summaryrefslogtreecommitdiff
path: root/kernel/trace/trace_probe.h
AgeCommit message (Collapse)Author
2019-09-19tracing/probe: Reject exactly same probe eventMasami Hiramatsu
Reject exactly same probe events as existing probes. Multiprobe allows user to define multiple probes on same event. If user appends a probe which exactly same definition (same probe address and same arguments) on existing event, the event will record same probe information twice. That can be confusing users, so reject it. Link: http://lkml.kernel.org/r/156879694602.31056.5533024778165036763.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/probe: Add immediate string parameter supportMasami Hiramatsu
Add immediate string parameter (\"string") support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching a string from memory. This feature looks odd, but imagine that you put a probe on a code to trace some string data. If the code is compiled into 2 instructions and 1 instruction has a string on memory but other has no string since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy string like foo=\"(optimized)":string instead of something like foo=+0(+0(%bp)):string. Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/probe: Add immediate parameter supportMasami Hiramatsu
Add immediate value parameter (\1234) support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching from memory or register. This feature looks odd, but imagine when you put a probe on a code to trace some data. If the code is compiled into 2 instructions and 1 instruction has a value but other has nothing since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy value like foo=\deadbeef instead of something like foo=%di. Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/kprobe: Add per-probe delete from eventMasami Hiramatsu
Allow user to delete a probe from event. This is done by head match. For example, if we have 2 probes on an event $ cat kprobe_events p:kprobes/testprobe _do_fork r1=%ax r2=%dx p:kprobes/testprobe idle_fork r1=%ax r2=%cx Then you can remove one of them by passing the head of definition which identify the probe. $ echo "-:kprobes/testprobe idle_fork" >> kprobe_events Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/kprobe: Add multi-probe per event supportMasami Hiramatsu
Add multi-probe per one event support to kprobe events. User can define several different probes on one trace event if those events have same "event signature", e.g. # echo p:testevent _do_fork > kprobe_events # echo p:testevent fork_idle >> kprobe_events # kprobe_events p:kprobes/testevent _do_fork p:kprobes/testevent fork_idle The event signature is defined by kprobe type (retprobe or not), the number of args, argument names, and argument types. Note that this only support appending method. Delete event operation will delete all probes on the event. Link: http://lkml.kernel.org/r/156095686913.28024.9357292202316540742.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/probe: Split trace_event related data from trace_probeMasami Hiramatsu
Split the trace_event related data from trace_probe data structure and introduce trace_probe_event data structure for its folder. This trace_probe_event data structure can have multiple trace_probe. Link: http://lkml.kernel.org/r/156095683995.28024.7552150340561557873.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/kprobe: Check registered state using kprobeMasami Hiramatsu
Change registered check only by trace_kprobe and remove TP_FLAG_REGISTERED from trace_probe, since this feature is only used for trace_kprobe. Link: http://lkml.kernel.org/r/155931588704.28323.4952266828256245833.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/probe: Add trace_event_call accesses APIsMasami Hiramatsu
Add trace_event_call access APIs for trace_probe. Instead of accessing trace_probe.call directly, use those accesses by trace_probe_event_call() method. This hides the relationship of trace_event_call and trace_probe from trace_kprobe and trace_uprobe. Link: http://lkml.kernel.org/r/155931587711.28323.8335129014686133120.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/probe: Add probe event name and group name accesses APIsMasami Hiramatsu
Add trace_probe_name() and trace_probe_group_name() functions for accessing probe name and group name of trace_probe. Link: http://lkml.kernel.org/r/155931586717.28323.8738615064952254761.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/probe: Add trace flag access APIs for trace_probeMasami Hiramatsu
Add trace_probe_test/set/clear_flag() functions for accessing trace_probe.flag field. This flags field should not be accessed directly. Link: http://lkml.kernel.org/r/155931585683.28323.314290023236905988.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/probe: Add trace_event_file access APIs for trace_probeMasami Hiramatsu
Add trace_event_file access APIs for trace_probe data structure. This simplifies enabling/disabling operations in uprobe and kprobe events so that those don't touch deep inside the trace_probe. This also removing a redundant synchronization when the kprobe event is used from perf, since the perf itself uses tracepoint_synchronize_unregister() after disabling (ftrace- defined) event, thus we don't have to synchronize in that path. Also we don't need to identify local trace_kprobe too anymore. Link: http://lkml.kernel.org/r/155931584587.28323.372301976283354629.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/probe: Add trace_event_call register API for trace_probeMasami Hiramatsu
Since trace_event_call is a field of trace_probe, these operations should be done in trace_probe.c. trace_kprobe and trace_uprobe use new functions to register/unregister trace_event_call. Link: http://lkml.kernel.org/r/155931583643.28323.14828411185591538876.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-16tracing/probe: Add trace_probe init and free functionsMasami Hiramatsu
Add common trace_probe init and cleanup function in trace_probe.c, and use it from trace_kprobe.c and trace_uprobe.c Link: http://lkml.kernel.org/r/155931582664.28323.5934870189034740822.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25tracing/probe: Support user-space dereferenceMasami Hiramatsu
Support user-space dereference syntax for probe event arguments to dereference the data-structure or array in user-space. The syntax is just adding 'u' before an offset value. +|-u<OFFSET>(<FETCHARG>) e.g. +u8(%ax), +u0(+0(%si)) For example, if you probe do_sched_setscheduler(pid, policy, param) and record param->sched_priority, you can add new probe as below; p do_sched_setscheduler priority=+u0($arg3) Note that kprobe event provides this and it doesn't change the dereference method automatically because we do not know whether the given address is in userspace or kernel on some archs. So as same as "ustring", this is an option for user, who has to carefully choose the dereference method. Link: http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2 Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25tracing/probe: Add ustring type for user-space stringMasami Hiramatsu
Add "ustring" type for fetching user-space string from kprobe event. User can specify ustring type at uprobe event, and it is same as "string" for uprobe. Note that probe-event provides this option but it doesn't choose the correct type automatically since we have not way to decide the address is in user-space or not on some arch (and on some other arch, you can fetch the string by "string" type). So user must carefully check the target code (e.g. if you see __user on the target variable) and use this new type. Link: http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2 Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-08tracing: uprobes: Re-enable $comm support for uprobe eventsMasami Hiramatsu
Since commit 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") dropped the $comm support from uprobe events, this re-enables it. For $comm support, uses strlcpy() instead of strncpy_from_user() to copy current task's comm. Because it is in the kernel space, strncpy_from_user() always fails to copy the comm. This also uses strlen() instead of strnlen_user() to measure the length of the comm. Note that this uses -ECOMM as a token value to fetch the comm string. If the user-space pointer points -ECOMM, it will be translated to task->comm. Link: http://lkml.kernel.org/r/155723734162.9149.4042756162201097965.stgit@devnote2 Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Reported-by: Andreas Ziegler <andreas.ziegler@fau.de> Acked-by: Andreas Ziegler <andreas.ziegler@fau.de> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-02tracing: Use tracing error_log with probe eventsMasami Hiramatsu
Use tracing error_log with probe events for logging error more precisely. This also makes all parse error returns -EINVAL (except for -ENOMEM), because user can see better error message in error_log file now. Link: http://lkml.kernel.org/r/6a4d90e141d138040ea61f4776b991597077451e.1554072478.git.tom.zanussi@linux.intel.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-03-14tracing/probe: Check the size of argument name and bodyMasami Hiramatsu
Check the size of argument name and expression is not 0 and smaller than maximum length. Link: http://lkml.kernel.org/r/155253783029.14922.12650939303827581096.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08tracing/kprobes: Use dyn_event framework for kprobe eventsMasami Hiramatsu
Use dyn_event framework for kprobe events. This shows kprobe events on "tracing/dynamic_events" file. User can also define new events via tracing/dynamic_events. Link: http://lkml.kernel.org/r/154140855646.17322.6619219995865980392.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: Integrate similar probe argument parsersMasami Hiramatsu
Integrate similar argument parsers for kprobes and uprobes events into traceprobe_parse_probe_arg(). Link: http://lkml.kernel.org/r/154140850016.17322.9836787731210512176.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>
2018-10-10tracing/kprobes: Allow kprobe-events to record module symbolMasami Hiramatsu
Allow kprobe-events to record module symbols. Since data symbols in a non-loaded module doesn't exist, it fails to define such symbol as an argument of kprobe-event. But if the kprobe event is defined on that module, we can defer to resolve the symbol address. Note that if given symbol is not found, the event is kept unavailable. User can enable it but the event is not recorded. Link: http://lkml.kernel.org/r/153547312336.26502.11432902826345374463.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> 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>
2018-10-10tracing: probeevent: Append traceprobe_ for exported functionMasami Hiramatsu
Append traceprobe_ for exported function set_print_fmt() as same as other functions. Link: http://lkml.kernel.org/r/152465877071.26224.11143125027282999726.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Return consumed bytes of dynamic areaMasami Hiramatsu
Cleanup string fetching routine so that returns the consumed bytes of dynamic area and store the string information as data_loc format instead of data_rloc. This simplifies the fetcharg loop. Link: http://lkml.kernel.org/r/152465874163.26224.12125143907501289031.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Unify fetch type tablesMasami Hiramatsu
Unify {k,u}probe_fetch_type_table to probe_fetch_type_table because the main difference of those type tables (fetcharg methods) are gone. Now we can consolidate it. Link: http://lkml.kernel.org/r/152465871274.26224.13999436317830479698.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Introduce new argument fetching codeMasami Hiramatsu
Replace {k,u}probe event argument fetching framework with switch-case based. Currently that is implemented with structures, macros and chain of function-pointers, which is more complicated than necessary and may get a performance penalty by retpoline. This simplify that with an array of "fetch_insn" (opcode and oprands), and make process_fetch_insn() just interprets it. No function pointers are used. Link: http://lkml.kernel.org/r/152465868340.26224.2551120475197839464.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Cleanup argument field definitionMasami Hiramatsu
Cleanup event argument definition code in one place for maintenancability. Link: http://lkml.kernel.org/r/152465862529.26224.9068605421476018902.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10tracing: probeevent: Cleanup print argument functionsMasami Hiramatsu
Cleanup the print-argument function to decouple it into print-name and print-value, so that it can support more flexible expression, like array type. Link: http://lkml.kernel.org/r/152465859635.26224.13452846788717102315.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10trace_uprobe: support reference counter in fd-based uprobeSong Liu
This patch enables uprobes with reference counter in fd-based uprobe. Highest 32 bits of perf_event_attr.config is used to stored offset of the reference count (semaphore). Format information in /sys/bus/event_source/devices/uprobe/format/ is updated to reflect this new feature. Link: http://lkml.kernel.org/r/20181002053636.1896903-1-songliubraving@fb.com Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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>
2018-03-29Merge branch 'perf/urgent' into perf/coreIngo Molnar
Conflicts: kernel/events/hw_breakpoint.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-23tracing: probeevent: Fix to support minus offset from symbolMasami Hiramatsu
In Documentation/trace/kprobetrace.txt, it says @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol) However, the parser doesn't parse minus offset correctly, since commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") drops minus ("-") offset support for kprobe probe address usage. This fixes the traceprobe_split_symbol_offset() to parse minus offset again with checking the offset range, and add a minus offset check in kprobe probe address usage. Link: http://lkml.kernel.org/r/152129028983.31874.13419301530285775521.stgit@devbox Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned") Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-02-17Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-06perf/core: Implement the 'perf_uprobe' PMUSong Liu
This patch adds perf_uprobe support with similar pattern as previous patch (for kprobe). Two functions, create_local_trace_uprobe() and destroy_local_trace_uprobe(), are created so a uprobe can be created and attached to the file descriptor created by perf_event_open(). Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Yonghong Song <yhs@fb.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Cc: <daniel@iogearbox.net> Cc: <davem@davemloft.net> Cc: <kernel-team@fb.com> Cc: <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171206224518.3598254-7-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-06perf/core: Implement the 'perf_kprobe' PMUSong Liu
A new PMU type, perf_kprobe is added. Based on attr from perf_event_open(), perf_kprobe creates a kprobe (or kretprobe) for the perf_event. This kprobe is private to this perf_event, and thus not added to global lists, and not available in tracefs. Two functions, create_local_trace_kprobe() and destroy_local_trace_kprobe() are added to created and destroy these local trace_kprobe. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Yonghong Song <yhs@fb.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Cc: <daniel@iogearbox.net> Cc: <davem@davemloft.net> Cc: <kernel-team@fb.com> Cc: <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171206224518.3598254-6-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-12tracing/kprobe: bpf: Check error injectable event is on function entryMasami Hiramatsu
Check whether error injectable event is on function entry or not. Currently it checks the event is ftrace-based kprobes or not, but that is wrong. It should check if the event is on the entry of target function. Since error injection will override a function to just return with modified return value, that operation must be done before the target function starts making stackframe. As a side effect, bpf error injection is no need to depend on function-tracer. It can work with sw-breakpoint based kprobe events too. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12bpf: add a bpf_override_function helperJosef Bacik
Error injection is sloppy and very ad-hoc. BPF could fill this niche perfectly with it's kprobe functionality. We could make sure errors are only triggered in specific call chains that we care about with very specific situations. Accomplish this with the bpf_override_funciton helper. This will modify the probe'd callers return value to the specified value and set the PC to an override function that simply returns, bypassing the originally probed function. This gives us a nice clean way to implement systematic error injection for all of our code paths. Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-10-04tracing: Make traceprobe parsing code reusableTom Zanussi
traceprobe_probes_write() and traceprobe_command() actually contain nothing that ties them to kprobes - the code is generically useful for similar types of parsing elsewhere, so separate it out and move it to trace.c/trace.h. Other than moving it, the only change is in naming: traceprobe_probes_write() becomes trace_parse_run_command() and traceprobe_command() becomes trace_run_command(). Link: http://lkml.kernel.org/r/ae5c26ea40c196a8986854d921eb6e713ede7e3f.1506105045.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>
2017-03-01perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTSAnton Blanchard
We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS. Consistently use the plurals. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: davem@davemloft.net Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-23ftrace: kprobe: uprobe: Show u8/u16/u32/u64 types in decimalMasami Hiramatsu
Change kprobe/uprobe-tracer to show the arguments type-casted with u8/u16/u32/u64 in decimal digits instead of hexadecimal. To minimize compatibility issue, the arguments without type casting are typed by x64 (or x32 for 32bit arch) by default. Note: all arguments set by old perf probe without types are shown in decimal by default. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Naohiro Aota <naohiro.aota@hgst.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/147151076135.12957.14684546093034343894.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-23ftrace: kprobe: uprobe: Add x8/x16/x32/x64 for hexadecimal typesMasami Hiramatsu
Add x8/x16/x32/x64 for hexadecimal type casting to kprobe/uprobe event tracer. These type casts can be used for integer arguments for explicitly showing them in hexadecimal digits in formatted text. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Naohiro Aota <naohiro.aota@hgst.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/147151067029.12957.11591314629326414783.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-20tracing: expose current->comm to [ku]probe eventsOmar Sandoval
ftrace is very quick to give up on saving the task command line (see `trace_save_cmdline()`). The workaround for events which really care about the command line is to explicitly assign it as part of the entry. However, this doesn't work for kprobe events, as there's no straightforward way to get access to current->comm. Add a kprobe/uprobe event variable $comm which provides exactly that. Link: http://lkml.kernel.org/r/f59b472033b943a370f5f48d0af37698f409108f.1465435894.git.osandov@fb.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-22kernel/trace_probe: is_good_name can be booleanYaowei Bai
This patch makes is_good_name return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1442929393-4753-2-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structures ftrace_event_call and ftrace_event_class have nothing to do with the function hooks, and are really trace_event structures. Rename ftrace_event_* to trace_event_*. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_file to trace_event_fileSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_event_file is really about trace events and not "ftrace". Rename it to trace_event_file. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-14Merge tag 'trace-v4.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Some clean ups and small fixes, but the biggest change is the addition of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints. Tracepoints have helper functions for the TP_printk() called __print_symbolic() and __print_flags() that lets a numeric number be displayed as a a human comprehensible text. What is placed in the TP_printk() is also shown in the tracepoint format file such that user space tools like perf and trace-cmd can parse the binary data and express the values too. Unfortunately, the way the TRACE_EVENT() macro works, anything placed in the TP_printk() will be shown pretty much exactly as is. The problem arises when enums are used. That's because unlike macros, enums will not be changed into their values by the C pre-processor. Thus, the enum string is exported to the format file, and this makes it useless for user space tools. The TRACE_DEFINE_ENUM() solves this by converting the enum strings in the TP_printk() format into their number, and that is what is shown to user space. For example, the tracepoint tlb_flush currently has this in its format file: __print_symbolic(REC->reason, { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }) After adding: TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH); TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN); Its format file will contain this: __print_symbolic(REC->reason, { 0, "flush on task switch" }, { 1, "remote shootdown" }, { 2, "local shootdown" }, { 3, "local mm shootdown" })" * tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits) tracing: Add enum_map file to show enums that have been mapped writeback: Export enums used by tracepoint to user space v4l: Export enums used by tracepoints to user space SUNRPC: Export enums in tracepoints to user space mm: tracing: Export enums in tracepoints to user space irq/tracing: Export enums in tracepoints to user space f2fs: Export the enums in the tracepoints to userspace net/9p/tracing: Export enums in tracepoints to userspace x86/tlb/trace: Export enums in used by tlb_flush tracepoint tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM() tracing: Allow for modules to convert their enums to values tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation tracing: Give system name a pointer brcmsmac: Move each system tracepoints to their own header iwlwifi: Move each system tracepoints to their own header mac80211: Move message tracepoints to their own header tracing: Add TRACE_SYSTEM_VAR to xhci-hcd tracing: Add TRACE_SYSTEM_VAR to kvm-s390 tracing: Add TRACE_SYSTEM_VAR to intel-sst ...
2015-03-25trace: Don't use __weak in header filesStephen Rothwell
The commit that added a check for this to checkpatch says: "Using weak declarations can have unintended link defects. The __weak on the declaration causes non-weak definitions to become weak." In this case, when a PowerPC kernel is built with CONFIG_KPROBE_EVENT but not CONFIG_UPROBE_EVENT, it generates the following warning: WARNING: 1 bad relocations c0000000014f2190 R_PPC64_ADDR64 uprobes_fetch_type_table This is fixed by passing the fetch_table arrays to traceprobe_parse_probe_arg() which also means that they can never be NULL. Link: http://lkml.kernel.org/r/20150312165834.4482cb48@canb.auug.org.au Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-03tracing: Convert the tracing facility over to use tracefsSteven Rostedt (Red Hat)
debugfs was fine for the tracing facility as a quick way to get an interface. Now that tracing has matured, it should separate itself from debugfs such that it can be mounted separately without needing to mount all of debugfs with it. That is, users resist using tracing because it requires mounting debugfs. Having tracing have its own file system lets users get the features of tracing without needing to bring in the rest of the kernel's debug infrastructure. Another reason for tracefs is that debubfs does not support mkdir. Currently, to create instances, one does a mkdir in the tracing/instance directory. This is implemented via a hack that forces debugfs to do something it is not intended on doing. By converting over to tracefs, this hack can be removed and mkdir can be properly implemented. This patch does not address this yet, but it lays the ground work for that to be done. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>