Commit Graph

28 Commits

Author SHA1 Message Date
Masami Hiramatsu
b4da3340ea tracing/kprobe: bpf: Check error injectable event is on function entry
Check whether error injectable event is on function entry or not.
Currently it checks the event is ftrace-based kprobes or not,
but that is wrong. It should check if the event is on the entry
of target function. Since error injection will override a function
to just return with modified return value, that operation must
be done before the target function starts making stackframe.

As a side effect, bpf error injection is no need to depend on
function-tracer. It can work with sw-breakpoint based kprobe
events too.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-12 17:33:37 -08:00
Josef Bacik
9802d86585 bpf: add a bpf_override_function helper
Error injection is sloppy and very ad-hoc.  BPF could fill this niche
perfectly with it's kprobe functionality.  We could make sure errors are
only triggered in specific call chains that we care about with very
specific situations.  Accomplish this with the bpf_override_funciton
helper.  This will modify the probe'd callers return value to the
specified value and set the PC to an override function that simply
returns, bypassing the originally probed function.  This gives us a nice
clean way to implement systematic error injection for all of our code
paths.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12 09:02:34 -08:00
Tom Zanussi
7e465baa80 tracing: Make traceprobe parsing code reusable
traceprobe_probes_write() and traceprobe_command() actually contain
nothing that ties them to kprobes - the code is generically useful for
similar types of parsing elsewhere, so separate it out and move it to
trace.c/trace.h.

Other than moving it, the only change is in naming:
traceprobe_probes_write() becomes trace_parse_run_command() and
traceprobe_command() becomes trace_run_command().

Link: http://lkml.kernel.org/r/ae5c26ea40c196a8986854d921eb6e713ede7e3f.1506105045.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-10-04 13:06:44 -04:00
Anton Blanchard
6b0b755142 perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS
We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as
well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS.

Consistently use the plurals.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: davem@davemloft.net
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-01 10:26:39 +01:00
Masami Hiramatsu
bdca79c2bf ftrace: kprobe: uprobe: Show u8/u16/u32/u64 types in decimal
Change kprobe/uprobe-tracer to show the arguments type-casted
with u8/u16/u32/u64 in decimal digits instead of hexadecimal.

To minimize compatibility issue, the arguments without type
casting are typed by x64 (or x32 for 32bit arch) by default.

Note: all arguments set by old perf probe without types are
shown in decimal by default.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naohiro Aota <naohiro.aota@hgst.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/147151076135.12957.14684546093034343894.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-23 17:06:38 -03:00
Masami Hiramatsu
17ce3dc7e5 ftrace: kprobe: uprobe: Add x8/x16/x32/x64 for hexadecimal types
Add x8/x16/x32/x64 for hexadecimal type casting to kprobe/uprobe event
tracer.

These type casts can be used for integer arguments for explicitly
showing them in hexadecimal digits in formatted text.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naohiro Aota <naohiro.aota@hgst.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/147151067029.12957.11591314629326414783.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-23 15:38:09 -03:00
Omar Sandoval
35abb67de7 tracing: expose current->comm to [ku]probe events
ftrace is very quick to give up on saving the task command line (see
`trace_save_cmdline()`). The workaround for events which really care
about the command line is to explicitly assign it as part of the entry.
However, this doesn't work for kprobe events, as there's no
straightforward way to get access to current->comm. Add a kprobe/uprobe
event variable $comm which provides exactly that.

Link: http://lkml.kernel.org/r/f59b472033b943a370f5f48d0af37698f409108f.1465435894.git.osandov@fb.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-06-20 09:54:19 -04:00
Yaowei Bai
f0132c4e0d kernel/trace_probe: is_good_name can be boolean
This patch makes is_good_name return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Link: http://lkml.kernel.org/r/1442929393-4753-2-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-22 13:11:30 -04:00
Steven Rostedt (Red Hat)
2425bcb924 tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structures ftrace_event_call and
ftrace_event_class have nothing to do with the function hooks, and are
really trace_event structures. Rename ftrace_event_* to trace_event_*.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:06:10 -04:00
Steven Rostedt (Red Hat)
7f1d2f8210 tracing: Rename ftrace_event_file to trace_event_file
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structure ftrace_event_file is really
about trace events and not "ftrace". Rename it to trace_event_file.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:05:16 -04:00
Linus Torvalds
eeee78cf77 Some clean ups and small fixes, but the biggest change is the addition
of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.
 
 Tracepoints have helper functions for the TP_printk() called
 __print_symbolic() and __print_flags() that lets a numeric number be
 displayed as a a human comprehensible text. What is placed in the
 TP_printk() is also shown in the tracepoint format file such that
 user space tools like perf and trace-cmd can parse the binary data
 and express the values too. Unfortunately, the way the TRACE_EVENT()
 macro works, anything placed in the TP_printk() will be shown pretty
 much exactly as is. The problem arises when enums are used. That's
 because unlike macros, enums will not be changed into their values
 by the C pre-processor. Thus, the enum string is exported to the
 format file, and this makes it useless for user space tools.
 
 The TRACE_DEFINE_ENUM() solves this by converting the enum strings
 in the TP_printk() format into their number, and that is what is
 shown to user space. For example, the tracepoint tlb_flush currently
 has this in its format file:
 
      __print_symbolic(REC->reason,
         { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
         { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
         { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
         { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })
 
 After adding:
 
      TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
      TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
      TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
      TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);
 
 Its format file will contain this:
 
      __print_symbolic(REC->reason,
         { 0, "flush on task switch" },
         { 1, "remote shootdown" },
         { 2, "local shootdown" },
         { 3, "local mm shootdown" })
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Merge tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Some clean ups and small fixes, but the biggest change is the addition
  of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.

  Tracepoints have helper functions for the TP_printk() called
  __print_symbolic() and __print_flags() that lets a numeric number be
  displayed as a a human comprehensible text.  What is placed in the
  TP_printk() is also shown in the tracepoint format file such that user
  space tools like perf and trace-cmd can parse the binary data and
  express the values too.  Unfortunately, the way the TRACE_EVENT()
  macro works, anything placed in the TP_printk() will be shown pretty
  much exactly as is.  The problem arises when enums are used.  That's
  because unlike macros, enums will not be changed into their values by
  the C pre-processor.  Thus, the enum string is exported to the format
  file, and this makes it useless for user space tools.

  The TRACE_DEFINE_ENUM() solves this by converting the enum strings in
  the TP_printk() format into their number, and that is what is shown to
  user space.  For example, the tracepoint tlb_flush currently has this
  in its format file:

     __print_symbolic(REC->reason,
        { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
        { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
        { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
        { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })

  After adding:

     TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
     TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);

  Its format file will contain this:

     __print_symbolic(REC->reason,
        { 0, "flush on task switch" },
        { 1, "remote shootdown" },
        { 2, "local shootdown" },
        { 3, "local mm shootdown" })"

* tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Add enum_map file to show enums that have been mapped
  writeback: Export enums used by tracepoint to user space
  v4l: Export enums used by tracepoints to user space
  SUNRPC: Export enums in tracepoints to user space
  mm: tracing: Export enums in tracepoints to user space
  irq/tracing: Export enums in tracepoints to user space
  f2fs: Export the enums in the tracepoints to userspace
  net/9p/tracing: Export enums in tracepoints to userspace
  x86/tlb/trace: Export enums in used by tlb_flush tracepoint
  tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
  tracing: Allow for modules to convert their enums to values
  tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values
  tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
  tracing: Give system name a pointer
  brcmsmac: Move each system tracepoints to their own header
  iwlwifi: Move each system tracepoints to their own header
  mac80211: Move message tracepoints to their own header
  tracing: Add TRACE_SYSTEM_VAR to xhci-hcd
  tracing: Add TRACE_SYSTEM_VAR to kvm-s390
  tracing: Add TRACE_SYSTEM_VAR to intel-sst
  ...
2015-04-14 10:49:03 -07:00
Stephen Rothwell
d9a16d3ab8 trace: Don't use __weak in header files
The commit that added a check for this to checkpatch says:

"Using weak declarations can have unintended link defects.  The __weak on
the declaration causes non-weak definitions to become weak."

In this case, when a PowerPC kernel is built with CONFIG_KPROBE_EVENT
but not CONFIG_UPROBE_EVENT, it generates the following warning:

WARNING: 1 bad relocations
c0000000014f2190 R_PPC64_ADDR64    uprobes_fetch_type_table

This is fixed by passing the fetch_table arrays to
traceprobe_parse_probe_arg() which also means that they can never be NULL.

Link: http://lkml.kernel.org/r/20150312165834.4482cb48@canb.auug.org.au

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-03-25 08:57:23 -04:00
Steven Rostedt (Red Hat)
8434dc9340 tracing: Convert the tracing facility over to use tracefs
debugfs was fine for the tracing facility as a quick way to get
an interface. Now that tracing has matured, it should separate itself
from debugfs such that it can be mounted separately without needing
to mount all of debugfs with it. That is, users resist using tracing
because it requires mounting debugfs. Having tracing have its own file
system lets users get the features of tracing without needing to bring
in the rest of the kernel's debug infrastructure.

Another reason for tracefs is that debubfs does not support mkdir.
Currently, to create instances, one does a mkdir in the tracing/instance
directory. This is implemented via a hack that forces debugfs to do
something it is not intended on doing. By converting over to tracefs, this
hack can be removed and mkdir can be properly implemented. This patch does
not address this yet, but it lays the ground work for that to be done.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-03 12:48:41 -05:00
Masami Hiramatsu
3da0f18007 kprobes, ftrace: Use NOKPROBE_SYMBOL macro in ftrace
Use NOKPROBE_SYMBOL macro to protect functions from
kprobes instead of __kprobes annotation in ftrace.
This applies nokprobe_inline annotation for some cases,
because NOKPROBE_SYMBOL() will inhibit inlining by
referring the symbol address.

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/20140417081828.26341.55152.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24 10:26:39 +02:00
zhangwei(Jovi)
70ed91c6ec tracing/uprobes: Support ftrace_event_file base multibuffer
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>
2014-02-20 12:30:09 -05:00
Namhyung Kim
e0d18fe063 tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT
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>
2014-01-03 15:27:18 -05:00
Namhyung Kim
b7e0bf341f tracing/uprobes: Add @+file_offset fetch method
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>
2014-01-02 20:57:05 -05:00
Namhyung Kim
5baaa59ef0 tracing/probes: Implement 'memory' fetch method for uprobes
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>
2014-01-02 16:17:43 -05:00
Namhyung Kim
1301a44e77 tracing/probes: Move 'symbol' fetch method to kprobes
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>
2014-01-02 16:17:41 -05:00
Namhyung Kim
3fd996a295 tracing/probes: Implement 'stack' fetch method for uprobes
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>
2014-01-02 16:17:40 -05:00
Namhyung Kim
34fee3a104 tracing/probes: Split [ku]probes_fetch_type_table
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>
2014-01-02 16:17:39 -05:00
Namhyung Kim
b26c74e116 tracing/probes: Move fetch function helpers to trace_probe.h
Move fetch function helper macros/functions to the header file and
make them external.  This is preparation of supporting uprobe fetch
table in next patch.

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>
2014-01-02 16:17:38 -05:00
Namhyung Kim
5bf652aaf4 tracing/probes: Integrate duplicate set_print_fmt()
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>
2014-01-02 16:17:38 -05:00
Namhyung Kim
2dc1018372 tracing/kprobes: Move common functions to trace_probe.h
The __get_data_size() and store_trace_args() will be used by uprobes
too.  Move them to a common location.

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>
2014-01-02 16:17:37 -05:00
Namhyung Kim
c31ffb3ff6 tracing/kprobes: Factor out struct trace_probe
There are functions that can be shared to both of kprobes and uprobes.
Separate common data structure to struct trace_probe and use it from
the shared functions.

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>
2014-01-02 16:17:29 -05:00
Oleg Nesterov
b64b007797 uprobes/tracing: Introduce is_trace_uprobe_enabled()
probe_event_enable/disable() check tu->consumer != NULL to avoid the
wrong uprobe_register/unregister().

We are going to kill this pointer and "struct uprobe_trace_consumer",
so we add the new helper, is_trace_uprobe_enabled(), which can rely
on TP_FLAG_TRACE/TP_FLAG_PROFILE instead.

Note: the current logic doesn't look optimal, it is not clear why
TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive, we will probably
change this later.

Also kill the unused TP_FLAG_UPROBE.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-02-08 18:24:30 +01:00
Srikar Dronamraju
f3f096cfed tracing: Provide trace events interface for uprobes
Implements trace_event support for uprobes. In its current form
it can be used to put probes at a specified offset in a file and
dump the required registers when the code flow reaches the
probed address.

The following example shows how to dump the instruction pointer
and %ax a register at the probed text address.  Here we are
trying to probe zfree in /bin/zsh:

 # cd /sys/kernel/debug/tracing/
 # cat /proc/`pgrep  zsh`/maps | grep /bin/zsh | grep r-xp
 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh
 # objdump -T /bin/zsh | grep -w zfree
 0000000000446420 g    DF .text  0000000000000012  Base
 zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events
 # cat uprobe_events
 p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420
 # echo 1 > events/uprobes/enable
 # sleep 20
 # echo 0 > events/uprobes/enable
 # cat trace
 # tracer: nop
 #
 #           TASK-PID    CPU#    TIMESTAMP  FUNCTION
 #              | |       |          |         |
              zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
              zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
              zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
              zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-07 14:30:17 +02:00
Srikar Dronamraju
8ab83f5647 tracing: Extract out common code for kprobes/uprobes trace events
Move parts of trace_kprobe.c that can be shared with upcoming
trace_uprobe.c. Common code to kernel/trace/trace_probe.h and
kernel/trace/trace_probe.c. There are no functional changes.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120409091144.8343.76218.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-07 14:29:57 +02:00