user/sven/linux.git/kernel/trace, branch v3.18.79

tracing: Erase irqsoff trace with empty write

2017-10-05T07:35:50Z

commit 8dd33bcb7050dd6f8c1432732f930932c9d3a33e upstream. One convenient way to erase trace is "echo > trace". However, this is currently broken if the current tracer is irqsoff tracer. This is because irqsoff tracer use max_buffer as the default trace buffer. Set the max_buffer as the one to be cleared when it's the trace buffer currently in use. Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com Cc: Fixes: 4acd4d00f ("tracing: give easy way to clear trace buffer") Signed-off-by: Bo Yan Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Fix trace_pipe behavior for instance traces

2017-10-05T07:35:50Z

commit 75df6e688ccd517e339a7c422ef7ad73045b18a2 upstream. When reading data from trace_pipe, tracing_wait_pipe() performs a check to see if tracing has been turned off after some data was read. Currently, this check always looks at global trace state, but it should be checking the trace instance where trace_pipe is located at. Because of this bug, cat instances/i1/trace_pipe in the following script will immediately exit instead of waiting for data: cd /sys/kernel/debug/tracing echo 0 > tracing_on mkdir -p instances/i1 echo 1 > instances/i1/tracing_on echo 1 > instances/i1/events/sched/sched_process_exec/enable cat instances/i1/trace_pipe Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com Fixes: 10246fa35d4f ("tracing: give easy way to clear trace buffer") Signed-off-by: Tahsin Erdogan Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Apply trace_clock changes to instance max buffer

2017-09-27T08:57:21Z

commit 170b3b1050e28d1ba0700e262f0899ffa4fccc52 upstream. Currently trace_clock timestamps are applied to both regular and max buffers only for global trace. For instance trace, trace_clock timestamps are applied only to regular buffer. But, regular and max buffers can be swapped, for example, following a snapshot. So, for instance trace, bad timestamps can be seen following a snapshot. Let's apply trace_clock timestamps to instance max buffer as well. Link: http://lkml.kernel.org/r/ebdb168d0be042dcdf51f81e696b17fabe3609c1.1504642143.git.tom.zanussi@linux.intel.com Fixes: 277ba0446 ("tracing: Add interface to allow multiple trace buffers") Signed-off-by: Baohong Liu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

ftrace: Fix selftest goto location on error

2017-09-27T08:57:21Z

commit 46320a6acc4fb58f04bcf78c4c942cc43b20f986 upstream. In the second iteration of trace_selftest_ops(), the error goto label is wrong in the case where trace_selftest_test_global_cnt is off. In the case of error, it leaks the dynamic ops that was allocated. Fixes: 95950c2e ("ftrace: Add self-tests for multiple function trace users") Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Fix freeing of filter in create_filter() when set_str is false

2017-08-30T08:16:55Z

commit 8b0db1a5bdfcee0dbfa89607672598ae203c9045 upstream. Performing the following task with kmemleak enabled: # cd /sys/kernel/tracing/events/irq/irq_handler_entry/ # echo 'enable_event:kmem:kmalloc:3 if irq >' > trigger # echo 'enable_event:kmem:kmalloc:3 if irq > 31' > trigger # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8800b9290308 (size 32): comm "bash", pid 1114, jiffies 4294848451 (age 141.139s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmemleak_alloc+0x4a/0xa0 [] kmem_cache_alloc_trace+0x158/0x290 [] create_filter_start.constprop.28+0x99/0x940 [] create_filter+0xa9/0x160 [] create_event_filter+0xc/0x10 [] set_trigger_filter+0xe5/0x210 [] event_enable_trigger_func+0x324/0x490 [] event_trigger_write+0x1a2/0x260 [] __vfs_write+0xd7/0x380 [] vfs_write+0x101/0x260 [] SyS_write+0xab/0x130 [] entry_SYSCALL_64_fastpath+0x1f/0xbe [] 0xffffffffffffffff The function create_filter() is passed a 'filterp' pointer that gets allocated, and if "set_str" is true, it is up to the caller to free it, even on error. The problem is that the pointer is not freed by create_filter() when set_str is false. This is a bug, and it is not up to the caller to free the filter on error if it doesn't care about the string. Link: http://lkml.kernel.org/r/1502705898-27571-2-git-send-email-chuhu@redhat.com Fixes: 38b78eb85 ("tracing: Factorize filter creation") Reported-by: Chunyu Hu Tested-by: Chunyu Hu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Fix kmemleak in instance_rmdir

2017-07-27T22:03:29Z

commit db9108e054700c96322b0f0028546aa4e643cf0b upstream. Hit the kmemleak when executing instance_rmdir, it forgot releasing mem of tracing_cpumask. With this fix, the warn does not appear any more. unreferenced object 0xffff93a8dfaa7c18 (size 8): comm "mkdir", pid 1436, jiffies 4294763622 (age 9134.308s) hex dump (first 8 bytes): ff ff ff ff ff ff ff ff ........ backtrace: [] kmemleak_alloc+0x4a/0xa0 [] __kmalloc_node+0xf1/0x280 [] alloc_cpumask_var_node+0x23/0x30 [] alloc_cpumask_var+0xe/0x10 [] instance_mkdir+0x90/0x240 [] tracefs_syscall_mkdir+0x40/0x70 [] vfs_mkdir+0x109/0x1b0 [] SyS_mkdir+0xd0/0x100 [] do_syscall_64+0x67/0x150 [] return_from_SYSCALL_64+0x0/0x6a [] 0xffffffffffffffff Link: http://lkml.kernel.org/r/1500546969-12594-1-git-send-email-chuhu@redhat.com Fixes: ccfe9e42e451 ("tracing: Make tracing_cpumask available for all instances") Signed-off-by: Chunyu Hu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results

2017-07-21T06:12:23Z

commit c59f29cb144a6a0dfac16ede9dc8eafc02dc56ca upstream. The 's' flag is supposed to indicate that a softirq is running. This can be detected by testing the preempt_count with SOFTIRQ_OFFSET. The current code tests the preempt_count with SOFTIRQ_MASK, which would be true even when softirqs are disabled but not serving a softirq. Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org Signed-off-by: Pavankumar Kondeti Signed-off-by: Steven Rostedt Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

tracing/kprobes: Allow to create probe with a module name starting with a digit

2017-07-15T08:14:39Z

commit 9e52b32567126fe146f198971364f68d3bc5233f upstream. Always try to parse an address, since kstrtoul() will safely fail when given a symbol as input. If that fails (which will be the case for a symbol), try to parse a symbol instead. This allows creating a probe such as: p:probe/vlan_gro_receive 8021q:vlan_gro_receive+0 Which is necessary for this command to work: perf probe -m 8021q -a vlan_gro_receive Link: http://lkml.kernel.org/r/fd72d666f45b114e2c5b9cf7e27b91de1ec966f1.1498122881.git.sd@queasysnail.net Fixes: 413d37d1e ("tracing: Add kprobe-based event tracer") Acked-by: Masami Hiramatsu Signed-off-by: Sabrina Dubroca Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing/kprobes: Enforce kprobes teardown after testing

2017-05-25T12:18:02Z

commit 30e7d894c1478c88d50ce94ddcdbd7f9763d9cdd upstream. Enabling the tracer selftest triggers occasionally the warning in text_poke(), which warns when the to be modified page is not marked reserved. The reason is that the tracer selftest installs kprobes on functions marked __init for testing. These probes are removed after the tests, but that removal schedules the delayed kprobes_optimizer work, which will do the actual text poke. If the work is executed after the init text is freed, then the warning triggers. The bug can be reproduced reliably when the work delay is increased. Flush the optimizer work and wait for the optimizing/unoptimizing lists to become empty before returning from the kprobes tracer selftest. That ensures that all operations which were queued due to the probes removal have completed. Link: http://lkml.kernel.org/r/20170516094802.76a468bb@gandalf.local.home Signed-off-by: Thomas Gleixner Acked-by: Masami Hiramatsu Fixes: 6274de498 ("kprobes: Support delayed unoptimizing") Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

perf: Avoid horrible stack usage

2017-04-30T03:49:15Z

commit 86038c5ea81b519a8a1fcfcd5e4599aab0cdd119 upstream. Both Linus (most recent) and Steve (a while ago) reported that perf related callbacks have massive stack bloat. The problem is that software events need a pt_regs in order to properly report the event location and unwind stack. And because we could not assume one was present we allocated one on stack and filled it with minimal bits required for operation. Now, pt_regs is quite large, so this is undesirable. Furthermore it turns out that most sites actually have a pt_regs pointer available, making this even more onerous, as the stack space is pointless waste. This patch addresses the problem by observing that software events have well defined nesting semantics, therefore we can use static per-cpu storage instead of on-stack. Linus made the further observation that all but the scheduler callers of perf_sw_event() have a pt_regs available, so we change the regular perf_sw_event() to require a valid pt_regs (where it used to be optional) and add perf_sw_event_sched() for the scheduler. We have a scheduler specific call instead of a more generic _noregs() like construct because we can assume non-recursion from the scheduler and thereby simplify the code further (_noregs would have to put the recursion context call inline in order to assertain which __perf_regs element to use). One last note on the implementation of perf_trace_buf_prepare(); we allow .regs = NULL for those cases where we already have a pt_regs pointer available and do not need another. Reported-by: Linus Torvalds Reported-by: Steven Rostedt Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Javi Merino Cc: Linus Torvalds Cc: Mathieu Desnoyers Cc: Oleg Nesterov Cc: Paul Mackerras Cc: Petr Mladek Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vaibhav Nagarnaik Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar Cc: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman