linux-stable.git/kernel/trace/ftrace.c, branch v4.4.263 Linux kernel stable tree fgraph: Initialize tracing_graph_pause at task creation 2021-02-23T12:58:12+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2021-01-29T15:13:53+00:00 67776ca342399b60c8abef63e3962c1138bc284d commit 7e0a9220467dbcfdc5bc62825724f3e52e50ab31 upstream. On some archs, the idle task can call into cpu_suspend(). The cpu_suspend() will disable or pause function graph tracing, as there's some paths in bringing down the CPU that can have issues with its return address being modified. The task_struct structure has a "tracing_graph_pause" atomic counter, that when set to something other than zero, the function graph tracer will not modify the return address. The problem is that the tracing_graph_pause counter is initialized when the function graph tracer is enabled. This can corrupt the counter for the idle task if it is suspended in these architectures. CPU 1 CPU 2 ----- ----- do_idle() cpu_suspend() pause_graph_tracing() task_struct->tracing_graph_pause++ (0 -> 1) start_graph_tracing() for_each_online_cpu(cpu) { ftrace_graph_init_idle_task(cpu) task-struct->tracing_graph_pause = 0 (1 -> 0) unpause_graph_tracing() task_struct->tracing_graph_pause-- (0 -> -1) The above should have gone from 1 to zero, and enabled function graph tracing again. But instead, it is set to -1, which keeps it disabled. There's no reason that the field tracing_graph_pause on the task_struct can not be initialized at boot up. Cc: stable@vger.kernel.org Fixes: 380c4b1411ccd ("tracing/function-graph-tracer: append the tracing_graph_flag") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211339 Reported-by: pierre.gondois@arm.com Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7e0a9220467dbcfdc5bc62825724f3e52e50ab31 upstream.

On some archs, the idle task can call into cpu_suspend(). The cpu_suspend()
will disable or pause function graph tracing, as there's some paths in
bringing down the CPU that can have issues with its return address being
modified. The task_struct structure has a "tracing_graph_pause" atomic
counter, that when set to something other than zero, the function graph
tracer will not modify the return address.

The problem is that the tracing_graph_pause counter is initialized when the
function graph tracer is enabled. This can corrupt the counter for the idle
task if it is suspended in these architectures.

   CPU 1				CPU 2
   -----				-----
  do_idle()
    cpu_suspend()
      pause_graph_tracing()
          task_struct->tracing_graph_pause++ (0 -> 1)

				start_graph_tracing()
				  for_each_online_cpu(cpu) {
				    ftrace_graph_init_idle_task(cpu)
				      task-struct->tracing_graph_pause = 0 (1 -> 0)

      unpause_graph_tracing()
          task_struct->tracing_graph_pause-- (0 -> -1)

The above should have gone from 1 to zero, and enabled function graph
tracing again. But instead, it is set to -1, which keeps it disabled.

There's no reason that the field tracing_graph_pause on the task_struct can
not be initialized at boot up.

Cc: stable@vger.kernel.org
Fixes: 380c4b1411ccd ("tracing/function-graph-tracer: append the tracing_graph_flag")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211339
Reported-by: pierre.gondois@arm.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Setup correct FTRACE_FL_REGS flags for module 2020-10-01T09:11:49+00:00 Chengming Zhou zhouchengming@bytedance.com 2020-07-28T18:05:53+00:00 2d81575a4bda48981dec3d51509569fc9ae67044 [ Upstream commit 8a224ffb3f52b0027f6b7279854c71a31c48fc97 ] When module loaded and enabled, we will use __ftrace_replace_code for module if any ftrace_ops referenced it found. But we will get wrong ftrace_addr for module rec in ftrace_get_addr_new, because rec->flags has not been setup correctly. It can cause the callback function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called with pt_regs set to NULL. So setup correct FTRACE_FL_REGS flags for rec when we call referenced_filters to find ftrace_ops references it. Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com Cc: stable@vger.kernel.org Fixes: 8c4f3c3fa9681 ("ftrace: Check module functions being traced on reload") Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8a224ffb3f52b0027f6b7279854c71a31c48fc97 ]

When module loaded and enabled, we will use __ftrace_replace_code
for module if any ftrace_ops referenced it found. But we will get
wrong ftrace_addr for module rec in ftrace_get_addr_new, because
rec->flags has not been setup correctly. It can cause the callback
function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.

Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com

Cc: stable@vger.kernel.org
Fixes: 8c4f3c3fa9681 ("ftrace: Check module functions being traced on reload")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ftrace: Avoid potential division by zero in function profiler 2020-01-12T10:22:43+00:00 Wen Yang wenyang@linux.alibaba.com 2020-01-03T03:02:48+00:00 015f0fd0fcc338513f80044add27fa46cf71d217 commit e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d upstream. The ftrace_profile->counter is unsigned long and do_div truncates it to 32 bits, which means it can test non-zero and be truncated to zero for division. Fix this issue by using div64_ul() instead. Link: http://lkml.kernel.org/r/20200103030248.14516-1-wenyang@linux.alibaba.com Cc: stable@vger.kernel.org Fixes: e330b3bcd8319 ("tracing: Show sample std dev in function profiling") Fixes: 34886c8bc590f ("tracing: add average time in function to function profiler") Signed-off-by: Wen Yang <wenyang@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d upstream.

The ftrace_profile->counter is unsigned long and
do_div truncates it to 32 bits, which means it can test
non-zero and be truncated to zero for division.
Fix this issue by using div64_ul() instead.

Link: http://lkml.kernel.org/r/20200103030248.14516-1-wenyang@linux.alibaba.com

Cc: stable@vger.kernel.org
Fixes: e330b3bcd8319 ("tracing: Show sample std dev in function profiling")
Fixes: 34886c8bc590f ("tracing: add average time in function to function profiler")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kprobes: Mark ftrace mcount handler functions nokprobe 2019-04-27T07:34:02+00:00 Masami Hiramatsu mhiramat@kernel.org 2019-02-23T16:50:20+00:00 abb5b93fe0f54695d6f7ef2f38610835cd12981c commit fabe38ab6b2bd9418350284c63825f13b8a6abba upstream. Mark ftrace mcount handler functions nokprobe since probing on these functions with kretprobe pushes return address incorrectly on kretprobe shadow stack. Reported-by: Francis Deslauriers <francis.deslauriers@efficios.com> Tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fabe38ab6b2bd9418350284c63825f13b8a6abba upstream.

Mark ftrace mcount handler functions nokprobe since
probing on these functions with kretprobe pushes
return address incorrectly on kretprobe shadow stack.

Reported-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing: Fix memory leak of instance function hash filters 2018-12-21T13:09:51+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2018-12-11T04:58:01+00:00 f2e7e67e459394faf1c56f1391c0e6dd4bd9e2f0 commit 2840f84f74035e5a535959d5f17269c69fa6edc5 upstream. The following commands will cause a memory leak: # cd /sys/kernel/tracing # mkdir instances/foo # echo schedule > instance/foo/set_ftrace_filter # rmdir instances/foo The reason is that the hashes that hold the filters to set_ftrace_filter and set_ftrace_notrace are not freed if they contain any data on the instance and the instance is removed. Found by kmemleak detector. Cc: stable@vger.kernel.org Fixes: 591dffdade9f ("ftrace: Allow for function tracing instance to filter functions") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2840f84f74035e5a535959d5f17269c69fa6edc5 upstream.

The following commands will cause a memory leak:

 # cd /sys/kernel/tracing
 # mkdir instances/foo
 # echo schedule > instance/foo/set_ftrace_filter
 # rmdir instances/foo

The reason is that the hashes that hold the filters to set_ftrace_filter and
set_ftrace_notrace are not freed if they contain any data on the instance
and the instance is removed.

Found by kmemleak detector.

Cc: stable@vger.kernel.org
Fixes: 591dffdade9f ("ftrace: Allow for function tracing instance to filter functions")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Remove incorrect setting of glob search field 2018-02-16T19:09:47+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2018-02-06T03:05:31+00:00 a94d7722b39206e96e639cd5cf2cf037c69d5ce8 commit 7b6586562708d2b3a04fe49f217ddbadbbbb0546 upstream. __unregister_ftrace_function_probe() will incorrectly parse the glob filter because it resets the search variable that was setup by filter_parse_regex(). Al Viro reported this: After that call of filter_parse_regex() we could have func_g.search not equal to glob only if glob started with '!' or '*'. In the former case we would've buggered off with -EINVAL (not = 1). In the latter we would've set func_g.search equal to glob + 1, calculated the length of that thing in func_g.len and proceeded to reset func_g.search back to glob. Suppose the glob is e.g. *foo*. We end up with func_g.type = MATCH_MIDDLE_ONLY; func_g.len = 3; func_g.search = "*foo"; Feeding that to ftrace_match_record() will not do anything sane - we will be looking for names containing "*foo" (->len is ignored for that one). Link: http://lkml.kernel.org/r/20180127031706.GE13338@ZenIV.linux.org.uk Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure") Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7b6586562708d2b3a04fe49f217ddbadbbbb0546 upstream.

__unregister_ftrace_function_probe() will incorrectly parse the glob filter
because it resets the search variable that was setup by filter_parse_regex().

Al Viro reported this:

    After that call of filter_parse_regex() we could have func_g.search not
    equal to glob only if glob started with '!' or '*'.  In the former case
    we would've buggered off with -EINVAL (not = 1).  In the latter we
    would've set func_g.search equal to glob + 1, calculated the length of
    that thing in func_g.len and proceeded to reset func_g.search back to
    glob.

    Suppose the glob is e.g. *foo*.  We end up with
	    func_g.type = MATCH_MIDDLE_ONLY;
	    func_g.len = 3;
	    func_g.search = "*foo";
    Feeding that to ftrace_match_record() will not do anything sane - we
    will be looking for names containing "*foo" (->len is ignored for that
    one).

Link: http://lkml.kernel.org/r/20180127031706.GE13338@ZenIV.linux.org.uk

Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure")
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Fix kmemleak in unregister_ftrace_graph 2017-10-12T09:27:33+00:00 Shu Wang shuwang@redhat.com 2017-09-12T02:14:54+00:00 87509592ecc3a31dbfd669bb49d53e33cb6b6304 commit 2b0b8499ae75df91455bbeb7491d45affc384fb0 upstream. The trampoline allocated by function tracer was overwriten by function_graph tracer, and caused a memory leak. The save_global_trampoline should have saved the previous trampoline in register_ftrace_graph() and restored it in unregister_ftrace_graph(). But as it is implemented, save_global_trampoline was only used in unregister_ftrace_graph as default value 0, and it overwrote the previous trampoline's value. Causing the previous allocated trampoline to be lost. kmmeleak backtrace: kmemleak_vmalloc+0x77/0xc0 __vmalloc_node_range+0x1b5/0x2c0 module_alloc+0x7c/0xd0 arch_ftrace_update_trampoline+0xb5/0x290 ftrace_startup+0x78/0x210 register_ftrace_function+0x8b/0xd0 function_trace_init+0x4f/0x80 tracing_set_tracer+0xe6/0x170 tracing_set_trace_write+0x90/0xd0 __vfs_write+0x37/0x170 vfs_write+0xb2/0x1b0 SyS_write+0x55/0xc0 do_syscall_64+0x67/0x180 return_from_SYSCALL_64+0x0/0x6a [ Looking further into this, I found that this was left over from when the function and function graph tracers shared the same ftrace_ops. But in commit 5f151b2401 ("ftrace: Fix function_profiler and function tracer together"), the two were separated, and the save_global_trampoline no longer was necessary (and it may have been broken back then too). -- Steven Rostedt ] Link: http://lkml.kernel.org/r/20170912021454.5976-1-shuwang@redhat.com Fixes: 5f151b2401 ("ftrace: Fix function_profiler and function tracer together") Signed-off-by: Shu Wang <shuwang@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2b0b8499ae75df91455bbeb7491d45affc384fb0 upstream.

The trampoline allocated by function tracer was overwriten by function_graph
tracer, and caused a memory leak. The save_global_trampoline should have
saved the previous trampoline in register_ftrace_graph() and restored it in
unregister_ftrace_graph(). But as it is implemented, save_global_trampoline was
only used in unregister_ftrace_graph as default value 0, and it overwrote the
previous trampoline's value. Causing the previous allocated trampoline to be
lost.

kmmeleak backtrace:
    kmemleak_vmalloc+0x77/0xc0
    __vmalloc_node_range+0x1b5/0x2c0
    module_alloc+0x7c/0xd0
    arch_ftrace_update_trampoline+0xb5/0x290
    ftrace_startup+0x78/0x210
    register_ftrace_function+0x8b/0xd0
    function_trace_init+0x4f/0x80
    tracing_set_tracer+0xe6/0x170
    tracing_set_trace_write+0x90/0xd0
    __vfs_write+0x37/0x170
    vfs_write+0xb2/0x1b0
    SyS_write+0x55/0xc0
    do_syscall_64+0x67/0x180
    return_from_SYSCALL_64+0x0/0x6a

[
  Looking further into this, I found that this was left over from when the
  function and function graph tracers shared the same ftrace_ops. But in
  commit 5f151b2401 ("ftrace: Fix function_profiler and function tracer
  together"), the two were separated, and the save_global_trampoline no
  longer was necessary (and it may have been broken back then too).
  -- Steven Rostedt
]

Link: http://lkml.kernel.org/r/20170912021454.5976-1-shuwang@redhat.com

Fixes: 5f151b2401 ("ftrace: Fix function_profiler and function tracer together")
Signed-off-by: Shu Wang <shuwang@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Fix memleak when unregistering dynamic ops when tracing disabled 2017-09-27T09:00:17+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2017-09-01T16:18:28+00:00 ed1bf4397d2219d4b9ec2d5517416ba102186650 commit edb096e00724f02db5f6ec7900f3bbd465c6c76f upstream. If function tracing is disabled by the user via the function-trace option or the proc sysctl file, and a ftrace_ops that was allocated on the heap is unregistered, then the shutdown code exits out without doing the proper clean up. This was found via kmemleak and running the ftrace selftests, as one of the tests unregisters with function tracing disabled. # cat kmemleak unreferenced object 0xffffffffa0020000 (size 4096): comm "swapper/0", pid 1, jiffies 4294668889 (age 569.209s) hex dump (first 32 bytes): 55 ff 74 24 10 55 48 89 e5 ff 74 24 18 55 48 89 U.t$.UH...t$.UH. e5 48 81 ec a8 00 00 00 48 89 44 24 50 48 89 4c .H......H.D$PH.L backtrace: [<ffffffff81d64665>] kmemleak_vmalloc+0x85/0xf0 [<ffffffff81355631>] __vmalloc_node_range+0x281/0x3e0 [<ffffffff8109697f>] module_alloc+0x4f/0x90 [<ffffffff81091170>] arch_ftrace_update_trampoline+0x160/0x420 [<ffffffff81249947>] ftrace_startup+0xe7/0x300 [<ffffffff81249bd2>] register_ftrace_function+0x72/0x90 [<ffffffff81263786>] trace_selftest_ops+0x204/0x397 [<ffffffff82bb8971>] trace_selftest_startup_function+0x394/0x624 [<ffffffff81263a75>] run_tracer_selftest+0x15c/0x1d7 [<ffffffff82bb83f1>] init_trace_selftests+0x75/0x192 [<ffffffff81002230>] do_one_initcall+0x90/0x1e2 [<ffffffff82b7d620>] kernel_init_freeable+0x350/0x3fe [<ffffffff81d61ec3>] kernel_init+0x13/0x122 [<ffffffff81d72c6a>] ret_from_fork+0x2a/0x40 [<ffffffffffffffff>] 0xffffffffffffffff Fixes: 12cce594fa ("ftrace/x86: Allow !CONFIG_PREEMPT dynamic ops to use allocated trampolines") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit edb096e00724f02db5f6ec7900f3bbd465c6c76f upstream.

If function tracing is disabled by the user via the function-trace option or
the proc sysctl file, and a ftrace_ops that was allocated on the heap is
unregistered, then the shutdown code exits out without doing the proper
clean up. This was found via kmemleak and running the ftrace selftests, as
one of the tests unregisters with function tracing disabled.

 # cat kmemleak
unreferenced object 0xffffffffa0020000 (size 4096):
  comm "swapper/0", pid 1, jiffies 4294668889 (age 569.209s)
  hex dump (first 32 bytes):
    55 ff 74 24 10 55 48 89 e5 ff 74 24 18 55 48 89  U.t$.UH...t$.UH.
    e5 48 81 ec a8 00 00 00 48 89 44 24 50 48 89 4c  .H......H.D$PH.L
  backtrace:
    [<ffffffff81d64665>] kmemleak_vmalloc+0x85/0xf0
    [<ffffffff81355631>] __vmalloc_node_range+0x281/0x3e0
    [<ffffffff8109697f>] module_alloc+0x4f/0x90
    [<ffffffff81091170>] arch_ftrace_update_trampoline+0x160/0x420
    [<ffffffff81249947>] ftrace_startup+0xe7/0x300
    [<ffffffff81249bd2>] register_ftrace_function+0x72/0x90
    [<ffffffff81263786>] trace_selftest_ops+0x204/0x397
    [<ffffffff82bb8971>] trace_selftest_startup_function+0x394/0x624
    [<ffffffff81263a75>] run_tracer_selftest+0x15c/0x1d7
    [<ffffffff82bb83f1>] init_trace_selftests+0x75/0x192
    [<ffffffff81002230>] do_one_initcall+0x90/0x1e2
    [<ffffffff82b7d620>] kernel_init_freeable+0x350/0x3fe
    [<ffffffff81d61ec3>] kernel_init+0x13/0x122
    [<ffffffff81d72c6a>] ret_from_fork+0x2a/0x40
    [<ffffffffffffffff>] 0xffffffffffffffff

Fixes: 12cce594fa ("ftrace/x86: Allow !CONFIG_PREEMPT dynamic ops to use allocated trampolines")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Fix uninitialized variable in match_records() 2017-07-27T22:06:07+00:00 Dan Carpenter dan.carpenter@oracle.com 2017-07-12T07:35:57+00:00 75202d3ffca4dddfb2be9b6f8071c605335ad424 commit 2e028c4fe12907f226b8221815f16c2486ad3aa7 upstream. My static checker complains that if "func" is NULL then "clear_filter" is uninitialized. This seems like it could be true, although it's possible something subtle is happening that I haven't seen. kernel/trace/ftrace.c:3844 match_records() error: uninitialized symbol 'clear_filter'. Link: http://lkml.kernel.org/r/20170712073556.h6tkpjcdzjaozozs@mwanda Fixes: f0a3b154bd7 ("ftrace: Clarify code for mod command") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2e028c4fe12907f226b8221815f16c2486ad3aa7 upstream.

My static checker complains that if "func" is NULL then "clear_filter"
is uninitialized.  This seems like it could be true, although it's
possible something subtle is happening that I haven't seen.

    kernel/trace/ftrace.c:3844 match_records()
    error: uninitialized symbol 'clear_filter'.

Link: http://lkml.kernel.org/r/20170712073556.h6tkpjcdzjaozozs@mwanda

Fixes: f0a3b154bd7 ("ftrace: Clarify code for mod command")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Fix removing of second function probe 2017-04-21T07:30:06+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2017-04-14T21:45:45+00:00 7fe57118a7c002c59e4087806f8f5a9f4a0b037f commit 82cc4fc2e70ec5baeff8f776f2773abc8b2cc0ae upstream. When two function probes are added to set_ftrace_filter, and then one of them is removed, the update to the function locations is not performed, and the record keeping of the function states are corrupted, and causes an ftrace_bug() to occur. This is easily reproducable by adding two probes, removing one, and then adding it back again. # cd /sys/kernel/debug/tracing # echo schedule:traceoff > set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter Causes: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220 Modules linked in: [...] CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 Call Trace: dump_stack+0x68/0x9f __warn+0x111/0x130 ? trace_irq_work_interrupt+0xa0/0xa0 warn_slowpath_null+0x1d/0x20 ftrace_get_addr_curr+0x143/0x220 ? __fentry__+0x10/0x10 ftrace_replace_code+0xe3/0x4f0 ? ftrace_int3_handler+0x90/0x90 ? printk+0x99/0xb5 ? 0xffffffff81000000 ftrace_modify_all_code+0x97/0x110 arch_ftrace_update_code+0x10/0x20 ftrace_run_update_code+0x1c/0x60 ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0 register_ftrace_function_probe+0x4b6/0x590 ? ftrace_startup+0x310/0x310 ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30 ? update_stack_state+0x88/0x110 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? preempt_count_sub+0x18/0xd0 ? mutex_lock_nested+0x104/0x800 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? __unwind_start+0x1c0/0x1c0 ? _mutex_lock_nest_lock+0x800/0x800 ftrace_trace_probe_callback.isra.3+0xc0/0x130 ? func_set_flag+0xe0/0xe0 ? __lock_acquire+0x642/0x1790 ? __might_fault+0x1e/0x20 ? trace_get_user+0x398/0x470 ? strcmp+0x35/0x60 ftrace_trace_onoff_callback+0x48/0x70 ftrace_regex_write.isra.43.part.44+0x251/0x320 ? match_records+0x420/0x420 ftrace_filter_write+0x2b/0x30 __vfs_write+0xd7/0x330 ? do_loop_readv_writev+0x120/0x120 ? locks_remove_posix+0x90/0x2f0 ? do_lock_file_wait+0x160/0x160 ? __lock_is_held+0x93/0x100 ? rcu_read_lock_sched_held+0x5c/0xb0 ? preempt_count_sub+0x18/0xd0 ? __sb_start_write+0x10a/0x230 ? vfs_write+0x222/0x240 vfs_write+0xef/0x240 SyS_write+0xab/0x130 ? SyS_read+0x130/0x130 ? trace_hardirqs_on_caller+0x182/0x280 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7fe61c157c30 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c ? trace_hardirqs_off_caller+0xc0/0x110 ---[ end trace 99fa09b3d9869c2c ]--- Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150) Fixes: 59df055f1991 ("ftrace: trace different functions with a different tracer") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 82cc4fc2e70ec5baeff8f776f2773abc8b2cc0ae upstream.

When two function probes are added to set_ftrace_filter, and then one of
them is removed, the update to the function locations is not performed, and
the record keeping of the function states are corrupted, and causes an
ftrace_bug() to occur.

This is easily reproducable by adding two probes, removing one, and then
adding it back again.

 # cd /sys/kernel/debug/tracing
 # echo schedule:traceoff > set_ftrace_filter
 # echo do_IRQ:traceoff > set_ftrace_filter
 # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter
 # echo do_IRQ:traceoff > set_ftrace_filter

Causes:
 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220
 Modules linked in: [...]
 CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
 Call Trace:
  dump_stack+0x68/0x9f
  __warn+0x111/0x130
  ? trace_irq_work_interrupt+0xa0/0xa0
  warn_slowpath_null+0x1d/0x20
  ftrace_get_addr_curr+0x143/0x220
  ? __fentry__+0x10/0x10
  ftrace_replace_code+0xe3/0x4f0
  ? ftrace_int3_handler+0x90/0x90
  ? printk+0x99/0xb5
  ? 0xffffffff81000000
  ftrace_modify_all_code+0x97/0x110
  arch_ftrace_update_code+0x10/0x20
  ftrace_run_update_code+0x1c/0x60
  ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0
  register_ftrace_function_probe+0x4b6/0x590
  ? ftrace_startup+0x310/0x310
  ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30
  ? update_stack_state+0x88/0x110
  ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320
  ? preempt_count_sub+0x18/0xd0
  ? mutex_lock_nested+0x104/0x800
  ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320
  ? __unwind_start+0x1c0/0x1c0
  ? _mutex_lock_nest_lock+0x800/0x800
  ftrace_trace_probe_callback.isra.3+0xc0/0x130
  ? func_set_flag+0xe0/0xe0
  ? __lock_acquire+0x642/0x1790
  ? __might_fault+0x1e/0x20
  ? trace_get_user+0x398/0x470
  ? strcmp+0x35/0x60
  ftrace_trace_onoff_callback+0x48/0x70
  ftrace_regex_write.isra.43.part.44+0x251/0x320
  ? match_records+0x420/0x420
  ftrace_filter_write+0x2b/0x30
  __vfs_write+0xd7/0x330
  ? do_loop_readv_writev+0x120/0x120
  ? locks_remove_posix+0x90/0x2f0
  ? do_lock_file_wait+0x160/0x160
  ? __lock_is_held+0x93/0x100
  ? rcu_read_lock_sched_held+0x5c/0xb0
  ? preempt_count_sub+0x18/0xd0
  ? __sb_start_write+0x10a/0x230
  ? vfs_write+0x222/0x240
  vfs_write+0xef/0x240
  SyS_write+0xab/0x130
  ? SyS_read+0x130/0x130
  ? trace_hardirqs_on_caller+0x182/0x280
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL_64_fastpath+0x18/0xad
 RIP: 0033:0x7fe61c157c30
 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30
 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001
 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400
 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c
  ? trace_hardirqs_off_caller+0xc0/0x110
 ---[ end trace 99fa09b3d9869c2c ]---
 Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150)

Fixes: 59df055f1991 ("ftrace: trace different functions with a different tracer")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>