<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/kernel/trace/trace_event_perf.c, branch v5.10.258</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>trace/trace_event_perf: remove duplicate samples on the first tracepoint event</title>
<updated>2024-12-14T18:47:57+00:00</updated>
<author>
<name>Levi Yun</name>
<email>yeoreum.yun@arm.com</email>
</author>
<published>2024-09-13T02:13:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=62a8d90e32212b2fb0fa1aa9b0acc17291e862d6'/>
<id>62a8d90e32212b2fb0fa1aa9b0acc17291e862d6</id>
<content type='text'>
[ Upstream commit afe5960dc208fe069ddaaeb0994d857b24ac19d1 ]

When a tracepoint event is created with attr.freq = 1,
'hwc-&gt;period_left' is not initialized correctly. As a result,
in the perf_swevent_overflow() function, when the first time the event occurs,
it calculates the event overflow and the perf_swevent_set_period() returns 3,
this leads to the event are recorded for three duplicate times.

Step to reproduce:
    1. Enable the tracepoint event &amp; starting tracing
         $ echo 1 &gt; /sys/kernel/tracing/events/module/module_free
         $ echo 1 &gt; /sys/kernel/tracing/tracing_on

    2. Record with perf
         $ perf record -a --strict-freq -F 1 -e "module:module_free"

    3. Trigger module_free event.
         $ modprobe -i sunrpc
         $ modprobe -r sunrpc

Result:
     - Trace pipe result:
         $ cat trace_pipe
         modprobe-174509  [003] .....  6504.868896: module_free: sunrpc

     - perf sample:
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc

By setting period_left via perf_swevent_set_period() as other sw_event did,
This problem could be solved.

After patch:
     - Trace pipe result:
         $ cat trace_pipe
         modprobe 1153096 [068] 613468.867774: module:module_free: xfs

     - perf sample
         modprobe 1153096 [068] 613468.867794: module:module_free: xfs

Link: https://lore.kernel.org/20240913021347.595330-1-yeoreum.yun@arm.com
Fixes: bd2b5b12849a ("perf_counter: More aggressive frequency adjustment")
Signed-off-by: Levi Yun &lt;yeoreum.yun@arm.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit afe5960dc208fe069ddaaeb0994d857b24ac19d1 ]

When a tracepoint event is created with attr.freq = 1,
'hwc-&gt;period_left' is not initialized correctly. As a result,
in the perf_swevent_overflow() function, when the first time the event occurs,
it calculates the event overflow and the perf_swevent_set_period() returns 3,
this leads to the event are recorded for three duplicate times.

Step to reproduce:
    1. Enable the tracepoint event &amp; starting tracing
         $ echo 1 &gt; /sys/kernel/tracing/events/module/module_free
         $ echo 1 &gt; /sys/kernel/tracing/tracing_on

    2. Record with perf
         $ perf record -a --strict-freq -F 1 -e "module:module_free"

    3. Trigger module_free event.
         $ modprobe -i sunrpc
         $ modprobe -r sunrpc

Result:
     - Trace pipe result:
         $ cat trace_pipe
         modprobe-174509  [003] .....  6504.868896: module_free: sunrpc

     - perf sample:
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc

By setting period_left via perf_swevent_set_period() as other sw_event did,
This problem could be solved.

After patch:
     - Trace pipe result:
         $ cat trace_pipe
         modprobe 1153096 [068] 613468.867774: module:module_free: xfs

     - perf sample
         modprobe 1153096 [068] 613468.867794: module:module_free: xfs

Link: https://lore.kernel.org/20240913021347.595330-1-yeoreum.yun@arm.com
Fixes: bd2b5b12849a ("perf_counter: More aggressive frequency adjustment")
Signed-off-by: Levi Yun &lt;yeoreum.yun@arm.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Show size of requested perf buffer</title>
<updated>2024-05-02T14:23:43+00:00</updated>
<author>
<name>Robin H. Johnson</name>
<email>robbat2@gentoo.org</email>
</author>
<published>2021-08-31T04:37:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ffbeb5d4f9df43950f438fa6311c7893d51d96f8'/>
<id>ffbeb5d4f9df43950f438fa6311c7893d51d96f8</id>
<content type='text'>
commit a90afe8d020da9298c98fddb19b7a6372e2feb45 upstream.

If the perf buffer isn't large enough, provide a hint about how large it
needs to be for whatever is running.

Link: https://lkml.kernel.org/r/20210831043723.13481-1-robbat2@gentoo.org

Signed-off-by: Robin H. Johnson &lt;robbat2@gentoo.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Thadeu Lima de Souza Cascardo &lt;cascardo@igalia.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a90afe8d020da9298c98fddb19b7a6372e2feb45 upstream.

If the perf buffer isn't large enough, provide a hint about how large it
needs to be for whatever is running.

Link: https://lkml.kernel.org/r/20210831043723.13481-1-robbat2@gentoo.org

Signed-off-by: Robin H. Johnson &lt;robbat2@gentoo.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Thadeu Lima de Souza Cascardo &lt;cascardo@igalia.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'perf/urgent' into perf/core, to pick up fixes</title>
<updated>2019-10-28T11:38:26+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2019-10-28T11:38:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=65133033ee6ee34724ea3d82d5d1cfc6839ffdae'/>
<id>65133033ee6ee34724ea3d82d5d1cfc6839ffdae</id>
<content type='text'>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Fix race in perf_trace_buf initialization</title>
<updated>2019-10-21T23:38:28+00:00</updated>
<author>
<name>Prateek Sood</name>
<email>prsood@codeaurora.org</email>
</author>
<published>2019-10-15T06:17:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=6b1340cc00edeadd52ebd8a45171f38c8de2a387'/>
<id>6b1340cc00edeadd52ebd8a45171f38c8de2a387</id>
<content type='text'>
A race condition exists while initialiazing perf_trace_buf from
perf_trace_init() and perf_kprobe_init().

      CPU0                                        CPU1
perf_trace_init()
  mutex_lock(&amp;event_mutex)
    perf_trace_event_init()
      perf_trace_event_reg()
        total_ref_count == 0
	buf = alloc_percpu()
        perf_trace_buf[i] = buf
        tp_event-&gt;class-&gt;reg() //fails       perf_kprobe_init()
	goto fail                              perf_trace_event_init()
                                                 perf_trace_event_reg()
        fail:
	  total_ref_count == 0

                                                   total_ref_count == 0
                                                   buf = alloc_percpu()
                                                   perf_trace_buf[i] = buf
                                                   tp_event-&gt;class-&gt;reg()
                                                   total_ref_count++

          free_percpu(perf_trace_buf[i])
          perf_trace_buf[i] = NULL

Any subsequent call to perf_trace_event_reg() will observe total_ref_count &gt; 0,
causing the perf_trace_buf to be always NULL. This can result in perf_trace_buf
getting accessed from perf_trace_buf_alloc() without being initialized. Acquiring
event_mutex in perf_kprobe_init() before calling perf_trace_event_init() should
fix this race.

The race caused the following bug:

 Unable to handle kernel paging request at virtual address 0000003106f2003c
 Mem abort info:
   ESR = 0x96000045
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000045
   CM = 0, WnR = 1
 user pgtable: 4k pages, 39-bit VAs, pgdp = ffffffc034b9b000
 [0000003106f2003c] pgd=0000000000000000, pud=0000000000000000
 Internal error: Oops: 96000045 [#1] PREEMPT SMP
 Process syz-executor (pid: 18393, stack limit = 0xffffffc093190000)
 pstate: 80400005 (Nzcv daif +PAN -UAO)
 pc : __memset+0x20/0x1ac
 lr : memset+0x3c/0x50
 sp : ffffffc09319fc50

  __memset+0x20/0x1ac
  perf_trace_buf_alloc+0x140/0x1a0
  perf_trace_sys_enter+0x158/0x310
  syscall_trace_enter+0x348/0x7c0
  el0_svc_common+0x11c/0x368
  el0_svc_handler+0x12c/0x198
  el0_svc+0x8/0xc

Ramdumps showed the following:
  total_ref_count = 3
  perf_trace_buf = (
      0x0 -&gt; NULL,
      0x0 -&gt; NULL,
      0x0 -&gt; NULL,
      0x0 -&gt; NULL)

Link: http://lkml.kernel.org/r/1571120245-4186-1-git-send-email-prsood@codeaurora.org

Cc: stable@vger.kernel.org
Fixes: e12f03d7031a9 ("perf/core: Implement the 'perf_kprobe' PMU")
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Prateek Sood &lt;prsood@codeaurora.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A race condition exists while initialiazing perf_trace_buf from
perf_trace_init() and perf_kprobe_init().

      CPU0                                        CPU1
perf_trace_init()
  mutex_lock(&amp;event_mutex)
    perf_trace_event_init()
      perf_trace_event_reg()
        total_ref_count == 0
	buf = alloc_percpu()
        perf_trace_buf[i] = buf
        tp_event-&gt;class-&gt;reg() //fails       perf_kprobe_init()
	goto fail                              perf_trace_event_init()
                                                 perf_trace_event_reg()
        fail:
	  total_ref_count == 0

                                                   total_ref_count == 0
                                                   buf = alloc_percpu()
                                                   perf_trace_buf[i] = buf
                                                   tp_event-&gt;class-&gt;reg()
                                                   total_ref_count++

          free_percpu(perf_trace_buf[i])
          perf_trace_buf[i] = NULL

Any subsequent call to perf_trace_event_reg() will observe total_ref_count &gt; 0,
causing the perf_trace_buf to be always NULL. This can result in perf_trace_buf
getting accessed from perf_trace_buf_alloc() without being initialized. Acquiring
event_mutex in perf_kprobe_init() before calling perf_trace_event_init() should
fix this race.

The race caused the following bug:

 Unable to handle kernel paging request at virtual address 0000003106f2003c
 Mem abort info:
   ESR = 0x96000045
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000045
   CM = 0, WnR = 1
 user pgtable: 4k pages, 39-bit VAs, pgdp = ffffffc034b9b000
 [0000003106f2003c] pgd=0000000000000000, pud=0000000000000000
 Internal error: Oops: 96000045 [#1] PREEMPT SMP
 Process syz-executor (pid: 18393, stack limit = 0xffffffc093190000)
 pstate: 80400005 (Nzcv daif +PAN -UAO)
 pc : __memset+0x20/0x1ac
 lr : memset+0x3c/0x50
 sp : ffffffc09319fc50

  __memset+0x20/0x1ac
  perf_trace_buf_alloc+0x140/0x1a0
  perf_trace_sys_enter+0x158/0x310
  syscall_trace_enter+0x348/0x7c0
  el0_svc_common+0x11c/0x368
  el0_svc_handler+0x12c/0x198
  el0_svc+0x8/0xc

Ramdumps showed the following:
  total_ref_count = 3
  perf_trace_buf = (
      0x0 -&gt; NULL,
      0x0 -&gt; NULL,
      0x0 -&gt; NULL,
      0x0 -&gt; NULL)

Link: http://lkml.kernel.org/r/1571120245-4186-1-git-send-email-prsood@codeaurora.org

Cc: stable@vger.kernel.org
Fixes: e12f03d7031a9 ("perf/core: Implement the 'perf_kprobe' PMU")
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Prateek Sood &lt;prsood@codeaurora.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf_event: Add support for LSM and SELinux checks</title>
<updated>2019-10-17T19:31:55+00:00</updated>
<author>
<name>Joel Fernandes (Google)</name>
<email>joel@joelfernandes.org</email>
</author>
<published>2019-10-14T17:03:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=da97e18458fb42d7c00fac5fd1c56a3896ec666e'/>
<id>da97e18458fb42d7c00fac5fd1c56a3896ec666e</id>
<content type='text'>
In current mainline, the degree of access to perf_event_open(2) system
call depends on the perf_event_paranoid sysctl.  This has a number of
limitations:

1. The sysctl is only a single value. Many types of accesses are controlled
   based on the single value thus making the control very limited and
   coarse grained.
2. The sysctl is global, so if the sysctl is changed, then that means
   all processes get access to perf_event_open(2) opening the door to
   security issues.

This patch adds LSM and SELinux access checking which will be used in
Android to access perf_event_open(2) for the purposes of attaching BPF
programs to tracepoints, perf profiling and other operations from
userspace. These operations are intended for production systems.

5 new LSM hooks are added:
1. perf_event_open: This controls access during the perf_event_open(2)
   syscall itself. The hook is called from all the places that the
   perf_event_paranoid sysctl is checked to keep it consistent with the
   systctl. The hook gets passed a 'type' argument which controls CPU,
   kernel and tracepoint accesses (in this context, CPU, kernel and
   tracepoint have the same semantics as the perf_event_paranoid sysctl).
   Additionally, I added an 'open' type which is similar to
   perf_event_paranoid sysctl == 3 patch carried in Android and several other
   distros but was rejected in mainline [1] in 2016.

2. perf_event_alloc: This allocates a new security object for the event
   which stores the current SID within the event. It will be useful when
   the perf event's FD is passed through IPC to another process which may
   try to read the FD. Appropriate security checks will limit access.

3. perf_event_free: Called when the event is closed.

4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event.

5. perf_event_write: Called from the ioctl(2) syscalls for the event.

[1] https://lwn.net/Articles/696240/

Since Peter had suggest LSM hooks in 2016 [1], I am adding his
Suggested-by tag below.

To use this patch, we set the perf_event_paranoid sysctl to -1 and then
apply selinux checking as appropriate (default deny everything, and then
add policy rules to give access to domains that need it). In the future
we can remove the perf_event_paranoid sysctl altogether.

Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Co-developed-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: James Morris &lt;jmorris@namei.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: rostedt@goodmis.org
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: jeffv@google.com
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: primiano@google.com
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: rsavitski@google.com
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Matthew Garrett &lt;matthewgarrett@google.com&gt;
Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In current mainline, the degree of access to perf_event_open(2) system
call depends on the perf_event_paranoid sysctl.  This has a number of
limitations:

1. The sysctl is only a single value. Many types of accesses are controlled
   based on the single value thus making the control very limited and
   coarse grained.
2. The sysctl is global, so if the sysctl is changed, then that means
   all processes get access to perf_event_open(2) opening the door to
   security issues.

This patch adds LSM and SELinux access checking which will be used in
Android to access perf_event_open(2) for the purposes of attaching BPF
programs to tracepoints, perf profiling and other operations from
userspace. These operations are intended for production systems.

5 new LSM hooks are added:
1. perf_event_open: This controls access during the perf_event_open(2)
   syscall itself. The hook is called from all the places that the
   perf_event_paranoid sysctl is checked to keep it consistent with the
   systctl. The hook gets passed a 'type' argument which controls CPU,
   kernel and tracepoint accesses (in this context, CPU, kernel and
   tracepoint have the same semantics as the perf_event_paranoid sysctl).
   Additionally, I added an 'open' type which is similar to
   perf_event_paranoid sysctl == 3 patch carried in Android and several other
   distros but was rejected in mainline [1] in 2016.

2. perf_event_alloc: This allocates a new security object for the event
   which stores the current SID within the event. It will be useful when
   the perf event's FD is passed through IPC to another process which may
   try to read the FD. Appropriate security checks will limit access.

3. perf_event_free: Called when the event is closed.

4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event.

5. perf_event_write: Called from the ioctl(2) syscalls for the event.

[1] https://lwn.net/Articles/696240/

Since Peter had suggest LSM hooks in 2016 [1], I am adding his
Suggested-by tag below.

To use this patch, we set the perf_event_paranoid sysctl to -1 and then
apply selinux checking as appropriate (default deny everything, and then
add policy rules to give access to domains that need it). In the future
we can remove the perf_event_paranoid sysctl altogether.

Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Co-developed-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: James Morris &lt;jmorris@namei.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: rostedt@goodmis.org
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: jeffv@google.com
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: primiano@google.com
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: rsavitski@google.com
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Matthew Garrett &lt;matthewgarrett@google.com&gt;
Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Pass type into tracing_generic_entry_update()</title>
<updated>2019-07-16T19:14:48+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2019-05-25T16:57:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=46710f3a34b592ac5c51a95f696b2d2a2a0d9419'/>
<id>46710f3a34b592ac5c51a95f696b2d2a2a0d9419</id>
<content type='text'>
All callers of tracing_generic_entry_update() have to initialize
entry-&gt;type, so let's just simply move it inside.
Link: http://lkml.kernel.org/r/20190525165802.25944-2-xiyou.wangcong@gmail.com

Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All callers of tracing_generic_entry_update() have to initialize
entry-&gt;type, so let's just simply move it inside.
Link: http://lkml.kernel.org/r/20190525165802.25944-2-xiyou.wangcong@gmail.com

Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/perf: Use strndup_user() instead of buggy open-coded version</title>
<updated>2019-02-21T15:35:10+00:00</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2019-02-20T16:54:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=83540fbc8812a580b6ad8f93f4c29e62e417687e'/>
<id>83540fbc8812a580b6ad8f93f4c29e62e417687e</id>
<content type='text'>
The first version of this method was missing the check for
`ret == PATH_MAX`; then such a check was added, but it didn't call kfree()
on error, so there was still a small memory leak in the error case.
Fix it by using strndup_user() instead of open-coding it.

Link: http://lkml.kernel.org/r/20190220165443.152385-1-jannh@google.com

Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: stable@vger.kernel.org
Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()")
Reviewed-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The first version of this method was missing the check for
`ret == PATH_MAX`; then such a check was added, but it didn't call kfree()
on error, so there was still a small memory leak in the error case.
Fix it by using strndup_user() instead of open-coding it.

Link: http://lkml.kernel.org/r/20190220165443.152385-1-jannh@google.com

Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: stable@vger.kernel.org
Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()")
Reviewed-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>trace_uprobe: support reference counter in fd-based uprobe</title>
<updated>2018-10-11T02:14:17+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2018-10-02T05:36:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=a6ca88b241d5e929e6e60b12ad8cd288f0ffa256'/>
<id>a6ca88b241d5e929e6e60b12ad8cd288f0ffa256</id>
<content type='text'>
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 &lt;oleg@redhat.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-and-tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;oleg@redhat.com&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-and-tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Add SPDX License format tags to tracing files</title>
<updated>2018-08-16T23:08:06+00:00</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2018-08-16T15:23:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=bcea3f96e11cf2f0232d851e0fdb854f5ada425a'/>
<id>bcea3f96e11cf2f0232d851e0fdb854f5ada425a</id>
<content type='text'>
Add the SPDX License header to ease license compliance management.

Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the SPDX License header to ease license compliance management.

Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Fix perf_uprobe_init()</title>
<updated>2018-04-10T05:33:10+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2018-04-09T18:31:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=0eadcc7a7bc03e991d2da1cf88143fb7cc0342c1'/>
<id>0eadcc7a7bc03e991d2da1cf88143fb7cc0342c1</id>
<content type='text'>
Similarly to the uprobe PMU fix in perf_kprobe_init(), fix error
handling in perf_uprobe_init() as well.

Reported-by: 范龙飞 &lt;long7573@126.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Acked-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Fixes: e12f03d7031a ("perf/core: Implement the 'perf_kprobe' PMU")
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Similarly to the uprobe PMU fix in perf_kprobe_init(), fix error
handling in perf_uprobe_init() as well.

Reported-by: 范龙飞 &lt;long7573@126.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Acked-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Fixes: e12f03d7031a ("perf/core: Implement the 'perf_kprobe' PMU")
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
