summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_uprobe.c
Commit message (Collapse)AuthorAgeFilesLines
* tracing: Deletion of an unnecessary check before iput()Markus Elfring2014-11-191-2/+1
| | | | | | | | | | | | The iput() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/5468F875.7080907@users.sourceforge.net Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Do not use return values of trace_seq_printf()Steven Rostedt (Red Hat)2014-11-191-13/+10
| | | | | | | | | | | | | | The functions trace_seq_printf() and friends will soon no longer have return values. Using trace_seq_has_overflowed() and trace_handle_return() should be used instead. Link: http://lkml.kernel.org/r/20141114011411.693008134@goodmis.org Link: http://lkml.kernel.org/r/20141115050602.333705855@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatu.pt@hitachi.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* trace: Replace single-character seq_puts with seq_putcRasmus Villemoes2014-11-141-1/+1
| | | | | | | | | | | Printing a single character to a seqfile might as well be done with seq_putc instead of seq_puts; this avoids a strlen() call and a memory access. It also shaves another few bytes off the generated code. Link: http://lkml.kernel.org/r/1415479332-25944-4-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Replace seq_printf by simpler equivalentsRasmus Villemoes2014-11-131-1/+1
| | | | | | | | | | | | | | | | | | | Using seq_printf to print a simple string or a single character is a lot more expensive than it needs to be, since seq_puts and seq_putc exist. These patches do seq_printf(m, s) -> seq_puts(m, s) seq_printf(m, "%s", s) -> seq_puts(m, s) seq_printf(m, "%c", c) -> seq_putc(m, c) Subsequent patches will simplify further. Link: http://lkml.kernel.org/r/1415479332-25944-2-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Kill the dead TRACE_EVENT_FL_USE_CALL_FILTER logicOleg Nesterov2014-07-161-2/+1
| | | | | | | | | | | | | | | alloc_trace_uprobe() sets TRACE_EVENT_FL_USE_CALL_FILTER for unknown reason and this is simply wrong. Fortunately this has no effect because register_uprobe_event() clears call->flags after that. Kill both. This trace_uprobe was kzalloc'ed and we rely on this fact anyway. Link: http://lkml.kernel.org/p/20140715184824.GA20505@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable()Oleg Nesterov2014-06-301-12/+19
| | | | | | | | | | | | | | | | | | | | | The usage of uprobe_buffer_enable() added by dcad1a20 is very wrong, 1. uprobe_buffer_enable() and uprobe_buffer_disable() are not balanced, _enable() should be called only if !enabled. 2. If uprobe_buffer_enable() fails probe_event_enable() should clear tp.flags and free event_file_link. 3. If uprobe_register() fails it should do uprobe_buffer_disable(). Link: http://lkml.kernel.org/p/20140627170146.GA18332@redhat.com Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Fixes: dcad1a204f72 "tracing/uprobes: Fetch args before reserving a ring buffer" Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in ↵Oleg Nesterov2014-06-301-6/+0
| | | | | | | | | | | | | | | | | | | | | | uprobe_dispatcher() I do not know why dd9fa555d7bb "tracing/uprobes: Move argument fetching to uprobe_dispatcher()" added the UPROBE_HANDLER_REMOVE, but it looks wrong. OK, perhaps it makes sense to avoid store_trace_args() if the tracee is nacked by uprobe_perf_filter(). But then we should kill the same code in uprobe_perf_func() and unify the TRACE/PROFILE filtering (we need to do this anyway to mix perf/ftrace). Until then this code actually adds the pessimization because uprobe_perf_filter() will be called twice and return T in likely case. Link: http://lkml.kernel.org/p/20140627170143.GA18329@redhat.com Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Revert "Support mix of ftrace and perf"Oleg Nesterov2014-06-301-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 43fe98913c9f67e3b523615ee3316f9520a623e0. This patch is very wrong. Firstly, this change leads to unbalanced uprobe_unregister(). Just for example, # perf probe -x /lib/libc.so.6 syscall # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable # perf record -e probe_libc:syscall whatever after that uprobe is dead (unregistered) but the user of ftrace/perf can't know this, and it looks as if nobody hits this probe. This would be easy to fix, but there are other reasons why it is not simple to mix ftrace and perf. If nothing else, they can't share the same ->consumer.filter. This is fixable too, but probably we need to fix the poorly designed uprobe_register() interface first. At least "register" and "apply" should be clearly separated. Link: http://lkml.kernel.org/p/20140627170136.GA18319@redhat.com Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com> Cc: stable@vger.kernel.org # v3.14 Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'perf/kprobes' into perf/coreIngo Molnar2014-06-051-10/+10
|\ | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/traps.c The kprobes enhancements are fully cooked, ship them upstream. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * kprobes, ftrace: Allow probing on some functionsMasami Hiramatsu2014-04-241-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need to prohibit probing on the functions used for preparation and uprobe only fetch functions. Those are safely probed because those are not invoked from kprobe's breakpoint/fault/debug handlers. So there is no chance to cause recursive exceptions. Following functions are now removed from the kprobes blacklist: update_bitfield_fetch_param free_bitfield_fetch_param kprobe_register FETCH_FUNC_NAME(stack, type) in trace_uprobe.c FETCH_FUNC_NAME(memory, type) in trace_uprobe.c FETCH_FUNC_NAME(memory, string) in trace_uprobe.c FETCH_FUNC_NAME(memory, string_size) in trace_uprobe.c FETCH_FUNC_NAME(file_offset, type) in trace_uprobe.c Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20140417081800.26341.56504.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | uprobes/tracing: Fix uprobe_perf_open() on uprobe_apply() failureOleg Nesterov2014-04-301-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | uprobe_perf_open()->uprobe_apply() can fail, but this error is wrongly ignored. Change uprobe_perf_open() to do uprobe_perf_close() and return the error code in this case. Change uprobe_perf_close() to propogate the error from uprobe_apply() as well, although it should not fail. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
* | uprobes/tracing: Make uprobe_perf_close() visible to uprobe_perf_open()Oleg Nesterov2014-04-301-18/+18
|/ | | | | | | | | Preparation. Move uprobe_perf_close() up before uprobe_perf_open() to avoid the forward declaration in the next patch and make it readable. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
* tracing/uprobes: Fix uprobe_cpu_buffer memory leakzhangwei(Jovi)2014-04-171-0/+6
| | | | | | | | | | | Forgot to free uprobe_cpu_buffer percpu page in uprobe_buffer_disable(). Link: http://lkml.kernel.org/p/534F8B3F.1090407@huawei.com Cc: stable@vger.kernel.org # v3.14+ Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracepoint: Use struct pointer instead of name hash for reg/unreg tracepointsMathieu Desnoyers2014-04-081-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Register/unregister tracepoint probes with struct tracepoint pointer rather than tracepoint name. This change, which vastly simplifies tracepoint.c, has been proposed by Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux size. From this point on, the tracers need to pass a struct tracepoint pointer to probe register/unregister. A probe can now only be connected to a tracepoint that exists. Moreover, tracers are responsible for unregistering the probe before the module containing its associated tracepoint is unloaded. text data bss dec hex filename 10443444 4282528 10391552 25117524 17f4354 vmlinux.orig 10434930 4282848 10391552 25109330 17f2352 vmlinux Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com CC: Ingo Molnar <mingo@kernel.org> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frank Ch. Eigler <fche@redhat.com> CC: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [ SDR - fixed return val in void func in tracepoint_module_going() ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Support mix of ftrace and perfNamhyung Kim2014-02-201-8/+1
| | | | | | | | | | | | | | | | It seems there's no reason to prevent mixed used of ftrace and perf for a single uprobe event. At least the kprobes already support it. Link: http://lkml.kernel.org/r/1389946120-19610-6-git-send-email-namhyung@kernel.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Support event triggeringNamhyung Kim2014-02-201-2/+4
| | | | | | | | | | | | | | | | | Add support for event triggering to uprobes. This is same as kprobes support added by Tom (plus cleanup by Steven). Link: http://lkml.kernel.org/r/1389946120-19610-5-git-send-email-namhyung@kernel.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Support ftrace_event_file base multibufferzhangwei(Jovi)2014-02-201-21/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support multi-buffer on uprobe-based dynamic events by using ftrace_event_file. This patch is based kprobe-based dynamic events multibuffer support work initially, commited by Masami(commit 41a7dd420c), but revised as below: Oleg changed the kprobe-based multibuffer design from array-pointers of ftrace_event_file into simple list, so this patch also change to the list design. rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func, to synchronize with ftrace_event_file list add and delete. Even though we allow multi-uprobes instances now, but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive in probe_event_enable currently, this means we cannot allow one user is using uprobe-tracer, and another user is using perf-probe on same uprobe concurrently. (Perhaps this will be fix in future, kprobe don't have this limitation now) Link: http://lkml.kernel.org/r/1389946120-19610-4-git-send-email-namhyung@kernel.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Move argument fetching to uprobe_dispatcher()Namhyung Kim2014-02-201-37/+56
| | | | | | | | | | | | | | | | | | | A single uprobe event might serve different users like ftrace and perf. And this is especially important for upcoming multi buffer support. But in this case it'll fetch (same) data from userspace multiple times. So move it to the beginning of the dispatcher function and reuse it for each users. Link: http://lkml.kernel.org/r/1389946120-19610-3-git-send-email-namhyung@kernel.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Rename uprobe_{trace,perf}_print() functionsNamhyung Kim2014-02-201-6/+6
| | | | | | | | | | | | | | | | | | The uprobe_{trace,perf}_print functions are misnomers since what they do is not printing. There's also a real print function named print_uprobe_event() so they'll only increase confusion IMHO. Rename them with double underscores to follow convention of kprobe. Link: http://lkml.kernel.org/r/1389946120-19610-2-git-send-email-namhyung@kernel.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/probes: Fix build break on !CONFIG_KPROBE_EVENTNamhyung Kim2014-01-031-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kprobe-based dynamic event tracer is not enabled, it caused following build error: kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c8dd): undefined reference to `fetch_symbol_u8' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c8e9): undefined reference to `fetch_symbol_u16' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c8f5): undefined reference to `fetch_symbol_u32' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c901): undefined reference to `fetch_symbol_u64' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c909): undefined reference to `fetch_symbol_string' kernel/built-in.o: In function `traceprobe_update_arg': (.text+0x10c913): undefined reference to `fetch_symbol_string_size' ... It was due to the fetch methods are referred from CHECK_FETCH_FUNCS macro and since it was only defined in trace_kprobe.c. Move NULL definition of such fetch functions to the header file. Note, it also requires CONFIG_BRANCH_PROFILING enabled to trigger this failure as well. This is because the "fetch_symbol_*" variables are referenced in a "else if" statement that will only call update_symbol_cache(), which is a static inline stub function when CONFIG_KPROBE_EVENT is not enabled. gcc is smart enough to optimize this "else if" out and that also removes the code that references the undefined variables. But when BRANCH_PROFILING is enabled, it fools gcc into keeping the if statement around and thus references the undefined symbols and fails to build. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Add @+file_offset fetch methodNamhyung Kim2014-01-021-0/+40
| | | | | | | | | | | | | | | | | Enable to fetch data from a file offset. Currently it only supports fetching from same binary uprobe set. It'll translate the file offset to a proper virtual address in the process. The syntax is "@+OFFSET" as it does similar to normal memory fetching (@ADDR) which does no address translation. Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/uprobes: Fetch args before reserving a ring bufferNamhyung Kim2014-01-021-14/+132
| | | | | | | | | | | | | | | | | | | | | | Fetching from user space should be done in a non-atomic context. So use a per-cpu buffer and copy its content to the ring buffer atomically. Note that we can migrate during accessing user memory thus use a per-cpu mutex to protect concurrent accesses. This is needed since we'll be able to fetch args from an user memory which can be swapped out. Before that uprobes could fetch args from registers only which saved in a kernel space. While at it, use __get_data_size() and store_trace_args() to reduce code duplication. And add struct uprobe_cpu_buffer and its helpers as suggested by Oleg. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/uprobes: Pass 'is_return' to traceprobe_parse_probe_arg()Namhyung Kim2014-01-021-1/+1
| | | | | | | | | | | | | Currently uprobes don't pass is_return to the argument parser so that it cannot make use of "$retval" fetch method since it only works for return probes. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/probes: Implement 'memory' fetch method for uprobesNamhyung Kim2014-01-021-0/+52
| | | | | | | | | | | | | Use separate method to fetch from memory. Move existing functions to trace_kprobe.c and make them static. Also add new memory fetch implementation for uprobes. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/probes: Move 'symbol' fetch method to kprobesNamhyung Kim2014-01-021-0/+8
| | | | | | | | | | | | | | Move existing functions to trace_kprobe.c and add NULL entries to the uprobes fetch type table. I don't make them static since some generic routines like update/free_XXX_fetch_param() require pointers to the functions. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/probes: Implement 'stack' fetch method for uprobesNamhyung Kim2014-01-021-0/+41
| | | | | | | | | | | | | Use separate method to fetch from stack. Move existing functions to trace_kprobe.c and make them static. Also add new stack fetch implementation for uprobes. Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/probes: Split [ku]probes_fetch_type_tableNamhyung Kim2014-01-021-0/+20
| | | | | | | | | | | | | | | | | | Use separate fetch_type_table for kprobes and uprobes. It currently shares all fetch methods but some of them will be implemented differently later. This is not to break build if [ku]probes is configured alone (like !CONFIG_KPROBE_EVENT and CONFIG_UPROBE_EVENT). So I added '__weak' to the table declaration so that it can be safely omitted when it configured out. Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/probes: Integrate duplicate set_print_fmt()Namhyung Kim2014-01-021-54/+1
| | | | | | | | | | | | The set_print_fmt() functions are implemented almost same for [ku]probes. Move it to a common place and get rid of the duplication. Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/uprobes: Convert to struct trace_probeNamhyung Kim2014-01-021-80/+79
| | | | | | | | | | | | Convert struct trace_uprobe to make use of the common trace_probe structure. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing/uprobes: Fix documentation of uprobe registration syntaxNamhyung Kim2014-01-021-1/+1
| | | | | | | | | | | The uprobe syntax requires an offset after a file path not a symbol. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
* tracing: Update event filters for multibufferTom Zanussi2013-11-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace event filters are still tied to event calls rather than event files, which means you don't get what you'd expect when using filters in the multibuffer case: Before: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 2048 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 Setting the filter in tracing/instances/test1/events shouldn't affect the same event in tracing/events as it does above. After: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 We'd like to just move the filter directly from ftrace_event_call to ftrace_event_file, but there are a couple cases that don't yet have multibuffer support and therefore have to continue using the current event_call-based filters. For those cases, a new USE_CALL_FILTER bit is added to the event_call flags, whose main purpose is to keep the old behavior for those cases until they can be updated with multibuffer support; at that point, the USE_CALL_FILTER flag (and the new associated call_filter_check_discard() function) can go away. The multibuffer support also made filter_current_check_discard() redundant, so this change removes that function as well and replaces it with filter_check_discard() (or call_filter_check_discard() as appropriate). Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/uprobes: Fail to unregister if probe event files are in useSteven Rostedt (Red Hat)2013-08-011-13/+38
| | | | | | | | | | | | | | | | | | | | | | Uprobes suffer the same problem that kprobes have. There's a race between writing to the "enable" file and removing the probe. The probe checks for it being in use and if it is not, goes about deleting the probe and the event that represents it. But the problem with that is, after it checks if it is in use it can be enabled, and the deletion of the event (access to the probe) will fail, as it is in use. But the uprobe will still be deleted. This is a problem as the event can reference the uprobe that was deleted. The fix is to remove the event first, and check to make sure the event removal succeeds. Then it is safe to remove the probe. When the event exists, either ftrace or perf can enable the probe and prevent the event from being removed. Link: http://lkml.kernel.org/r/20130704034038.991525256@goodmis.org Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/perf: Move the PERF_MAX_TRACE_SIZE check into perf_trace_buf_prepare()Oleg Nesterov2013-07-181-2/+0
| | | | | | | | | | | | | | | | | | | | Every perf_trace_buf_prepare() caller does WARN_ONCE(size > PERF_MAX_TRACE_SIZE, message) and "message" is almost the same. Shift this WARN_ONCE() into perf_trace_buf_prepare(). This changes the meaning of _ONCE, but I think this is fine. - 4947014 2932448 10104832 17984294 1126b26 vmlinux + 4948422 2932448 10104832 17985702 11270a6 vmlinux on my build. Link: http://lkml.kernel.org/r/20130617170211.GA19813@redhat.com Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* uprobes: Fix return value in error handling pathzhangwei(Jovi)2013-07-021-1/+3
| | | | | | | | | | | | | | | | | | | | | When wrong argument is passed into uprobe_events it does not return an error: [root@jovi tracing]# echo 'p:myprobe /bin/bash' > uprobe_events [root@jovi tracing]# The proper response is: [root@jovi tracing]# echo 'p:myprobe /bin/bash' > uprobe_events -bash: echo: write error: Invalid argument Link: http://lkml.kernel.org/r/51B964FF.5000106@huawei.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <srikar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 3.5+ Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is emptyOleg Nesterov2013-04-151-1/+4
| | | | | | | | | | perf_trace_buf_prepare() + perf_trace_buf_submit() make no sense if this task/CPU has no active counters. Change uprobe_perf_print() to return if hlist_empty(call->perf_events). Note: this is not uprobe-specific, we can change other users too. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
* uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()Oleg Nesterov2013-04-131-5/+3
| | | | | | | | | | uprobe_perf_print() passes addr=ip to perf_trace_buf_submit() for no reason. This sets perf_sample_data->addr for PERF_SAMPLE_ADDR, we already have perf_sample_data->ip initialized if PERF_SAMPLE_IP. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
* uprobes/tracing: Change create_trace_uprobe() to support uretprobesOleg Nesterov2013-04-131-4/+7
| | | | | | | | | Finally change create_trace_uprobe() to check if argv[0][0] == 'r' and pass the correct "is_ret" to alloc_trace_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Make seq_printf() code uretprobe-friendlyOleg Nesterov2013-04-131-4/+13
| | | | | | | | | Change probes_seq_show() and print_uprobe_event() to check is_ret_probe() and print the correct data. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendlyOleg Nesterov2013-04-131-4/+15
| | | | | | | | | Change uprobe_event_define_fields(), and __set_print_fmt() to check is_ret_probe() and use the appropriate format/fields. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendlyOleg Nesterov2013-04-131-9/+25
| | | | | | | | | | | | | | Change uprobe_trace_print() and uprobe_perf_print() to check is_ret_probe() and fill ring_buffer_event accordingly. Also change uprobe_trace_func() and uprobe_perf_func() to not _print() if is_ret_probe() is true. Note that we keep ->handler() nontrivial even for uretprobe, we need this for filtering and for other potential extensions. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()Oleg Nesterov2013-04-131-2/+40
| | | | | | | | | | | Create the new functions we need to support uretprobes, and change alloc_trace_uprobe() to initialize consumer.ret_handler if the new "is_ret" argument is true. Curently this argument is always false, so the new code is never called and is_ret_probe(tu) is false too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpersOleg Nesterov2013-04-131-9/+20
| | | | | | | | | | | Extract the output code from uprobe_trace_func() and uprobe_perf_func() into the new helpers, they will be used by ->ret_handler() too. We also add the unused "unsigned long func" argument in advance, to simplify the next changes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Generalize struct uprobe_trace_entry_headOleg Nesterov2013-04-131-26/+36
| | | | | | | | | | | | | | | | struct uprobe_trace_entry_head has a single member for reporting, "unsigned long ip". If we want to support uretprobes we need to create another struct which has "func" and "ret_ip" and duplicate a lot of functions, like trace_kprobe.c does. To avoid this copy-and-paste horror we turn ->ip into ->vaddr[] and add couple of trivial helpers to calculate sizeof/data. This uglifies the code a bit, but this allows us to avoid a lot more complications later, when we add the support for ret-probes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Kill the pointless local_save_flags/preempt_count callsOleg Nesterov2013-04-131-7/+3
| | | | | | | | | | uprobe_trace_func() is never called with irqs or preemption disabled, no need to ask preempt_count() or local_save_flags(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Kill the pointless seq_print_ip_sym() callOleg Nesterov2013-04-131-7/+1
| | | | | | | | | seq_print_ip_sym(ip) in print_uprobe_event() is pointless, kallsyms_lookup(ip) can not resolve a user-space address. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/tracing: Kill the pointless task_pt_regs() callsOleg Nesterov2013-04-131-2/+2
| | | | | | | | | uprobe_trace_func() and uprobe_perf_func() do not need task_pt_regs(), we already have "struct pt_regs *regs". Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
* uprobes/perf: Avoid uprobe_apply() whenever possibleOleg Nesterov2013-02-081-6/+36
| | | | | | | | | | | | | | | | | | | | uprobe_perf_open/close call the costly uprobe_apply() every time, we can avoid it if: - "nr_systemwide != 0" is not changed. - There is another process/thread with the same ->mm. - copy_proccess() does inherit_event(). dup_mmap() preserves the inserted breakpoints. - event->attr.enable_on_exec == T, we can rely on uprobe_mmap() called by exec/mmap paths. - tp_target is exiting. Only _close() checks PF_EXITING, I don't think TRACE_REG_PERF_OPEN can hit the dying task too often. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
* uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVEOleg Nesterov2013-02-081-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change uprobe_dispatcher() to return "trace_ret | perf_ret" although this is not needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive. The only functional change is that uprobe_perf_func() checks the filtering too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current. Testing: # perf probe -x /lib/libc.so.6 syscall # perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 20 A child process doesn't have a counter, but still it hits this breakoint "copied" by dup_mmap(). After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 11 The child process hits this int3 only once and does unapply_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com>
* uprobes/perf: Teach trace_uprobe/perf code to pre-filterOleg Nesterov2013-02-081-3/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Finally implement uprobe_perf_filter() which checks ->nr_systemwide or ->perf_events to figure out whether we need to insert the breakpoint. uprobe_perf_open/close are changed to do uprobe_apply(true/false) when the new perf event comes or goes away. Note that currently this is very suboptimal: - uprobe_register() called by TRACE_REG_PERF_REGISTER becomes a heavy nop, consumer->filter() always returns F at this stage. As it was already discussed we need uprobe_register_only() to avoid the costly register_for_each_vma() when possible. - uprobe_apply() is oftenly overkill. Unless "nr_systemwide != 0" changes we need uprobe_apply_mm(), unapply_uprobe() is almost what we need. - uprobe_apply() can be simply avoided sometimes, see the next changes. Testing: # perf probe -x /lib/libc.so.6 syscall # perl -e 'syscall -1 while 1' & [1] 530 # perf record -e probe_libc:syscall perl -e 'syscall -1 for 1..10; sleep 1' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 79291 A huge ->nrhit == 79291 reflects the fact that the background process 530 constantly hits this breakpoint too, even if doesn't contribute to the output. After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 10 This shows that only the target process was punished by int3. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
* uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event'sOleg Nesterov2013-02-081-0/+55
| | | | | | | | | | | | | | | | | Introduce "struct trace_uprobe_filter" which records the "active" perf_event's attached to ftrace_event_call. For the start we simply use list_head, we can optimize this later if needed. For example, we do not really need to record an event with ->parent != NULL, we can rely on parent->child_list. And we can certainly do some optimizations for the case when 2 events have the same ->tp_target or tp_target->mm. Change trace_uprobe_register() to process TRACE_REG_PERF_OPEN/CLOSE and add/del this perf_event to the list. We can probably avoid any locking, but lets start with the "obvioulsy correct" trace_uprobe_filter->rwlock which protects everything. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
OpenPOWER on IntegriCloud