Commit graph

35334 commits

Author SHA1 Message Date
Steven Rostedt (VMware) 99e22ce73c tracing: Make hash-ptr option default
Since the original behavior of the trace events is to hash the %p pointers,
make that the default, and have developers have to enable the option in
order to have them unhashed.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-12 11:52:59 -05:00
Masami Hiramatsu a345a6718b tracing: Add ptr-hash option to show the hashed pointer value
Add tracefs/options/hash-ptr option to show hashed pointer
value by %p in event printk format string.

For the security reason, normal printk will show the hashed
pointer value (encrypted by random number) with %p to printk
buffer to hide the real address. But the tracefs/trace always
shows real address for debug. To bridge those outputs, add an
option to switch the output format. Ftrace users can use it
to find the hashed value corresponding to the real address
in trace log.

Link: https://lkml.kernel.org/r/160277372504.29307.14909828808982012211.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-11 16:31:57 -05:00
Masami Hiramatsu efbbdaa22b tracing: Show real address for trace event arguments
To help debugging kernel, show real address for trace event arguments
in tracefs/trace{,pipe} instead of hashed pointer value.

Since ftrace human-readable format uses vsprintf(), all %p are
translated to hash values instead of pointer address.

However, when debugging the kernel, raw address value gives a
hint when comparing with the memory mapping in the kernel.
(Those are sometimes used with crash log, which is not hashed too)
So converting %p with %px when calling trace_seq_printf().

Moreover, this is not improving the security because the tracefs
can be used only by root user and the raw address values are readable
from tracefs/percpu/cpu*/trace_pipe_raw file.

Link: https://lkml.kernel.org/r/160277370703.29307.5134475491761971203.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-11 16:31:57 -05:00
Tom Zanussi 8b5ab6bd0b tracing: Add a backward-compatibility check for synthetic event creation
The synthetic event parsing rework now requires semicolons between
synthetic event fields.  That requirement breaks existing users who
might already have used the old synthetic event command format, so
this adds an inner loop that can parse more than one field, if
present, between semicolons.  For each field, parse_synth_field()
checks in which version that field was introduced, using
check_field_version().  The caller, __create_synth_event() can then use
that version information to determine whether or not to enforce the
requirement on the command as a whole.

In the future, if/when new features are added, the requirement will be
that any field/string containing the new feature must use semicolons,
and the check_field_version() check can then check for those and
enforce it.  Using a version number allows this scheme to be extended
if necessary.

Link: https://lkml.kernel.org/r/74fcc500d561b40ce91c5ee94818c70c6b0c9330.1612208610.git.zanussi@kernel.org

[ zanussi: added check_field_version() comment from rostedt@goodmis.org ]
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:52:15 -05:00
Tom Zanussi 8d3e816523 tracing: Update synth command errors
Since array types are handled differently, errors referencing them
also need to be handled differently.  Add and use a new
INVALID_ARRAY_SPEC error.  Also add INVALID_CMD and INVALID_DYN_CMD to
catch and display the correct form for badly-formed commands, which
can also be used in place of CMD_INCOMPLETE, which is removed, and
remove CMD_TOO_LONG, since it's no longer used.

Link: https://lkml.kernel.org/r/b9dd434dc6458dcff11adc6ed616fe93a8794770.1612208610.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:52:15 -05:00
Tom Zanussi c9e759b1e8 tracing: Rework synthetic event command parsing
Now that command parsing has been delegated to the create functions
and we're no longer constrained by argv_split(), we can modify the
synthetic event command parser to better match the higher-level
structure of the synthetic event commands, which is basically an event
name followed by a set of semicolon-separated fields.

Since we're also now passed the raw command, we can also save it
directly and can get rid of save_cmdstr().

Link: https://lkml.kernel.org/r/cb9e2be92d992ce59f2b4f132264a5d467f3933f.1612208610.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:52:15 -05:00
Masami Hiramatsu d262271d04 tracing/dynevent: Delegate parsing to create function
Delegate command parsing to each create function so that the
command syntax can be customized.

This requires changes to the kprobe/uprobe/synthetic event handling,
which are also included here.

Link: https://lkml.kernel.org/r/e488726f49cbdbc01568618f8680584306c4c79f.1612208610.git.zanussi@kernel.org

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ zanussi@kernel.org: added synthetic event modifications ]
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:52:15 -05:00
Masami Hiramatsu 33b1d14668 kprobes: Warn if the kprobe is reregistered
Warn if the kprobe is reregistered, since there must be
a software bug (actively used resource must not be re-registered)
and caller must be fixed.

Link: https://lkml.kernel.org/r/161236436734.194052.4058506306336814476.stgit@devnote2

Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:44:32 -05:00
Steven Rostedt (VMware) 7211f0a257 tracepoints: Code clean up
Restructure the code a bit to make it simpler, fix some formatting problems
and add READ_ONCE/WRITE_ONCE to make sure there's no compiler load/store
tearing to the variables that can be accessed across CPUs.

Started with Mathieu Desnoyers's patch:

  Link: https://lore.kernel.org/lkml/20210203175741.20665-1-mathieu.desnoyers@efficios.com/

And will keep his signature, but I will take the responsibility of this
being correct, and keep the authorship.

Link: https://lkml.kernel.org/r/20210204143004.61126582@gandalf.local.home

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:27:29 -05:00
Steven Rostedt (VMware) 2d396cb3b1 tracing: Do not create "enable" or "filter" files for ftrace event subsystem
The ftrace event subsystem is only created for showing the format files of
events created by the ftrace tracers, and are not trace events. The ftrace
subsystem currently has both the "enable" and "filter" files that in other
subsystems are used to enable/disable all events within the subsystem or set
a filter for all the subsystem events.

As ftrace subsystem events do not use enable or filter operations, these
files are useless in the ftrace subsystem. Remove them.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-05 18:04:39 -05:00
Song Chen 4b9091e1c1 kernel: trace: preemptirq_delay_test: add cpu affinity
The kernel thread executing test can run on any cpu, which might be
different cpu latency tracer is running on, as a result, the
big latency caused by preemptirq delay test can't be detected.

Therefore, the argument cpu_affinity is added to be passed to test,
ensure it's running on the same cpu with latency tracer.

e.g.
cyclictest -p 90 -m -c 0 -i 1000 -a 3
modprobe preemptirq_delay_test test_mode=preempt delay=500 \
burst_size=3 cpu_affinity=3

Link: https://lkml.kernel.org/r/1611797713-20965-1-git-send-email-chensong_2000@189.cn

Signed-off-by: Song Chen <chensong_2000@189.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Steven Rostedt (VMware) befe6d9465 tracepoint: Do not fail unregistering a probe due to memory failure
The list of tracepoint callbacks is managed by an array that is protected
by RCU. To update this array, a new array is allocated, the updates are
copied over to the new array, and then the list of functions for the
tracepoint is switched over to the new array. After a completion of an RCU
grace period, the old array is freed.

This process happens for both adding a callback as well as removing one.
But on removing a callback, if the new array fails to be allocated, the
callback is not removed, and may be used after it is freed by the clients
of the tracepoint.

There's really no reason to fail if the allocation for a new array fails
when removing a function. Instead, the function can simply be replaced by a
stub function that could be cleaned up on the next modification of the
array. That is, instead of calling the function registered to the
tracepoint, it would call a stub function in its place.

Link: https://lore.kernel.org/r/20201115055256.65625-1-mmullins@mmlx.us
Link: https://lore.kernel.org/r/20201116175107.02db396d@gandalf.local.home
Link: https://lore.kernel.org/r/20201117211836.54acaef2@oasis.local.home
Link: https://lkml.kernel.org/r/20201118093405.7a6d2290@gandalf.local.home

[ Note, this version does use undefined compiler behavior (assuming that
  a stub function with no parameters or return, can be called by a location
  that thinks it has parameters but still no return value. Static calls
  do the same thing, so this trick is not without precedent.

  There's another solution that uses RCU tricks and is more complex, but
  can be an alternative if this solution becomes an issue.

  Link: https://lore.kernel.org/lkml/20210127170721.58bce7cc@gandalf.local.home/
]

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@chromium.org>
Cc: netdev <netdev@vger.kernel.org>
Cc: bpf <bpf@vger.kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Florian Weimer <fw@deneb.enyo.de>
Fixes: 97e1c18e8d ("tracing: Kernel Tracepoints")
Reported-by: syzbot+83aa762ef23b6f0d1991@syzkaller.appspotmail.com
Reported-by: syzbot+d29e58bb557324e55e5e@syzkaller.appspotmail.com
Reported-by: Matt Mullins <mmullins@mmlx.us>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Tested-by: Matt Mullins <mmullins@mmlx.us>
2021-02-02 17:02:07 -05:00
Tom Rix f2a99ddfd0 tracing: Remove definition of DEBUG in trace_mmiotrace.c
Defining DEBUG should only be done in development.
So remove DEBUG.

Link: https://lkml.kernel.org/r/20210115153348.131791-1-trix@redhat.com

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Bean Huo 557d50e79d tracing: Fix a kernel doc warning
Add description for trace_array_put() parameter.

kernel/trace/trace.c:464: warning: Function parameter or member 'this_tr' not described in 'trace_array_put'

Link: https://lkml.kernel.org/r/20210112111202.23508-1-huobean@gmail.com

Signed-off-by: Bean Huo <beanhuo@micron.com>
[ Merged as one of the original fixes was already fixed by someone else ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Bhaskar Chowdhury 39bcdd6a96 tracing: Fix spelling of controlling in uprobes
s/controling/controlling/p

Link: https://lkml.kernel.org/r/20210112045008.29834-1-unixbhaskar@gmail.com

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Colin Ian King 28cc65a173 tracing: Fix spelling mistake in Kconfig "infinit" -> "infinite"
There is a spelling mistake in the Kconfig help text. Fix it.

Link: https://lkml.kernel.org/r/20201216114051.12056-1-colin.king@canonical.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Sebastian Andrzej Siewior fe427886bf tracing: Use in_serving_softirq() to deduct softirq status.
PREEMPT_RT does not report "serving softirq" because the tracing core
looks at the preemption counter while PREEMPT_RT does not update it
while processing softirqs in order to remain preemptible. The
information is stored somewhere else.
The in_serving_softirq() macro and the SOFTIRQ_OFFSET define are still
working but not on the preempt-counter.

Use in_serving_softirq() macro which works on PREEMPT_RT. On !PREEMPT_RT
the compiler (gcc-10 / clang-11) is smart enough to optimize the
in_serving_softirq() related read of the preemption counter away.
The only difference I noticed by using in_serving_softirq() on
!PREEMPT_RT is that gcc-10 implemented tracing_gen_ctx_flags() as
reading FLAG, jmp _tracing_gen_ctx_flags(). Without in_serving_softirq()
it inlined _tracing_gen_ctx_flags() into tracing_gen_ctx_flags().

Link: https://lkml.kernel.org/r/20210125194511.3924915-4-bigeasy@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Sebastian Andrzej Siewior 0c02006e6f tracing: Inline tracing_gen_ctx_flags()
Inline tracing_gen_ctx_flags(). This allows to have one ifdef
CONFIG_TRACE_IRQFLAGS_SUPPORT.

This requires to move `trace_flag_type' so tracing_gen_ctx_flags() can
use it.

Link: https://lkml.kernel.org/r/20210125194511.3924915-3-bigeasy@linutronix.de

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20210125140323.6b1ff20c@gandalf.local.home
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Sebastian Andrzej Siewior 36590c50b2 tracing: Merge irqflags + preempt counter.
The state of the interrupts (irqflags) and the preemption counter are
both passed down to tracing_generic_entry_update(). Only one bit of
irqflags is actually required: The on/off state. The complete 32bit
of the preemption counter isn't needed. Just whether of the upper bits
(softirq, hardirq and NMI) are set and the preemption depth is needed.

The irqflags and the preemption counter could be evaluated early and the
information stored in an integer `trace_ctx'.
tracing_generic_entry_update() would use the upper bits as the
TRACE_FLAG_* and the lower 8bit as the disabled-preemption depth
(considering that one must be substracted from the counter in one
special cases).

The actual preemption value is not used except for the tracing record.
The `irqflags' variable is mostly used only for the tracing record. An
exception here is for instance wakeup_tracer_call() or
probe_wakeup_sched_switch() which explicilty disable interrupts and use
that `irqflags' to save (and restore) the IRQ state and to record the
state.

Struct trace_event_buffer has also the `pc' and flags' members which can
be replaced with `trace_ctx' since their actual value is not used
outside of trace recording.

This will reduce tracing_generic_entry_update() to simply assign values
to struct trace_entry. The evaluation of the TRACE_FLAG_* bits is moved
to _tracing_gen_ctx_flags() which replaces preempt_count() and
local_save_flags() invocations.

As an example, ftrace_syscall_enter() may invoke:
- trace_buffer_lock_reserve() -> … -> tracing_generic_entry_update()
- event_trigger_unlock_commit()
  -> ftrace_trace_stack() -> … -> tracing_generic_entry_update()
  -> ftrace_trace_userstack() -> … -> tracing_generic_entry_update()

In this case the TRACE_FLAG_* bits were evaluated three times. By using
the `trace_ctx' they are evaluated once and assigned three times.

A build with all tracers enabled on x86-64 with and without the patch:

    text     data      bss      dec      hex    filename
21970669 17084168  7639260 46694097  2c87ed1 vmlinux.old
21970293 17084168  7639260 46693721  2c87d59 vmlinux.new

text shrank by 379 bytes, data remained constant.

Link: https://lkml.kernel.org/r/20210125194511.3924915-2-bigeasy@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Qiujun Huang c6358bacdc ring-buffer: Drop unneeded check in ring_buffer_resize()
Remove the cpumask check, as we has done it at the beginning of
the function.
Also fix a typo. s/also the on the/also on the/

Link: https://lkml.kernel.org/r/20201224144634.3210-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Qiujun Huang 6689bed36c ring-buffer: Remove cpu_buffer argument from the rb_inc_page()
The cpu_buffer argument is not used inside the rb_inc_page() after
commit 3adc54fa82 ("ring-buffer: make the buffer a true circular link
list").
And cpu_buffer argument is not used inside the two functions too,
rb_is_head_page/rb_set_list_to_head.

Link: https://lkml.kernel.org/r/20201225140356.23008-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Qiujun Huang 18d14ebdbd tracing: Remove get/put_cpu() from function_trace_init
Since commit b6f11df26f ("trace: Call tracing_reset_online_cpus before
tracer->init()"), get/put_cpu() are not needed anymore.
We can use raw_smp_processor_id() instead.

Link: https://lkml.kernel.org/r/20201230140521.31920-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:05 -05:00
Qiujun Huang b3ca59f6fe tracing: Update trace_ignore_this_task() kernel-doc comment
Update kernel-doc parameter after
commit b3b1e6eded ("ftrace: Create set_ftrace_notrace_pid to not trace tasks")
added @filtered_no_pids.

Link: https://lkml.kernel.org/r/20201231153558.4804-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:05 -05:00
Wang ShaoBo 0188b87899 kretprobe: Avoid re-registration of the same kretprobe earlier
Our system encountered a re-init error when re-registering same kretprobe,
where the kretprobe_instance in rp->free_instances is illegally accessed
after re-init.

Implementation to avoid re-registration has been introduced for kprobe
before, but lags for register_kretprobe(). We must check if kprobe has
been re-registered before re-initializing kretprobe, otherwise it will
destroy the data struct of kretprobe registered, which can lead to memory
leak, system crash, also some unexpected behaviors.

We use check_kprobe_rereg() to check if kprobe has been re-registered
before running register_kretprobe()'s body, for giving a warning message
and terminate registration process.

Link: https://lkml.kernel.org/r/20210128124427.2031088-1-bobo.shaobowang@huawei.com

Cc: stable@vger.kernel.org
Fixes: 1f0ab40976 ("kprobes: Prevent re-registration of the same kprobe")
[ The above commit should have been done for kretprobes too ]
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 17:29:16 -05:00
Masami Hiramatsu 97c753e62e tracing/kprobe: Fix to support kretprobe events on unloaded modules
Fix kprobe_on_func_entry() returns error code instead of false so that
register_kretprobe() can return an appropriate error code.

append_trace_kprobe() expects the kprobe registration returns -ENOENT
when the target symbol is not found, and it checks whether the target
module is unloaded or not. If the target module doesn't exist, it
defers to probe the target symbol until the module is loaded.

However, since register_kretprobe() returns -EINVAL instead of -ENOENT
in that case, it always fail on putting the kretprobe event on unloaded
modules. e.g.

Kprobe event:
/sys/kernel/debug/tracing # echo p xfs:xfs_end_io >> kprobe_events
[   16.515574] trace_kprobe: This probe might be able to register after target module is loaded. Continue.

Kretprobe event: (p -> r)
/sys/kernel/debug/tracing # echo r xfs:xfs_end_io >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/debug/tracing # cat error_log
[   41.122514] trace_kprobe: error: Failed to register probe event
  Command: r xfs:xfs_end_io
             ^

To fix this bug, change kprobe_on_func_entry() to detect symbol lookup
failure and return -ENOENT in that case. Otherwise it returns -EINVAL
or 0 (succeeded, given address is on the entry).

Link: https://lkml.kernel.org/r/161176187132.1067016.8118042342894378981.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 59158ec4ae ("tracing/kprobes: Check the probe on unloaded module correctly")
Reported-by: Jianlin Lv <Jianlin.Lv@arm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 15:39:48 -05:00
Viktor Rosendahl da7f84cdf0 tracing: Use pause-on-trace with the latency tracers
Eaerlier, tracing was disabled when reading the trace file. This behavior
was changed with:

commit 06e0a548ba ("tracing: Do not disable tracing when reading the
trace file").

This doesn't seem to work with the latency tracers.

The above mentioned commit dit not only change the behavior but also added
an option to emulate the old behavior. The idea with this patch is to
enable this pause-on-trace option when the latency tracers are used.

Link: https://lkml.kernel.org/r/20210119164344.37500-2-Viktor.Rosendahl@bmw.de

Cc: stable@vger.kernel.org
Fixes: 06e0a548ba ("tracing: Do not disable tracing when reading the trace file")
Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 15:35:33 -05:00
Steven Rostedt (VMware) 7e0a922046 fgraph: Initialize tracing_graph_pause at task creation
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: 380c4b1411 ("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>
2021-01-29 15:07:32 -05:00
Linus Torvalds e68061375f - Fix a kernel panic in mips-cpu due to invalid irq domain hierarchy.
- Fix to not lose IPIs on bcm2836.
 
  - Fix for a bogus marking of ITS devices as shared due to unitialized
    stack variable.
 
  - Clear a phantom interrupt on qcom-pdc to unblock suspend.
 
  - Small cleanups, warning and build fixes.
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Merge tag 'irq_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Borislav Petkov:

 - Fix a kernel panic in mips-cpu due to invalid irq domain hierarchy.

 - Fix to not lose IPIs on bcm2836.

 - Fix for a bogus marking of ITS devices as shared due to unitialized
   stack variable.

 - Clear a phantom interrupt on qcom-pdc to unblock suspend.

 - Small cleanups, warning and build fixes.

* tag 'irq_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Export irq_check_status_bit()
  irqchip/mips-cpu: Set IPI domain parent chip
  irqchip/pruss: Simplify the TI_PRUSS_INTC Kconfig
  irqchip/loongson-liointc: Fix build warnings
  driver core: platform: Add extra error check in devm_platform_get_irqs_affinity()
  irqchip/bcm2836: Fix IPI acknowledgement after conversion to handle_percpu_devid_irq
  irqchip/irq-sl28cpld: Convert comma to semicolon
  genirq/msi: Initialize msi_alloc_info before calling msi_domain_prepare_irqs()
2021-01-24 10:24:20 -08:00
Linus Torvalds 24c56ee06c - Correct the marking of kthreads which are supposed to run on a specific,
single CPU vs such which are affine to only one CPU, mark per-cpu workqueue
  threads as such and make sure that marking "survives" CPU hotplug. Fix CPU
  hotplug issues with such kthreads.
 
  - A fix to not push away tasks on CPUs coming online.
 
  - Have workqueue CPU hotplug code use cpu_possible_mask when breaking affinity
    on CPU offlining so that pending workers can finish on newly arrived onlined
    CPUs too.
 
  - Dump tasks which haven't vacated a CPU which is currently being unplugged.
 
  - Register a special scale invariance callback which gets called on resume
  from RAM to read out APERF/MPERF after resume and thus make the schedutil
  scaling governor more precise.
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Merge tag 'sched_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Borislav Petkov:

 - Correct the marking of kthreads which are supposed to run on a
   specific, single CPU vs such which are affine to only one CPU, mark
   per-cpu workqueue threads as such and make sure that marking
   "survives" CPU hotplug. Fix CPU hotplug issues with such kthreads.

 - A fix to not push away tasks on CPUs coming online.

 - Have workqueue CPU hotplug code use cpu_possible_mask when breaking
   affinity on CPU offlining so that pending workers can finish on newly
   arrived onlined CPUs too.

 - Dump tasks which haven't vacated a CPU which is currently being
   unplugged.

 - Register a special scale invariance callback which gets called on
   resume from RAM to read out APERF/MPERF after resume and thus make
   the schedutil scaling governor more precise.

* tag 'sched_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Relax the set_cpus_allowed_ptr() semantics
  sched: Fix CPU hotplug / tighten is_per_cpu_kthread()
  sched: Prepare to use balance_push in ttwu()
  workqueue: Restrict affinity change to rescuer
  workqueue: Tag bound workers with KTHREAD_IS_PER_CPU
  kthread: Extract KTHREAD_IS_PER_CPU
  sched: Don't run cpu-online with balance_push() enabled
  workqueue: Use cpu_possible_mask instead of cpu_active_mask to break affinity
  sched/core: Print out straggler tasks in sched_cpu_dying()
  x86: PM: Register syscore_ops for scale invariance
2021-01-24 10:09:20 -08:00
Linus Torvalds 025929f468 - Fix an integer overflow in the NTP RTC synchronization which lead to latter
happening every 2 seconds instead of the intended every 11 minutes.
 
  - Get rid of now unused get_seconds().
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Merge tag 'timers_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Borislav Petkov:

 - Fix an integer overflow in the NTP RTC synchronization which led to
   the latter happening every 2 seconds instead of the intended every 11
   minutes.

 - Get rid of now unused get_seconds().

* tag 'timers_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ntp: Fix RTC synchronization on 32-bit platforms
  timekeeping: Remove unused get_seconds()
2021-01-24 09:58:38 -08:00
Linus Torvalds 17b6c49da3 - Add a new Intel model number for Alder Lake
- Differentiate which aspects of the FPU state get saved/restored when the FPU
    is used in-kernel and fix a boot crash on K7 due to early MXCSR access before
    CR4.OSFXSR is even set.
 
  - A couple of noinstr annotation fixes
 
  - Correct die ID setting on AMD for users of topology information which need
    the correct die ID
 
  - A SEV-ES fix to handle string port IO to/from kernel memory properly
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Merge tag 'x86_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Add a new Intel model number for Alder Lake

 - Differentiate which aspects of the FPU state get saved/restored when
   the FPU is used in-kernel and fix a boot crash on K7 due to early
   MXCSR access before CR4.OSFXSR is even set.

 - A couple of noinstr annotation fixes

 - Correct die ID setting on AMD for users of topology information which
   need the correct die ID

 - A SEV-ES fix to handle string port IO to/from kernel memory properly

* tag 'x86_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add another Alder Lake CPU to the Intel family
  x86/mmx: Use KFPU_387 for MMX string operations
  x86/fpu: Add kernel_fpu_begin_mask() to selectively initialize state
  x86/topology: Make __max_die_per_package available unconditionally
  x86: __always_inline __{rd,wr}msr()
  x86/mce: Remove explicit/superfluous tracing
  locking/lockdep: Avoid noinstr warning for DEBUG_LOCKDEP
  locking/lockdep: Cure noinstr fail
  x86/sev: Fix nonistr violation
  x86/entry: Fix noinstr fail
  x86/cpu/amd: Set __max_die_per_package on AMD
  x86/sev-es: Handle string port IO to kernel memory properly
2021-01-24 09:46:05 -08:00
Linus Torvalds c509ce2378 for-linus-2021-01-24
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Merge tag 'for-linus-2021-01-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull misc fixes from Christian Brauner:

 - Jann reported sparse complaints because of a missing __user
   annotation in a helper we added way back when we added
   pidfd_send_signal() to avoid compat syscall handling. Fix it.

 - Yanfei replaces a reference in a comment to the _do_fork() helper I
   removed a while ago with a reference to the new kernel_clone()
   replacement

 - Alexander Guril added a simple coding style fix

* tag 'for-linus-2021-01-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  kthread: remove comments about old _do_fork() helper
  Kernel: fork.c: Fix coding style: Do not use {} around single-line statements
  signal: Add missing __user annotation to copy_siginfo_from_user_any
2021-01-24 09:35:28 -08:00
Peter Zijlstra 741ba80f6f sched: Relax the set_cpus_allowed_ptr() semantics
Now that we have KTHREAD_IS_PER_CPU to denote the critical per-cpu
tasks to retain during CPU offline, we can relax the warning in
set_cpus_allowed_ptr(). Any spurious kthread that wants to get on at
the last minute will get pushed off before it can run.

While during CPU online there is no harm, and actual benefit, to
allowing kthreads back on early, it simplifies hotplug code and fixes
a number of outstanding races.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Lai jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103507.240724591@infradead.org
2021-01-22 15:09:44 +01:00
Peter Zijlstra 5ba2ffba13 sched: Fix CPU hotplug / tighten is_per_cpu_kthread()
Prior to commit 1cf12e08bc ("sched/hotplug: Consolidate task
migration on CPU unplug") we'd leave any task on the dying CPU and
break affinity and force them off at the very end.

This scheme had to change in order to enable migrate_disable(). One
cannot wait for migrate_disable() to complete while stuck in
stop_machine(). Furthermore, since we need at the very least: idle,
hotplug and stop threads at any point before stop_machine, we can't
break affinity and/or push those away.

Under the assumption that all per-cpu kthreads are sanely handled by
CPU hotplug, the new code no long breaks affinity or migrates any of
them (which then includes the critical ones above).

However, there's an important difference between per-cpu kthreads and
kthreads that happen to have a single CPU affinity which is lost. The
latter class very much relies on the forced affinity breaking and
migration semantics previously provided.

Use the new kthread_is_per_cpu() infrastructure to tighten
is_per_cpu_kthread() and fix the hot-unplug problems stemming from the
change.

Fixes: 1cf12e08bc ("sched/hotplug: Consolidate task migration on CPU unplug")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103507.102416009@infradead.org
2021-01-22 15:09:44 +01:00
Peter Zijlstra 975707f227 sched: Prepare to use balance_push in ttwu()
In preparation of using the balance_push state in ttwu() we need it to
provide a reliable and consistent state.

The immediate problem is that rq->balance_callback gets cleared every
schedule() and then re-set in the balance_push_callback() itself. This
is not a reliable signal, so add a variable that stays set during the
entire time.

Also move setting it before the synchronize_rcu() in
sched_cpu_deactivate(), such that we get guaranteed visibility to
ttwu(), which is a preempt-disable region.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.966069627@infradead.org
2021-01-22 15:09:43 +01:00
Peter Zijlstra 640f17c824 workqueue: Restrict affinity change to rescuer
create_worker() will already set the right affinity using
kthread_bind_mask(), this means only the rescuer will need to change
it's affinity.

Howveer, while in cpu-hot-unplug a regular task is not allowed to run
on online&&!active as it would be pushed away quite agressively. We
need KTHREAD_IS_PER_CPU to survive in that environment.

Therefore set the affinity after getting that magic flag.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.826629830@infradead.org
2021-01-22 15:09:43 +01:00
Peter Zijlstra 5c25b5ff89 workqueue: Tag bound workers with KTHREAD_IS_PER_CPU
Mark the per-cpu workqueue workers as KTHREAD_IS_PER_CPU.

Workqueues have unfortunate semantics in that per-cpu workers are not
default flushed and parked during hotplug, however a subset does
manual flush on hotplug and hard relies on them for correctness.

Therefore play silly games..

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.693465814@infradead.org
2021-01-22 15:09:42 +01:00
Peter Zijlstra ac687e6e8c kthread: Extract KTHREAD_IS_PER_CPU
There is a need to distinguish geniune per-cpu kthreads from kthreads
that happen to have a single CPU affinity.

Geniune per-cpu kthreads are kthreads that are CPU affine for
correctness, these will obviously have PF_KTHREAD set, but must also
have PF_NO_SETAFFINITY set, lest userspace modify their affinity and
ruins things.

However, these two things are not sufficient, PF_NO_SETAFFINITY is
also set on other tasks that have their affinities controlled through
other means, like for instance workqueues.

Therefore another bit is needed; it turns out kthread_create_per_cpu()
already has such a bit: KTHREAD_IS_PER_CPU, which is used to make
kthread_park()/kthread_unpark() work correctly.

Expose this flag and remove the implicit setting of it from
kthread_create_on_cpu(); the io_uring usage of it seems dubious at
best.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.557620262@infradead.org
2021-01-22 15:09:42 +01:00
Peter Zijlstra 22f667c97a sched: Don't run cpu-online with balance_push() enabled
We don't need to push away tasks when we come online, mark the push
complete right before the CPU dies.

XXX hotplug state machine has trouble with rollback here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.415606087@infradead.org
2021-01-22 15:09:42 +01:00
Lai Jiangshan 547a77d02f workqueue: Use cpu_possible_mask instead of cpu_active_mask to break affinity
The scheduler won't break affinity for us any more, and we should
"emulate" the same behavior when the scheduler breaks affinity for
us.  The behavior is "changing the cpumask to cpu_possible_mask".

And there might be some other CPUs online later while the worker is
still running with the pending work items.  The worker should be allowed
to use the later online CPUs as before and process the work items ASAP.
If we use cpu_active_mask here, we can't achieve this goal but
using cpu_possible_mask can.

Fixes: 06249738a4 ("workqueue: Manually break affinity on hotplug")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210111152638.2417-4-jiangshanlai@gmail.com
2021-01-22 15:09:41 +01:00
Valentin Schneider 36c6e17bf1 sched/core: Print out straggler tasks in sched_cpu_dying()
Since commit

  1cf12e08bc ("sched/hotplug: Consolidate task migration on CPU unplug")

tasks are expected to move themselves out of a out-going CPU. For most
tasks this will be done automagically via BALANCE_PUSH, but percpu kthreads
will have to cooperate and move themselves away one way or another.

Currently, some percpu kthreads (workqueues being a notable exemple) do not
cooperate nicely and can end up on an out-going CPU at the time
sched_cpu_dying() is invoked.

Print the dying rq's tasks to shed some light on the stragglers.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210113183141.11974-1-valentin.schneider@arm.com
2021-01-22 15:09:41 +01:00
Linus Torvalds 2561bbbe2e Printk fixes for 5.11-rc5
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Merge tag 'printk-for-5.11-printk-rework-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixes from Petr Mladek:

 - Fix line counting and buffer size calculation. Both regressions
   caused that a reader buffer might not get filled as much as possible.

 - Restore non-documented behavior of printk() reader API and make it
   official.

   It did not fill the last byte of the provided buffer before 5.10. Two
   architectures, powerpc and um, used it to add the trailing '\0'.
   There might theoretically be more callers depending on this behavior
   in userspace.

* tag 'printk-for-5.11-printk-rework-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: fix buffer overflow potential for print_text()
  printk: fix kmsg_dump_get_buffer length calulations
  printk: ringbuffer: fix line counting
2021-01-21 11:37:22 -08:00
Petr Mladek 535b6a122c Merge branch 'printk-rework' into for-linus 2021-01-21 16:06:21 +01:00
Linus Torvalds 75439bc439 Networking fixes for 5.11-rc5, including fixes from bpf, wireless,
and can trees.
 
 Current release - regressions:
 
  - nfc: nci: fix the wrong NCI_CORE_INIT parameters
 
 Current release - new code bugs:
 
  - bpf: allow empty module BTFs
 
 Previous releases - regressions:
 
  - bpf: fix signed_{sub,add32}_overflows type handling
 
  - tcp: do not mess with cloned skbs in tcp_add_backlog()
 
  - bpf: prevent double bpf_prog_put call from bpf_tracing_prog_attach
 
  - bpf: don't leak memory in bpf getsockopt when optlen == 0
 
  - tcp: fix potential use-after-free due to double kfree()
 
  - mac80211: fix encryption issues with WEP
 
  - devlink: use right genl user_ptr when handling port param get/set
 
  - ipv6: set multicast flag on the multicast route
 
  - tcp: fix TCP_USER_TIMEOUT with zero window
 
 Previous releases - always broken:
 
  - bpf: local storage helpers should check nullness of owner ptr passed
 
  - mac80211: fix incorrect strlen of .write in debugfs
 
  - cls_flower: call nla_ok() before nla_next()
 
  - skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.11-rc5, including fixes from bpf, wireless, and
  can trees.

  Current release - regressions:

   - nfc: nci: fix the wrong NCI_CORE_INIT parameters

  Current release - new code bugs:

   - bpf: allow empty module BTFs

  Previous releases - regressions:

   - bpf: fix signed_{sub,add32}_overflows type handling

   - tcp: do not mess with cloned skbs in tcp_add_backlog()

   - bpf: prevent double bpf_prog_put call from bpf_tracing_prog_attach

   - bpf: don't leak memory in bpf getsockopt when optlen == 0

   - tcp: fix potential use-after-free due to double kfree()

   - mac80211: fix encryption issues with WEP

   - devlink: use right genl user_ptr when handling port param get/set

   - ipv6: set multicast flag on the multicast route

   - tcp: fix TCP_USER_TIMEOUT with zero window

  Previous releases - always broken:

   - bpf: local storage helpers should check nullness of owner ptr passed

   - mac80211: fix incorrect strlen of .write in debugfs

   - cls_flower: call nla_ok() before nla_next()

   - skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too"

* tag 'net-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (52 commits)
  net: systemport: free dev before on error path
  net: usb: cdc_ncm: don't spew notifications
  net: mscc: ocelot: Fix multicast to the CPU port
  tcp: Fix potential use-after-free due to double kfree()
  bpf: Fix signed_{sub,add32}_overflows type handling
  can: peak_usb: fix use after free bugs
  can: vxcan: vxcan_xmit: fix use after free bug
  can: dev: can_restart: fix use after free bug
  tcp: fix TCP socket rehash stats mis-accounting
  net: dsa: b53: fix an off by one in checking "vlan->vid"
  tcp: do not mess with cloned skbs in tcp_add_backlog()
  selftests: net: fib_tests: remove duplicate log test
  net: nfc: nci: fix the wrong NCI_CORE_INIT parameters
  sh_eth: Fix power down vs. is_opened flag ordering
  net: Disable NETIF_F_HW_TLS_RX when RXCSUM is disabled
  netfilter: rpfilter: mask ecn bits before fib lookup
  udp: mask TOS bits in udp_v4_early_demux()
  xsk: Clear pool even for inactive queues
  bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback
  sh_eth: Make PHY access aware of Runtime PM to fix reboot crash
  ...
2021-01-20 11:52:21 -08:00
Daniel Borkmann bc895e8b2a bpf: Fix signed_{sub,add32}_overflows type handling
Fix incorrect signed_{sub,add32}_overflows() input types (and a related buggy
comment). It looks like this might have slipped in via copy/paste issue, also
given prior to 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
the signature of signed_sub_overflows() had s64 a and s64 b as its input args
whereas now they are truncated to s32. Thus restore proper types. Also, the case
of signed_add32_overflows() is not consistent to signed_sub32_overflows(). Both
have s32 as inputs, therefore align the former.

Fixes: 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: De4dCr0w <sa516203@mail.ustc.edu.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-01-20 17:19:40 +01:00
Linus Torvalds 45dfb8a565 task_work-2021-01-19
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Merge tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block

Pull task_work fix from Jens Axboe:
 "The TIF_NOTIFY_SIGNAL change inadvertently removed the unconditional
  task_work run we had in get_signal().

  This caused a regression for some setups, since we're relying on eg
  ____fput() being run to close and release, for example, a pipe and
  wake the other end.

  For 5.11, I prefer the simple solution of just reinstating the
  unconditional run, even if it conceptually doesn't make much sense -
  if you need that kind of guarantee, you should be using TWA_SIGNAL
  instead of TWA_NOTIFY. But it's the trivial fix for 5.11, and would
  ensure that other potential gotchas/assumptions for task_work don't
  regress for 5.11.

  We're looking into further simplifying the task_work notifications for
  5.12 which would resolve that too"

* tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block:
  task_work: unconditionally run task_work from get_signal()
2021-01-19 13:26:05 -08:00
Mircea Cirjaliu 301a33d518 bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback
I assume this was obtained by copy/paste. Point it to bpf_map_peek_elem()
instead of bpf_map_pop_elem(). In practice it may have been less likely
hit when under JIT given shielded via 84430d4232 ("bpf, verifier: avoid
retpoline for map push/pop/peek operation").

Fixes: f1a2e44a3a ("bpf: add queue and stack maps")
Signed-off-by: Mircea Cirjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mauricio Vasquez <mauriciovasquezbernal@gmail.com>
Link: https://lore.kernel.org/bpf/AM7PR02MB6082663DFDCCE8DA7A6DD6B1BBA30@AM7PR02MB6082.eurprd02.prod.outlook.com
2021-01-19 22:04:08 +01:00
John Ogness f0e386ee0c printk: fix buffer overflow potential for print_text()
Before the commit 896fbe20b4 ("printk: use the lockless
ringbuffer"), msg_print_text() would only write up to size-1 bytes
into the provided buffer. Some callers expect this behavior and
append a terminator to returned string. In particular:

arch/powerpc/xmon/xmon.c:dump_log_buf()
arch/um/kernel/kmsg_dump.c:kmsg_dumper_stdout()

msg_print_text() has been replaced by record_print_text(), which
currently fills the full size of the buffer. This causes a
buffer overflow for the above callers.

Change record_print_text() so that it will only use size-1 bytes
for text data. Also, for paranoia sakes, add a terminator after
the text data.

And finally, document this behavior so that it is clear that only
size-1 bytes are used and a terminator is added.

Fixes: 896fbe20b4 ("printk: use the lockless ringbuffer")
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210114170412.4819-1-john.ogness@linutronix.de
2021-01-19 11:42:14 +01:00
Jakub Kicinski e23a8d0021 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-01-16

1) Fix a double bpf_prog_put() for BPF_PROG_{TYPE_EXT,TYPE_TRACING} types in
   link creation's error path causing a refcount underflow, from Jiri Olsa.

2) Fix BTF validation errors for the case where kernel modules don't declare
   any new types and end up with an empty BTF, from Andrii Nakryiko.

3) Fix BPF local storage helpers to first check their {task,inode} owners for
   being NULL before access, from KP Singh.

4) Fix a memory leak in BPF setsockopt handling for the case where optlen is
   zero and thus temporary optval buffer should be freed, from Stanislav Fomichev.

5) Fix a syzbot memory allocation splat in BPF_PROG_TEST_RUN infra for
   raw_tracepoint caused by too big ctx_size_in, from Song Liu.

6) Fix LLVM code generation issues with verifier where PTR_TO_MEM{,_OR_NULL}
   registers were spilled to stack but not recognized, from Gilad Reti.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  MAINTAINERS: Update my email address
  selftests/bpf: Add verifier test for PTR_TO_MEM spill
  bpf: Support PTR_TO_MEM{,_OR_NULL} register spilling
  bpf: Reject too big ctx_size_in for raw_tp test run
  libbpf: Allow loading empty BTFs
  bpf: Allow empty module BTFs
  bpf: Don't leak memory in bpf getsockopt when optlen == 0
  bpf: Update local storage test to check handling of null ptrs
  bpf: Fix typo in bpf_inode_storage.c
  bpf: Local storage helpers should check nullness of owner ptr passed
  bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach
====================

Link: https://lore.kernel.org/r/20210116002025.15706-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15 16:34:59 -08:00
John Ogness 89ccf18f03 printk: fix kmsg_dump_get_buffer length calulations
kmsg_dump_get_buffer() uses @syslog to determine if the syslog
prefix should be written to the buffer. However, when calculating
the maximum number of records that can fit into the buffer, it
always counts the bytes from the syslog prefix.

Use @syslog when calculating the maximum number of records that can
fit into the buffer.

Fixes: e2ae715d66 ("kmsg - kmsg_dump() use iterator to receive log buffer content")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210113164413.1599-1-john.ogness@linutronix.de
2021-01-15 11:32:52 +01:00