-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no reason to do it twice: from commit b6f11df26fdc28 ("trace: Call tracing_reset_online_cpus before tracer->init()") resetting of per-CPU buffers done before tracer->init() call. tracer->init() calls {irqs,preempt,preemptirqs}off_tracer_init() and it calls __irqsoff_tracer_init(), which resets per-CPU ringbuffer second time. It's slowpath, but anyway. Link: http://lkml.kernel.org/r/1445278226-16187-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix crash from reading trace_pipe with sendfileSteven Rostedt (Red Hat)2016-03-181-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If tracing contains data and the trace_pipe file is read with sendfile(), then it can trigger a NULL pointer dereference and various BUG_ON within the VM code. There's a patch to fix this in the splice_to_pipe() code, but it's also a good idea to not let that happen from trace_pipe either. Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in Cc: stable@vger.kernel.org # 2.6.30+ Reported-by: Rabin Vincent <rabin.vincent@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Have preempt(irqs)off trace preempt disabled functionsSteven Rostedt (Red Hat)2016-03-181-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Joel Fernandes reported that the function tracing of preempt disabled sections was not being reported when running either the preemptirqsoff or preemptoff tracers. This was due to the fact that the function tracer callback for those tracers checked if irqs were disabled before tracing. But this fails when we want to trace preempt off locations as well. Joel explained that he wanted to see funcitons where interrupts are enabled but preemption was disabled. The expected output he wanted: <...>-2265 1d.h1 3419us : preempt_count_sub <-irq_exit <...>-2265 1d..1 3419us : __do_softirq <-irq_exit <...>-2265 1d..1 3419us : msecs_to_jiffies <-__do_softirq <...>-2265 1d..1 3420us : irqtime_account_irq <-__do_softirq <...>-2265 1d..1 3420us : __local_bh_disable_ip <-__do_softirq <...>-2265 1..s1 3421us : run_timer_softirq <-__do_softirq <...>-2265 1..s1 3421us : hrtimer_run_pending <-run_timer_softirq <...>-2265 1..s1 3421us : _raw_spin_lock_irq <-run_timer_softirq <...>-2265 1d.s1 3422us : preempt_count_add <-_raw_spin_lock_irq <...>-2265 1d.s2 3422us : _raw_spin_unlock_irq <-run_timer_softirq <...>-2265 1..s2 3422us : preempt_count_sub <-_raw_spin_unlock_irq <...>-2265 1..s1 3423us : rcu_bh_qs <-__do_softirq <...>-2265 1d.s1 3423us : irqtime_account_irq <-__do_softirq <...>-2265 1d.s1 3423us : __local_bh_enable <-__do_softirq There's a comment saying that the irq disabled check is because there's a possible race that tracing_cpu may be set when the function is executed. But I don't remember that race. For now, I added a check for preemption being enabled too to not record the function, as there would be no race if that was the case. I need to re-investigate this, as I'm now thinking that the tracing_cpu will always be correct. But no harm in keeping the check for now, except for the slight performance hit. Link: http://lkml.kernel.org/r/1457770386-88717-1-git-send-email-agnel.joel@gmail.com Fixes: 5e6d2b9cfa3a "tracing: Use one prologue for the preempt irqs off tracer function tracers" Cc: stable@vget.kernel.org # 2.6.37+ Reported-by: Joel Fernandes <agnel.joel@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix return while holding a lock in register_tracer()Chunyu Hu2016-03-181-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d39cdd2036a6 ("tracing: Make tracer_flags use the right set_flag callback") introduces a potential mutex deadlock issue, as it forgets to free the mutex when allocaing the tracer_flags gets fail. The issue was found by Dan Carpenter through Smatch static code check tool. Link: http://lkml.kernel.org/r/1457958941-30265-1-git-send-email-chuhu@redhat.com Fixes: d39cdd2036a6 ("tracing: Make tracer_flags use the right set_flag callback") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Use kasprintf() in ftrace_profile_tracefs()Geliang Tang2016-03-181-3/+1
| | | | | | | | | | | | | | | | | | | | Use kasprintf() instead of kmalloc() and snprintf(). Link: http://lkml.kernel.org/r/135a7bc36e51fd9eaa57124dd2140285b771f738.1458050835.git.geliangtang@163.com Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Update dynamic ftrace calls only if necessaryJiri Olsa2016-03-181-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently dynamic ftrace calls are updated any time the ftrace_ops is un/registered. If we do this update only when it's needed, we save lot of time for perf system wide ftrace function sampling/counting. The reason is that for system wide sampling/counting, perf creates event for each cpu in the system. Each event then registers separate copy of ftrace_ops, which ends up in FTRACE_UPDATE_CALLS updates. On servers with many cpus that means serious stall (240 cpus server): Counting: # time ./perf stat -e ftrace:function -a sleep 1 Performance counter stats for 'system wide': 370,663 ftrace:function 1.401427505 seconds time elapsed real 3m51.743s user 0m0.023s sys 3m48.569s Sampling: # time ./perf record -e ftrace:function -a sleep 1 [ perf record: Woken up 0 times to write data ] Warning: Processed 141200 events and lost 5 chunks! [ perf record: Captured and wrote 10.703 MB perf.data (135950 samples) ] real 2m31.429s user 0m0.213s sys 2m29.494s There's no reason to do the FTRACE_UPDATE_CALLS update for each event in perf case, because all the ftrace_ops always share the same filter, so the updated calls are always the same. It's required that only first ftrace_ops registration does the FTRACE_UPDATE_CALLS update (also sometimes the second if the first one used the trampoline), but the rest can be only cheaply linked into the ftrace_ops list. Counting: # time ./perf stat -e ftrace:function -a sleep 1 Performance counter stats for 'system wide': 398,571 ftrace:function 1.377503733 seconds time elapsed real 0m2.787s user 0m0.005s sys 0m1.883s Sampling: # time ./perf record -e ftrace:function -a sleep 1 [ perf record: Woken up 0 times to write data ] Warning: Processed 261730 events and lost 9 chunks! [ perf record: Captured and wrote 19.907 MB perf.data (256293 samples) ] real 1m31.948s user 0m0.309s sys 1m32.051s Link: http://lkml.kernel.org/r/1458138873-1553-6-git-send-email-jolsa@kernel.org Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Make ftrace_hash_rec_enable return update boolJiri Olsa2016-03-181-10/+17
| | | | | | | | | | | | | | | | | | | | | | | | Change __ftrace_hash_rec_update to return true in case we need to update dynamic ftrace call records. It return false in case no update is needed. Link: http://lkml.kernel.org/r/1458138873-1553-5-git-send-email-jolsa@kernel.org Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix typoes in code comment and printk in trace_nop.cChunyu Hu2016-03-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | echo nop > /sys/kernel/debug/tracing/options/current_tracer echo 1 > /sys/kernel/debug/tracing/options/test_nop_accept echo 0 > /sys/kernel/debug/tracing/options/test_nop_accept echo 1 > /sys/kernel/debug/tracing/options/test_nop_refuse Before the fix, the dmesg is a bit ugly since a align issue. [ 191.973081] nop_test_accept flag set to 1: we accept. Now cat trace_options to see the result [ 195.156942] nop_test_refuse flag set to 1: we refuse.Now cat trace_options to see the result After the fix, the dmesg will show aligned log for nop_test_refuse and nop_test_accept. [ 2718.032413] nop_test_refuse flag set to 1: we refuse. Now cat trace_options to see the result [ 2734.253360] nop_test_accept flag set to 1: we accept. Now cat trace_options to see the result Link: http://lkml.kernel.org/r/1457444222-8654-2-git-send-email-chuhu@redhat.com Signed-off-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Use flags instead of bool in trigger structureSteven Rostedt (Red Hat)2016-03-082-30/+49
| | | | | | | | | | | | | | gcc isn't known for handling bool in structures. Instead of using bool, use an integer mask and use bit flags instead. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add an unreg_all() callback to trigger commandsTom Zanussi2016-03-082-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new unreg_all() callback that can be used to remove all command-specific triggers from an event and arrange to have it called whenever a trigger file is opened with O_TRUNC set. Commands that don't want truncate semantics, or existing commands that don't implement this function simply do nothing and their triggers remain intact. Link: http://lkml.kernel.org/r/2b7d62854d01f28c19185e1bbb8f826f385edfba.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add needs_rec flag to event triggersTom Zanussi2016-03-082-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new needs_rec flag for triggers that require unconditional access to trace records in order to function. Normally a trigger requires access to the contents of a trace record only if it has a filter associated with it (since filters need the contents of a record in order to make a filtering decision). Some types of triggers, such as 'hist' triggers, require access to trace record contents independent of the presence of filters, so add a new flag for those triggers. Link: http://lkml.kernel.org/r/7be8fa38f9b90fdb6c47ca0f98d20a07b9fd512b.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add a per-event-trigger 'paused' fieldTom Zanussi2016-03-082-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a simple per-trigger 'paused' flag, allowing individual triggers to pause. We could leave it to individual triggers that need this functionality to do it themselves, but we also want to allow other events to control pausing, so add it to the trigger data. Link: http://lkml.kernel.org/r/fed37e4879684d7dcc57fe00ce0cbf170032b06d.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add get_syscall_name()Tom Zanussi2016-03-082-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | Add a utility function to grab the syscall name from the syscall metadata, given a syscall id. Link: http://lkml.kernel.org/r/be26a8dfe3f15e16a837799f1c1e2b4d62742843.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add event record param to trigger_ops.func()Tom Zanussi2016-03-082-19/+23
| | | | | | | | | | | | | | | | | | | | | | | | Some triggers may need access to the trace event, so pass it in. Also fix up the existing trigger funcs and their callers. Link: http://lkml.kernel.org/r/543e31e9fc445ef61077421ab219033401c39846.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Make event trigger functions availableTom Zanussi2016-03-082-15/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | Make various event trigger utility functions available outside of trace_events_trigger.c so that new triggers can be defined outside of that file. Link: http://lkml.kernel.org/r/4a40c1695dd43cac6cd475d72e13ffe30ba84bff.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Make ftrace_event_field checking functions availableTom Zanussi2016-03-082-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | Make is_string_field() and is_function_field() accessible outside of trace_event_filters.c for other users of ftrace_event_fields. Link: http://lkml.kernel.org/r/2d3f00d3311702e556e82eed7754bae6f017939f.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Make tracer_flags use the right set_flag callbackChunyu Hu2016-03-083-14/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I was updating the ftrace_stress test of ltp. I encountered a strange phenomemon, excute following steps: echo nop > /sys/kernel/debug/tracing/current_tracer echo 0 > /sys/kernel/debug/tracing/options/funcgraph-cpu bash: echo: write error: Invalid argument check dmesg: [ 1024.903855] nop_test_refuse flag set to 0: we refuse.Now cat trace_options to see the result The reason is that the trace option test will randomly setup trace option under tracing/options no matter what the current_tracer is. but the set_tracer_option is always using the set_flag callback from the current_tracer. This patch adds a pointer to tracer_flags and make it point to the tracer it belongs to. When the option is setup, the set_flag of the right tracer will be used no matter what the the current_tracer is. And the old dummy_tracer_flags is used for all the tracers which doesn't have a tracer_flags, having issue to use it to save the pointer of a tracer. So remove it and use dynamic dummy tracer_flags for tracers needing a dummy tracer_flags, as a result, there are no tracers sharing tracer_flags, so remove the check code. And save the current tracer to trace_option_dentry seems not good as it may waste mem space when mount the debug/trace fs more than one time. Link: http://lkml.kernel.org/r/1457444222-8654-1-git-send-email-chuhu@redhat.com Signed-off-by: Chunyu Hu <chuhu@redhat.com> [ Fixed up function tracer options to work with the change ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2016-03-242-38/+82
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree contains various perf fixes on the kernel side, plus three hw/event-enablement late additions: - Intel Memory Bandwidth Monitoring events and handling - the AMD Accumulated Power Mechanism reporting facility - more IOMMU events ... and a final round of perf tooling updates/fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) perf llvm: Use strerror_r instead of the thread unsafe strerror one perf llvm: Use realpath to canonicalize paths perf tools: Unexport some methods unused outside strbuf.c perf probe: No need to use formatting strbuf method perf help: Use asprintf instead of adhoc equivalents perf tools: Remove unused perf_pathdup, xstrdup functions perf tools: Do not include stringify.h from the kernel sources tools include: Copy linux/stringify.h from the kernel tools lib traceevent: Remove redundant CPU output perf tools: Remove needless 'extern' from function prototypes perf tools: Simplify die() mechanism perf tools: Remove unused DIE_IF macro perf script: Remove lots of unused arguments perf thread: Rename perf_event__preprocess_sample_addr to thread__resolve perf machine: Rename perf_event__preprocess_sample to machine__resolve perf tools: Add cpumode to struct perf_sample perf tests: Forward the perf_sample in the dwarf unwind test perf tools: Remove misplaced __maybe_unused perf list: Fix documentation of :ppp perf bench numa: Fix assertion for nodes bitfield ...
| * | perf/core: Document some hotplug bitsPeter Zijlstra2016-03-211-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Document some of the hotplug notifier usage. Requested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | perf/core: Fix Undefined behaviour in rb_alloc()Peter Zijlstra2016-03-211-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha reported: [ 3494.030114] UBSAN: Undefined behaviour in kernel/events/ring_buffer.c:685:22 [ 3494.030647] shift exponent -1 is negative Andrey spotted that this is because: It happens if nr_pages = 0: rb->page_order = ilog2(nr_pages); Fix it by making both assignments conditional on nr_pages; since otherwise they should both be 0 anyway, and will be because of the kzalloc() used to allocate the structure. Reported-by: Sasha Levin <sasha.levin@oracle.com> Reported-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20160129141751.GA407@worktop Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | perf/core: Fix dynamic interrupt throttlePeter Zijlstra2016-03-211-36/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There were two problems with the dynamic interrupt throttle mechanism, both triggered by the same action. When you (or perf_fuzzer) write a huge value into /proc/sys/kernel/perf_event_max_sample_rate the computed perf_sample_allowed_ns becomes 0. This effectively disables the whole dynamic throttle. This is fixed by ensuring update_perf_cpu_limits() never sets the value to 0. However, we allow disabling of the dynamic throttle by writing 100 to /proc/sys/kernel/perf_cpu_time_max_percent. This will generate a warning in dmesg. The second problem is that by setting the max_sample_rate to a huge number, the adaptive process can take a few tries, since it halfs the limit each time. Change that to directly compute a new value based on the observed duration. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | perf/core: Fix the unthrottle logicPeter Zijlstra2016-03-211-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Its possible to IOC_PERIOD while the event is throttled, this would re-start the event and the next tick would then try to unthrottle it, and find the event wasn't actually stopped anymore. This would tickle a WARN in the x86-pmu code which isn't expecting to start a !stopped event. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: dvyukov@google.com Cc: oleg@redhat.com Cc: panand@redhat.com Cc: sasha.levin@oracle.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/20160310143924.GR6356@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2016-03-245-55/+72
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixes: a cgroup fix, a fair-scheduler migration accounting fix, a cputime fix and two cpuacct cleanups" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/cpuacct: Simplify the cpuacct code sched/cpuacct: Rename parameter in cpuusage_write() for readability sched/fair: Add comments to explain select_idle_sibling() sched/fair: Fix fairness issue on migration sched/cgroup: Fix/cleanup cgroup teardown/init sched/cputime: Fix steal time accounting vs. CPU hotplug
| * | | sched/cpuacct: Simplify the cpuacct codeZhao Lei2016-03-212-25/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Use for() instead of while() loop in some functions to make the code simpler. - Use this_cpu_ptr() instead of per_cpu_ptr() to make the code cleaner and a bit faster. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tejun Heo <htejun@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/d8a7ef9592f55224630cb26dea239f05b6398a4e.1458187654.git.zhaolei@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/cpuacct: Rename parameter in cpuusage_write() for readabilityDongsheng Yang2016-03-211-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The name of the 'reset' parameter to cpuusage_write() is quite confusing, because the only valid value we allow is '0', so !reset is actually the case that resets ... Rename it to 'val' and explain it in a comment that we only allow 0. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: cgroups@vger.kernel.org Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1450696483-2864-1-git-send-email-yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/fair: Add comments to explain select_idle_sibling()Matt Fleming2016-03-211-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not entirely obvious how the main loop in select_idle_sibling() works on first glance. Sprinkle a few comments to explain the design and intention behind the loop based on some conversations with Mike and Peter. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.com> Cc: Mike Galbraith <mgalbraith@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1457535548-15329-1-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/fair: Fix fairness issue on migrationPeter Zijlstra2016-03-211-6/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pavan reported that in the presence of very light tasks (or cgroups) the placement of migrated tasks can cause severe fairness issues. The problem is that enqueue_entity() places the task before it updates time, thereby it can place the task far in the past (remember that light tasks will shoot virtual time forward at a high speed, so in relation to the pre-existing light task, we can land far in the past). This is done because update_curr() needs the current task, and we might be placing the current task. The obvious solution is to differentiate between the current and any other task; placing the current before we update time, and placing any other task after, such that !curr tasks end up at the current moment in time, and not in the past. Reported-by: Pavan Kondeti <pkondeti@codeaurora.org> Tested-by: Pavan Kondeti <pkondeti@codeaurora.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ben Segall <bsegall@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: byungchul.park@lge.com Link: http://lkml.kernel.org/r/20160309120403.GK6344@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/cgroup: Fix/cleanup cgroup teardown/initPeter Zijlstra2016-03-211-21/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CPU controller hasn't kept up with the various changes in the whole cgroup initialization / destruction sequence, and commit: 2e91fa7f6d45 ("cgroup: keep zombies associated with their original cgroups") caused it to explode. The reason for this is that zombies do not inhibit css_offline() from being called, but do stall css_released(). Now we tear down the cfs_rq structures on css_offline() but zombies can run after that, leading to use-after-free issues. The solution is to move the tear-down to css_released(), which guarantees nobody (including no zombies) is still using our cgroup. Furthermore, a few simple cleanups are possible too. There doesn't appear to be any point to us using css_online() (anymore?) so fold that in css_alloc(). And since cgroup code guarantees an RCU grace period between css_released() and css_free() we can forgo using call_rcu() and free the stuff immediately. Suggested-by: Tejun Heo <tj@kernel.org> Reported-by: Kazuki Yamaguchi <k@rhe.jp> Reported-by: Niklas Cassel <niklas.cassel@axis.com> Tested-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 2e91fa7f6d45 ("cgroup: keep zombies associated with their original cgroups") Link: http://lkml.kernel.org/r/20160316152245.GY6344@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Merge branch 'linus' into sched/urgent, to pick up dependenciesIngo Molnar2016-03-2162-1360/+3518
| |\| | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/cputime: Fix steal time accounting vs. CPU hotplugThomas Gleixner2016-03-052-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On CPU hotplug the steal time accounting can keep a stale rq->prev_steal_time value over CPU down and up. So after the CPU comes up again the delta calculation in steal_account_process_tick() wreckages itself due to the unsigned math: u64 steal = paravirt_steal_clock(smp_processor_id()); steal -= this_rq()->prev_steal_time; So if steal is smaller than rq->prev_steal_time we end up with an insane large value which then gets added to rq->prev_steal_time, resulting in a permanent wreckage of the accounting. As a consequence the per CPU stats in /proc/stat become stale. Nice trick to tell the world how idle the system is (100%) while the CPU is 100% busy running tasks. Though we prefer realistic numbers. None of the accounting values which use a previous value to account for fractions is reset at CPU hotplug time. update_rq_clock_task() has a sanity check for prev_irq_time and prev_steal_time_rq, but that sanity check solely deals with clock warps and limits the /proc/stat visible wreckage. The prev_time values are still wrong. Solution is simple: Reset rq->prev_*_time when the CPU is plugged in again. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: commit 095c0aa83e52 "sched: adjust scheduler cpu power for stolen time" Fixes: commit aa483808516c "sched: Remove irq time from available CPU power" Fixes: commit e6e6685accfa "KVM guest: Steal time accounting" Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1603041539490.3686@nanos Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | kernel/...: convert pr_warning to pr_warnJoe Perches2016-03-2213-60/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the more common logging method with the eventual goal of removing pr_warning altogether. Miscellanea: - Realign arguments - Coalesce formats - Add missing space between a few coalesced formats Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [kernel/power/suspend.c] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memremap: add MEMREMAP_WC flagBrian Starkey2016-03-221-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a flag to memremap() for writecombine mappings. Mappings satisfied by this flag will not be cached, however writes may be delayed or combined into more efficient bursts. This is most suitable for buffers written sequentially by the CPU for use by other DMA devices. Signed-off-by: Brian Starkey <brian.starkey@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memremap: don't modify flagsBrian Starkey2016-03-221-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These patches implement a MEMREMAP_WC flag for memremap(), which can be used to obtain writecombine mappings. This is then used for setting up dma_coherent_mem regions which use the DMA_MEMORY_MAP flag. The motivation is to fix an alignment fault on arm64, and the suggestion to implement MEMREMAP_WC for this case was made at [1]. That particular issue is handled in patch 4, which makes sure that the appropriate memset function is used when zeroing allocations mapped as IO memory. This patch (of 4): Don't modify the flags input argument to memremap(). MEMREMAP_WB is already a special case so we can check for it directly instead of clearing flag bits in each mapper. Signed-off-by: Brian Starkey <brian.starkey@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kernel/signal.c: add compile-time check for __ARCH_SI_PREAMBLE_SIZEHelge Deller2016-03-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The value of __ARCH_SI_PREAMBLE_SIZE defines the size (including padding) of the part of the struct siginfo that is before the union, and it is then used to calculate the needed padding (SI_PAD_SIZE) to make the size of struct siginfo equal to 128 (SI_MAX_SIZE) bytes. Depending on the target architecture and word width it equals to either 3 or 4 times sizeof int. Since the very beginning we had __ARCH_SI_PREAMBLE_SIZE wrong on the parisc architecture for the 64bit kernel build. It's even more frustrating, because it can easily be checked at compile time if the value was defined correctly. This patch adds such a check for the correctness of __ARCH_SI_PREAMBLE_SIZE in the hope that it will prevent existing and future architectures from running into the same problem. I refrained from replacing __ARCH_SI_PREAMBLE_SIZE by offsetof() in copy_siginfo() in include/asm-generic/siginfo.h, because a) it doesn't make any difference and b) it's used in the Documentation/kmemcheck.txt example. I ran this patch through the 0-DAY kernel test infrastructure and only the parisc architecture triggered as expected. That means that this patch should be OK for all major architectures. Signed-off-by: Helge Deller <deller@gmx.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kernel: add kcov code coverageDmitry Vyukov2016-03-227-0/+301
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kcov provides code coverage collection for coverage-guided fuzzing (randomized testing). Coverage-guided fuzzing is a testing technique that uses coverage feedback to determine new interesting inputs to a system. A notable user-space example is AFL (http://lcamtuf.coredump.cx/afl/). However, this technique is not widely used for kernel testing due to missing compiler and kernel support. kcov does not aim to collect as much coverage as possible. It aims to collect more or less stable coverage that is function of syscall inputs. To achieve this goal it does not collect coverage in soft/hard interrupts and instrumentation of some inherently non-deterministic or non-interesting parts of kernel is disbled (e.g. scheduler, locking). Currently there is a single coverage collection mode (tracing), but the API anticipates additional collection modes. Initially I also implemented a second mode which exposes coverage in a fixed-size hash table of counters (what Quentin used in his original patch). I've dropped the second mode for simplicity. This patch adds the necessary support on kernel side. The complimentary compiler support was added in gcc revision 231296. We've used this support to build syzkaller system call fuzzer, which has found 90 kernel bugs in just 2 months: https://github.com/google/syzkaller/wiki/Found-Bugs We've also found 30+ bugs in our internal systems with syzkaller. Another (yet unexplored) direction where kcov coverage would greatly help is more traditional "blob mutation". For example, mounting a random blob as a filesystem, or receiving a random blob over wire. Why not gcov. Typical fuzzing loop looks as follows: (1) reset coverage, (2) execute a bit of code, (3) collect coverage, repeat. A typical coverage can be just a dozen of basic blocks (e.g. an invalid input). In such context gcov becomes prohibitively expensive as reset/collect coverage steps depend on total number of basic blocks/edges in program (in case of kernel it is about 2M). Cost of kcov depends only on number of executed basic blocks/edges. On top of that, kernel requires per-thread coverage because there are always background threads and unrelated processes that also produce coverage. With inlined gcov instrumentation per-thread coverage is not possible. kcov exposes kernel PCs and control flow to user-space which is insecure. But debugfs should not be mapped as user accessible. Based on a patch by Quentin Casasnovas. [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode'] [akpm@linux-foundation.org: unbreak allmodconfig] [akpm@linux-foundation.org: follow x86 Makefile layout standards] Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tavis Ormandy <taviso@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@google.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: David Drysdale <drysdale@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | profile: hide unused functions when !CONFIG_PROC_FSArnd Bergmann2016-03-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A couple of functions and variables in the profile implementation are used only on SMP systems by the procfs code, but are unused if either procfs is disabled or in uniprocessor kernels. gcc prints a harmless warning about the unused symbols: kernel/profile.c:243:13: error: 'profile_flip_buffers' defined but not used [-Werror=unused-function] static void profile_flip_buffers(void) ^ kernel/profile.c:266:13: error: 'profile_discard_flip_buffers' defined but not used [-Werror=unused-function] static void profile_discard_flip_buffers(void) ^ kernel/profile.c:330:12: error: 'profile_cpu_callback' defined but not used [-Werror=unused-function] static int profile_cpu_callback(struct notifier_block *info, ^ This adds further #ifdef to the file, to annotate exactly in which cases they are used. I have done several thousand ARM randconfig kernels with this patch applied and no longer get any warnings in this file. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Robin Holt <robinmholt@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | panic: change nmi_panic from macro to functionHidehiro Kawai2016-03-221-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 1717f2096b54 ("panic, x86: Fix re-entrance problem due to panic on NMI") and commit 58c5661f2144 ("panic, x86: Allow CPUs to save registers even if looping in NMI context") introduced nmi_panic() which prevents concurrent/recursive execution of panic(). It also saves registers for the crash dump on x86. However, there are some cases where NMI handlers still use panic(). This patch set partially replaces them with nmi_panic() in those cases. Even this patchset is applied, some NMI or similar handlers (e.g. MCE handler) continue to use panic(). This is because I can't test them well and actual problems won't happen. For example, the possibility that normal panic and panic on MCE happen simultaneously is very low. This patch (of 3): Convert nmi_panic() to a proper function and export it instead of exporting internal implementation details to modules, for obvious reasons. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | fs/coredump: prevent fsuid=0 dumps into user-controlled directoriesJann Horn2016-03-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | ptrace: change __ptrace_unlink() to clear ->ptrace under ->siglockOleg Nesterov2016-03-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This test-case (simplified version of generated by syzkaller) #include <unistd.h> #include <sys/ptrace.h> #include <sys/wait.h> void test(void) { for (;;) { if (fork()) { wait(NULL); continue; } ptrace(PTRACE_SEIZE, getppid(), 0, 0); ptrace(PTRACE_INTERRUPT, getppid(), 0, 0); _exit(0); } } int main(void) { int np; for (np = 0; np < 8; ++np) if (!fork()) test(); while (wait(NULL) > 0) ; return 0; } triggers the 2nd WARN_ON_ONCE(!signr) warning in do_jobctl_trap(). The problem is that __ptrace_unlink() clears task->jobctl under siglock but task->ptrace is cleared without this lock held; this fools the "else" branch which assumes that !PT_SEIZED means PT_PTRACED. Note also that most of other PTRACE_SEIZE checks can race with detach from the exiting tracer too. Say, the callers of ptrace_trap_notify() assume that SEIZED can't go away after it was checked. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | auditsc: for seccomp events, log syscall compat state using in_compat_syscallAndy Lutomirski2016-03-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Except on SPARC, this is what the code always did. SPARC compat seccomp was buggy, although the impact of the bug was limited because SPARC 32-bit and 64-bit syscall numbers are the same. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Paul Moore <paul@paul-moore.com> Cc: Eric Paris <eparis@redhat.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | ptrace: in PEEK_SIGINFO, check syscall bitness, not task bitnessAndy Lutomirski2016-03-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Users of the 32-bit ptrace() ABI expect the full 32-bit ABI. siginfo translation should check ptrace() ABI, not caller task ABI. This is an ABI change on SPARC. Let's hope that no one relied on the old buggy ABI. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | seccomp: check in_compat_syscall, not is_compat_task, in strict modeAndy Lutomirski2016-03-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Seccomp wants to know the syscall bitness, not the caller task bitness, when it selects the syscall whitelist. As far as I know, this makes no difference on any architecture, so it's not a security problem. (It generates identical code everywhere except sparc, and, on sparc, the syscall numbering is the same for both ABIs.) Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kernel/hung_task.c: use timeout diff when timeout is updatedTetsuo Handa2016-03-221-8/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When new timeout is written to /proc/sys/kernel/hung_task_timeout_secs, khungtaskd is interrupted and again sleeps for full timeout duration. This means that hang task will not be checked if new timeout is written periodically within old timeout duration and/or checking of hang task will be delayed for up to previous timeout duration. Fix this by remembering last time khungtaskd checked hang task. This change will allow other watchdog tasks (if any) to share khungtaskd by sleeping for minimal timeout diff of all watchdog tasks. Doing more watchdog tasks from khungtaskd will reduce the possibility of printk() collisions by multiple watchdog threads. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'for-4.6-ns' of ↵Linus Torvalds2016-03-214-11/+247
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup namespace support from Tejun Heo: "These are changes to implement namespace support for cgroup which has been pending for quite some time now. It is very straight-forward and only affects what part of cgroup hierarchies are visible. After unsharing, mounting a cgroup fs will be scoped to the cgroups the task belonged to at the time of unsharing and the cgroup paths exposed to userland would be adjusted accordingly" * 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix and restructure error handling in copy_cgroup_ns() cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns() Add FS_USERNS_FLAG to cgroup fs cgroup: Add documentation for cgroup namespaces cgroup: mount cgroupns-root when inside non-init cgroupns kernfs: define kernfs_node_dentry cgroup: cgroup namespace setns support cgroup: introduce cgroup namespaces sched: new clone flag CLONE_NEWCGROUP for cgroup namespace kernfs: Add API to generate relative kernfs path
| * | | | cgroup: fix and restructure error handling in copy_cgroup_ns()Tejun Heo2016-02-291-13/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_cgroup_ns()'s error handling was broken and the attempt to fix it d22025570e2e ("cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns()") was broken too in that it ended up trying an ERR_PTR() value. There's only one place where copy_cgroup_ns() needs to perform cleanup after failure. Simplify and fix the error handling by removing the goto's. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
| * | | | cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns()Tejun Heo2016-02-181-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_cgroup_ns() returns an ERR_PTR value on error but copy_cgroup_ns() was checking for NULL for error. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>