linux-toradex.git/kernel/trace, branch v3.12.7

ftrace: Initialize the ftrace profiler for each possible cpu

2014-01-09T20:25:09+00:00

commit c4602c1c818bd6626178d6d3fcc152d9f2f48ac0 upstream.

Ftrace currently initializes only the online CPUs. This implementation has
two problems:
- If we online a CPU after we enable the function profile, and then run the
  test, we will lose the trace information on that CPU.
  Steps to reproduce:
  # echo 0 > /sys/devices/system/cpu/cpu1/online
  # cd /tracing/
  # echo  >> set_ftrace_filter
  # echo 1 > function_profile_enabled
  # echo 1 > /sys/devices/system/cpu/cpu1/online
  # run test
- If we offline a CPU before we enable the function profile, we will not clear
  the trace information when we enable the function profile. It will trouble
  the users.
  Steps to reproduce:
  # cd /tracing/
  # echo  >> set_ftrace_filter
  # echo 1 > function_profile_enabled
  # run test
  # cat trace_stat/function*
  # echo 0 > /sys/devices/system/cpu/cpu1/online
  # echo 0 > function_profile_enabled
  # echo 1 > function_profile_enabled
  # cat trace_stat/function*
  # run test
  # cat trace_stat/function*

So it is better that we initialize the ftrace profiler for each possible cpu
every time we enable the function profile instead of just the online ones.

Link: http://lkml.kernel.org/r/1387178401-10619-1-git-send-email-miaox@cn.fujitsu.com

Signed-off-by: Miao Xie 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

ftrace: Fix function graph with loading of modules

2013-12-04T19:05:41+00:00

commit 8a56d7761d2d041ae5e8215d20b4167d8aa93f51 upstream.

Commit 8c4f3c3fa9681 "ftrace: Check module functions being traced on reload"
fixed module loading and unloading with respect to function tracing, but
it missed the function graph tracer. If you perform the following

 # cd /sys/kernel/debug/tracing
 # echo function_graph > current_tracer
 # modprobe nfsd
 # echo nop > current_tracer

You'll get the following oops message:

 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 2910 at /linux.git/kernel/trace/ftrace.c:1640 __ftrace_hash_rec_update.part.35+0x168/0x1b9()
 Modules linked in: nfsd exportfs nfs_acl lockd ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables uinput snd_hda_codec_idt
 CPU: 2 PID: 2910 Comm: bash Not tainted 3.13.0-rc1-test #7
 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
  0000000000000668 ffff8800787efcf8 ffffffff814fe193 ffff88007d500000
  0000000000000000 ffff8800787efd38 ffffffff8103b80a 0000000000000668
  ffffffff810b2b9a ffffffff81a48370 0000000000000001 ffff880037aea000
 Call Trace:
  [] dump_stack+0x4f/0x7c
  [] warn_slowpath_common+0x81/0x9b
  [] ? __ftrace_hash_rec_update.part.35+0x168/0x1b9
  [] warn_slowpath_null+0x1a/0x1c
  [] __ftrace_hash_rec_update.part.35+0x168/0x1b9
  [] ? __mutex_lock_slowpath+0x364/0x364
  [] ftrace_shutdown+0xd7/0x12b
  [] unregister_ftrace_graph+0x49/0x78
  [] graph_trace_reset+0xe/0x10
  [] tracing_set_tracer+0xa7/0x26a
  [] tracing_set_trace_write+0x8b/0xbd
  [] ? ftrace_return_to_handler+0xb2/0xde
  [] ? __sb_end_write+0x5e/0x5e
  [] vfs_write+0xab/0xf6
  [] ftrace_graph_caller+0x85/0x85
  [] SyS_write+0x59/0x82
  [] ftrace_graph_caller+0x85/0x85
  [] system_call_fastpath+0x16/0x1b
 ---[ end trace 940358030751eafb ]---

The above mentioned commit didn't go far enough. Well, it covered the
function tracer by adding checks in __register_ftrace_function(). The
problem is that the function graph tracer circumvents that (for a slight
efficiency gain when function graph trace is running with a function
tracer. The gain was not worth this).

The problem came with ftrace_startup() which should always be called after
__register_ftrace_function(), if you want this bug to be completely fixed.

Anyway, this solution moves __register_ftrace_function() inside of
ftrace_startup() and removes the need to call them both.

Reported-by: Dave Wysochanski 
Fixes: ed926f9b35cd ("ftrace: Use counters to enable functions to trace")
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

perf/ftrace: Fix paranoid level for enabling function tracer

2013-11-29T19:27:55+00:00

commit 12ae030d54ef250706da5642fc7697cc60ad0df7 upstream.

The current default perf paranoid level is "1" which has
"perf_paranoid_kernel()" return false, and giving any operations that
use it, access to normal users. Unfortunately, this includes function
tracing and normal users should not be allowed to enable function
tracing by default.

The proper level is defined at "-1" (full perf access), which
"perf_paranoid_tracepoint_raw()" will only give access to. Use that
check instead for enabling function tracing.

Reported-by: Dave Jones 
Reported-by: Vince Weaver 
Tested-by: Vince Weaver 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Frederic Weisbecker 
CVE: CVE-2013-2930
Fixes: ced39002f5ea ("ftrace, perf: Add support to use function tracepoint in perf")
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix potential out-of-bounds in trace_get_user()

2013-11-20T20:37:36+00:00

commit 057db8488b53d5e4faa0cedb2f39d4ae75dfbdbb upstream.

Andrey reported the following report:

ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3
ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3)
Accessed by thread T13003:
  #0 ffffffff810dd2da (asan_report_error+0x32a/0x440)
  #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40)
  #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20)
  #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260)
  #4 ffffffff812a1065 (__fput+0x155/0x360)
  #5 ffffffff812a12de (____fput+0x1e/0x30)
  #6 ffffffff8111708d (task_work_run+0x10d/0x140)
  #7 ffffffff810ea043 (do_exit+0x433/0x11f0)
  #8 ffffffff810eaee4 (do_group_exit+0x84/0x130)
  #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30)
  #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Allocated by thread T5167:
  #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0)
  #1 ffffffff8128337c (__kmalloc+0xbc/0x500)
  #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90)
  #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0)
  #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40)
  #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430)
  #6 ffffffff8129b668 (finish_open+0x68/0xa0)
  #7 ffffffff812b66ac (do_last+0xb8c/0x1710)
  #8 ffffffff812b7350 (path_openat+0x120/0xb50)
  #9 ffffffff812b8884 (do_filp_open+0x54/0xb0)
  #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0)
  #11 ffffffff8129d4b7 (SyS_open+0x37/0x50)
  #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b)

Shadow bytes around the buggy address:
  ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa
  ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb
  ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
  ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap redzone:          fa
  Heap kmalloc redzone:  fb
  Freed heap region:     fd
  Shadow gap:            fe

The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;'

Although the crash happened in ftrace_regex_open() the real bug
occurred in trace_get_user() where there's an incrementation to
parser->idx without a check against the size. The way it is triggered
is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop
that reads the last character stores it and then breaks out because
there is no more characters. Then the last character is read to determine
what to do next, and the index is incremented without checking size.

Then the caller of trace_get_user() usually nulls out the last character
with a zero, but since the index is equal to the size, it writes a nul
character after the allocated space, which can corrupt memory.

Luckily, only root user has write access to this file.

Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home

Reported-by: Andrey Konovalov 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-09-09T21:42:15+00:00

Pull tracing updates from Steven Rostedt:
 "Not much changes for the 3.12 merge window.  The major tracing changes
  are still in flux, and will have to wait for 3.13.

  The changes for 3.12 are mostly clean ups and minor fixes.

  H Peter Anvin added a check to x86_32 static function tracing that
  helps a small segment of the kernel community.

  Oleg Nesterov had a few changes from 3.11, but were mostly clean ups
  and not worth pushing in the -rc time frame.

  Li Zefan had small clean up with annotating a raw_init with __init.

  I fixed a slight race in updating function callbacks, but the race is
  so small and the bug that happens when it occurs is so minor it's not
  even worth pushing to stable.

  The only real enhancement is from Alexander Z Lam that made the
  tracing_cpumask work for trace buffer instances, instead of them all
  sharing a global cpumask"

* tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/rcu: Do not trace debug_lockdep_rcu_enabled()
  x86-32, ftrace: Fix static ftrace when early microcode is enabled
  ftrace: Fix a slight race in modifying what function callback gets traced
  tracing: Make tracing_cpumask available for all instances
  tracing: Kill the !CONFIG_MODULES code in trace_events.c
  tracing: Don't pass file_operations array to event_create_dir()
  tracing: Kill trace_create_file_ops() and friends
  tracing/syscalls: Annotate raw_init function with __init

ftrace: Fix a slight race in modifying what function callback gets traced

2013-09-03T23:36:26+00:00

There's a slight race when going from a list function to a non list
function. That is, when only one callback is registered to the function
tracer, it gets called directly by the mcount trampoline. But if this
function has filters, it may be called by the wrong functions.

As the list ops callback that handles multiple callbacks that are
registered to ftrace, it also handles what functions they call. While
the transaction is taking place, use the list function always, and
after all the updates are finished (only the functions that should be
traced are being traced), then we can update the trampoline to call
the function directly.

Signed-off-by: Steven Rostedt

Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2013-09-03T05:41:11+00:00

Pull RCU updates from Paul E. McKenney:

"
 * Update RCU documentation.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/611.

 * Miscellaneous fixes.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/619.

 * Full-system idle detection.  This is for use by Frederic
   Weisbecker's adaptive-ticks mechanism.  Its purpose is
   to allow the timekeeping CPU to shut off its tick when
   all other CPUs are idle.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/648.

 * Improve rcutorture test coverage.  These were posted to LKML at
   https://lkml.org/lkml/2013/8/19/675.
"

Signed-off-by: Ingo Molnar

tracing: Make tracing_cpumask available for all instances

2013-08-22T16:45:24+00:00

Allow tracer instances to disable tracing by cpu by moving
the static global tracing_cpumask into trace_array.

Link: http://lkml.kernel.org/r/921622317f239bfc2283cac2242647801ef584f2.1375980149.git.azl@google.com

Cc: Vaibhav Nagarnaik 
Cc: David Sharp 
Cc: Alexander Z Lam 
Signed-off-by: Alexander Z Lam 
Signed-off-by: Steven Rostedt

tracing: Kill the !CONFIG_MODULES code in trace_events.c

2013-08-22T03:28:03+00:00

Move trace_module_nb under CONFIG_MODULES and kill the dummy
trace_module_notify(). Imho it doesn't make sense to define
"struct notifier_block" and its .notifier_call just to avoid
"ifdef" in event_trace_init(), and all other !CONFIG_MODULES
code has already gone away.

Link: http://lkml.kernel.org/r/20130731173137.GA31043@redhat.com

Signed-off-by: Oleg Nesterov 
Signed-off-by: Steven Rostedt

tracing: Don't pass file_operations array to event_create_dir()

2013-08-22T03:25:06+00:00

Now that event_create_dir() and __trace_add_new_event() always
use the same file_operations we can kill these arguments and
simplify the code.

Link: http://lkml.kernel.org/r/20130731173135.GA31040@redhat.com

Signed-off-by: Oleg Nesterov 
Signed-off-by: Steven Rostedt