Commit Graph

158 Commits

Author SHA1 Message Date
Linus Torvalds e310396bb8 Tracing updates:
- Added new "bootconfig".
    Looks for a file appended to initrd to add boot config options.
    This 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
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Merge tag 'trace-v5.6-2' of 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
  ...
2020-02-06 07:12:11 +00:00
Linus Torvalds c0e809e244 Merge branch 'perf-core-for-linus' of 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
  ...
2020-01-28 09:44:15 -08:00
Masami Hiramatsu b61387cb73 tracing/uprobe: Fix to make trace_uprobe_filter alignment safe
Commit 99c9a923e9 ("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: 99c9a923e9 ("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>
2020-01-22 07:09:20 -05:00
Masami Hiramatsu 99c9a923e9 tracing/uprobe: Fix double perf_event linking on multiprobe uprobe
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 60d53e2c3b ("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: 60d53e2c3b ("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>
2020-01-14 15:57:59 -05:00
Steven Rostedt (VMware) 1329249437 tracing: Make struct ring_buffer less ambiguous
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>
2020-01-13 13:19:38 -05:00
Peter Zijlstra 04ae87a520 ftrace: Rework event_create_dir()
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>
2019-11-27 07:44:25 +01:00
Steven Rostedt (VMware) 17911ff38a tracing: Add locked_down checks to the open calls of files created for tracefs
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>
2019-10-12 20:48:06 -04:00
Srikar Dronamraju f8d7ab2bde tracing/probe: Fix same probe event argument matching
Commit fe60b0ce8e ("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: fe60b0ce8e ("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>
2019-09-25 06:34:06 -04:00
Masami Hiramatsu fe60b0ce8e tracing/probe: Reject exactly same probe event
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>
2019-09-19 11:09:16 -04:00
Masami Hiramatsu a42e3c4de9 tracing/probe: Add immediate string parameter support
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>
2019-08-31 12:19:39 -04:00
Masami Hiramatsu ab10d69eb7 tracing/uprobe: Add per-probe delete from event
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>
2019-08-31 12:19:39 -04:00
Masami Hiramatsu 41af3cf587 tracing/uprobe: Add multi-probe per uprobe event support
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>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu 30199137c8 tracing/dynevent: Pass extra arguments to match operation
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>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu 60d53e2c3b tracing/probe: Split trace_event related data from trace_probe
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>
2019-08-31 12:19:38 -04:00
Linus Torvalds 818e95c768 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.
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Merge tag 'trace-v5.3' of 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
  ...
2019-07-18 11:51:00 -07:00
Masami Hiramatsu e3dc9f898e tracing/probe: Add trace_event_call accesses APIs
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>
2019-07-16 15:14:47 -04:00
Masami Hiramatsu b55ce203a8 tracing/probe: Add probe event name and group name accesses APIs
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>
2019-07-16 15:14:47 -04:00
Masami Hiramatsu 747774d6b0 tracing/probe: Add trace flag access APIs for trace_probe
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>
2019-07-16 15:14:47 -04:00
Masami Hiramatsu b5f935ee13 tracing/probe: Add trace_event_file access APIs for trace_probe
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>
2019-07-16 15:14:47 -04:00
Masami Hiramatsu 46e5376d40 tracing/probe: Add trace_event_call register API for trace_probe
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>
2019-07-16 15:14:47 -04:00
Masami Hiramatsu 455b289973 tracing/probe: Add trace_probe init and free functions
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>
2019-07-16 15:14:47 -04:00
Masami Hiramatsu b4d4b96be8 tracing/uprobe: Set print format when parsing command
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>
2019-07-16 15:14:47 -04:00
Ingo Molnar b9271f0c65 Linux 5.2-rc6
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Merge tag 'v5.2-rc6' into perf/core, to refresh branch

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-24 19:25:52 +02:00
Eiichi Tsukata a4158345ec tracing/uprobe: Fix obsolete comment on trace_uprobe_create()
Commit 0597c49c69 ("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>
2019-06-14 17:00:36 -04:00
Eiichi Tsukata f01098c74b tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
Just like the case of commit 8b05a3a750 ("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: 0597c49c69 ("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>
2019-06-14 16:51:14 -04:00
Song Liu 9fd2e48b9a perf/core: Allow non-privileged uprobe for user processes
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>
2019-06-03 11:58:18 +02:00
Masami Hiramatsu e65f7ae7f4 tracing/probe: Support user-space dereference
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>
2019-05-25 23:04:42 -04:00
Masami Hiramatsu 88903c4643 tracing/probe: Add ustring type for user-space string
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>
2019-05-25 23:04:42 -04:00
Masami Hiramatsu 4dd537aca2 tracing: uprobes: Re-enable $comm support for uprobe events
Since commit 533059281e ("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: 533059281e ("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>
2019-05-08 12:15:11 -04:00
Masami Hiramatsu ab105a4fb8 tracing: Use tracing error_log with probe events
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>
2019-04-02 18:24:07 -04:00
Linus Torvalds aa2e3ac64a This contains a series of last minute clean ups, small fixes and
error checks.
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Merge tag 'trace-v5.1-2' of 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
2019-03-15 14:47:02 -07:00
Masami Hiramatsu a039480e9e tracing/probe: Verify alloc_trace_*probe() result
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>
2019-03-14 19:54:21 -04:00
Masami Hiramatsu 5b7a962209 tracing/probe: Check event/group naming rule at parsing
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>
2019-03-14 19:54:11 -04:00
Andreas Ziegler 0722069a53 tracing/uprobes: Fix output for multiple string arguments
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: 5baaa59ef0 ("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>
2019-01-17 10:54:08 -05:00
Andreas Ziegler ea6eb5e7d1 tracing: uprobes: Fix typo in pr_fmt string
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: 7257634135 ("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>
2019-01-17 09:51:42 -05:00
Steven Rostedt (VMware) 7e1413edd6 tracing: Consolidate trace_add/remove_event_call back to the nolock functions
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>
2018-12-10 12:22:10 -05:00
Masami Hiramatsu 0597c49c69 tracing/uprobes: Use dyn_event framework for uprobe events
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>
2018-12-08 20:54:10 -05:00
Masami Hiramatsu d00bbea945 tracing: Integrate similar probe argument parsers
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>
2018-12-08 20:54:09 -05:00
Masami Hiramatsu 547cd9eacd tracing/uprobes: Add busy check when cleanup all uprobes
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>
2018-12-08 20:54:08 -05:00
Masami Hiramatsu f3f58935ed tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
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>
2018-10-10 22:19:11 -04:00
Masami Hiramatsu a1303af5d7 tracing: probeevent: Add $argN for accessing function args
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>
2018-10-10 22:19:11 -04:00
Masami Hiramatsu 9b960a3883 tracing: probeevent: Unify fetch_insn processing common part
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>
2018-10-10 22:19:09 -04:00
Masami Hiramatsu 0a46c8549f tracing: probeevent: Append traceprobe_ for exported function
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>
2018-10-10 22:19:09 -04:00
Masami Hiramatsu 9178412ddf tracing: probeevent: Return consumed bytes of dynamic area
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>
2018-10-10 22:19:08 -04:00
Masami Hiramatsu f451bc89d8 tracing: probeevent: Unify fetch type tables
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>
2018-10-10 22:19:08 -04:00
Masami Hiramatsu 533059281e tracing: probeevent: Introduce new argument fetching code
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>
2018-10-10 22:19:07 -04:00
Masami Hiramatsu eeb07b0615 tracing: probeevent: Cleanup argument field definition
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>
2018-10-10 22:19:06 -04:00
Masami Hiramatsu 56de763052 tracing: probeevent: Cleanup print argument functions
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>
2018-10-10 22:19:06 -04:00
Song Liu a6ca88b241 trace_uprobe: support reference counter in fd-based uprobe
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>
2018-10-10 22:14:17 -04:00
Ravi Bangoria ccea8727dc trace_uprobe/sdt: Prevent multiple reference counter for same uprobe
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>
2018-09-24 04:44:54 -04:00