- Jul 31, 2018
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Joel Fernandes (Google) authored
This patch detaches the preemptirq tracepoints from the tracers and keeps it separate. Advantages: * Lockdep and irqsoff event can now run in parallel since they no longer have their own calls. * This unifies the usecase of adding hooks to an irqsoff and irqson event, and a preemptoff and preempton event. 3 users of the events exist: - Lockdep - irqsoff and preemptoff tracers - irqs and preempt trace events The unification cleans up several ifdefs and makes the code in preempt tracer and irqsoff tracers simpler. It gets rid of all the horrific ifdeferry around PROVE_LOCKING and makes configuration of the different users of the tracepoints more easy and understandable. It also gets rid of the time_* function calls from the lockdep hooks used to call into the preemptirq tracer which is not needed anymore. The negative delta in lines of code in this patch is quite large too. In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS as a single point for registering probes onto the tracepoints. With this, the web of config options for preempt/irq toggle tracepoints and its users becomes: PREEMPT_TRACER PREEMPTIRQ_EVENTS IRQSOFF_TRACER PROVE_LOCKING | | \ | | \ (selects) / \ \ (selects) / TRACE_PREEMPT_TOGGLE ----> TRACE_IRQFLAGS \ / \ (depends on) / PREEMPTIRQ_TRACEPOINTS Other than the performance tests mentioned in the previous patch, I also ran the locking API test suite. I verified that all tests cases are passing. I also injected issues by not registering lockdep probes onto the tracepoints and I see failures to confirm that the probes are indeed working. This series + lockdep probes not registered (just to inject errors): [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12:FAILED|FAILED| ok | [ 0.000000] sirq-safe-A => hirqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | With this series + lockdep probes registered, all locking tests pass: [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.org Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by:
Namhyung Kim <namhyung@kernel.org> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Joel Fernandes (Google) authored
In recent tests with IRQ on/off tracepoints, a large performance overhead ~10% is noticed when running hackbench. This is root caused to calls to rcu_irq_enter_irqson and rcu_irq_exit_irqson from the tracepoint code. Following a long discussion on the list [1] about this, we concluded that srcu is a better alternative for use during rcu idle. Although it does involve extra barriers, its lighter than the sched-rcu version which has to do additional RCU calls to notify RCU idle about entry into RCU sections. In this patch, we change the underlying implementation of the trace_*_rcuidle API to use SRCU. This has shown to improve performance alot for the high frequency irq enable/disable tracepoints. Test: Tested idle and preempt/irq tracepoints. Here are some performance numbers: With a run of the following 30 times on a single core x86 Qemu instance with 1GB memory: hackbench -g 4 -f 2 -l 3000 Completion times in seconds. CONFIG_PROVE_LOCKING=y. No patches (without this series) Mean: 3.048 Median: 3.025 Std Dev: 0.064 With Lockdep using irq tracepoints with RCU implementation: Mean: 3.451 (-11.66 %) Median: 3.447 (-12.22%) Std Dev: 0.049 With Lockdep using irq tracepoints with SRCU implementation (this series): Mean: 3.020 (I would consider the improvement against the "without this series" case as just noise). Median: 3.013 Std Dev: 0.033 [1] https://patchwork.kernel.org/patch/10344297/ [remove rcu_read_lock_sched_notrace as its the equivalent of preempt_disable_notrace and is unnecessary to call in tracepoint code] Link: http://lkml.kernel.org/r/20180730222423.196630-3-joel@joelfernandes.org Cleaned-up-by:
Peter Zijlstra <peterz@infradead.org> Acked-by:
Peter Zijlstra <peterz@infradead.org> Reviewed-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> [ Simplified WARN_ON_ONCE() ] Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Joel Fernandes (Google) authored
get_cpu_var disables preemption which has the potential to call into the preemption disable trace points causing some complications. There's also no need to disable preemption in uses of get_lock_stats anyway since preempt is already disabled. So lets simplify the code. Link: http://lkml.kernel.org/r/20180730222423.196630-2-joel@joelfernandes.org Suggested-by:
Peter Zijlstra <peterz@infradead.org> Acked-by:
Peter Zijlstra <peterz@infradead.org> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Fix kprobe string argument testcase to not probe notrace function. Instead, it probes tracefs function which must be available with ftrace. Link: http://lkml.kernel.org/r/153294607107.32740.1664854684396589624.stgit@devbox Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Francis Deslauriers authored
Move selftest function to its own compile unit so it can be compiled with the ftrace cflags (CC_FLAGS_FTRACE) allowing it to be probed during the ftrace startup tests. Link: http://lkml.kernel.org/r/153294604271.32740.16490677128630177030.stgit@devbox Signed-off-by:
Francis Deslauriers <francis.deslauriers@efficios.com> Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Prohibit kprobe-events probing on notrace functions. Since probing on a notrace function can cause a recursive event call. In most cases those are just skipped, but in some cases it falls into an infinite recursive call. This protection can be disabled by the kconfig CONFIG_KPROBE_EVENTS_ON_NOTRACE=y, but it is highly recommended to keep it "n" for normal kernel builds. Note that this is only available if "kprobes on ftrace" has been implemented on the target arch and CONFIG_KPROBES_ON_FTRACE=y. Link: http://lkml.kernel.org/r/153294601436.32740.10557881188933661239.stgit@devbox Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Tested-by:
Francis Deslauriers <francis.deslauriers@efficios.com> [ Slight grammar and spelling fixes ] Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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- Jul 28, 2018
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kbuild test robot authored
Automatically found by kbuild test robot. Fixes: ffdc73a3b2ad ("lib: Add module for testing preemptoff/irqsoff latency tracers") Signed-off-by:
kbuild test robot <fengguang.wu@intel.com> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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- Jul 27, 2018
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Steven Rostedt (VMware) authored
The function enable_trace_kprobe() performs slightly differently if the file parameter is passed in as NULL on non-NULL. Instead of checking file twice, move the code between the two tests into a static inline helper function to make the code easier to follow. Link: http://lkml.kernel.org/r/20180725224728.7b1d5db2@vmware.local.home Link: http://lkml.kernel.org/r/20180726121152.4dd54330@gandalf.local.home Reviewed-by:
Josh Poimboeuf <jpoimboe@redhat.com> Acked-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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- Jul 26, 2018
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Masami Hiramatsu authored
Remove ftrace_nr_registered_ops() because it is no longer used. ftrace_nr_registered_ops() has been introduced by commit ea701f11 ("ftrace: Add selftest to test function trace recursion protection"), but its caller has been removed by commit 05cbbf64 ("tracing: Fix selftest function recursion accounting"). So it is not called anymore. Link: http://lkml.kernel.org/r/153260907227.12474.5234899025934963683.stgit@devbox Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Remove using_ftrace_ops_list_func() since it is no longer used. Using ftrace_ops_list_func() has been introduced by commit 7eea4fce ("tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_func") as a helper function, but its caller has been removed by commit 72ac426a ("tracing: Clean up stack tracing and fix fentry updates"). So it is not called anymore. Link: http://lkml.kernel.org/r/153260904427.12474.9952096317439329851.stgit@devbox Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Steven Rostedt (VMware) authored
Nothing uses unregister_trigger() outside of trace_events_trigger.c file, thus it should be static. Not sure why this was ever converted, because its counter part, register_trigger(), was always static. Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Joel Fernandes (Google) authored
Here we add unit tests for the preemptoff and irqsoff tracer by using a kernel module introduced previously to trigger long preempt or irq disabled sections in the kernel. Link: http://lkml.kernel.org/r/20180711063540.91101-3-joel@joelfernandes.org Reviewed-by:
Masami Hiramatsu <mhiramat@kernel.org> Acked-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Joel Fernandes (Google) authored
Here we introduce a test module for introducing a long preempt or irq disable delay in the kernel which the preemptoff or irqsoff tracers can detect. This module is to be used only for test purposes and is default disabled. Following is the expected output (only briefly shown) that can be parsed to verify that the tracers are working correctly. We will use this from the kselftests in future patches. For the preemptoff tracer: echo preemptoff > /d/tracing/current_tracer sleep 1 insmod ./preemptirq_delay_test.ko test_mode=preempt delay=500000 sleep 1 bash-4.3# cat /d/tracing/trace preempt -1066 2...2 0us@: preemptirq_delay_run <-preemptirq_delay_run preempt -1066 2...2 500002us : preemptirq_delay_run <-preemptirq_delay_run preempt -1066 2...2 500004us : tracer_preempt_on <-preemptirq_delay_run preempt -1066 2...2 500012us : <stack trace> => kthread => ret_from_fork For the irqsoff tracer: echo irqsoff > /d/tracing/current_tracer sleep 1 insmod ./preemptirq_delay_test.ko test_mode=irq delay=500000 sleep 1 bash-4.3# cat /d/tracing/trace irq dis -1069 1d..1 0us@: preemptirq_delay_run irq dis -1069 1d..1 500001us : preemptirq_delay_run irq dis -1069 1d..1 500002us : tracer_hardirqs_on <-preemptirq_delay_run irq dis -1069 1d..1 500005us : <stack trace> => ret_from_fork Link: http://lkml.kernel.org/r/20180712213611.GA8743@joelaf.mtv.corp.google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Julia Cartwright <julia@ni.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Glexiner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> [ Erick is a co-developer of this commit ] Signed-off-by:
Erick Reyes <erickreyes@google.com> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Joel Fernandes (Google) authored
Split reset functions into seperate functions in preparation of future patches that need to do tracer specific reset. Link: http://lkml.kernel.org/r/20180628182149.226164-4-joel@joelfernandes.org Reviewed-by:
Namhyung Kim <namhyung@kernel.org> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Joel Fernandes (Google) authored
In the last patch in this series, we are making lockdep register hooks onto the irq_{disable,enable} tracepoints. These tracepoints use the _rcuidle tracepoint variant. In this series we switch the _rcuidle tracepoint callers to use SRCU instead of sched-RCU. Inorder to dereference the pointer to the probe functions, we could call srcu_dereference, however this API will call back into lockdep to check if the lock is held *before* the lockdep probe hooks have a chance to run and annotate the IRQ enabled/disabled state. For this reason we need a notrace variant of srcu_dereference since otherwise we get lockdep splats. This patch adds the needed srcu_dereference_notrace variant. Link: http://lkml.kernel.org/r/20180628182149.226164-3-joel@joelfernandes.org Reviewed-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Paul McKenney authored
This is needed for a future tracepoint patch that uses srcu, and to make sure it doesn't call into lockdep. tracepoint code already calls notrace variants for rcu_read_lock_sched so this patch does the same for srcu which will be used in a later patch. Keeps it consistent with rcu-sched. [Joel: Added commit message] Link: http://lkml.kernel.org/r/20180628182149.226164-2-joel@joelfernandes.org Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by:
Paul McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Snild Dolkow authored
There is a window for racing when printing directly to task->comm, allowing other threads to see a non-terminated string. The vsnprintf function fills the buffer, counts the truncated chars, then finally writes the \0 at the end. creator other vsnprintf: fill (not terminated) count the rest trace_sched_waking(p): ... memcpy(comm, p->comm, TASK_COMM_LEN) write \0 The consequences depend on how 'other' uses the string. In our case, it was copied into the tracing system's saved cmdlines, a buffer of adjacent TASK_COMM_LEN-byte buffers (note the 'n' where 0 should be): crash-arm64> x/1024s savedcmd->saved_cmdlines | grep 'evenk' 0xffffffd5b3818640: "irq/497-pwr_evenkworker/u16:12" ...and a strcpy out of there would cause stack corruption: [224761.522292] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffff9bf9783c78 crash-arm64> kbt | grep 'comm\|trace_print_context' #6 0xffffff9bf9783c78 in trace_print_context+0x18c(+396) comm (char [16]) = "irq/497-pwr_even" crash-arm64> rd 0xffffffd4d0e17d14 8 ffffffd4d0e17d14: 2f71726900000000 5f7277702d373934 ....irq/497-pwr_ ffffffd4d0e17d24: 726f776b6e657665 3a3631752f72656b evenkworker/u16: ffffffd4d0e17d34: f9780248ff003231 cede60e0ffffff9b 12..H.x......`.. ffffffd4d0e17d44: cede60c8ffffffd4 00000fffffffffd4 .....`.......... The workaround in e09e2867 (use strlcpy in __trace_find_cmdline) was likely needed because of this same bug. Solved by vsnprintf:ing to a local buffer, then using set_task_comm(). This way, there won't be a window where comm is not terminated. Link: http://lkml.kernel.org/r/20180726071539.188015-1-snild@sony.com Cc: stable@vger.kernel.org Fixes: bc0c38d1 ("ftrace: latency tracer infrastructure") Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by:
Snild Dolkow <snild@sony.com> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Steven Rostedt (VMware) authored
Commit 57ea2a34 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure") added an if statement that depends on another if statement that gcc doesn't see will initialize the "link" variable and gives the warning: "warning: 'link' may be used uninitialized in this function" It is really a false positive, but to quiet the warning, and also to make sure that it never actually is used uninitialized, initialize the "link" variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler thinks it could be used uninitialized. Cc: stable@vger.kernel.org Fixes: 57ea2a34 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure") Reported-by:
kbuild test robot <lkp@intel.com> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Steven Rostedt (VMware) authored
There was a case that triggered a double free in event_trigger_callback() due to the called reg() function freeing the trigger_data and then it getting freed again by the error return by the caller. The solution there was to up the trigger_data ref count. Code inspection found that event_enable_trigger_func() has the same issue, but is not as easy to trigger (requires harder to trigger failures). It needs to be solved slightly different as it needs more to clean up when the reg() function fails. Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 7862ad18 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands") Reivewed-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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- Jul 25, 2018
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Artem Savkov authored
If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe it returns an error, but does not unset the tp flags it set previously. This results in a probe being considered enabled and failures like being unable to remove the probe through kprobe_events file since probes_open() expects every probe to be disabled. Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 41a7dd42 ("tracing/kprobes: Support ftrace_event_file base multibuffer") Acked-by:
Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by:
Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by:
Artem Savkov <asavkov@redhat.com> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Add a testcase for checking snapshot and tracing_on relationship. This ensures that the snapshotting doesn't affect current tracing on/off settings. Link: http://lkml.kernel.org/r/153149932412.11274.15289227592627901488.stgit@devbox Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp> Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-kselftest@vger.kernel.org Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Maintain the tracing on/off setting of the ring_buffer when switching to the trace buffer snapshot. Taking a snapshot is done by swapping the backup ring buffer (max_tr_buffer). But since the tracing on/off setting is defined by the ring buffer, when swapping it, the tracing on/off setting can also be changed. This causes a strange result like below: /sys/kernel/debug/tracing # cat tracing_on 1 /sys/kernel/debug/tracing # echo 0 > tracing_on /sys/kernel/debug/tracing # cat tracing_on 0 /sys/kernel/debug/tracing # echo 1 > snapshot /sys/kernel/debug/tracing # cat tracing_on 1 /sys/kernel/debug/tracing # echo 1 > snapshot /sys/kernel/debug/tracing # cat tracing_on 0 We don't touch tracing_on, but snapshot changes tracing_on setting each time. This is an anomaly, because user doesn't know that each "ring_buffer" stores its own tracing-enable state and the snapshot is done by swapping ring buffers. Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp> Cc: stable@vger.kernel.org Fixes: debdd57f ("tracing: Make a snapshot feature available from userspace") Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> [ Updated commit log and comment in the code ] Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Steven Rostedt (VMware) authored
Running the following: # cd /sys/kernel/debug/tracing # echo 500000 > buffer_size_kb [ Or some other number that takes up most of memory ] # echo snapshot > events/sched/sched_switch/trigger Triggers the following bug: ------------[ cut here ]------------ kernel BUG at mm/slub.c:296! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:kfree+0x16c/0x180 Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246 RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80 RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500 RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00 FS: 00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0 Call Trace: event_trigger_callback+0xee/0x1d0 event_trigger_write+0xfc/0x1a0 __vfs_write+0x33/0x190 ? handle_mm_fault+0x115/0x230 ? _cond_resched+0x16/0x40 vfs_write+0xb0/0x190 ksys_write+0x52/0xc0 do_syscall_64+0x5a/0x160 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f363e16ab50 Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24 RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50 RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001 RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009 R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0 Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper 86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e ---[ end trace d301afa879ddfa25 ]--- The cause is because the register_snapshot_trigger() call failed to allocate the snapshot buffer, and then called unregister_trigger() which freed the data that was passed to it. Then on return to the function that called register_snapshot_trigger(), as it sees it failed to register, it frees the trigger_data again and causes a double free. By calling event_trigger_init() on the trigger_data (which only ups the reference counter for it), and then event_trigger_free() afterward, the trigger_data would not get freed by the registering trigger function as it would only up and lower the ref count for it. If the register trigger function fails, then the event_trigger_free() called after it will free the trigger data normally. Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home Cc: stable@vger.kerne.org Fixes: 93e31ffb ("tracing: Add 'snapshot' event trigger command") Reported-by:
Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by:
Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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- Jul 23, 2018
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Linus Torvalds authored
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git://git.infradead.org/nvmeLinus Torvalds authored
Pull NVMe fixes from Christoph Hellwig: - fix a regression in 4.18 that causes a memory leak on probe failure (Keith Bush) - fix a deadlock in the passthrough ioctl code (Scott Bauer) - don't enable AENs if not supported (Weiping Zhang) - fix an old regression in metadata handling in the passthrough ioctl code (Roland Dreier) * tag 'nvme-for-4.18' of git://git.infradead.org/nvme: nvme: fix handling of metadata_len for NVME_IOCTL_IO_CMD nvme: don't enable AEN if not supported nvme: ensure forward progress during Admin passthru nvme-pci: fix memory leak on probe failure
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull vfs fixes from Al Viro: "Fix several places that screw up cleanups after failures halfway through opening a file (one open-coding filp_clone_open() and getting it wrong, two misusing alloc_file()). That part is -stable fodder from the 'work.open' branch. And Christoph's regression fix for uapi breakage in aio series; include/uapi/linux/aio_abi.h shouldn't be pulling in the kernel definition of sigset_t, the reason for doing so in the first place had been bogus - there's no need to expose struct __aio_sigset in aio_abi.h at all" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: aio: don't expose __aio_sigset in uapi ocxlflash_getfile(): fix double-iput() on alloc_file() failures cxl_getfile(): fix double-iput() on alloc_file() failures drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open()
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Al Viro authored
kernel_wait4() expects a userland address for status - it's only rusage that goes as a kernel one (and needs a copyout afterwards) [ Also, fix the prototype of kernel_wait4() to have that __user annotation - Linus ] Fixes: 92ebce5a ("osf_wait4: switch to kernel_wait4()") Cc: stable@kernel.org # v4.13+ Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- Jul 22, 2018
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-socLinus Torvalds authored
Pull ARM SoC fixes from Olof Johansson: - Fix interrupt type on ethernet switch for i.MX-based RDU2 - GPC on i.MX exposed too large a register window which resulted in userspace being able to crash the machine. - Fixup of bad merge resolution moving GPIO DT nodes under pinctrl on droid4. * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: dts: imx6: RDU2: fix irq type for mv88e6xxx switch soc: imx: gpc: restrict register range for regmap access ARM: dts: omap4-droid4: fix dts w.r.t. pwm
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fix from Ingo Molnar: "A single fix for a MCE-polling regression, which prevented the disabling of polling" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/MCE: Remove min interval polling limitation
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 pti fixes from Ingo Molnar: "An APM fix, and a BTS hardware-tracing fix related to PTI changes" * 'x86-pti-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apm: Don't access __preempt_count with zeroed fs x86/events/intel/ds: Fix bts_interrupt_threshold alignment
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler fixes from Ingo Molnar: "Two fixes: a stop-machine preemption fix and a SCHED_DEADLINE fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Fix switched_from_dl() warning stop_machine: Disable preemption when waking two stopper threads
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull core kernel fixes from Ingo Molnar: "This is mostly the copy_to_user_mcsafe() related fixes from Dan Williams, and an ORC fix for Clang" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm/memcpy_mcsafe: Fix copy_to_user_mcsafe() exception handling lib/iov_iter: Fix pipe handling in _copy_to_iter_mcsafe() lib/iov_iter: Document _copy_to_iter_flushcache() lib/iov_iter: Document _copy_to_iter_mcsafe() objtool: Use '.strtab' if '.shstrtab' doesn't exist, to support ORC tables on Clang
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Michael Ellerman: "Two regression fixes, one for xmon disassembly formatting and the other to fix the E500 build. Two commits to fix a potential security issue in the VFIO code under obscure circumstances. And finally a fix to the Power9 idle code to restore SPRG3, which is user visible and used for sched_getcpu(). Thanks to: Alexey Kardashevskiy, David Gibson. Gautham R. Shenoy, James Clarke" * tag 'powerpc-4.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle) powerpc/Makefile: Assemble with -me500 when building for E500 KVM: PPC: Check if IOMMU page is contained in the pinned physical page vfio/spapr: Use IOMMU pageshift rather than pagesize powerpc/xmon: Fix disassembly since printf changes
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds authored
Pull btrfs fix from David Sterba: "A fix of a corruption regarding fsync and clone, under some very specific conditions explained in the patch. The fix is marked for stable 3.16+ so I'd like to get it merged now given the impact" * tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix file data corruption after cloning a range and fsync
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Linus Torvalds authored
Like vm_area_dup(), it initializes the anon_vma_chain head, and the basic mm pointer. The rest of the fields end up being different for different users, although the plan is to also initialize the 'vm_ops' field to a dummy entry. Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
.. and re-initialize th eanon_vma_chain head. This removes some boiler-plate from the users, and also makes it clear why it didn't need use the 'zalloc()' version. Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
The vm_area_struct is one of the most fundamental memory management objects, but the management of it is entirely open-coded evertwhere, ranging from allocation and freeing (using kmem_cache_[z]alloc and kmem_cache_free) to initializing all the fields. We want to unify this in order to end up having some unified initialization of the vmas, and the first step to this is to at least have basic allocation functions. Right now those functions are literally just wrappers around the kmem_cache_*() calls. This is a purely mechanical conversion: # new vma: kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc() # copy old vma kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old) # free vma kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma) to the point where the old vma passed in to the vm_area_dup() function isn't even used yet (because I've left all the old manual initialization alone). Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
Merge fixes from Andrew Morton: "5 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: memcg: fix use after free in mem_cgroup_iter() mm/huge_memory.c: fix data loss when splitting a file pmd fat: fix memory allocation failure handling of match_strdup() MAINTAINERS: Peter has moved mm/memblock: add missing include <linux/bootmem.h>
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Jing Xia authored
It was reported that a kernel crash happened in mem_cgroup_iter(), which can be triggered if the legacy cgroup-v1 non-hierarchical mode is used. Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b8f ...... Call trace: mem_cgroup_iter+0x2e0/0x6d4 shrink_zone+0x8c/0x324 balance_pgdat+0x450/0x640 kswapd+0x130/0x4b8 kthread+0xe8/0xfc ret_from_fork+0x10/0x20 mem_cgroup_iter(): ...... if (css_tryget(css)) <-- crash here break; ...... The crashing reason is that mem_cgroup_iter() uses the memcg object whose pointer is stored in iter->position, which has been freed before and filled with POISON_FREE(0x6b). And the root cause of the use-after-free issue is that invalidate_reclaim_iterators() fails to reset the value of iter->position to NULL when the css of the memcg is released in non- hierarchical mode. Link: http://lkml.kernel.org/r/1531994807-25639-1-git-send-email-jing.xia@unisoc.com Fixes: 6df38689 ("mm: memcontrol: fix possible memcg leak due to interrupted reclaim") Signed-off-by:
Jing Xia <jing.xia.mail@gmail.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <chunyan.zhang@unisoc.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Hugh Dickins authored
__split_huge_pmd_locked() must check if the cleared huge pmd was dirty, and propagate that to PageDirty: otherwise, data may be lost when a huge tmpfs page is modified then split then reclaimed. How has this taken so long to be noticed? Because there was no problem when the huge page is written by a write system call (shmem_write_end() calls set_page_dirty()), nor when the page is allocated for a write fault (fault_dirty_shared_page() calls set_page_dirty()); but when allocated for a read fault (which MAP_POPULATE simulates), no set_page_dirty(). Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1807111741430.1106@eggly.anvils Fixes: d21b9e57 ("thp: handle file pages in split_huge_pmd()") Signed-off-by:
Hugh Dickins <hughd@google.com> Reported-by:
Ashwin Chaugule <ashwinch@google.com> Reviewed-by:
Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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