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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>
2019-01-17tracing/uprobes: Fix output for multiple string argumentsAndreas Ziegler
When printing multiple uprobe arguments as strings the output for the earlier arguments would also include all later string arguments. This is best explained in an example: Consider adding a uprobe to a function receiving two strings as parameters which is at offset 0xa0 in strlib.so and we want to print both parameters when the uprobe is hit (on x86_64): $ echo 'p:func /lib/strlib.so:0xa0 +0(%di):string +0(%si):string' > \ /sys/kernel/debug/tracing/uprobe_events When the function is called as func("foo", "bar") and we hit the probe, the trace file shows a line like the following: [...] func: (0x7f7e683706a0) arg1="foobar" arg2="bar" Note the extra "bar" printed as part of arg1. This behaviour stacks up for additional string arguments. The strings are stored in a dynamically growing part of the uprobe buffer by fetch_store_string() after copying them from userspace via strncpy_from_user(). The return value of strncpy_from_user() is then directly used as the required size for the string. However, this does not take the terminating null byte into account as the documentation for strncpy_from_user() cleary states that it "[...] returns the length of the string (not including the trailing NUL)" even though the null byte will be copied to the destination. Therefore, subsequent calls to fetch_store_string() will overwrite the terminating null byte of the most recently fetched string with the first character of the current string, leading to the "accumulation" of strings in earlier arguments in the output. Fix this by incrementing the return value of strncpy_from_user() by one if we did not hit the maximum buffer size. Link: http://lkml.kernel.org/r/20190116141629.5752-1-andreas.ziegler@fau.de Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 5baaa59ef09e ("tracing/probes: Implement 'memory' fetch method for uprobes") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-01-17tracing: uprobes: Fix typo in pr_fmt stringAndreas Ziegler
The subsystem-specific message prefix for uprobes was also "trace_kprobe: " instead of "trace_uprobe: " as described in the original commit message. Link: http://lkml.kernel.org/r/20190117133023.19292-1-andreas.ziegler@fau.de Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 7257634135c24 ("tracing/probe: Show subsystem name in messages") Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-10tracing: Consolidate trace_add/remove_event_call back to the nolock functionsSteven Rostedt (VMware)
The trace_add/remove_event_call_nolock() functions were added to allow the tace_add/remove_event_call() code be called when the event_mutex lock was already taken. Now that all callers are done within the event_mutex, there's no reason to have two different interfaces. Remove the current wrapper trace_add/remove_event_call()s and rename the _nolock versions back to the original names. Link: http://lkml.kernel.org/r/154140866955.17322.2081425494660638846.stgit@devbox Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08tracing/uprobes: Use dyn_event framework for uprobe eventsMasami Hiramatsu
Use dyn_event framework for uprobe events. This shows uprobe events on "dynamic_events" file. User can also define new uprobe events via dynamic_events. Link: http://lkml.kernel.org/r/154140858481.17322.9091293846515154065.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>
2018-12-08tracing/uprobes: Add busy check when cleanup all uprobesMasami Hiramatsu
Add a busy check loop in cleanup_all_probes() before trying to remove all events in uprobe_events, the same way that kprobe_events does. Without this change, writing null to uprobe_events will try to remove events but if one of them is enabled, it will stop there leaving some events cleared and others not clceared. With this change, writing null to uprobe_events makes sure all events are not enabled before removing events. So, it clears all events, or returns an error (-EBUSY) with keeping all events. Link: http://lkml.kernel.org/r/154140841557.17322.12653952888762532401.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/uprobes: Fix to return -EFAULT if copy_from_user failedMasami Hiramatsu
Fix probe_mem_read() to return -EFAULT if copy_from_user() failed. The copy_from_user() returns remaining bytes when it failed, but probe_mem_read() caller expects it returns error code like as probe_kernel_read(). Link: http://lkml.kernel.org/r/153547306719.26502.8353484532699160223.stgit@devbox Reported-by: Dan Carpenter <dan.carpenter@oracle.com> 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: Unify fetch_insn processing common partMasami Hiramatsu
Unify the fetch_insn bottom process (from stage 2: dereference indirect data) from kprobe and uprobe events, since those are mostly same. Link: http://lkml.kernel.org/r/152465879965.26224.8547240824606804815.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>
2018-09-24trace_uprobe/sdt: Prevent multiple reference counter for same uprobeRavi Bangoria
We assume to have only one reference counter for one uprobe. Don't allow user to add multiple trace_uprobe entries having same inode+offset but different reference counter. Ex, # echo "p:sdt_tick/loop2 /home/ravi/tick:0x6e4(0x10036)" > uprobe_events # echo "p:sdt_tick/loop2_1 /home/ravi/tick:0x6e4(0xfffff)" >> uprobe_events bash: echo: write error: Invalid argument # dmesg trace_kprobe: Reference counter offset mismatch. There is one exception though: When user is trying to replace the old entry with the new one, we allow this if the new entry does not conflict with any other existing entries. Link: http://lkml.kernel.org/r/20180820044250.11659-4-ravi.bangoria@linux.ibm.com Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Song Liu <songliubraving@fb.com> Reviewed-by: Oleg Nesterov <oleg@redhat.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>
2018-09-24uprobes: 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>
2018-08-16tracing: 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>
2018-08-10uprobes: Use synchronize_rcu() not synchronize_sched()Steven Rostedt (VMware)
While debugging another bug, I was looking at all the synchronize*() functions being used in kernel/trace, and noticed that trace_uprobes was using synchronize_sched(), with a comment to synchronize with {u,ret}_probe_trace_func(). When looking at those functions, the data is protected with "rcu_read_lock()" and not with "rcu_read_lock_sched()". This is using the wrong synchronize_*() function. Link: http://lkml.kernel.org/r/20180809160553.469e1e32@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 70ed91c6ec7f8 ("tracing/uprobes: Support ftrace_event_file base multibuffer") Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-24bpf: introduce bpf subcommand BPF_TASK_FD_QUERYYonghong Song
Currently, suppose a userspace application has loaded a bpf program and attached it to a tracepoint/kprobe/uprobe, and a bpf introspection tool, e.g., bpftool, wants to show which bpf program is attached to which tracepoint/kprobe/uprobe. Such attachment information will be really useful to understand the overall bpf deployment in the system. There is a name field (16 bytes) for each program, which could be used to encode the attachment point. There are some drawbacks for this approaches. First, bpftool user (e.g., an admin) may not really understand the association between the name and the attachment point. Second, if one program is attached to multiple places, encoding a proper name which can imply all these attachments becomes difficult. This patch introduces a new bpf subcommand BPF_TASK_FD_QUERY. Given a pid and fd, if the <pid, fd> is associated with a tracepoint/kprobe/uprobe perf event, BPF_TASK_FD_QUERY will return . prog_id . tracepoint name, or . k[ret]probe funcname + offset or kernel addr, or . u[ret]probe filename + offset to the userspace. The user can use "bpftool prog" to find more information about bpf program itself with prog_id. Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-04-26tracing: Fix bad use of igrab in trace_uprobe.cSong Liu
As Miklos reported and suggested: This pattern repeats two times in trace_uprobe.c and in kernel/events/core.c as well: ret = kern_path(filename, LOOKUP_FOLLOW, &path); if (ret) goto fail_address_parse; inode = igrab(d_inode(path.dentry)); path_put(&path); And it's wrong. You can only hold a reference to the inode if you have an active ref to the superblock as well (which is normally through path.mnt) or holding s_umount. This way unmounting the containing filesystem while the tracepoint is active will give you the "VFS: Busy inodes after unmount..." message and a crash when the inode is finally put. Solution: store path instead of inode. This patch fixes two instances in trace_uprobe.c. struct path is added to struct trace_uprobe to keep the inode and containing mount point referenced. Link: http://lkml.kernel.org/r/20180423172135.4050588-1-songliubraving@fb.com Fixes: f3f096cfedf8 ("tracing: Provide trace events interface for uprobes") Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU") Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Howard McLauchlan <hmclauchlan@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Miklos Szeredi <mszeredi@redhat.com> Reported-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-04-15Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Thomas Gleixner: "A rather large set of perf updates: Kernel: - Fix various initialization issues - Prevent creating [ku]probes for not CAP_SYS_ADMIN users Tooling: - Show only failing syscalls with 'perf trace --failure' (Arnaldo Carvalho de Melo) e.g: See what 'openat' syscalls are failing: # perf trace --failure -e openat 762.323 ( 0.007 ms): VideoCapture/4566 openat(dfd: CWD, filename: /dev/video2) = -1 ENOENT No such file or directory <SNIP N /dev/videoN open attempts... sigh, where is that improvised camera lid?!? > 790.228 ( 0.008 ms): VideoCapture/4566 openat(dfd: CWD, filename: /dev/video63) = -1 ENOENT No such file or directory ^C# - Show information about the event (freq, nr_samples, total period/nr_events) in the annotate --tui and --stdio2 'perf annotate' output, similar to the first line in the 'perf report --tui', but just for the samples for a the annotated symbol (Arnaldo Carvalho de Melo) - Introduce 'perf version --build-options' to show what features were linked, aliased as well as a shorter 'perf -vv' (Jin Yao) - Add a "dso_size" sort order (Kim Phillips) - Remove redundant ')' in the tracepoint output in 'perf trace' (Changbin Du) - Synchronize x86's cpufeatures.h, no effect on toolss (Arnaldo Carvalho de Melo) - Show group details on the title line in the annotate browser and 'perf annotate --stdio2' output, so that the per-event columns can have headers (Arnaldo Carvalho de Melo) - Fixup vertical line separating metrics from instructions and cleaning unused lines at the bottom, both in the annotate TUI browser (Arnaldo Carvalho de Melo) - Remove duplicated 'samples' in lost samples warning in 'perf report' (Arnaldo Carvalho de Melo) - Synchronize i915_drm.h, silencing the perf build process, automagically adding support for the new DRM_I915_QUERY ioctl (Arnaldo Carvalho de Melo) - Make auxtrace_queues__add_buffer() allocate struct buffer, from a patchkit already applied (Adrian Hunter) - Fix the --stdio2/TUI annotate output to include group details, be it for a recorded '{a,b,f}' explicit event group or when forcing group display using 'perf report --group' for a set of events not recorded as a group (Arnaldo Carvalho de Melo) - Fix display artifacts in the ui browser (base class for the annotate and main report/top TUI browser) related to the extra title lines work (Arnaldo Carvalho de Melo) - perf auxtrace refactorings, leftovers from a previously partially processed patchset (Adrian Hunter) - Fix the builtin clang build (Sandipan Das, Arnaldo Carvalho de Melo) - Synchronize i915_drm.h, silencing a perf build warning and in the process automagically adding support for a new ioctl command (Arnaldo Carvalho de Melo) - Fix a strncpy issue in uprobe tracing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) perf/core: Need CAP_SYS_ADMIN to create k/uprobe with perf_event_open() tracing/uprobe_event: Fix strncpy corner case perf/core: Fix perf_uprobe_init() perf/core: Fix perf_kprobe_init() perf/core: Fix use-after-free in uprobe_perf_close() perf tests clang: Fix function name for clang IR test perf clang: Add support for recent clang versions perf tools: Fix perf builds with clang support perf tools: No need to include namespaces.h in util.h perf hists browser: Remove leftover from row returned from refresh perf hists browser: Show extra_title_lines in the 'D' debug hotkey perf auxtrace: Make auxtrace_queues__add_buffer() do CPU filtering tools headers uapi: Synchronize i915_drm.h perf report: Remove duplicated 'samples' in lost samples warning perf ui browser: Fixup cleaning unused lines at the bottom perf annotate browser: Fixup vertical line separating metrics from instructions perf annotate: Show group details on the title line perf auxtrace: Make auxtrace_queues__add_buffer() allocate struct buffer perf/x86/intel: Move regs->flags EXACT bit init perf trace: Remove redundant ')' ...
2018-04-12Merge tag 'trace-v4.17-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "A few clean ups and bug fixes: - replace open coded "ARRAY_SIZE()" with macro - updates to uprobes - bug fix for perf event filter on error path" * tag 'trace-v4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Enforce passing in filter=NULL to create_filter() trace_uprobe: Simplify probes_seq_show() trace_uprobe: Use %lx to display offset tracing/uprobe: Add support for overlayfs tracing: Use ARRAY_SIZE() macro instead of open coding it
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