- 15 Oct, 2020 2 commits
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Gaurav Kohli authored
Below race can come, if trace_open and resize of cpu buffer is running parallely on different cpus CPUX CPUY ring_buffer_resize atomic_read(&buffer->resize_disabled) tracing_open tracing_reset_online_cpus ring_buffer_reset_cpu rb_reset_cpu rb_update_pages remove/insert pages resetting pointer This race can cause data abort or some times infinte loop in rb_remove_pages and rb_insert_pages while checking pages for sanity. Take buffer lock to fix this. Link: https://lkml.kernel.org/r/1601976833-24377-1-git-send-email-gkohli@codeaurora.org Cc: stable@vger.kernel.org Fixes: b23d7a5f ("ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU") Signed-off-by:
Gaurav Kohli <gkohli@codeaurora.org> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
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Steven Rostedt (VMware) authored
After having a typo for writing a histogram trigger. Wrote: echo 'hist:key=pid:ts=common_timestamp.usec' > events/sched/sched_waking/trigger Instead of: echo 'hist:key=pid:ts=common_timestamp.usecs' > events/sched/sched_waking/trigger and the following crash happened: BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 4 PID: 1641 Comm: sh Not tainted 5.9.0-rc5-test+ #549 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:event_hist_trigger_func+0x70b/0x1ee0 Code: 24 08 89 d5 49 89 cc e9 8c 00 00 00 4c 89 f2 41 b9 00 10 00 00 4c 89 e1 44 89 ee 4c 89 ff e8 dc d3 ff ff 45 89 ea 4b 8b 14 d7 <f6> 42 08 04 74 17 41 8b 8f c0 00 00 00 8d 71 01 41 89 b7 c0 00 00 RSP: 0018:ffff959213d53db0 EFLAGS: 00010202 RAX: ffffffffffffffea RBX: 0000000000000000 RCX: 0000000000084c04 RDX: 0000000000000000 RSI: df7326aefebd174c RDI: 0000000000031080 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000046 R12: ffff959211dcf690 R13: 0000000000000001 R14: ffff95925a36e370 R15: ffff959251c89800 FS: 00007fb9ea934740(0000) GS:ffff95925ab00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 00000000c976c005 CR4: 00000000001706e0 Call Trace: ? trigger_process_regex+0x78/0x110 trigger_process_regex+0xc5/0x110 event_trigger_write+0x71/0xd0 vfs_write+0xca/0x210 ksys_write+0x70/0xf0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fb9eaa29487 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 This was caused by accessing the hlist_data fields after the call to __create_val_fields() without checking if the creation succeed. Link: https://lkml.kernel.org/r/20201013154852.3abd8702@gandalf.local.home Fixes: 63a1e5de ("tracing: Save normal string variables") Reviewed-by:
Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by:
Tom Zanussi <zanussi@kernel.org> Signed-off-by:
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- 08 Oct, 2020 11 commits
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Steven Rostedt (VMware) authored
A cut and paste error had the check to use __get_str() test "is_dynamic" twice, instead of checking "is_string && is_dynamic". Link: https://lore.kernel.org/r/d34dccd5-96ba-a2d9-46ea-de8807525deb@canonical.comReported-by:
Colin Ian King <colin.king@canonical.com> Acked-by:
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Sudip Mukherjee authored
The variable 'len' has been assigned a value but is not used after that. So, remove the assignement. Link: https://lkml.kernel.org/r/20200930184303.22896-1-sudipm.mukherjee@gmail.comSigned-off-by:
Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by:
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Wei Yang authored
Fix the comment to comply with the code. Link: https://lkml.kernel.org/r/20200831031104.23322-7-richard.weiyang@linux.alibaba.comSigned-off-by:
Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by:
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Steven Rostedt (VMware) authored
I hate when unrelated variables are declared on the same line. Split them. Signed-off-by: -
Wei Yang authored
Based on the following two reasones, we could simplify the calculation: - If the number after roundup count is not power of 2, we would definitely have more than 1 empty page with a higher order. - get_count_order() just return current order, so one lower order could meet the requirement. The calculation could be simplified by lower one order level when pages are not power of 2. Link: https://lkml.kernel.org/r/20200831031104.23322-5-richard.weiyang@linux.alibaba.comSigned-off-by: -
Wei Yang authored
All the three macro are defined to be used for ftrace_rec_count(). This can be achieved by (flags & FTRACE_REF_MAX) directly. Since no other places would use those macros, remove them for clarity. Also it fixes a typo in the comment. Link: https://lkml.kernel.org/r/20200831031104.23322-4-richard.weiyang@linux.alibaba.comSigned-off-by:
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Steven Rostedt (VMware) authored
No need to add a check to subtract the number of bits if bits is zero after fls(). Just divide the size by two before calling it. This does give the same answer for size of 0 and 1, but that's fine. Signed-off-by: -
Wei Yang authored
The effect here is to get the number of bits, lets use fls() to do this job. Link: https://lkml.kernel.org/r/20200831031104.23322-3-richard.weiyang@linux.alibaba.comSigned-off-by:
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Steven Rostedt (VMware) authored
Change the format for printing synthetic field strings to limit the length of the string printed even if it's not correctly terminated. Link: https://lore.kernel.org/r/20201002210036.0200371b@oasis.local.home Link: https://lkml.kernel.org/r/b6bdb34e70d970e8026daa3503db6b8e5cdad524.1601848695.git.zanussi@kernel.orgSigned-off-by:
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Tom Zanussi authored
Add a selftest that defines and traces a synthetic event that uses a dynamic string event field. Link: https://lkml.kernel.org/r/74445afb005046d76d59fb06696a2ceaa164dec9.1601848695.git.zanussi@kernel.orgAcked-by:
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Tom Zanussi authored
Add an entry with a basic description of events/synthetic_events along with a simple example. Link: https://lkml.kernel.org/r/3c7f178cf95aaeebc01eda7d95600dd937233eb7.1601848695.git.zanussi@kernel.orgReviewed-by:
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- 05 Oct, 2020 4 commits
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Tom Zanussi authored
Currently, sythetic events only support static string fields such as: # echo 'test_latency u64 lat; char somename[32]' > /sys/kernel/debug/tracing/synthetic_events Which is fine, but wastes a lot of space in the event. It also prevents the most commonly-defined strings in the existing trace events e.g. those defined using __string(), from being passed to synthetic events via the trace() action. With this change, synthetic events with dynamic fields can be defined: # echo 'test_latency u64 lat; char somename[]' > /sys/kernel/debug/tracing/synthetic_events And the trace() action can be used to generate events using either dynamic or static strings: # echo 'hist:keys=name:lat=common_timestamp.usecs-$ts0:onmatch(sys.event).test_latency($lat,name)' > /sys/kernel/debug/tracing/events The synthetic event dynamic strings are implemented in the same way as the existing __data_loc strings and appear as such in the format file. [ <rostedt@goodmis.org>: added __set_synth_event_print_fmt() changes: I added the following to make it work with trace-cmd. Dynamic strings must have __get_str() for events in the print_fmt otherwise it can't be parsed correctly. ] Link: https://lore.kernel.org/r/cover.1601588066.git.zanussi@kernel.org Link: https://lkml.kernel.org/r/3ed35b6d0e390f5b94cb4a9ba1cc18f5982ab277.1601848695.git.zanussi@kernel.orgTested-by:
Axel Rasmussen <axelrasmussen@google.com> Signed-off-by:
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Tom Zanussi authored
String variables created as field variables and save variables are already handled properly by having their values copied when set. The same isn't done for normal variables, but needs to be - simply saving a pointer to a string contained in an old event isn't sufficient, since that event's data may quickly become overwritten and therefore a string pointer to it could yield garbage. This change uses the same mechanism as field variables and simply appends the new strings to the existing per-element field_var_str[] array allocated for that purpose. Link: https://lkml.kernel.org/r/1c1a03798b02e67307412a0c719d1bfb69b13007.1601848695.git.zanussi@kernel.org Fixes: 02205a67 (tracing: Add support for 'field variables') Signed-off-by:
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Tom Zanussi authored
synth_field_size() returns either a positive size or an error (zero or a negative value). However, the existing code assumes the only error value is 0. It doesn't handle negative error codes, as it assigns directly to field->size (a size_t; unsigned), thereby interpreting the error code as a valid size instead. Do the test before assignment to field->size. [ axelrasmussen@google.com: changelog addition, first paragraph above ] Link: https://lkml.kernel.org/r/9b6946d9776b2eeb43227678158196de1c3c6e1d.1601848695.git.zanussi@kernel.org Fixes: 4b147936 (tracing: Add support for 'synthetic' events) Reviewed-by:
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Tom Zanussi authored
32 is too small for this value, and anyway it makes more sense to use MAX_FILTER_STR_VAL, as this is also the value used for variable-length __strings. Link: https://lkml.kernel.org/r/6adfd1668ac1fd8670bd58206944a762061a5559.1601848695.git.zanussi@kernel.orgTested-by:
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- 02 Oct, 2020 1 commit
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Qiujun Huang authored
s/coorditate/coordinate/ s/emty/empty/ s/preeptive/preemptive/ s/succes/success/ s/carefule/careful/ Link: https://lkml.kernel.org/r/20201002143126.2890-1-hqjagain@gmail.comSigned-off-by:
Qiujun Huang <hqjagain@gmail.com> Signed-off-by:
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- 28 Sep, 2020 1 commit
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Steven Rostedt (VMware) authored
7f47d8cc ("x86, tracing, perf: Add trace point for MSR accesses") added tracing of msr read and write, but because of complexity in having tracepoints in headers, and even more so for a core header like msr.h, not to mention the bloat a tracepoint adds to inline functions, a helper function is needed to be called from the header. Use the new tracepoint_enabled() macro in tracepoint-defs.h to test if the tracepoint is active before calling the helper function, instead of open coding the same logic, which requires knowing the internals of a tracepoint. Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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- 25 Sep, 2020 3 commits
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Steven Rostedt (VMware) authored
As more use cases of checking if a tracepoint is enabled in a header are coming to fruition, a helper macro, tracepoint_enabled(), has been added to check if a tracepoint is enabled or not, and can be used with minimal header requirements (avoid "include hell"). Convert the page_ref logic over to the new helper macro. Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: -
Steven Rostedt (VMware) authored
As tracepoints are discouraged from being added in a header because it can cause side effects if other tracepoints are in headers, as well as bloat the kernel as the trace_<tracepoint>() function is not a small inline, the common workaround is to add a function call that calls a wrapper function in a C file that then calls the tracepoint. But as function calls add overhead, this function should only be called when the tracepoint in question is enabled. To get around this overhead, a static_branch can be used to only have the tracepoint wrapper get called when the tracepoint is enabled. Add a tracepoint_enabled(tp) macro that gets passed the name of the tracepoint, and this becomes a static_branch that is enabled when the tracepoint is enabled and is a nop when the tracepoint is disabled. Signed-off-by: -
Masami Hiramatsu authored
Initialize per-instance event list in early boot time (before initializing instance directory on tracefs). This fixes boot-time tracing to correctly handle the boot-time per-instance settings. Link: https://lkml.kernel.org/r/160096560826.182763.17110991546046128881.stgit@devnote2 Fixes: 4114fbfd ("tracing: Enable creating new instance early boot") Signed-off-by:
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- 22 Sep, 2020 18 commits
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Masami Hiramatsu authored
Add the note about when to start the boot-time tracing. This will be needed for the people who wants to trace earlier boot sequence. Link: https://lkml.kernel.org/r/159974156678.478751.10215894815285734481.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Initialize boot-time tracing in core_initcall_sync instead of fs_initcall, and initialize required tracers (kprobes and synth) in core_initcall. This will allow the boot-time tracing to trace __init code from the beginning of postcore_initcall stage. Link: https://lkml.kernel.org/r/159974155727.478751.7486926132902849578.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Enable creating new trace_array instance in early boot stage. If the instances directory is not created, postpone it until the tracefs is initialized. Link: https://lkml.kernel.org/r/159974154763.478751.6289753509587233103.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Split the event fields initialization from creating new event directory. This allows the boot-time tracing to define dynamic events before initializing events directory on tracefs. Link: https://lkml.kernel.org/r/159974153790.478751.3475515065034825374.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Define event fields at early stage so that boot-time tracing can access the event fields (like per-event filter setting). Link: https://lkml.kernel.org/r/159974152862.478751.2023768466808361350.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Init kprobes feature in early_initcall as same as jump_label and dynamic_debug does, so that we can use kprobes events in earlier boot stage. Link: https://lkml.kernel.org/r/159974151897.478751.8342374158615496628.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Add kprobe %return suffix testcase and syntax error tests for %return suffix. Link: https://lkml.kernel.org/r/159972817653.428528.9180599115849301184.stgit@devnote2Acked-by:
Shuah Khan <skhan@linuxfoundation.org> Signed-off-by:
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Masami Hiramatsu authored
Add an example of tracing function calls on a specific function. Link: https://lkml.kernel.org/r/159972816669.428528.12390560334549382316.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Add a description of the %return suffix option for kprobe event and uprobe event. Link: https://lkml.kernel.org/r/159972815624.428528.10450874184415697524.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Support perf-style return probe ("SYMBOL%return") for uprobe events as same as kprobe events does. Link: https://lkml.kernel.org/r/159972814601.428528.7641183316212425445.stgit@devnote2Signed-off-by: -
Masami Hiramatsu authored
Support perf-style return probe ("SYMBOL%return") for kprobe events. This will allow boot-time tracing user to define a return probe event. Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2Signed-off-by: -
Masami Hiramatsu authored
Add tracing_on option description to the boot-time tracer. Link: https://lkml.kernel.org/r/159978523520.485820.9250337223076929279.stgit@devnote2Signed-off-by:
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Masami Hiramatsu authored
Add per-instance tracing_on option, which will be useful with traceon/traceoff event trigger actions. For example, if we disable tracing_on by default and set traceon and traceoff on a pair of events, we can trace functions between the pair of events. Link: https://lkml.kernel.org/r/159972811538.428528.2561315102284268611.stgit@devnote2Signed-off-by:
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Davidlohr Bueso authored
It seems that alloc_retstack_tasklist() can also take a lockless approach for scanning the tasklist, instead of using the big global tasklist_lock. For this we also kill another deprecated and rcu-unsafe tsk->thread_group user replacing it with for_each_process_thread(), maintaining semantics. Here tasklist_lock does not protect anything other than the list against concurrent fork/exit. And considering that the whole thing is capped by FTRACE_RETSTACK_ALLOC_SIZE (32), it should not be a problem to have a pontentially stale, yet stable, list. The task cannot go away either, so we don't risk racing with ftrace_graph_exit_task() which clears the retstack. The tsk->ret_stack management is not protected by tasklist_lock, being serialized with the corresponding publish/subscribe barriers against concurrent ftrace_push_return_trace(). In addition this plays nicer with cachelines by avoiding two atomic ops in the uncontended case. Link: https://lkml.kernel.org/r/20200907013326.9870-1-dave@stgolabs.netAcked-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
Davidlohr Bueso <dbueso@suse.de> Signed-off-by:
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Dan Carpenter authored
The "tr" is a stack variable so setting it to NULL before a return is a no-op. Delete the assignment. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Jarkko Sakkinen authored
It is advised to use module_name() macro instead of dereferencing mod->name directly. This makes sense for consistencys sake and also it prevents a hard dependency to CONFIG_MODULES. Link: https://lkml.kernel.org/r/20200818050857.117998-1-jarkko.sakkinen@linux.intel.com Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mm@kvack.org Cc: Andi Kleen <ak@linux.intel.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com>, Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Acked-by:
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by:
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Xianting Tian authored
The code is executed with preemption disabled, so it's safe to use __this_cpu_read(). Link: https://lkml.kernel.org/r/20200813112803.12256-1-tian.xianting@h3c.comSigned-off-by:
Xianting Tian <tian.xianting@h3c.com> Signed-off-by:
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Randy Dunlap authored
Drop repeated words in kernel/trace/. {and, the, not} Link: https://lkml.kernel.org/r/20200807033259.13778-1-rdunlap@infradead.org Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by:Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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