<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/kernel/trace, branch v5.10.1</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.10.1</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.10.1'/>
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<updated>2020-12-11T22:19:07Z</updated>
<entry>
<title>bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers</title>
<updated>2020-12-11T22:19:07Z</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2020-12-11T21:36:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b7906b70a2337e445b8dca3ce7ba8976b6ebd07d'/>
<id>urn:sha1:b7906b70a2337e445b8dca3ce7ba8976b6ebd07d</id>
<content type='text'>
Remove bpf_ prefix, which causes these helpers to be reported in verifier
dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets
fix it as long as it is still possible before UAPI freezes on these helpers.

Fixes: eaa6bcb71ef6 ("bpf: Introduce bpf_per_cpu_ptr()")
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace</title>
<updated>2020-12-07T19:20:26Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-12-07T19:20:26Z</published>
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<id>urn:sha1:cd796ed3345030aa1bb332fe5c793b3dddaf56e7</id>
<content type='text'>
Pull tracing fix from Steven Rostedt:
 "Fix userstacktrace option for instances

  While writing an application that requires user stack trace option to
  work in instances, I found that the instance option has a bug that
  makes it a nop. The check for performing the user stack trace in an
  instance, checks the top level options (not the instance options) to
  determine if a user stack trace should be performed or not.

  This is not only incorrect, but also confusing for users. It confused
  me for a bit!"

* tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix userstacktrace option for instances
</content>
</entry>
<entry>
<title>tracing: Fix userstacktrace option for instances</title>
<updated>2020-12-04T21:36:16Z</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2020-12-04T21:36:16Z</published>
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<id>urn:sha1:bcee5278958802b40ee8b26679155a6d9231783e</id>
<content type='text'>
When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 16270145ce6b ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace</title>
<updated>2020-12-01T23:30:18Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-12-01T23:30:18Z</published>
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<id>urn:sha1:ef6900acc89ecfc78ceb0eb1605c954dd6f2ca05</id>
<content type='text'>
Pull tracing fixes from Steven Rostedt:

 - Use correct timestamp variable for ring buffer write stamp update

 - Fix up before stamp and write stamp when crossing ring buffer sub
   buffers

 - Keep a zero delta in ring buffer in slow path if cmpxchg fails

 - Fix trace_printk static buffer for archs that care

 - Fix ftrace record accounting for ftrace ops with trampolines

 - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency

 - Remove WARN_ON in hwlat tracer that triggers on something that is OK

 - Make "my_tramp" trampoline in ftrace direct sample code global

 - Fixes in the bootconfig tool for better alignment management

* tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Always check to put back before stamp when crossing pages
  ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  ftrace: Fix updating FTRACE_FL_TRAMP
  tracing: Fix alignment of static buffer
  tracing: Remove WARN_ON in start_thread()
  samples/ftrace: Mark my_tramp[12]? global
  ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
  ring-buffer: Update write stamp with the correct ts
  docs: bootconfig: Update file format on initrd image
  tools/bootconfig: Align the bootconfig applied initrd image size to 4
  tools/bootconfig: Fix to check the write failure correctly
  tools/bootconfig: Fix errno reference after printf()
</content>
</entry>
<entry>
<title>ring-buffer: Always check to put back before stamp when crossing pages</title>
<updated>2020-12-01T04:21:51Z</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2020-12-01T04:16:03Z</published>
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<id>urn:sha1:68e10d5ff512b503dcba1246ad5620f32035e135</id>
<content type='text'>
The current ring buffer logic checks to see if the updating of the event
buffer was interrupted, and if it is, it will try to fix up the before stamp
with the write stamp to make them equal again. This logic is flawed, because
if it is not interrupted, the two are guaranteed to be different, as the
current event just updated the before stamp before allocation. This
guarantees that the next event (this one or another interrupting one) will
think it interrupted the time updates of a previous event and inject an
absolute time stamp to compensate.

The correct logic is to always update the timestamps when traversing to a
new sub buffer.

Cc: stable@vger.kernel.org
Fixes: a389d86f7fd09 ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency</title>
<updated>2020-12-01T02:43:08Z</updated>
<author>
<name>Naveen N. Rao</name>
<email>naveen.n.rao@linux.vnet.ibm.com</email>
</author>
<published>2020-11-26T18:08:39Z</published>
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<id>urn:sha1:49a962c075dfa41c78e34784772329bc8784d217</id>
<content type='text'>
DYNAMIC_FTRACE_WITH_DIRECT_CALLS should depend on
DYNAMIC_FTRACE_WITH_REGS since we need ftrace_regs_caller().

Link: https://lkml.kernel.org/r/fc4b257ea8689a36f086d2389a9ed989496ca63a.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 763e34e74bb7d5c ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Fix updating FTRACE_FL_TRAMP</title>
<updated>2020-12-01T02:43:07Z</updated>
<author>
<name>Naveen N. Rao</name>
<email>naveen.n.rao@linux.vnet.ibm.com</email>
</author>
<published>2020-11-26T18:08:38Z</published>
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<id>urn:sha1:4c75b0ff4e4bf7a45b5aef9639799719c28d0073</id>
<content type='text'>
On powerpc, kprobe-direct.tc triggered FTRACE_WARN_ON() in
ftrace_get_addr_new() followed by the below message:
  Bad trampoline accounting at: 000000004222522f (wake_up_process+0xc/0x20) (f0000001)

The set of steps leading to this involved:
- modprobe ftrace-direct-too
- enable_probe
- modprobe ftrace-direct
- rmmod ftrace-direct &lt;-- trigger

The problem turned out to be that we were not updating flags in the
ftrace record properly. From the above message about the trampoline
accounting being bad, it can be seen that the ftrace record still has
FTRACE_FL_TRAMP set though ftrace-direct module is going away. This
happens because we are checking if any ftrace_ops has the
FTRACE_FL_TRAMP flag set _before_ updating the filter hash.

The fix for this is to look for any _other_ ftrace_ops that also needs
FTRACE_FL_TRAMP.

Link: https://lkml.kernel.org/r/56c113aa9c3e10c19144a36d9684c7882bf09af5.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: a124692b698b0 ("ftrace: Enable trampoline when rec count returns back to one")
Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Fix alignment of static buffer</title>
<updated>2020-12-01T02:43:07Z</updated>
<author>
<name>Minchan Kim</name>
<email>minchan@kernel.org</email>
</author>
<published>2020-11-25T22:56:54Z</published>
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<id>urn:sha1:8fa655a3a0013a0c2a2aada6f39a93ee6fc25549</id>
<content type='text'>
With 5.9 kernel on ARM64, I found ftrace_dump output was broken but
it had no problem with normal output "cat /sys/kernel/debug/tracing/trace".

With investigation, it seems coping the data into temporal buffer seems to
break the align binary printf expects if the static buffer is not aligned
with 4-byte. IIUC, get_arg in bstr_printf expects that args has already
right align to be decoded and seq_buf_bprintf says ``the arguments are saved
in a 32bit word array that is defined by the format string constraints``.
So if we don't keep the align under copy to temporal buffer, the output
will be broken by shifting some bytes.

This patch fixes it.

Link: https://lkml.kernel.org/r/20201125225654.1618966-1-minchan@kernel.org

Cc: &lt;stable@vger.kernel.org&gt;
Fixes: 8e99cf91b99bb ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Minchan Kim &lt;minchan@kernel.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Remove WARN_ON in start_thread()</title>
<updated>2020-12-01T02:43:07Z</updated>
<author>
<name>Vasily Averin</name>
<email>vvs@virtuozzo.com</email>
</author>
<published>2020-11-18T12:05:20Z</published>
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<id>urn:sha1:310e3a4b5a4fc718a72201c1e4cf5c64ac6f5442</id>
<content type='text'>
This patch reverts commit 978defee11a5 ("tracing: Do a WARN_ON()
 if start_thread() in hwlat is called when thread exists")

.start hook can be legally called several times if according
tracer is stopped

screen window 1
[root@localhost ~]# echo 1 &gt; /sys/kernel/tracing/events/kmem/kfree/enable
[root@localhost ~]# echo 1 &gt; /sys/kernel/tracing/options/pause-on-trace
[root@localhost ~]# less -F /sys/kernel/tracing/trace

screen window 2
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo hwlat &gt;  /sys/kernel/debug/tracing/current_tracer
[root@localhost ~]# echo 1 &gt; /sys/kernel/debug/tracing/tracing_on
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo 2 &gt; /sys/kernel/debug/tracing/tracing_on

triggers warning in dmesg:
WARNING: CPU: 3 PID: 1403 at kernel/trace/trace_hwlat.c:371 hwlat_tracer_start+0xc9/0xd0

Link: https://lkml.kernel.org/r/bd4d3e70-400d-9c82-7b73-a2d695e86b58@virtuozzo.com

Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: stable@vger.kernel.org
Fixes: 978defee11a5 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists")
Signed-off-by: Vasily Averin &lt;vvs@virtuozzo.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()</title>
<updated>2020-11-30T20:22:05Z</updated>
<author>
<name>Andrea Righi</name>
<email>andrea.righi@canonical.com</email>
</author>
<published>2020-11-28T09:15:17Z</published>
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<id>urn:sha1:8785f51a17083eee7c37606079c6447afc6ba102</id>
<content type='text'>
In the slow path of __rb_reserve_next() a nested event(s) can happen
between evaluating the timestamp delta of the current event and updating
write_stamp via local_cmpxchg(); in this case the delta is not valid
anymore and it should be set to 0 (same timestamp as the interrupting
event), since the event that we are currently processing is not the last
event in the buffer.

Link: https://lkml.kernel.org/r/X8IVJcp1gRE+FJCJ@xps-13-7390

Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lwn.net/Articles/831207
Fixes: a389d86f7fd0 ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Andrea Righi &lt;andrea.righi@canonical.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
</feed>
