summaryrefslogtreecommitdiff
path: root/kernel/trace/trace.c
AgeCommit message (Collapse)Author
2019-03-15Merge tag 'trace-v5.1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes and cleanups from Steven Rostedt: "This contains a series of last minute clean ups, small fixes and error checks" * tag 'trace-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/probe: Verify alloc_trace_*probe() result tracing/probe: Check event/group naming rule at parsing tracing/probe: Check the size of argument name and body tracing/probe: Check event name length correctly tracing/probe: Check maxactive error cases tracing: kdb: Fix ftdump to not sleep trace/probes: Remove kernel doc style from non kernel doc comment tracing/probes: Make reserved_field_names static
2019-03-13tracing: kdb: Fix ftdump to not sleepDouglas Anderson
As reported back in 2016-11 [1], the "ftdump" kdb command triggers a BUG for "sleeping function called from invalid context". kdb's "ftdump" command wants to call ring_buffer_read_prepare() in atomic context. A very simple solution for this is to add allocation flags to ring_buffer_read_prepare() so kdb can call it without triggering the allocation error. This patch does that. Note that in the original email thread about this, it was suggested that perhaps the solution for kdb was to either preallocate the buffer ahead of time or create our own iterator. I'm hoping that this alternative of adding allocation flags to ring_buffer_read_prepare() can be considered since it means I don't need to duplicate more of the core trace code into "trace_kdb.c" (for either creating my own iterator or re-preparing a ring allocator whose memory was already allocated). NOTE: another option for kdb is to actually figure out how to make it reuse the existing ftrace_dump() function and totally eliminate the duplication. This sounds very appealing and actually works (the "sr z" command can be seen to properly dump the ftrace buffer). The downside here is that ftrace_dump() fully consumes the trace buffer. Unless that is changed I'd rather not use it because it means "ftdump | grep xyz" won't be very useful to search the ftrace buffer since it will throw away the whole trace on the first grep. A future patch to dump only the last few lines of the buffer will also be hard to implement. [1] https://lkml.kernel.org/r/20161117191605.GA21459@google.com Link: http://lkml.kernel.org/r/20190308193205.213659-1-dianders@chromium.org Reported-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-03-12Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted fixes (really no common topic here)" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Make __vfs_write() static vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1 pipe: stop using ->can_merge splice: don't merge into linked buffers fs: move generic stat response attr handling to vfs_getattr_nosec orangefs: don't reinitialize result_mask in ->getattr fs/devpts: always delete dcache dentry-s in dput()
2019-03-11Merge tag 'trace-v5.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The biggest change for this release is in the histogram code: - Add "onchange(var)" histogram handler that executes a action when $var changes. - Add new "snapshot()" action for histogram handlers, that causes a snapshot of the ring buffer when triggered. ie. onchange(var).snapshot() will trigger a snapshot if var changes. - Add alternative for "trace()" action. Currently, to trigger a synthetic event, the name of that event is used as the handler name, which is inconsistent with the other actions. onchange(var).synthetic(param) where it can now be onchange(var).trace(synthetic, param). The older method will still be allowed, as long as the synthetic events do not overlap with other handler names. - The histogram documentation at testcases were updated for the new changes. Outside of the histogram code, we have: - Added a quicker way to enable set_ftrace_filter files, that will make it much quicker to bisect tracing a function that shouldn't be traced and crashes the kernel. (You can echo in numbers to set_ftrace_filter, and it will select the corresponding function that is in available_filter_functions). - Some better displaying of the tracing data (and more information was added). The rest are small fixes and more clean ups to the code" * tag 'trace-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (37 commits) tracing: Use strncpy instead of memcpy when copying comm in trace.c tracing: Use strncpy instead of memcpy when copying comm for hist triggers tracing: Use strncpy instead of memcpy for string keys in hist triggers tracing: Use str_has_prefix() in synth_event_create() x86/ftrace: Fix warning and considate ftrace_jmp_replace() and ftrace_call_replace() tracing/perf: Use strndup_user() instead of buggy open-coded version doc: trace: Fix documentation for uprobe_profile tracing: Fix spelling mistake: "analagous" -> "analogous" tracing: Comment why cond_snapshot is checked outside of max_lock protection tracing: Add hist trigger action 'expected fail' test case tracing: Add alternative synthetic event trace action test case tracing: Add hist trigger onchange() handler test case tracing: Add hist trigger snapshot() action test case tracing: Add SPDX license GPL-2.0 license identifier to inter-event testcases tracing: Add alternative synthetic event trace action syntax tracing: Add hist trigger onchange() handler Documentation tracing: Add hist trigger onchange() handler tracing: Add hist trigger snapshot() action Documentation tracing: Add hist trigger snapshot() action tracing: Add conditional snapshot ...
2019-03-05tracing: Use strncpy instead of memcpy when copying comm in trace.cTom Zanussi
Because there may be random garbage beyond a string's null terminator, code that might use the entire comm array e.g. histogram keys, can give unexpected results if that garbage is copied in too, so avoid that possibility by using strncpy instead of memcpy. Link: http://lkml.kernel.org/r/1d6ebac26570c2a29ce9fb575379f17ef5c8b81b.1551802084.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Fix spelling mistake: "analagous" -> "analogous"Colin Ian King
There is a spelling mistake in the mini-howto help text. Fix it. Link: http://lkml.kernel.org/r/20190217223222.16479-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Comment why cond_snapshot is checked outside of max_lock protectionSteven Rostedt (VMware)
Before setting tr->cond_snapshot, it must be NULL before it can be updated. It can go to NULL when a trace event hist trigger is created or removed, and can only be modified under the max_lock spin lock. But because it can only be set to something other than NULL under both the max_lock spin lock as well as the trace_types_lock, we can perform the check if it is not NULL only under the trace_types_lock and fail out without having to grab the max_lock spin lock. This is very subtle, and deserves a comment. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Add alternative synthetic event trace action syntaxTom Zanussi
Add a 'trace(synthetic_event_name, params)' alternative to synthetic_event_name(params). Currently, the syntax used for generating synthetic events is to invoke synthetic_event_name(params) i.e. use the synthetic event name as a function call. Users requested a new form that more explicitly shows that the synthetic event is in effect being traced. In this version, a new 'trace()' keyword is used, and the synthetic event name is passed in as the first argument. In addition, for the sake of consistency with other actions, change the documention to emphasize the trace() form over the function-call form, which remains documented as equivalent. Link: http://lkml.kernel.org/r/d082773e50232a001480cf837679a1e01c1a2eb7.1550100284.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Add hist trigger onchange() handlerTom Zanussi
Add support for a hist:onchange($var) handler, similar to the onmax() handler but triggering whenever there's any change in $var, not just a max. Link: http://lkml.kernel.org/r/dfbc7e4ada242603e9ec3f049b5ad076a07dfd03.1550100284.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Add hist trigger snapshot() actionTom Zanussi
Add support for hist:handlerXXX($var).snapshot(), which will take a snapshot of the current trace buffer whenever handlerXXX is hit. As a first user, this also adds snapshot() action support for the onmax() handler i.e. hist:onmax($var).snapshot(). Also, the hist trigger key printing is moved into a separate function so the snapshot() action can print a histogram key outside the histogram display - add and use hist_trigger_print_key() for that purpose. Link: http://lkml.kernel.org/r/2f1a952c0dcd8aca8702ce81269581a692396d45.1550100284.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Add conditional snapshotTom Zanussi
Currently, tracing snapshots are context-free - they capture the ring buffer contents at the time the tracing_snapshot() function was invoked, and nothing else. Additionally, they're always taken unconditionally - the calling code can decide whether or not to take a snapshot, but the data used to make that decision is kept separately from the snapshot itself. This change adds the ability to associate with each trace instance some user data, along with an 'update' function that can use that data to determine whether or not to actually take a snapshot. The update function can then update that data along with any other state (as part of the data presumably), if warranted. Because snapshots are 'global' per-instance, only one user can enable and use a conditional snapshot for any given trace instance. To enable a conditional snapshot (see details in the function and data structure comments), the user calls tracing_snapshot_cond_enable(). Similarly, to disable a conditional snapshot and free it up for other users, tracing_snapshot_cond_disable() should be called. To actually initiate a conditional snapshot, tracing_snapshot_cond() should be called. tracing_snapshot_cond() will invoke the update() callback, allowing the user to decide whether or not to actually take the snapshot and update the user-defined data associated with the snapshot. If the callback returns 'true', tracing_snapshot_cond() will then actually take the snapshot and return. This scheme allows for flexibility in snapshot implementations - for example, by implementing slightly different update() callbacks, snapshots can be taken in situations where the user is only interested in taking a snapshot when a new maximum in hit versus when a value changes in any way at all. Future patches will demonstrate both cases. Link: http://lkml.kernel.org/r/1bea07828d5fd6864a585f83b1eed47ce097eb45.1550100284.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Split up onmatch action dataTom Zanussi
Currently, the onmatch action data binds the onmatch action to data related to synthetic event generation. Since we want to allow the onmatch handler to potentially invoke a different action, and because we expect other handlers to generate synthetic events, we need to separate the data related to these two functions. Also rename the onmatch data to something more descriptive, and create and use common action data destroy function. Link: http://lkml.kernel.org/r/b9abbf9aae69fe3920cdc8ddbcaad544dd258d78.1550100284.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20tracing: Do not free iter->trace in fail path of tracing_open_pipe()zhangyi (F)
Commit d716ff71dd12 ("tracing: Remove taking of trace_types_lock in pipe files") use the current tracer instead of the copy in tracing_open_pipe(), but it forget to remove the freeing sentence in the error path. There's an error path that can call kfree(iter->trace) after the iter->trace was assigned to tr->current_trace, which would be bad to free. Link: http://lkml.kernel.org/r/1550060946-45984-1-git-send-email-yi.zhang@huawei.com Cc: stable@vger.kernel.org Fixes: d716ff71dd12 ("tracing: Remove taking of trace_types_lock in pipe files") Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-15tracing: Fix number of entries in trace headerQuentin Perret
The following commit 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") removed the call to print_event_info() from print_func_help_header_irq() which results in the ftrace header not reporting the number of entries written in the buffer. As this wasn't the original intent of the patch, re-introduce the call to print_event_info() to restore the orginal behaviour. Link: http://lkml.kernel.org/r/20190214152950.4179-1-quentin.perret@arm.com Acked-by: Joel Fernandes <joelaf@google.com> Cc: stable@vger.kernel.org Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") Signed-off-by: Quentin Perret <quentin.perret@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-01pipe: stop using ->can_mergeJann Horn
Al Viro pointed out that since there is only one pipe buffer type to which new data can be appended, it isn't necessary to have a ->can_merge field in struct pipe_buf_operations, we can just check for a magic type. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-31Merge tag 'trace-v4.21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Rework of the kprobe/uprobe and synthetic events to consolidate all the dynamic event code. This will make changes in the future easier. - Partial rewrite of the function graph tracing infrastructure. This will allow for multiple users of hooking onto functions to get the callback (return) of the function. This is the ground work for having kprobes and function graph tracer using one code base. - Clean up of the histogram code that will facilitate adding more features to the histograms in the future. - Addition of str_has_prefix() and a few use cases. There currently is a similar function strstart() that is used in a few places, but only returns a bool and not a length. These instances will be removed in the future to use str_has_prefix() instead. - A few other various clean ups as well. * tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits) tracing: Use the return of str_has_prefix() to remove open coded numbers tracing: Have the historgram use the result of str_has_prefix() for len of prefix tracing: Use str_has_prefix() instead of using fixed sizes tracing: Use str_has_prefix() helper for histogram code string.h: Add str_has_prefix() helper function tracing: Make function ‘ftrace_exports’ static tracing: Simplify printf'ing in seq_print_sym tracing: Avoid -Wformat-nonliteral warning tracing: Merge seq_print_sym_short() and seq_print_sym_offset() tracing: Add hist trigger comments for variable-related fields tracing: Remove hist trigger synth_var_refs tracing: Use hist trigger's var_ref array to destroy var_refs tracing: Remove open-coding of hist trigger var_ref management tracing: Use var_refs[] for hist trigger reference checking tracing: Change strlen to sizeof for hist trigger static strings tracing: Remove unnecessary hist trigger struct field tracing: Fix ftrace_graph_get_ret_stack() to use task and not current seq_buf: Use size_t for len in seq_buf_puts() seq_buf: Make seq_buf_puts() null-terminate the buffer arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack ...
2018-12-22tracing: Use the return of str_has_prefix() to remove open coded numbersSteven Rostedt (VMware)
There are several locations that compare constants to the beginning of string variables to determine what commands should be done, then the constant length is used to index into the string. This is error prone as the hard coded numbers have to match the size of the constants. Instead, use the len returned from str_has_prefix() and remove the open coded string length sizes. Cc: Joe Perches <joe@perches.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> (for trace_probe part) Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-22tracing: Use str_has_prefix() instead of using fixed sizesSteven Rostedt (VMware)
There are several instances of strncmp(str, "const", 123), where 123 is the strlen of the const string to check if "const" is the prefix of str. But this can be error prone. Use str_has_prefix() instead. Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-22tracing: Make function ‘ftrace_exports’ staticMathieu Malaterre
In commit 478409dd683d ("tracing: Add hook to function tracing for other subsystems to use"), a new function ‘ftrace_exports’ was added. Since this function can be made static, make it so. Silence the following warning triggered using W=1: kernel/trace/trace.c:2451:6: warning: no previous prototype for ‘ftrace_exports’ [-Wmissing-prototypes] Link: http://lkml.kernel.org/r/20180516193012.25390-1-malat@debian.org Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08tracing: Use dyn_event framework for synthetic eventsMasami Hiramatsu
Use dyn_event framework for synthetic events. This shows synthetic events on "tracing/dynamic_events" file in addition to tracing/synthetic_events interface. User can also define new events via tracing/dynamic_events with "s:" prefix. So, the new syntax is below; s:[synthetic/]EVENT_NAME TYPE ARG; [TYPE ARG;]... To remove events via tracing/dynamic_events, you can use "-:" prefix as same as other events. Link: http://lkml.kernel.org/r/154140861301.17322.15454611233735614508.stgit@devbox Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08tracing: Add unified dynamic event frameworkMasami Hiramatsu
Add unified dynamic event framework for ftrace kprobes, uprobes and synthetic events. Those dynamic events can be co-exist on same file because those syntax doesn't overlap. This introduces a framework part which provides a unified tracefs interface and operations. Link: http://lkml.kernel.org/r/154140852824.17322.12250362185969352095.stgit@devbox Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08tracing: Change default buffer_percent to 50Steven Rostedt (VMware)
After running several tests, it appears that having the reader wait till half the buffer is full before starting to read (and causing its own events to fill up the ring buffer constantly), works well. It keeps trace-cmd (the main user of this interface) from dominating the traces it records. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08tracing: Add tracefs file buffer_percentageSteven Rostedt (VMware)
Add a "buffer_percentage" file, that allows users to specify how much of the buffer (percentage of pages) need to be filled before waking up a task blocked on a per cpu trace_pipe_raw file. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08ring-buffer: Add percentage of ring buffer full to wake up readerSteven Rostedt (VMware)
Instead of just waiting for a page to be full before waking up a pending reader, allow the reader to pass in a "percentage" of pages that have content before waking up a reader. This should help keep the process of reading the events not cause wake ups that constantly cause reading of the buffer. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27tracing: Replace synchronize_sched() and call_rcu_sched()Paul E. McKenney
Now that synchronize_rcu() waits for preempt-disable regions of code as well as RCU read-side critical sections, synchronize_sched() can be replaced by synchronize_rcu(). Similarly, call_rcu_sched() can be replaced by call_rcu(). This commit therefore makes these changes. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: <linux-kernel@vger.kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-27tracing: Export trace_dump_stack to modulesNikolay Borisov
There is no reason for this function to be unexprted and it's a useful debugging aid. Link: http://lkml.kernel.org/r/1539759103-5923-1-git-send-email-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Add $argN for accessing function argsMasami Hiramatsu
Add $argN special fetch variable for accessing function arguments. This allows user to trace the Nth argument easily at the function entry. Note that this returns most probably assignment of registers and stacks. In some case, it may not work well. If you need to access correct registers or stacks you should use perf-probe. Link: http://lkml.kernel.org/r/152465888632.26224.3412465701570253696.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Add array type supportMasami Hiramatsu
Add array type support for probe events. This allows user to get arraied types from memory address. The array type syntax is TYPE[N] Where TYPE is one of types (u8/16/32/64,s8/16/32/64, x8/16/32/64, symbol, string) and N is a fixed value less than 64. The string array type is a bit different from other types. For other base types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself represents "char array", but string array type represents "char * array". So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string. Link: http://lkml.kernel.org/r/152465891533.26224.6150658225601339931.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Add symbol typeMasami Hiramatsu
Add "symbol" type to probeevent, which is an alias of u32 or u64 (depends on BITS_PER_LONG). This shows the result value in symbol+offset style. This type is only available with kprobe events. Link: http://lkml.kernel.org/r/152465882860.26224.14779072294412467338.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-09-24uprobes: Support SDT markers having reference count (semaphore)Ravi Bangoria
Userspace Statically Defined Tracepoints[1] are dtrace style markers inside userspace applications. Applications like PostgreSQL, MySQL, Pthread, Perl, Python, Java, Ruby, Node.js, libvirt, QEMU, glib etc have these markers embedded in them. These markers are added by developer at important places in the code. Each marker source expands to a single nop instruction in the compiled code but there may be additional overhead for computing the marker arguments which expands to couple of instructions. In case the overhead is more, execution of it can be omitted by runtime if() condition when no one is tracing on the marker: if (reference_counter > 0) { Execute marker instructions; } Default value of reference counter is 0. Tracer has to increment the reference counter before tracing on a marker and decrement it when done with the tracing. Implement the reference counter logic in core uprobe. User will be able to use it from trace_uprobe as well as from kernel module. New trace_uprobe definition with reference counter will now be: <path>:<offset>[(ref_ctr_offset)] where ref_ctr_offset is an optional field. For kernel module, new variant of uprobe_register() has been introduced: uprobe_register_refctr(inode, offset, ref_ctr_offset, consumer) No new variant for uprobe_unregister() because it's assumed to have only one reference counter for one uprobe. [1] https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation Note: 'reference counter' is called as 'semaphore' in original Dtrace (or Systemtap, bcc and even in ELF) documentation and code. But the term 'semaphore' is misleading in this context. This is just a counter used to hold number of tracers tracing on a marker. This is not really used for any synchronization. So we are calling it a 'reference counter' in kernel / perf code. Link: http://lkml.kernel.org/r/20180820044250.11659-2-ravi.bangoria@linux.ibm.com Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> [Only trace_uprobe.c] Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Song Liu <songliubraving@fb.com> Tested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-20Merge tag 'trace-v4.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Restructure of lockdep and latency tracers This is the biggest change. Joel Fernandes restructured the hooks from irqs and preemption disabling and enabling. He got rid of a lot of the preprocessor #ifdef mess that they caused. He turned both lockdep and the latency tracers to use trace events inserted in the preempt/irqs disabling paths. But unfortunately, these started to cause issues in corner cases. Thus, parts of the code was reverted back to where lockdep and the latency tracers just get called directly (without using the trace events). But because the original change cleaned up the code very nicely we kept that, as well as the trace events for preempt and irqs disabling, but they are limited to not being called in NMIs. - Have trace events use SRCU for "rcu idle" calls. This was required for the preempt/irqs off trace events. But it also had to not allow them to be called in NMI context. Waiting till Paul makes an NMI safe SRCU API. - New notrace SRCU API to allow trace events to use SRCU. - Addition of mcount-nop option support - SPDX headers replacing GPL templates. - Various other fixes and clean ups. - Some fixes are marked for stable, but were not fully tested before the merge window opened. * tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix SPDX format headers to use C++ style comments tracing: Add SPDX License format tags to tracing files tracing: Add SPDX License format to bpf_trace.c blktrace: Add SPDX License format header s390/ftrace: Add -mfentry and -mnop-mcount support tracing: Add -mcount-nop option support tracing: Avoid calling cc-option -mrecord-mcount for every Makefile tracing: Handle CC_FLAGS_FTRACE more accurately Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() Uprobes: Simplify uprobe_register() body tracepoints: Free early tracepoints after RCU is initialized uprobes: Use synchronize_rcu() not synchronize_sched() tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister() ftrace: Remove unused pointer ftrace_swapper_pid tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing/irqsoff: Handle preempt_count for different configs tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing: irqsoff: Account for additional preempt_disable trace: Use rcu_dereference_raw for hooks from trace-event subsystem tracing/kprobes: Fix within_notrace_func() to check only notrace functions ...
2018-08-16tracing: Add SPDX License format tags to tracing filesSteven Rostedt (VMware)
Add the SPDX License header to ease license compliance management. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-15Merge tag 'printk-for-4.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Different vendors have a different expectation about a console quietness. Make it configurable to reduce bike-shedding about the upstream default - Decide about the message visibility when the message is stored. It avoids races caused by a delayed console handling - Always store printk() messages into the per-CPU buffers again in NMI. The only exception is when flushing trace log in panic(). There the risk of loosing messages is worth an eventual reordering - Handle invalid %pO printf modifiers correctly - Better handle %p printf modifier tests before crng is initialized - Some clean up * tag 'printk-for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Do not handle %pO[^F] as %px printk: Fix warning about unused suppress_message_printing printk/nmi: Prevent deadlock when accessing the main log buffer in NMI printk: Create helper function to queue deferred console handling printk: Split the code for storing a message into the log buffer printk: Clean up syslog_print_all() printk: Remove unnecessary kmalloc() from syslog during clear printk: Make CONSOLE_LOGLEVEL_QUIET configurable printk: make sure to print log on console. lib/test_printf.c: accept "ptrval" as valid result for plain 'p' tests
2018-08-01tracing: Make tracer_tracing_is_on() return boolSteven Rostedt (VMware)
There's code that expects tracer_tracing_is_on() to be either true or false, not some random number. Currently, it should only return one or zero, but just in case, change its return value to bool, to enforce it. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01tracing: Do not call start/stop() functions when tracing_on does not changeSteven Rostedt (VMware)
Currently, when one echo's in 1 into tracing_on, the current tracer's "start()" function is executed, even if tracing_on was already one. This can lead to strange side effects. One being that if the hwlat tracer is enabled, and someone does "echo 1 > tracing_on" into tracing_on, the hwlat tracer's start() function is called again which will recreate another kernel thread, and make it unable to remove the old one. Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de Cc: stable@vger.kernel.org Fixes: 2df8f8a6a897e ("tracing: Fix regression with irqsoff tracer and tracing_on file") Reported-by: Erica Bugden <erica.bugden@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25ring_buffer: tracing: Inherit the tracing setting to next ring bufferMasami Hiramatsu
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: debdd57f5145 ("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>
2018-07-12tracing: Reorder display of TGID to be after PIDJoel Fernandes (Google)
Currently ftrace displays data in trace output like so: _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU TGID |||| TIMESTAMP FUNCTION | | | | |||| | | bash-1091 [000] ( 1091) d..2 28.313544: sched_switch: However Android's trace visualization tools expect a slightly different format due to an out-of-tree patch patch that was been carried for a decade, notice that the TGID and CPU fields are reversed: _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID TGID CPU |||| TIMESTAMP FUNCTION | | | | |||| | | bash-1091 ( 1091) [002] d..2 64.965177: sched_switch: From kernel v4.13 onwards, during which TGID was introduced, tracing with systrace on all Android kernels will break (most Android kernels have been on 4.9 with Android patches, so this issues hasn't been seen yet). From v4.13 onwards things will break. The chrome browser's tracing tools also embed the systrace viewer which uses the legacy TGID format and updates to that are known to be difficult to make. Considering this, I suggest we make this change to the upstream kernel and backport it to all Android kernels. I believe this feature is merged recently enough into the upstream kernel that it shouldn't be a problem. Also logically, IMO it makes more sense to group the TGID with the TASK-PID and the CPU after these. Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org Cc: jreck@google.com Cc: tkjos@google.com Cc: stable@vger.kernel.org Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-09printk/nmi: Prevent deadlock when accessing the main log buffer in NMIPetr Mladek
The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") brought back the possible deadlocks in printk() and NMI. The check of logbuf_lock is done only in printk_nmi_enter() to prevent mixed output. But another CPU might take the lock later, enter NMI, and: + Both NMIs might be serialized by yet another lock, for example, the one in nmi_cpu_backtrace(). + The other CPU might get stopped in NMI, see smp_send_stop() in panic(). The only safe solution is to use trylock when storing the message into the main log-buffer. It might cause reordering when some lines go to the main lock buffer directly and others are delayed via the per-CPU buffer. It means that it is not useful in general. This patch replaces the problematic NMI deferred context with NMI direct context. It can be used to mark a code that might produce many messages in NMI and the risk of losing them is more critical than problems with eventual reordering. The context is then used when dumping trace buffers on oops. It was the primary motivation for the original fix. Also the reordering is even smaller issue there because some traces have their own time stamps. Finally, nmi_cpu_backtrace() need not longer be serialized because it will always us the per-CPU buffers again. Fixes: 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20180627142028.11259-1-pmladek@suse.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-07-03tracing: Use __printf markup to silence compilerMathieu Malaterre
Silence warnings (triggered at W=1) by adding relevant __printf attributes. CC kernel/trace/trace.o kernel/trace/trace.c: In function ‘__trace_array_vprintk’: kernel/trace/trace.c:2979:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format] len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); ^~~ AR kernel/trace/built-in.o Link: http://lkml.kernel.org/r/20180308205843.27447-1-malat@debian.org Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-06-21tracing: Use swap macro in update_max_trGustavo A. R. Silva
Make use of the swap macro and remove unnecessary variable _buf_. This makes the code easier to read and maintain. Also, reduces the stack usage. This code was detected with the help of Coccinelle. Link: http://lkml.kernel.org/r/20180209175316.GA18720@embeddedgus Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-06-12treewide: kzalloc() -> kcalloc()Kees Cook
The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12treewide: kmalloc() -> kmalloc_array()Kees Cook
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-05tracing: Use match_string() instead of open coding it in trace_set_options()Yisheng Xie
match_string() returns the index of an array for a matching string, which can be used to simplify the code. Link: http://lkml.kernel.org/r/1526546163-4609-1-git-send-email-xieyisheng1@huawei.com Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-29tracing: Add trigger file for trace_markers tracefs/ftrace/printSteven Rostedt (VMware)
Allow writing to the trace_markers file initiate triggers defined in tracefs/ftrace/print/trigger file. This will allow of user space to trigger the same type of triggers (including histograms) that the trace events use. Had to create a ftrace_event_register() function that will become the trace_marker print event's reg() function. This is required because of how triggers are enabled: event_trigger_write() { event_trigger_regex_write() { trigger_process_regex() { for p in trigger_commands { p->func(); /* trigger_snapshot_cmd->func */ event_trigger_callback() { cmd_ops->reg() /* register_trigger() */ { trace_event_trigger_enable_disable() { trace_event_enable_disable() { call->class->reg(); Without the reg() function, the trigger code will call a NULL pointer and crash the system. Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Clark Williams <williams@redhat.com> Cc: Karim Yaghmour <karim.yaghmour@opersys.com> Cc: Brendan Gregg <bgregg@netflix.com> Suggested-by: Joel Fernandes <joelaf@google.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-29tracing: Have event_trace_init() called by trace_init_tracefs()Steven Rostedt (VMware)
Instead of having both trace_init_tracefs() and event_trace_init() be called by fs_initcall() routines, have event_trace_init() called directly by trace_init_tracefs(). This will guarantee order of how the events are created with respect to the rest of the ftrace infrastructure. This is needed to be able to assoctiate event files with ftrace internal events, such as the trace_marker. Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-28tracing: Make the snapshot trigger work with instancesSteven Rostedt (VMware)
The snapshot trigger currently only affects the main ring buffer, even when it is used by the instances. This can be confusing as the snapshot trigger is listed in the instance. > # cd /sys/kernel/tracing > # mkdir instances/foo > # echo snapshot > instances/foo/events/syscalls/sys_enter_fchownat/trigger > # echo top buffer > trace_marker > # echo foo buffer > instances/foo/trace_marker > # touch /tmp/bar > # chown rostedt /tmp/bar > # cat instances/foo/snapshot # tracer: nop # # # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') > # cat snapshot # tracer: nop # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | bash-1189 [000] .... 111.488323: tracing_mark_write: top buffer Not only did the snapshot occur in the top level buffer, but the instance snapshot buffer should have been allocated, and it is still free. Cc: stable@vger.kernel.org Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-04-26Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIMEThomas Gleixner
Revert commits 92af4dcb4e1c ("tracing: Unify the "boot" and "mono" tracing clocks") 127bfa5f4342 ("hrtimer: Unify MONOTONIC and BOOTTIME clock behavior") 7250a4047aa6 ("posix-timers: Unify MONOTONIC and BOOTTIME clock behavior") d6c7270e913d ("timekeeping: Remove boot time specific code") f2d6fdbfd238 ("Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior") d6ed449afdb3 ("timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock") 72199320d49d ("timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock") As stated in the pull request for the unification of CLOCK_MONOTONIC and CLOCK_BOOTTIME, it was clear that we might have to revert the change. As reported by several folks systemd and other applications rely on the documented behaviour of CLOCK_MONOTONIC on Linux and break with the above changes. After resume daemons time out and other timeout related issues are observed. Rafael compiled this list: * systemd kills daemons on resume, after >WatchdogSec seconds of suspending (Genki Sky). [Verified that that's because systemd uses CLOCK_MONOTONIC and expects it to not include the suspend time.] * systemd-journald misbehaves after resume: systemd-journald[7266]: File /var/log/journal/016627c3c4784cd4812d4b7e96a34226/system.journal corrupted or uncleanly shut down, renaming and replacing. (Mike Galbraith). * NetworkManager reports "networking disabled" and networking is broken after resume 50% of the time (Pavel). [May be because of systemd.] * MATE desktop dims the display and starts the screensaver right after system resume (Pavel). * Full system hang during resume (me). [May be due to systemd or NM or both.] That happens on debian and open suse systems. It's sad, that these problems were neither catched in -next nor by those folks who expressed interest in this change. Reported-by: Rafael J. Wysocki <rjw@rjwysocki.net> Reported-by: Genki Sky <sky@genki.is>, Reported-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Easton <kevin@guarana.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org>
2018-04-10Merge tag 'trace-v4.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "New features: - Tom Zanussi's extended histogram work. This adds the synthetic events to have histograms from multiple event data Adds triggers "onmatch" and "onmax" to call the synthetic events Several updates to the histogram code from this - Allow way to nest ring buffer calls in the same context - Allow absolute time stamps in ring buffer - Rewrite of filter code parsing based on Al Viro's suggestions - Setting of trace_clock to global if TSC is unstable (on boot) - Better OOM handling when allocating large ring buffers - Added initcall tracepoints (consolidated initcall_debug code with them) And other various fixes and clean ups" * tag 'trace-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits) init: Have initcall_debug still work without CONFIG_TRACEPOINTS init, tracing: Have printk come through the trace events for initcall_debug init, tracing: instrument security and console initcall trace events init, tracing: Add initcall trace events tracing: Add rcu dereference annotation for test func that touches filter->prog tracing: Add rcu dereference annotation for filter->prog tracing: Fixup logic inversion on setting trace_global_clock defaults tracing: Hide global trace clock from lockdep ring-buffer: Add set/clear_current_oom_origin() during allocations ring-buffer: Check if memory is available before allocation lockdep: Add print_irqtrace_events() to __warn vsprintf: Do not preprocess non-dereferenced pointers for bprintf (%px and %pK) tracing: Uninitialized variable in create_tracing_map_fields() tracing: Make sure variable string fields are NULL-terminated tracing: Add action comparisons when testing matching hist triggers tracing: Don't add flag strings when displaying variable references tracing: Fix display of hist trigger expressions containing timestamps ftrace: Drop a VLA in module_exists() tracing: Mention trace_clock=global when warning about unstable clocks tracing: Default to using trace_global_clock if sched_clock is unstable ...
2018-04-06tracing: Fixup logic inversion on setting trace_global_clock defaultsChris Wilson
In commit 932066a15335 ("tracing: Default to using trace_global_clock if sched_clock is unstable"), the logic for deciding to override the default clock if unstable was reversed from the earlier posting. I was trying to reduce the width of the message by using an early return rather than a if-block, but reverted back to using the if-block and accidentally left the predicate inverted. Link: http://lkml.kernel.org/r/20180404212450.26646-1-chris@chris-wilson.co.uk Fixes: 932066a15335 ("tracing: Default to using trace_global_clock if sched_clock is unstable") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-04-06tracing: Default to using trace_global_clock if sched_clock is unstableChris Wilson
Across suspend, we may see a very large drift in timestamps if the sched clock is unstable, prompting the global trace's ringbuffer code to warn and suggest switching to the global clock. Preempt this request by detecting when the sched clock is unstable (determined during late_initcall) and automatically switching the default clock over to trace_global_clock. This should prevent requiring user interaction to resolve warnings such as: Delta way too big! 18446743856563626466 ts=18446744054496180323 write stamp = 197932553857 If you just came from a suspend/resume, please switch to the trace global clock: echo global > /sys/kernel/debug/tracing/trace_clock Link: http://lkml.kernel.org/r/20180330150132.16903-1-chris@chris-wilson.co.uk Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
generated by cgit (git 2.34.1) at 2024-06-09 11:16:52 +0000