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2021-11-23tracing/uprobe: Fix uprobe_perf_open probes iterationJiri Olsa
Add missing 'tu' variable initialization in the probes loop, otherwise the head 'tu' is used instead of added probes. Link: https://lkml.kernel.org/r/20211123142801.182530-1-jolsa@kernel.org Cc: stable@vger.kernel.org Fixes: 99c9a923e97a ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-08tracing: Disable "other" permission bits in the tracefs filesSteven Rostedt (VMware)
When building the files in the tracefs file system, do not by default set any permissions for OTH (other). This will make it easier for admins who want to define a group for accessing tracefs and not having to first disable all the permission bits for "other" in the file system. As tracing can leak sensitive information, it should never by default allowing all users access. An admin can still set the permission bits for others to have access, which may be useful for creating a honeypot and seeing who takes advantage of it and roots the machine. Link: https://lkml.kernel.org/r/20210818153038.864149276@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19tracing/probes: Reject events which have the same name of existing oneMasami Hiramatsu
Since kprobe_events and uprobe_events only check whether the other same-type probe event has the same name or not, if the user gives the same name of the existing tracepoint event (or the other type of probe events), it silently fails to create the tracefs entry (but registered.) as below. /sys/kernel/tracing # ls events/task/task_rename enable filter format hist id trigger /sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events [ 113.048508] Could not create tracefs 'task_rename' directory /sys/kernel/tracing # cat kprobe_events p:task/task_rename vfs_read To fix this issue, check whether the existing events have the same name or not in trace_probe_register_event_call(). If exists, it rejects to register the new event. Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19tracing/probes: Have process_fetch_insn() take a void * instead of pt_regsSteven Rostedt (VMware)
In preparation to allow event probes to use the process_fetch_insn() callback in trace_probe_tmpl.h, change the data passed to it from a pointer to pt_regs, as the event probe will not be using regs, and make it a void pointer instead. Update the process_fetch_insn() callers for kprobe and uprobe events to have the regs defined in the function and just typecast the void pointer parameter. Link: https://lkml.kernel.org/r/20210819041842.291622924@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19tracing/probe: Change traceprobe_set_print_fmt() to take a typeSteven Rostedt (VMware)
Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will simplify adding different types. For example, the development of the event_probe, will need its own type as it prints an event, and not an IP. Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18tracing/probes: Use struct_size() instead of defining custom macrosSteven Rostedt (VMware)
Remove SIZEOF_TRACE_KPROBE() and SIZEOF_TRACE_UPROBE() and use struct_size() as that's what it is made for. No need to have custom macros. Especially since struct_size() has some extra memory checks for correctness. Link: https://lkml.kernel.org/r/20210817035027.795000217@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18tracing/probe: Have traceprobe_parse_probe_arg() take a const argSteven Rostedt (VMware)
The two places that call traceprobe_parse_probe_arg() allocate a temporary buffer to copy the argv[i] into, because argv[i] is constant and the traceprobe_parse_probe_arg() will modify it to do the parsing. These two places allocate this buffer and then free it right after calling this function, leaving the onus of this allocation to the caller. As there's about to be a third user of this function that will have to do the same thing, instead of having the caller allocate the temporary buffer, simply move that allocation into the traceprobe_parse_probe_arg() itself, which will simplify the code of the callers. Link: https://lkml.kernel.org/r/20210817035027.385422828@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18tracing: Have dynamic events have a ref counterSteven Rostedt (VMware)
As dynamic events are not created by modules, if something is attached to one, calling "try_module_get()" on its "mod" field, is not going to keep the dynamic event from going away. Since dynamic events do not need the "mod" pointer of the event structure, make a union out of it in order to save memory (there's one structure for each of the thousand+ events in the kernel), and have any event with the DYNAMIC flag set to use a ref counter instead. Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/ Link: https://lkml.kernel.org/r/20210817035027.174869074@goodmis.org Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18tracing: Add DYNAMIC flag for dynamic eventsSteven Rostedt (VMware)
To differentiate between static and dynamic events, add a new flag DYNAMIC to the event flags that all dynamic events have set. This will allow to differentiate when attaching to a dynamic event from a static event. Static events have a mod pointer that references the module they were created in (or NULL for core kernel). This can be incremented when the event has something attached to it. But there exists no such mechanism for dynamic events. This is dangerous as the dynamic events may now disappear without the "attachment" knowing that it no longer exists. To enforce the dynamic flag, change dyn_event_add() to pass the event that is being created such that it can set the DYNAMIC flag of the event. This helps make sure that no location that creates a dynamic event misses setting this flag. Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/ Link: https://lkml.kernel.org/r/20210817035026.936958254@goodmis.org Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09tracing/dynevent: Delegate parsing to create functionMasami Hiramatsu
Delegate command parsing to each create function so that the command syntax can be customized. This requires changes to the kprobe/uprobe/synthetic event handling, which are also included here. Link: https://lkml.kernel.org/r/e488726f49cbdbc01568618f8680584306c4c79f.1612208610.git.zanussi@kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> [ zanussi@kernel.org: added synthetic event modifications ] Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02tracing: Fix spelling of controlling in uprobesBhaskar Chowdhury
s/controling/controlling/p Link: https://lkml.kernel.org/r/20210112045008.29834-1-unixbhaskar@gmail.com Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02tracing: Merge irqflags + preempt counter.Sebastian Andrzej Siewior
The state of the interrupts (irqflags) and the preemption counter are both passed down to tracing_generic_entry_update(). Only one bit of irqflags is actually required: The on/off state. The complete 32bit of the preemption counter isn't needed. Just whether of the upper bits (softirq, hardirq and NMI) are set and the preemption depth is needed. The irqflags and the preemption counter could be evaluated early and the information stored in an integer `trace_ctx'. tracing_generic_entry_update() would use the upper bits as the TRACE_FLAG_* and the lower 8bit as the disabled-preemption depth (considering that one must be substracted from the counter in one special cases). The actual preemption value is not used except for the tracing record. The `irqflags' variable is mostly used only for the tracing record. An exception here is for instance wakeup_tracer_call() or probe_wakeup_sched_switch() which explicilty disable interrupts and use that `irqflags' to save (and restore) the IRQ state and to record the state. Struct trace_event_buffer has also the `pc' and flags' members which can be replaced with `trace_ctx' since their actual value is not used outside of trace recording. This will reduce tracing_generic_entry_update() to simply assign values to struct trace_entry. The evaluation of the TRACE_FLAG_* bits is moved to _tracing_gen_ctx_flags() which replaces preempt_count() and local_save_flags() invocations. As an example, ftrace_syscall_enter() may invoke: - trace_buffer_lock_reserve() -> … -> tracing_generic_entry_update() - event_trigger_unlock_commit() -> ftrace_trace_stack() -> … -> tracing_generic_entry_update() -> ftrace_trace_userstack() -> … -> tracing_generic_entry_update() In this case the TRACE_FLAG_* bits were evaluated three times. By using the `trace_ctx' they are evaluated once and assigned three times. A build with all tracers enabled on x86-64 with and without the patch: text data bss dec hex filename 21970669 17084168 7639260 46694097 2c87ed1 vmlinux.old 21970293 17084168 7639260 46693721 2c87d59 vmlinux.new text shrank by 379 bytes, data remained constant. Link: https://lkml.kernel.org/r/20210125194511.3924915-2-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21tracing/uprobes: Support perf-style return probeMasami Hiramatsu
Support perf-style return probe ("SYMBOL%return") for uprobe events as same as kprobe events does. Link: https://lkml.kernel.org/r/159972814601.428528.7641183316212425445.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18tracing: make tracing_init_dentry() returns an integer instead of a d_entry ↵Wei Yang
pointer Current tracing_init_dentry() return a d_entry pointer, while is not necessary. This function returns NULL on success or error on failure, which means there is no valid d_entry pointer return. Let's return 0 on success and negative value for error. Link: https://lkml.kernel.org/r/20200712011036.70948-5-richard.weiyang@linux.alibaba.com Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-03tracing/uprobe: Remove dead code in trace_uprobe_register()Peng Fan
In the function trace_uprobe_register(), the statement "return 0;" out of switch case is dead code, remove it. Link: https://lkml.kernel.org/r/1595561064-29186-1-git-send-email-fanpeng@loongson.cn Signed-off-by: Peng Fan <fanpeng@loongson.cn> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-09tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobesJean-Philippe Brucker
Commit 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") removed the trace_[ku]probe structure from the trace_event_call->data pointer. As bpf_get_[ku]probe_info() were forgotten in that change, fix them now. These functions are currently only used by the bpf_task_fd_query() syscall handler to collect information about a perf event. Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/bpf/20200608124531.819838-1-jean-philippe@linaro.org
2020-02-24bpf: disable preemption for bpf progs attached to uprobeAlexei Starovoitov
trace_call_bpf() no longer disables preemption on its own. All callers of this function has to do it explicitly. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2020-02-06Merge tag 'trace-v5.6-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Added new "bootconfig". This looks for a file appended to initrd to add boot config options, and has been discussed thoroughly at Linux Plumbers. Very useful for adding kprobes at bootup. Only enabled if "bootconfig" is on the real kernel command line. - Created dynamic event creation. Merges common code between creating synthetic events and kprobe events. - Rename perf "ring_buffer" structure to "perf_buffer" - Rename ftrace "ring_buffer" structure to "trace_buffer" Had to rename existing "trace_buffer" to "array_buffer" - Allow trace_printk() to work withing (some) tracing code. - Sort of tracing configs to be a little better organized - Fixed bug where ftrace_graph hash was not being protected properly - Various other small fixes and clean ups * tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits) bootconfig: Show the number of nodes on boot message tools/bootconfig: Show the number of bootconfig nodes bootconfig: Add more parse error messages bootconfig: Use bootconfig instead of boot config ftrace: Protect ftrace_graph_hash with ftrace_sync ftrace: Add comment to why rcu_dereference_sched() is open coded tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu tracing: Annotate ftrace_graph_hash pointer with __rcu bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline tracing: Use seq_buf for building dynevent_cmd string tracing: Remove useless code in dynevent_arg_pair_add() tracing: Remove check_arg() callbacks from dynevent args tracing: Consolidate some synth_event_trace code tracing: Fix now invalid var_ref_vals assumption in trace action tracing: Change trace_boot to use synth_event interface tracing: Move tracing selftests to bottom of menu tracing: Move mmio tracer config up with the other tracers tracing: Move tracing test module configs together tracing: Move all function tracing configs together tracing: Documentation for in-kernel synthetic event API ...
2020-01-28Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes: - Ftrace is one of the last W^X violators (after this only KLP is left). These patches move it over to the generic text_poke() interface and thereby get rid of this oddity. This requires a surprising amount of surgery, by Peter Zijlstra. - x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to count certain types of events that have a special, quirky hw ABI (by Kim Phillips) - kprobes fixes by Masami Hiramatsu Lots of tooling updates as well, the following subcommands were updated: annotate/report/top, c2c, clang, record, report/top TUI, sched timehist, tests; plus updates were done to the gtk ui, libperf, headers and the parser" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) perf/x86/amd: Add support for Large Increment per Cycle Events perf/x86/amd: Constrain Large Increment per Cycle events perf/x86/intel/rapl: Add Comet Lake support tracing: Initialize ret in syscall_enter_define_fields() perf header: Use last modification time for timestamp perf c2c: Fix return type for histogram sorting comparision functions perf beauty sockaddr: Fix augmented syscall format warning perf/ui/gtk: Fix gtk2 build perf ui gtk: Add missing zalloc object perf tools: Use %define api.pure full instead of %pure-parser libperf: Setup initial evlist::all_cpus value perf report: Fix no libunwind compiled warning break s390 issue perf tools: Support --prefix/--prefix-strip perf report: Clarify in help that --children is default tools build: Fix test-clang.cpp with Clang 8+ perf clang: Fix build with Clang 9 kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic tools lib: Fix builds when glibc contains strlcpy() perf report/top: Make 'e' visible in the help and make it toggle showing callchains perf report/top: Do not offer annotation for symbols without samples ...
2020-01-22tracing/uprobe: Fix to make trace_uprobe_filter alignment safeMasami Hiramatsu
Commit 99c9a923e97a ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe") moved trace_uprobe_filter on trace_probe_event. However, since it introduced a flexible data structure with char array and type casting, the alignment of trace_uprobe_filter can be broken. This changes the type of the array to trace_uprobe_filter data strucure to fix it. Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2 Fixes: 99c9a923e97a ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe") Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-14tracing/uprobe: Fix double perf_event linking on multiprobe uprobeMasami Hiramatsu
Fix double perf_event linking to trace_uprobe_filter on multiple uprobe event by moving trace_uprobe_filter under trace_probe_event. In uprobe perf event, trace_uprobe_filter data structure is managing target mm filters (in perf_event) related to each uprobe event. Since commit 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") left the trace_uprobe_filter data structure in trace_uprobe, if a trace_probe_event has multiple trace_uprobe (multi-probe event), a perf_event is added to different trace_uprobe_filter on each trace_uprobe. This leads a linked list corruption. To fix this issue, move trace_uprobe_filter to trace_probe_event and link it once on each event instead of each probe. Link: http://lkml.kernel.org/r/157862073931.1800.3800576241181489174.stgit@devnote2 Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S . Miller" <davem@davemloft.net> Cc: Namhyung Kim <namhyung@kernel.org> Cc: =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?b?w7hyZ2Vuc2Vu?= <thoiland@redhat.com> Cc: Jean-Tsung Hsiao <jhsiao@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: stable@vger.kernel.org Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Link: https://lkml.kernel.org/r/20200108171611.GA8472@kernel.org Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13tracing: Make struct ring_buffer less ambiguousSteven Rostedt (VMware)
As there's two struct ring_buffers in the kernel, it causes some confusion. The other one being the perf ring buffer. It was agreed upon that as neither of the ring buffers are generic enough to be used globally, they should be renamed as: perf's ring_buffer -> perf_buffer ftrace's ring_buffer -> trace_buffer This implements the changes to the ring buffer that ftrace uses. Link: https://lore.kernel.org/r/20191213140531.116b3200@gandalf.local.home Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-27ftrace: Rework event_create_dir()Peter Zijlstra
Rework event_create_dir() to use an array of static data instead of function pointers where possible. The problem is that it would call the function pointer on module load before parse_args(), possibly even before jump_labels were initialized. Luckily the generated functions don't use jump_labels but it still seems fragile. It also gets in the way of changing when we make the module map executable. The generated function are basically calling trace_define_field() with a bunch of static arguments. So instead of a function, capture these arguments in a static array, avoiding the function call. Now there are a number of cases where the fields are dynamic (syscall arguments, kprobes and uprobes), in which case a static array does not work, for these we preserve the function call. Luckily all these cases are not related to modules and so we can retain the function call for them. Also fix up all broken tracepoint definitions that now generate a compile error. Tested-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Alexei Starovoitov <ast@kernel.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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191111132458.342979914@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-12tracing: Add locked_down checks to the open calls of files created for tracefsSteven Rostedt (VMware)
Added various checks on open tracefs calls to see if tracefs is in lockdown mode, and if so, to return -EPERM. Note, the event format files (which are basically standard on all machines) as well as the enabled_functions file (which shows what is currently being traced) are not lockde down. Perhaps they should be, but it seems counter intuitive to lockdown information to help you know if the system has been modified. Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-25tracing/probe: Fix same probe event argument matchingSrikar Dronamraju
Commit fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event") tries to reject a event which matches an already existing probe. However it currently continues to match arguments and rejects adding a probe even when the arguments don't match. Fix this by only rejecting a probe if and only if all the arguments match. Link: http://lkml.kernel.org/r/20190924114906.14038-1-srikar@linux.vnet.ibm.com Fixes: fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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/uprobe: Add per-probe delete from eventMasami Hiramatsu
Add per-probe delete method from one event passing the head of definition. In other words, the events which match the head N parameters are deleted. Link: http://lkml.kernel.org/r/156095689811.28024.221706761151739433.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/uprobe: Add multi-probe per uprobe event supportMasami Hiramatsu
Allow user to define several probes on one uprobe event. Note that this only support appending method. So deleting event will delete all probes on the event. Link: http://lkml.kernel.org/r/156095687876.28024.13840331032234992863.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/dynevent: Pass extra arguments to match operationMasami Hiramatsu
Pass extra arguments to match operation for checking exact match. If the event doesn't support exact match, it will be ignored. Link: http://lkml.kernel.org/r/156095685930.28024.10405547027475590975.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>
2019-07-18Merge tag 'trace-v5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The main changes in this release include: - Add user space specific memory reading for kprobes - Allow kprobes to be executed earlier in boot The rest are mostly just various clean ups and small fixes" * tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Make trace_get_fields() global tracing: Let filter_assign_type() detect FILTER_PTR_STRING tracing: Pass type into tracing_generic_entry_update() ftrace/selftest: Test if set_event/ftrace_pid exists before writing ftrace/selftests: Return the skip code when tracing directory not configured in kernel tracing/kprobe: Check registered state using kprobe tracing/probe: Add trace_event_call accesses APIs tracing/probe: Add probe event name and group name accesses APIs tracing/probe: Add trace flag access APIs for trace_probe tracing/probe: Add trace_event_file access APIs for trace_probe tracing/probe: Add trace_event_call register API for trace_probe tracing/probe: Add trace_probe init and free functions tracing/uprobe: Set print format when parsing command tracing/kprobe: Set print format right after parsed command kprobes: Fix to init kprobes in subsys_initcall tracepoint: Use struct_size() in kmalloc() ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS ftrace: Enable trampoline when rec count returns back to one tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline tracing: Make a separate config for trace event self tests ...
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>
2019-07-16tracing/uprobe: Set print format when parsing commandMasami Hiramatsu
Set event call's print format right after parsed command for simplifying (un)register_uprobe_event(). Link: http://lkml.kernel.org/r/155931581659.28323.5404667166417404076.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-24Merge tag 'v5.2-rc6' into perf/core, to refresh branchIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-14tracing/uprobe: Fix obsolete comment on trace_uprobe_create()Eiichi Tsukata
Commit 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events") cleaned up the usage of trace_uprobe_create(), and the function has been no longer used for removing uprobe/uretprobe. Link: http://lkml.kernel.org/r/20190614074026.8045-2-devel@etsukata.com Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Eiichi Tsukata <devel@etsukata.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()Eiichi Tsukata
Just like the case of commit 8b05a3a7503c ("tracing/kprobes: Fix NULL pointer dereference in trace_kprobe_create()"), writing an incorrectly formatted string to uprobe_events can trigger NULL pointer dereference. Reporeducer: # echo r > /sys/kernel/debug/tracing/uprobe_events dmesg: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000079d12067 P4D 8000000079d12067 PUD 7b7ab067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 1903 Comm: bash Not tainted 5.2.0-rc3+ #15 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 RIP: 0010:strchr+0x0/0x30 Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c RSP: 0018:ffffb55fc0403d10 EFLAGS: 00010293 RAX: ffff993ffb793400 RBX: 0000000000000000 RCX: ffffffffa4852625 RDX: 0000000000000000 RSI: 000000000000002f RDI: 0000000000000000 RBP: ffffb55fc0403dd0 R08: ffff993ffb793400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff993ff9cc1668 R14: 0000000000000001 R15: 0000000000000000 FS: 00007f30c5147700(0000) GS:ffff993ffda00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007b628000 CR4: 00000000000006f0 Call Trace: trace_uprobe_create+0xe6/0xb10 ? __kmalloc_track_caller+0xe6/0x1c0 ? __kmalloc+0xf0/0x1d0 ? trace_uprobe_create+0xb10/0xb10 create_or_delete_trace_uprobe+0x35/0x90 ? trace_uprobe_create+0xb10/0xb10 trace_run_command+0x9c/0xb0 trace_parse_run_command+0xf9/0x1eb ? probes_open+0x80/0x80 __vfs_write+0x43/0x90 vfs_write+0x14a/0x2a0 ksys_write+0xa2/0x170 do_syscall_64+0x7f/0x200 entry_SYSCALL_64_after_hwframe+0x49/0xbe Link: http://lkml.kernel.org/r/20190614074026.8045-1-devel@etsukata.com Cc: stable@vger.kernel.org Fixes: 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events") Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Eiichi Tsukata <devel@etsukata.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-03perf/core: Allow non-privileged uprobe for user processesSong Liu
Currently, non-privileged user could only use uprobe with kernel.perf_event_paranoid = -1 However, setting perf_event_paranoid to -1 leaks other users' processes to non-privileged uprobes. To introduce proper permission control of uprobes, we are building the following system: A daemon with CAP_SYS_ADMIN is in charge to create uprobes via tracefs; Users asks the daemon to create uprobes; Then user can attach uprobe only to processes owned by the user. This patch allows non-privileged user to attach uprobe to processes owned by the user. The following example shows how to use uprobe with non-privileged user. This is based on Brendan's blog post [1] 1. Create uprobe with root: sudo perf probe -x 'readline%return +0($retval):string' 2. Then non-root user can use the uprobe as: perf record -vvv -e probe_bash:readline__return -p <pid> sleep 20 perf script [1] http://www.brendangregg.com/blog/2015-06-28/linux-ftrace-uprobe.html Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@fb.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190507161545.788381-1-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-25tracing/probe: Support user-space dereferenceMasami Hiramatsu
Support user-space dereference syntax for probe event arguments to dereference the data-structure or array in user-space. The syntax is just adding 'u' before an offset value. +|-u<OFFSET>(<FETCHARG>) e.g. +u8(%ax), +u0(+0(%si)) For example, if you probe do_sched_setscheduler(pid, policy, param) and record param->sched_priority, you can add new probe as below; p do_sched_setscheduler priority=+u0($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>
2019-03-15Merge 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
2019-03-14tracing/probe: Verify alloc_trace_*probe() resultMasami Hiramatsu
Since alloc_trace_*probe() returns -EINVAL only if !event && !group, it should not happen in trace_*probe_create(). If we catch that case there is a bug. So use WARN_ON_ONCE() instead of pr_info(). Link: http://lkml.kernel.org/r/155253785078.14922.16902223633734601469.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-03-14tracing/probe: Check event/group naming rule at parsingMasami Hiramatsu
Check event and group naming rule at parsing it instead of allocating probes. Link: http://lkml.kernel.org/r/155253784064.14922.2336893061156236237.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>