Commit Graph

34699 Commits

Author SHA1 Message Date
Peter Zijlstra
2714c3962f perf: Fix event multiplexing for exclusive groups
Commit 9e6302056f ("perf: Use hrtimers for event multiplexing")
placed the hrtimer (re)start call in the wrong place.  Instead of
capturing all scheduling failures, it only considered the PMU failure.

The result is that groups using perf_event_attr::exclusive are no
longer rotated.

Fixes: 9e6302056f ("perf: Use hrtimers for event multiplexing")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162902.038667689@infradead.org
2020-11-09 18:12:36 +01:00
Peter Zijlstra
251ff2d493 perf: Simplify group_sched_in()
Collate the error paths. Code duplication only leads to divergence and
extra bugs.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162901.972161394@infradead.org
2020-11-09 18:12:35 +01:00
Peter Zijlstra
8c7855d829 perf: Simplify group_sched_out()
Since event_sched_out() clears cpuctx->exclusive upon removal of an
exclusive event (and only group leaders can be exclusive), there is no
point in group_sched_out() trying to do it too. It is impossible for
cpuctx->exclusive to still be set here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162901.904060564@infradead.org
2020-11-09 18:12:35 +01:00
Peter Zijlstra
76a4efa809 perf/arch: Remove perf_sample_data::regs_user_copy
struct perf_sample_data lives on-stack, we should be careful about it's
size. Furthermore, the pt_regs copy in there is only because x86_64 is a
trainwreck, solve it differently.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
09da9c8125 perf: Optimize get_recursion_context()
"Look ma, no branches!"

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lkml.kernel.org/r/20201030151955.187580298@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
ce0f17fc93 perf: Fix get_recursion_context()
One should use in_serving_softirq() to detect SoftIRQ context.

Fixes: 96f6d44443 ("perf_counter: avoid recursion")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.120572175@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra
267fb27352 perf: Reduce stack usage of perf_output_begin()
__perf_output_begin() has an on-stack struct perf_sample_data in the
unlikely case it needs to generate a LOST record. However, every call
to perf_output_begin() must already have a perf_sample_data on-stack.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
2020-11-09 18:12:33 +01:00
kiyin(尹亮)
7bdb157cde perf/core: Fix a memory leak in perf_event_parse_addr_filter()
As shown through runtime testing, the "filename" allocation is not
always freed in perf_event_parse_addr_filter().

There are three possible ways that this could happen:

 - It could be allocated twice on subsequent iterations through the loop,
 - or leaked on the success path,
 - or on the failure path.

Clean up the code flow to make it obvious that 'filename' is always
freed in the reallocation path and in the two return paths as well.

We rely on the fact that kfree(NULL) is NOP and filename is initialized
with NULL.

This fixes the leak. No other side effects expected.

[ Dan Carpenter: cleaned up the code flow & added a changelog. ]
[ Ingo Molnar: updated the changelog some more. ]

Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Signed-off-by: "kiyin(尹亮)" <kiyin@tencent.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
Cc: Anthony Liguori <aliguori@amazon.com>
--
 kernel/events/core.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
2020-11-07 13:07:26 +01:00
Linus Torvalds
3249fe4563 Tracing fixes:
- Fix off-by-one error in retrieving the context buffer for trace_printk()
 
 - Fix off-by-one error in stack nesting limit
 
 - Fix recursion to not make all NMI code false positive as recursing
 
 - Stop losing events in function tracing when transitioning between irq context
 
 - Stop losing events in ring buffer when transitioning between irq context
 
 - Fix return code of error pointer in parse_synth_field() to prevent
   NULL pointer dereference.
 
 - Fix false positive of NMI recursion in kprobe event handling
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX6QqmRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qtWiAQCKf3xblmQDcge2BLQPy2H7ih5VCSSb
 vDPrQKgLa35pSgEAhGj7mgAKxb6kDbae1BqPorfa/qn9Bi13XfRNTxBK2Qw=
 =zKfd
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix off-by-one error in retrieving the context buffer for
   trace_printk()

 - Fix off-by-one error in stack nesting limit

 - Fix recursion to not make all NMI code false positive as recursing

 - Stop losing events in function tracing when transitioning between irq
   context

 - Stop losing events in ring buffer when transitioning between irq
   context

 - Fix return code of error pointer in parse_synth_field() to prevent
   NULL pointer dereference.

 - Fix false positive of NMI recursion in kprobe event handling

* tag 'trace-v5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kprobes: Tell lockdep about kprobe nesting
  tracing: Make -ENOMEM the default error for parse_synth_field()
  ring-buffer: Fix recursion protection transitions between interrupt context
  tracing: Fix the checking of stackidx in __ftrace_trace_stack
  ftrace: Handle tracing when switching between context
  ftrace: Fix recursion check for NMI test
  tracing: Fix out of bounds write in get_trace_buf
2020-11-05 11:41:38 -08:00
Linus Torvalds
f786dfa374 Power management fixes for 5.10-rc3.
- Unify the handling of managed and stateless device links in the
    runtime PM framework and prevent runtime PM references to devices
    from being leaked after device link removal (Rafael Wysocki).
 
  - Fix two mistakes in the cpuidle documentation (Julia Lawall).
 
  - Prevent the schedutil cpufreq governor from missing policy
    limits updates in some cases (Viresh Kumar).
 
  - Prevent static OPPs from being dropped by mistake (Viresh Kumar).
 
  - Prevent helper function in the OPP framework from returning
    prematurely (Viresh Kumar).
 
  - Prevent opp_table_lock from being held too long during removal
    of OPP tables with no more active references (Viresh Kumar).
 
  - Drop redundant semicolon from the Intel RAPL power capping
    driver (Tom Rix).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl+kAnUSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxND0P/j5e/wqFZ/34XEaUa4PIs27TDoJHq1Jh
 PfUxqSBEVO6Xm8TMCtOIuS8gw4x7ehenXC8gFdivy+Fu+4QNkPKYggF5/LgWO8Gl
 cMNzYwJ8shIBQWQZftIx01Bn5tAvk1YhV1mnSNf580Iy7FhKqojMnrvzQnpGD4jR
 piBkvBcbIJWDk+T96RzbqnqmMD0euvlYfzg1KnsyqsOpoRl7kZoH4ahWYskdIxDY
 NtA4SqQ8dvxjTwI8+a+JBb//ua9jjjDyjd7FUV87HMdcVh9rZKbmHKkk4Yv/3C4C
 jZuCTV6zaWIHCbbkZwi+OTNE8q21GgWm1xqwnGWVTFSGrs8ZyfjLs73/g9S5zI3N
 C/n4YUJxiYDVcnrAVwR7kSTEouiQ6mTuChOt7T3r1Ilx67rw4TDsI59Fk1Xn07bZ
 1wfaPASUPsFAxF7vMhkdzsidhpR3BYNgMwmAWo9R4Yvw4evyRN4tywoUQJ1X27zg
 ERir6mFVz6XCnXPrJhyx0bWLo+VD8J/arhfIPSTqHR7wn0tgc23aVeYy7wvfYiiu
 QQJqQ58Aoa0Z7ZpeAv3xbSung+eqQ/dDC9FnXqxdZCI6brYUhrZ19OhsFnEyzGUR
 IDRzcP1/72AxhidpjO71txOJSJFTqKF2LzL/wuS6kMbYwmFjYfj18xX5GvOUuXmL
 hO+E+QdleQFo
 =lKQA
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix the device links support in runtime PM, correct mistakes in
  the cpuidle documentation, fix the handling of policy limits changes
  in the schedutil cpufreq governor, fix assorted issues in the OPP
  (operating performance points) framework and make one janitorial
  change.

  Specifics:

   - Unify the handling of managed and stateless device links in the
     runtime PM framework and prevent runtime PM references to devices
     from being leaked after device link removal (Rafael Wysocki).

   - Fix two mistakes in the cpuidle documentation (Julia Lawall).

   - Prevent the schedutil cpufreq governor from missing policy limits
     updates in some cases (Viresh Kumar).

   - Prevent static OPPs from being dropped by mistake (Viresh Kumar).

   - Prevent helper function in the OPP framework from returning
     prematurely (Viresh Kumar).

   - Prevent opp_table_lock from being held too long during removal of
     OPP tables with no more active references (Viresh Kumar).

   - Drop redundant semicolon from the Intel RAPL power capping driver
     (Tom Rix)"

* tag 'pm-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: runtime: Resume the device earlier in __device_release_driver()
  PM: runtime: Drop pm_runtime_clean_up_links()
  PM: runtime: Drop runtime PM references to supplier on link removal
  powercap/intel_rapl: remove unneeded semicolon
  Documentation: PM: cpuidle: correct path name
  Documentation: PM: cpuidle: correct typo
  cpufreq: schedutil: Don't skip freq update if need_freq_update is set
  opp: Reduce the size of critical section in _opp_table_kref_release()
  opp: Fix early exit from dev_pm_opp_register_set_opp_helper()
  opp: Don't always remove static OPPs in _of_add_opp_table_v1()
2020-11-05 11:04:29 -08:00
Steven Rostedt (VMware)
645f224e7b kprobes: Tell lockdep about kprobe nesting
Since the kprobe handlers have protection that prohibits other handlers from
executing in other contexts (like if an NMI comes in while processing a
kprobe, and executes the same kprobe, it will get fail with a "busy"
return). Lockdep is unaware of this protection. Use lockdep's nesting api to
differentiate between locks taken in INT3 context and other context to
suppress the false warnings.

Link: https://lore.kernel.org/r/20201102160234.fa0ae70915ad9e2b21c08b85@kernel.org

Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-04 09:46:06 -05:00
Steven Rostedt (VMware)
561ca66910 tracing: Make -ENOMEM the default error for parse_synth_field()
parse_synth_field() returns a pointer and requires that errors get
surrounded by ERR_PTR(). The ret variable is initialized to zero, but should
never be used as zero, and if it is, it could cause a false return code and
produce a NULL pointer dereference. It makes no sense to set ret to zero.

Set ret to -ENOMEM (the most common error case), and have any other errors
set it to something else. This removes the need to initialize ret on *every*
error branch.

Fixes: 761a8c58db ("tracing, synthetic events: Replace buggy strcat() with seq_buf operations")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 15:58:32 -05:00
Steven Rostedt (VMware)
b02414c8f0 ring-buffer: Fix recursion protection transitions between interrupt context
The recursion protection of the ring buffer depends on preempt_count() to be
correct. But it is possible that the ring buffer gets called after an
interrupt comes in but before it updates the preempt_count(). This will
trigger a false positive in the recursion code.

Use the same trick from the ftrace function callback recursion code which
uses a "transition" bit that gets set, to allow for a single recursion for
to handle transitions between contexts.

Cc: stable@vger.kernel.org
Fixes: 567cd4da54 ("ring-buffer: User context bit recursion checking")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 15:58:32 -05:00
Lukas Bulwahn
3b70ae4f5c kernel/hung_task.c: make type annotations consistent
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
removed various __user annotations from function signatures as part of
its refactoring.

It also removed the __user annotation for proc_dohung_task_timeout_secs()
at its declaration in sched/sysctl.h, but not at its definition in
kernel/hung_task.c.

Hence, sparse complains:

  kernel/hung_task.c:271:5: error: symbol 'proc_dohung_task_timeout_secs' redeclared with different type (incompatible argument 3 (different address spaces))

Adjust the annotation at the definition fitting to that refactoring to make
sparse happy again, which also resolves this warning from sparse:

  kernel/hung_task.c:277:52: warning: incorrect type in argument 3 (different address spaces)
  kernel/hung_task.c:277:52:    expected void *
  kernel/hung_task.c:277:52:    got void [noderef] __user *buffer

No functional change. No change in object code.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Ignatov <rdna@fb.com>
Link: https://lkml.kernel.org/r/20201028130541.20320-1-lukas.bulwahn@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-02 12:14:19 -08:00
Zqiang
6993d0fdbe kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled
There is a small race window when a delayed work is being canceled and
the work still might be queued from the timer_fn:

	CPU0						CPU1
kthread_cancel_delayed_work_sync()
   __kthread_cancel_work_sync()
     __kthread_cancel_work()
        work->canceling++;
					      kthread_delayed_work_timer_fn()
						   kthread_insert_work();

BUG: kthread_insert_work() should not get called when work->canceling is
set.

Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201014083030.16895-1-qiang.zhang@windriver.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-02 12:14:19 -08:00
Oleg Nesterov
7b3c36fc4c ptrace: fix task_join_group_stop() for the case when current is traced
This testcase

	#include <stdio.h>
	#include <unistd.h>
	#include <signal.h>
	#include <sys/ptrace.h>
	#include <sys/wait.h>
	#include <pthread.h>
	#include <assert.h>

	void *tf(void *arg)
	{
		return NULL;
	}

	int main(void)
	{
		int pid = fork();
		if (!pid) {
			kill(getpid(), SIGSTOP);

			pthread_t th;
			pthread_create(&th, NULL, tf, NULL);

			return 0;
		}

		waitpid(pid, NULL, WSTOPPED);

		ptrace(PTRACE_SEIZE, pid, 0, PTRACE_O_TRACECLONE);
		waitpid(pid, NULL, 0);

		ptrace(PTRACE_CONT, pid, 0,0);
		waitpid(pid, NULL, 0);

		int status;
		int thread = waitpid(-1, &status, 0);
		assert(thread > 0 && thread != pid);
		assert(status == 0x80137f);

		return 0;
	}

fails and triggers WARN_ON_ONCE(!signr) in do_jobctl_trap().

This is because task_join_group_stop() has 2 problems when current is traced:

	1. We can't rely on the "JOBCTL_STOP_PENDING" check, a stopped tracee
	   can be woken up by debugger and it can clone another thread which
	   should join the group-stop.

	   We need to check group_stop_count || SIGNAL_STOP_STOPPED.

	2. If SIGNAL_STOP_STOPPED is already set, we should not increment
	   sig->group_stop_count and add JOBCTL_STOP_CONSUME. The new thread
	   should stop without another do_notify_parent_cldstop() report.

To clarify, the problem is very old and we should blame
ptrace_init_task().  But now that we have task_join_group_stop() it makes
more sense to fix this helper to avoid the code duplication.

Reported-by: syzbot+3485e3773f7da290eecc@syzkaller.appspotmail.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christian Brauner <christian@brauner.io>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201019134237.GA18810@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-02 12:14:19 -08:00
Viresh Kumar
23a881852f cpufreq: schedutil: Don't skip freq update if need_freq_update is set
The cpufreq policy's frequency limits (min/max) can get changed at any
point of time, while schedutil is trying to update the next frequency.
Though the schedutil governor has necessary locking and support in place
to make sure we don't miss any of those updates, there is a corner case
where the governor will find that the CPU is already running at the
desired frequency and so may skip an update.

For example, consider that the CPU can run at 1 GHz, 1.2 GHz and 1.4 GHz
and is running at 1 GHz currently. Schedutil tries to update the
frequency to 1.2 GHz, during this time the policy limits get changed as
policy->min = 1.4 GHz. As schedutil (and cpufreq core) does clamp the
frequency at various instances, we will eventually set the frequency to
1.4 GHz, while we will save 1.2 GHz in sg_policy->next_freq.

Now lets say the policy limits get changed back at this time with
policy->min as 1 GHz. The next time schedutil is invoked by the
scheduler, we will reevaluate the next frequency (because
need_freq_update will get set due to limits change event) and lets say
we want to set the frequency to 1.2 GHz again. At this point
sugov_update_next_freq() will find the next_freq == current_freq and
will abort the update, while the CPU actually runs at 1.4 GHz.

Until now need_freq_update was used as a flag to indicate that the
policy's frequency limits have changed, and that we should consider the
new limits while reevaluating the next frequency.

This patch fixes the above mentioned issue by extending the purpose of
the need_freq_update flag. If this flag is set now, the schedutil
governor will not try to abort a frequency change even if next_freq ==
current_freq.

As similar behavior is required in the case of
CPUFREQ_NEED_UPDATE_LIMITS flag as well, need_freq_update will never be
set to false if that flag is set for the driver.

We also don't need to consider the need_freq_update flag in
sugov_update_single() anymore to handle the special case of busy CPU, as
we won't abort a frequency update anymore.

Reported-by: zhuguangqing <zhuguangqing@xiaomi.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rearrange code to avoid a branch ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-02 17:57:49 +01:00
Qiujun Huang
906695e593 tracing: Fix the checking of stackidx in __ftrace_trace_stack
The array size is FTRACE_KSTACK_NESTING, so the index FTRACE_KSTACK_NESTING
is illegal too. And fix two typos by the way.

Link: https://lkml.kernel.org/r/20201031085714.2147-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 11:21:40 -05:00
Steven Rostedt (VMware)
726b3d3f14 ftrace: Handle tracing when switching between context
When an interrupt or NMI comes in and switches the context, there's a delay
from when the preempt_count() shows the update. As the preempt_count() is
used to detect recursion having each context have its own bit get set when
tracing starts, and if that bit is already set, it is considered a recursion
and the function exits. But if this happens in that section where context
has changed but preempt_count() has not been updated, this will be
incorrectly flagged as a recursion.

To handle this case, create another bit call TRANSITION and test it if the
current context bit is already set. Flag the call as a recursion if the
TRANSITION bit is already set, and if not, set it and continue. The
TRANSITION bit will be cleared normally on the return of the function that
set it, or if the current context bit is clear, set it and clear the
TRANSITION bit to allow for another transition between the current context
and an even higher one.

Cc: stable@vger.kernel.org
Fixes: edc15cafcb ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 08:52:18 -05:00
Steven Rostedt (VMware)
ee11b93f95 ftrace: Fix recursion check for NMI test
The code that checks recursion will work to only do the recursion check once
if there's nested checks. The top one will do the check, the other nested
checks will see recursion was already checked and return zero for its "bit".
On the return side, nothing will be done if the "bit" is zero.

The problem is that zero is returned for the "good" bit when in NMI context.
This will set the bit for NMIs making it look like *all* NMI tracing is
recursing, and prevent tracing of anything in NMI context!

The simple fix is to return "bit + 1" and subtract that bit on the end to
get the real bit.

Cc: stable@vger.kernel.org
Fixes: edc15cafcb ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 08:52:18 -05:00
Qiujun Huang
c1acb4ac1a tracing: Fix out of bounds write in get_trace_buf
The nesting count of trace_printk allows for 4 levels of nesting. The
nesting counter starts at zero and is incremented before being used to
retrieve the current context's buffer. But the index to the buffer uses the
nesting counter after it was incremented, and not its original number,
which in needs to do.

Link: https://lkml.kernel.org/r/20201029161905.4269-1-hqjagain@gmail.com

Cc: stable@vger.kernel.org
Fixes: 3d9622c12c ("tracing: Add barrier to trace_printk() buffer nesting modification")
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02 08:52:18 -05:00
Linus Torvalds
4312e0e8d3 A few fixes for timers/timekeeping:
- Prevent undefined behaviour in the timespec64_to_ns() conversion which
     is used for converting user supplied time input to nanoseconds. It
     lacked overflow protection.
 
   - Mark sched_clock_read_begin/retry() to prevent recursion in the tracer
 
   - Remove unused debug functions in the hrtimer and timerlist code
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+evaETHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoT69D/0Z3ZGdNQu3mAPYdMSaW7R3MfXnLKno
 biRCwre/T88Exv+Yu612iLthTlfNlxZbofAgUc5BvCwjAjtt+uXlmS8mwXNsbGFd
 516hisUnjJkjbcHI6WxrQQ7+YsK2XLjOeV90TpLs9zMgI94kQ+uzEzqKc6ZaRQP4
 Zi/emqgHeO/RoObNBWjNh9McrHqXllXU/LeqD7y82JXdLPik78PniKFkh7B1d6u8
 RL7kW1TeblkNaHMVjO4/lM9zR1hkZr4GPYbEHIbVN8FMQ10BAD2iswUR72U2mqx7
 zf2Jt+09UEzPRu2gOr4Lrvo6bJQKClu4ZUnRt4apU4BeTgyG0gi7pgy0VZ3M1xtq
 KUnN8dNSMBwTurv9GuGTdiNpfFad2nsnSAra8r7GlZDHxNe1wWIPJmyu/FV1xohD
 yUgRq2s7rvCb894oz159hyIwkI/ZNbFr/AJTCvdzowgf9nf4WS5/Y2/JVLF28LRT
 4xPhvuVUfrhHJajoZayuVvxYSVEPZFek2SgUEIFi6b1+FiMFwV6guv/f31D5GQ+E
 NHgvDMbDsVmzGt++c4zFHoqWvBrgC8Os8AEP8s2oczfvwMt2A8g7nIrGieAux+Jm
 eLO1DfXaXpQi/MmTBf/WD1dKwjuoLV9dT0Fp2y2docu9SXm/bMgRhxX7fm3uDge7
 W87XWkfIxd5fzA==
 =Gdoq
 -----END PGP SIGNATURE-----

Merge tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "A few fixes for timers/timekeeping:

   - Prevent undefined behaviour in the timespec64_to_ns() conversion
     which is used for converting user supplied time input to
     nanoseconds. It lacked overflow protection.

   - Mark sched_clock_read_begin/retry() to prevent recursion in the
     tracer

   - Remove unused debug functions in the hrtimer and timerlist code"

* tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Prevent undefined behaviour in timespec64_to_ns()
  timers: Remove unused inline funtion debug_timer_free()
  hrtimer: Remove unused inline function debug_hrtimer_free()
  time/sched_clock: Mark sched_clock_read_begin/retry() as notrace
2020-11-01 11:13:45 -08:00
Linus Torvalds
82423b46fc A single fix for stop machine. Mark functions no trace to prevent a crash
caused by recursion when enabling or disabling a tracer on RISC-V (probably
 all architectures which patch through stop machine).
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+evLQTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoQR6D/49PIepVEn63HmgsKdePUShUFzYb+v6
 mPV0iwaDCdW6BKXVEuHkzGdz3dB5ytdIZP6tJLV5a44tYxPhYESO+O4FwAJnqBxD
 JGWLUELxqeEESnjBHww26/YptxqRwcVir2G0WeRDIO0eV2JE424ptdRSisgRVC2s
 Kcu41D9Ry5SLayEKN29GyRXQPrMwLCUTAzeziN4TwJeRB2exSUMg6iDFiGC2uZy6
 IzSu9BXak5T61LL7q5urElkY8a+sGLx6N29QBtSNxazYeXCzCoEtX+1IQ2e9b3PO
 4abFsEtYJ9Mbw4R+iKm0lIpUMKmr/GOPWBs/PDTqK0aYhpc8UnKXTCr6hWLTvtkE
 Anb/08AqN7YtvgbBR+bEN4fPOP4jL5kQVjLbNlIKm5ktRjZ5Sfd9OKOc//c/Bs3e
 Auqe2u+UW2REDsB3lNiVFY+I/1nQUVwKLwfOsBHJW1KzH6O+BhJrJgigUERTeyTf
 B5eLsOIxKgP1vprA/qQgPc/VT25PFIMOtxr7KhH1qPBej9R/wGEOdeOGSdJoiNYM
 aH3kCTUMU0NP8IUSyVQFt4v2IhZ5aF+3rQmyVXifGRl54QCXKgb5gzqcQ/L2SFn+
 I4SkB35hAoEzJ9S4vtx5ZtWPXAO20V644qRMalYv5X739zMVZQ2AyHGB9rhhktmX
 a8ZDIVFCh0ssmw==
 =38RZ
 -----END PGP SIGNATURE-----

Merge tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp fix from Thomas Gleixner:
 "A single fix for stop machine.

  Mark functions no trace to prevent a crash caused by recursion when
  enabling or disabling a tracer on RISC-V (probably all architectures
  which patch through stop machine)"

* tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine, rcu: Mark functions as notrace
2020-11-01 11:11:38 -08:00
Linus Torvalds
8d99084efc A couple of locking fixes:
- Fix incorrect failure injection handling on the fuxtex code
 
  - Prevent a preemption warning in lockdep when tracking local_irq_enable()
    and interrupts are already enabled
 
  - Remove more raw_cpu_read() usage from lockdep which causes state
    corruption on !X86 architectures.
 
  - Make the nr_unused_locks accounting in lockdep correct again.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+evEUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYod93EADG90GmRBYQxn6y2eQUKE/9f5SMiMFJ
 KdvuqNBqHOhYm3iUPbZJcb0P/JZi1NHP0fBFMishdESGi96tD96K7T04WD0gmjtm
 ArWFroe8uzEYtY9atlEwM0Nrvq0w8ZBLv9x1adXzJ59vB8/8Uq+wzYioSWn9yMcv
 ye3jfVyAlM7ouFHDQAA36s/nhvZfxms4C0t+6S3gjVTIp/6riGuYh5t7dbXUMlnu
 nGLiIJFjU+ekurweVDGpqD/nAxYfqf3UxebWnrosf7iu6suwYwaPFZGZ/kxlbr5e
 qWx0B1RuhjAoefVJlPTkHmuhd0SnH/Gm/tTNkQ3LidJhPTIhLJlb7zffwyZlc510
 VdaUipfZ6bNqDD6/dK6fKJtdKSE4w/z3pT53954NUD5zw/jIcHlgnaQieh72DH+F
 1EKqmsNrwHAxYfMndQxLGdIoBScUAFzHzDnzsY9KKS2cfhChljzLa2nDIfMsDfKQ
 aROugzEbZPQEb1iWUEOF3XopcuZzZQCaPlLDLvAnsBeYEPm0gdmbKFPFsDjOyBVX
 /Qc41O7DyHKcoiLX2zM2c7CxnV5J6YEZz3jQSZLFlpH9Ih7jwAl9/6VirggNUNvV
 YVsgM/myhYQtJBqHHojNppZFFW3KdgfxWuY7+qt7Ox5w/ck5qYQwRnoB4FROwVHV
 pzcYTBE5qkQnIw==
 =S01o
 -----END PGP SIGNATURE-----

Merge tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "A couple of locking fixes:

   - Fix incorrect failure injection handling in the fuxtex code

   - Prevent a preemption warning in lockdep when tracking
     local_irq_enable() and interrupts are already enabled

   - Remove more raw_cpu_read() usage from lockdep which causes state
     corruption on !X86 architectures.

   - Make the nr_unused_locks accounting in lockdep correct again"

* tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix nr_unused_locks accounting
  locking/lockdep: Remove more raw_cpu_read() usage
  futex: Fix incorrect should_fail_futex() handling
  lockdep: Fix preemption WARN for spurious IRQ-enable
2020-11-01 11:08:17 -08:00
Linus Torvalds
53760f9b74 flexible-array member conversion patches for 5.10-rc2
Hi Linus,
 
 Please, pull the following patches that replace zero-length arrays with
 flexible-array members.
 
 Thanks
 --
 Gustavo
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEkmRahXBSurMIg1YvRwW0y0cG2zEFAl+cjRUACgkQRwW0y0cG
 2zGWAhAAjUfTsAmXWhKNaWFSCYR0Q822puTUWOKfiBd+jjGaO04luTtr2gjv2Dkb
 Vgad8H4N8oZU79xfh5JZ5PUyScaso8wE6ZJTh2PLKXpKmNd213f5x/pIt78CCDTa
 Y1L/eR41mmveTL3VNS3sf6WaZpT9owxJKGIY8JgdiOmSjxJQpX5zdaC1KYso4eXr
 lIXIRo9VLEmVLhhHhZi+QmX6+aQ05E1D9K0ENe4/uEnRsV525W78iwZ4fYeLzr+A
 krEOdgx6sPgzajPYnHoayrrcKNKxD5YY1SWuVSm2tqYYIhlRoK3f5xgLOd10RiHE
 YMgx8aWzGmGJwoUhgp1bo/l9EZ7O8OWRqM/GOP4x6Wgjdhqw2x5jgskmhsKNGEXu
 /BlbS+qL5aUrMCxhvNbApuZW6xBiBbva76MH3vU9vFhZbVz1CHLQdGI0tfxggYWS
 jc2UPgoxL9OQlf3jSc+gK7RMFhBGNWn2Aiy8GQas3BxPYXuYPvwOj+irDOG/qZ9D
 VZ5swUw4+th+DsF5K53mEFeLv0fONMgL9Ka5bNR6+k6HG0WNLYYVOiet3xYUDo1f
 eZbMZthfc+QW7R8cwG0WuFk6rC6mLqE+A9nQuLZoJD+VMuJd4pwW9+6EW8nDX08w
 FS4/o92xUFJfOCgaLRS61FSAuSmFENieN+yoKMK/Uf6PJVdNMb4=
 =vyu3
 -----END PGP SIGNATURE-----

Merge tag 'flexible-array-conversions-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull more flexible-array member conversions from Gustavo A. R. Silva:
 "Replace zero-length arrays with flexible-array members"

* tag 'flexible-array-conversions-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  printk: ringbuffer: Replace zero-length array with flexible-array member
  net/smc: Replace zero-length array with flexible-array member
  net/mlx5: Replace zero-length array with flexible-array member
  mei: hw: Replace zero-length array with flexible-array member
  gve: Replace zero-length array with flexible-array member
  Bluetooth: btintel: Replace zero-length array with flexible-array member
  scsi: target: tcmu: Replace zero-length array with flexible-array member
  ima: Replace zero-length array with flexible-array member
  enetc: Replace zero-length array with flexible-array member
  fs: Replace zero-length array with flexible-array member
  Bluetooth: Replace zero-length array with flexible-array member
  params: Replace zero-length array with flexible-array member
  tracepoint: Replace zero-length array with flexible-array member
  platform/chrome: cros_ec_proto: Replace zero-length array with flexible-array member
  platform/chrome: cros_ec_commands: Replace zero-length array with flexible-array member
  mailbox: zynqmp-ipi-message: Replace zero-length array with flexible-array member
  dmaengine: ti-cppi5: Replace zero-length array with flexible-array member
2020-10-31 14:31:28 -07:00
Gustavo A. R. Silva
a38283da05 printk: ringbuffer: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-30 16:57:42 -05:00
Linus Torvalds
8843f40550 Power management fixes for 5.10-rc2
- Modify Kconfig to prevent configuring either the "conservative"
    or the "ondemand" governor as the default cpufreq governor if
    intel_pstate is selected, in which case "schedutil" is the
    default choice for the default governor setting (Rafael Wysocki).
 
  - Modify the cpufreq core, intel_pstate and the schedutil governor
    to avoid missing updates of the HWP max limit when intel_pstate
    operates in the passive mode with HWP enabled (Rafael Wysocki).
 
  - Fix max_cstate module parameter handling in intel_idle for
    processor models with C-state tables coming from ACPI (Chen Yu).
 
  - Clean up assorted pieces of power management code (Jackie Zamow,
    Tom Rix, Zhang Qilong).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl+cOyISHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxxj0P/1qmvZeLR5ODvSKLURSlzQYPiF4Ud0uo
 7huByO3K63hJ9qpEQZVVzNl0Yuu5vCa7cliebnIRNDHMy4AVOVw5Qf9Uhz/tFlmZ
 ZBvSX1LGWdvMzUnx00AASdHbNOrFy+YyooQ5RfA8sFmtvAhRhPNRW9VCzc9Midoh
 cICSQ6fQDn+0wb+hv89HQlIRvbakM6a8QDL4xI6Y8aS/a5OwOHGJQnC7ZLPIoQLi
 BxD/IEDdNvDiLFPx8OpxJ93NtLaz1tyvWFJHvqSnOREDYB22YkG8WLZftY7h8pz6
 MMbXrZN11/Tex1H0KXDI4YscCBnwxNnFuBo1ur/FX6GvDm2Sm9ybpVHCXxYKux46
 ZFc8K2auqApt98xTlrqKru/rfCB2/fubypUustqpYeCjowBENPFbjyag8bRaKLh3
 awiDwwz1wZDd2mZfEl4iaxJI4gjUwRmPDC1UiT1dlc7nozaDzPxrGGiQghAshOnW
 JVQAiw+evERIFuH5YvJ+/si1sJYhreMjoQ7mICNMmpgJ2ElVvNufpW9aVRQiycp1
 9a0u1ZgGs9DI1580+YTl1nGvsRefdgvMDpozcESwxY8dmMm+027+lyLhwlrUTPfy
 gmakUcb4jbvIicG53huxus7teqBLwrX36HOHBb1l3tSJfOkcQieddGUZxuT8Q9xp
 rAY2mRMRr7SI
 =w+LI
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix a few issues related to running intel_pstate in the passive
  mode with HWP enabled, correct the handling of the max_cstate module
  parameter in intel_idle and make a few janitorial changes.

  Specifics:

   - Modify Kconfig to prevent configuring either the "conservative" or
     the "ondemand" governor as the default cpufreq governor if
     intel_pstate is selected, in which case "schedutil" is the default
     choice for the default governor setting (Rafael Wysocki).

   - Modify the cpufreq core, intel_pstate and the schedutil governor to
     avoid missing updates of the HWP max limit when intel_pstate
     operates in the passive mode with HWP enabled (Rafael Wysocki).

   - Fix max_cstate module parameter handling in intel_idle for
     processor models with C-state tables coming from ACPI (Chen Yu).

   - Clean up assorted pieces of power management code (Jackie Zamow,
     Tom Rix, Zhang Qilong)"

* tag 'pm-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: schedutil: Always call driver if CPUFREQ_NEED_UPDATE_LIMITS is set
  cpufreq: Introduce cpufreq_driver_test_flags()
  cpufreq: speedstep: remove unneeded semicolon
  PM: sleep: fix typo in kernel/power/process.c
  intel_idle: Fix max_cstate for processor models without C-state tables
  cpufreq: intel_pstate: Avoid missing HWP max updates in passive mode
  cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag
  cpufreq: Avoid configuring old governors as default with intel_pstate
  cpufreq: e_powersaver: remove unreachable break
2020-10-30 12:45:04 -07:00
Peter Zijlstra
1a39340865 lockdep: Fix nr_unused_locks accounting
Chris reported that commit 24d5a3bffef1 ("lockdep: Fix
usage_traceoverflow") breaks the nr_unused_locks validation code
triggered by /proc/lockdep_stats.

By fully splitting LOCK_USED and LOCK_USED_READ it becomes a bad
indicator for accounting nr_unused_locks; simplyfy by using any first
bit.

Fixes: 24d5a3bffef1 ("lockdep: Fix usage_traceoverflow")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://lkml.kernel.org/r/20201027124834.GL2628@hirez.programming.kicks-ass.net
2020-10-30 17:07:18 +01:00
Peter Zijlstra
d48e385003 locking/lockdep: Remove more raw_cpu_read() usage
I initially thought raw_cpu_read() was OK, since if it is !0 we have
IRQs disabled and can't get migrated, so if we get migrated both CPUs
must have 0 and it doesn't matter which 0 we read.

And while that is true; it isn't the whole store, on pretty much all
architectures (except x86) this can result in computing the address for
one CPU, getting migrated, the old CPU continuing execution with another
task (possibly setting recursion) and then the new CPU reading the value
of the old CPU, which is no longer 0.

Similer to:

  baffd723e4 ("lockdep: Revert "lockdep: Use raw_cpu_*() for per-cpu variables"")

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201026152256.GB2651@hirez.programming.kicks-ass.net
2020-10-30 17:07:18 +01:00
Rafael J. Wysocki
dea47cf45a Merge branches 'pm-cpuidle' and 'pm-sleep'
* pm-cpuidle:
  intel_idle: Fix max_cstate for processor models without C-state tables

* pm-sleep:
  PM: sleep: fix typo in kernel/power/process.c
2020-10-30 16:30:14 +01:00
Gustavo A. R. Silva
fa29c9c11d params: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00
Gustavo A. R. Silva
9d0a49c702 tracepoint: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00
Rafael J. Wysocki
d1e7c2996e cpufreq: schedutil: Always call driver if CPUFREQ_NEED_UPDATE_LIMITS is set
Because sugov_update_next_freq() may skip a frequency update even if
the need_freq_update flag has been set for the policy at hand, policy
limits updates may not take effect as expected.

For example, if the intel_pstate driver operates in the passive mode
with HWP enabled, it needs to update the HWP min and max limits when
the policy min and max limits change, respectively, but that may not
happen if the target frequency does not change along with the limit
at hand.  In particular, if the policy min is changed first, causing
the target frequency to be adjusted to it, and the policy max limit
is changed later to the same value, the HWP max limit will not be
updated to follow it as expected, because the target frequency is
still equal to the policy min limit and it will not change until
that limit is updated.

To address this issue, modify get_next_freq() to let the driver
callback run if the CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag
is set regardless of whether or not the new frequency to set is
equal to the previous one.

Fixes: f6ebbcf08f ("cpufreq: intel_pstate: Implement passive mode with HWP enabled")
Reported-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: 1c534352f4 cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS ...
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+: a62f68f5ca cpufreq: Introduce cpufreq_driver_test_flags()
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-29 14:12:18 +01:00
Linus Torvalds
23859ae444 Fix synthetic event "strcat" overrun
New synthetic event code used strcat() and miscalculated the ending, causing
 the concatenation to write beyond the allocated memory.
 
 Instead of using strncat(), the code is switched over to seq_buf which has
 all the mechanisms in place to protect against writing more than what is
 allocated, and cleans up the code a bit.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCX5lZkBQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qu8+AQDfg1UM12HUIs1XRhbXBxf9g3kjwrJh
 nuoMilEZZstSCgD8DDQiPckOS9NfrdkyCPQ86tIKoOsGPowoA21sNOHPvQQ=
 =+V+S
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix synthetic event "strcat" overrun

  New synthetic event code used strcat() and miscalculated the ending,
  causing the concatenation to write beyond the allocated memory.

  Instead of using strncat(), the code is switched over to seq_buf which
  has all the mechanisms in place to protect against writing more than
  what is allocated, and cleans up the code a bit"

* tag 'trace-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing, synthetic events: Replace buggy strcat() with seq_buf operations
2020-10-28 12:05:14 -07:00
Mateusz Nosek
921c7ebd13 futex: Fix incorrect should_fail_futex() handling
If should_futex_fail() returns true in futex_wake_pi(), then the 'ret'
variable is set to -EFAULT and then immediately overwritten. So the failure
injection is non-functional.

Fix it by actually leaving the function and returning -EFAULT.

The Fixes tag is kinda blury because the initial commit which introduced
failure injection was already sloppy, but the below mentioned commit broke
it completely.

[ tglx: Massaged changelog ]

Fixes: 6b4f4bc9cb ("locking/futex: Allow low-level atomic operations to return -EAGAIN")
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200927000858.24219-1-mateusznosek0@gmail.com
2020-10-28 15:48:51 +01:00
Jackie Zamow
4d4ce8053b PM: sleep: fix typo in kernel/power/process.c
Fix a typo in a comment in freeze_processes().

Signed-off-by: Jackie Zamow <jackie.zamow@gmail.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-27 19:11:44 +01:00
Steven Rostedt (VMware)
761a8c58db tracing, synthetic events: Replace buggy strcat() with seq_buf operations
There was a memory corruption bug happening while running the synthetic
event selftests:

 kmemleak: Cannot insert 0xffff8c196fa2afe5 into the object search tree (overlaps existing)
 CPU: 5 PID: 6866 Comm: ftracetest Tainted: G        W         5.9.0-rc5-test+ #577
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 Call Trace:
  dump_stack+0x8d/0xc0
  create_object.cold+0x3b/0x60
  slab_post_alloc_hook+0x57/0x510
  ? tracing_map_init+0x178/0x340
  __kmalloc+0x1b1/0x390
  tracing_map_init+0x178/0x340
  event_hist_trigger_func+0x523/0xa40
  trigger_process_regex+0xc5/0x110
  event_trigger_write+0x71/0xd0
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fef0a63a487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
 RSP: 002b:00007fff76f18398 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000039 RCX: 00007fef0a63a487
 RDX: 0000000000000039 RSI: 000055eb3b26d690 RDI: 0000000000000001
 RBP: 000055eb3b26d690 R08: 000000000000000a R09: 0000000000000038
 R10: 000055eb3b2cdb80 R11: 0000000000000246 R12: 0000000000000039
 R13: 00007fef0a70b500 R14: 0000000000000039 R15: 00007fef0a70b700
 kmemleak: Kernel memory leak detector disabled
 kmemleak: Object 0xffff8c196fa2afe0 (size 8):
 kmemleak:   comm "ftracetest", pid 6866, jiffies 4295082531
 kmemleak:   min_count = 1
 kmemleak:   count = 0
 kmemleak:   flags = 0x1
 kmemleak:   checksum = 0
 kmemleak:   backtrace:
      __kmalloc+0x1b1/0x390
      tracing_map_init+0x1be/0x340
      event_hist_trigger_func+0x523/0xa40
      trigger_process_regex+0xc5/0x110
      event_trigger_write+0x71/0xd0
      vfs_write+0xca/0x210
      ksys_write+0x70/0xf0
      do_syscall_64+0x33/0x40
      entry_SYSCALL_64_after_hwframe+0x44/0xa9

The cause came down to a use of strcat() that was adding an string that was
shorten, but the strcat() did not take that into account.

strcat() is extremely dangerous as it does not care how big the buffer is.
Replace it with seq_buf operations that prevent the buffer from being
overwritten if what is being written is bigger than the buffer.

Fixes: 10819e2579 ("tracing: Handle synthetic event array field type checking correctly")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-27 09:25:36 -04:00
Zong Li
4230e2deaa stop_machine, rcu: Mark functions as notrace
Some architectures assume that the stopped CPUs don't make function calls
to traceable functions when they are in the stopped state. See also commit
cb9d7fd51d ("watchdog: Mark watchdog touch functions as notrace").

Violating this assumption causes kernel crashes when switching tracer on
RISC-V.

Mark rcu_momentary_dyntick_idle() and stop_machine_yield() notrace to
prevent this.

Fixes: 4ecf0a43e7 ("processor: get rid of cpu_relax_yield")
Fixes: 366237e7b0 ("stop_machine: Provide RCU quiescent state in multi_cpu_stop()")
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201021073839.43935-1-zong.li@sifive.com
2020-10-26 12:12:27 +01:00
Zeng Tao
cb47755725 time: Prevent undefined behaviour in timespec64_to_ns()
UBSAN reports:

Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow:
17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
 timespec64_to_ns include/linux/time64.h:127 [inline]
 set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
 do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
 __x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
 do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295

Commit bd40a17576 ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.

Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.

[ tglx: Added comment and adjusted the fixes tag ]

Fixes: 361a3bf005 ("time64: Add time64.h header and define struct timespec64")
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com
2020-10-26 11:48:11 +01:00
YueHaibing
9010e3876e timers: Remove unused inline funtion debug_timer_free()
There is no caller in tree, remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200909134749.32300-1-yuehaibing@huawei.com
2020-10-26 11:39:21 +01:00
YueHaibing
5254cb87c0 hrtimer: Remove unused inline function debug_hrtimer_free()
There is no caller in tree, remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200909134850.21940-1-yuehaibing@huawei.com
2020-10-26 11:39:21 +01:00
Quanyang Wang
4cd2bb1298 time/sched_clock: Mark sched_clock_read_begin/retry() as notrace
Since sched_clock_read_begin() and sched_clock_read_retry() are called
by notrace function sched_clock(), they shouldn't be traceable either,
or else ftrace_graph_caller will run into a dead loop on the path
as below (arm for instance):

  ftrace_graph_caller()
    prepare_ftrace_return()
      function_graph_enter()
        ftrace_push_return_trace()
          trace_clock_local()
            sched_clock()
              sched_clock_read_begin/retry()

Fixes: 1b86abc1c6 ("sched_clock: Expose struct clock_read_data")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200929082027.16787-1-quanyang.wang@windriver.com
2020-10-26 11:34:31 +01:00
Joe Perches
33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Rasmus Villemoes
986b9eacb2 kernel/sys.c: fix prototype of prctl_get_tid_address()
tid_addr is not a "pointer to (pointer to int in userspace)"; it is in
fact a "pointer to (pointer to int in userspace) in userspace".  So
sparse rightfully complains about passing a kernel pointer to
put_user().

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 11:44:16 -07:00
Linus Torvalds
672f887126 A time namespace fix and a matching selftest. The futex absolute timeouts
which are based on CLOCK_MONOTONIC require time namespace corrected. This
 was missed in the original time namesapce support.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+VimUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoZKpEACuxPe0iHE5j2deQK7W6+bOSosh6tdI
 WlDoKoB+tfVqE+JLYNCk7hwKI4/mdgOIfzFbXQjUgfCsMFhJ5IOrKL+mmbqi0V02
 2Gy/9whww8kzhlk05/nbnKaK7LRVXhisWSbd9wZRrftIRwl2KKf64g9yWv90E3+j
 NNCTihRAyN0oXsg9nT2JnDTKSWvVGemlpW7ej0Yywh2WT/17p1ShKQXTBYXUJjvT
 3QC8Gfp7LJ2BSXuUzB2NwnjNxW7hVnwWSm+CKB0xtLGJ0KM/zLbJD9lFjqbEzlgs
 1yECw7PUQFFlhMubIOKJTP+kMvieRiQafi9v7iAh2UB1m3JyQO4daRPwxbDPhJKR
 3Hqln0Fl8i/Ge6XHTBWzo1SsRC5DdBxHxQVBNHsPI8hPCOlgKGgdYjNQC8V7AX0v
 bWrVSIFkVDreFOzOg4+LbGV/7HXdMSQCEb3XXCYtMPMMKOuxsLknHO884nqovM1E
 tL21Zw/TBHzBo4N4Kt7pNqmEKqmdcxl198aW3Lv+2UqWbVSo8UcYIlXq/jcPwXH+
 vnrsRBNaXZRBFUQYAmNsUbPjuIRJ6U9Ic0WxhbHrcTI2SyJXg/SjhCltoYEESJfT
 T2dyn2XEnysJ/RKZu3DHY81P6cn3NGSb/D/Po0faaACHgQu1InxR5BSABTuFWwAQ
 EXfTQfu0cDQ0wQ==
 =VFCv
 -----END PGP SIGNATURE-----

Merge tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "A time namespace fix and a matching selftest. The futex absolute
  timeouts which are based on CLOCK_MONOTONIC require time namespace
  corrected. This was missed in the original time namesapce support"

* tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/timens: Add a test for futex()
  futex: Adjust absolute futex timeouts with per time namespace offset
2020-10-25 11:28:49 -07:00
Linus Torvalds
87702a337f Two scheduler fixes:
- A trivial build fix for sched_feat() to compile correctly with
     CONFIG_JUMP_LABEL=n
 
   - Replace a zero lenght array with a flexible array.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl+VifUTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoW2FD/9u7iQw1QvvK6li6nW3QWr1j3E8Z5E2
 7cPq02AKQZmfsacEgRVe68Bn9NidW7d3PNO+IsomZJyoiov27PfFKqjPmvcFVQBI
 NIHkCUEc41wF0ZkWA0Z1VqixkzBMQ9al+iTHp6W20MDqe7lQFVbLHiKghN9+o2uL
 1b2YxbvTy4NbgN40bd23l5P2zTTCW9hnaZX0rhj35PHKD069brcdy1bSfONXoq4e
 b1VxwBhFXMRbhaifMf1yy1WaYYc+9dEePF28otXZQ5EiOwmf7bnIIU7mEV7NotkN
 XWB4iy4EFt+NKxUB8tWB8duzJ2x5T6tB4bVQoBsh4/hE4n3vO+LjsUEAArIabzi+
 wIbrAtPeScD4M7gsxlVgc6q0vbBXuR0ymh+TrDZvsE3wIXABYxgajTg6nGRlB1S5
 ZfKuCTNWT4JBnCJHtMChwInJ5+y/GHHd92TvUIN8+5kHbkTlp5GNQtw+B5eTwY9P
 XtUTTiSh4z2T9wQiRq0fjbyTqkGNL8wbo2lXbtHf0hA/XFa0OY3Gx/vJ9w+74Sy+
 X60eS8Ew2XkkdWm+litDQ+f8ulZvYqg3ejitvteYlOORoryX3mpNUOCeNoDQzegj
 PDKBE7SJSI5aqtpkO+bQoic0eC4A4CpJYES2ZH8a4nCu1a74OF0fiFh91AHjwqCI
 yyeJzYsLbMo3PQ==
 =RNOk
 -----END PGP SIGNATURE-----

Merge tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "Two scheduler fixes:

   - A trivial build fix for sched_feat() to compile correctly with
     CONFIG_JUMP_LABEL=n

   - Replace a zero lenght array with a flexible array"

* tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/features: Fix !CONFIG_JUMP_LABEL case
  sched: Replace zero-length array with flexible-array
2020-10-25 11:25:16 -07:00
Linus Torvalds
81ecf91eab SafeSetID changes for v5.10
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgvWslnM+qUy+sgVg5n2WYw6TPBAFAl+Ifu8ACgkQ5n2WYw6T
 PBCoxA/+Pn0XvwYa6V773lPNjon+Oa94Aq7Wl6YryDMJakiGDJFSJa0tEI8TmRkJ
 z21kjww2Us9gEvfmNoc0t4oDJ98UNAXERjc98fOZgxH1d1urpGUI7qdQ07YCo0xZ
 CDOvqXk/PobGF6p9BpF5QWqEJNq6G8xAKpA8nLa6OUPcjofHroWCgIs86Rl3CtTc
 DwjcOvCgUoTxFm9Vpvm04njFFkVuGUwmXuhyV3Xjh2vNhHvfpP/ibTPmmv1sx4dO
 9WE8BjW0HL5VMzms/BE/mnXmbu2BdPs+PW9/RjQfebbAH8DM3Noqr9f3Db8eqp7t
 TiqU8AO06TEVZa011+V3aywgz9rnH+XJ17TfutB28Z7lG3s4XPZYDgzubJxb1X8M
 4d2mCL3N/ao5otx6FqpgJ2oK0ZceB/voY9qyyfErEBhRumxifl7AQCHxt3LumH6m
 fvvNY+UcN/n7hZPJ7sgZVi/hnnwvO0e1eX0L9ZdNsDjR1bgzBQCdkY53XNxam+rM
 z7tmT3jlDpNtPzOzFCZeiJuTgWYMDdJFqekPLess/Vqaswzc4PPT2lyQ6N81NR5H
 +mzYf/PNIg5fqN8QlMQEkMTv2fnC19dHJT83NPgy4dQObpXzUqYGWAmdKcBxLpnG
 du8wDpPHusChRFMZKRMTXztdMvMAuNqY+KJ6bFojG0Z+qgR7oQk=
 =/anB
 -----END PGP SIGNATURE-----

Merge tag 'safesetid-5.10' of git://github.com/micah-morton/linux

Pull SafeSetID updates from Micah Morton:
 "The changes are mostly contained to within the SafeSetID LSM, with the
  exception of a few 1-line changes to change some ns_capable() calls to
  ns_capable_setid() -- causing a flag (CAP_OPT_INSETID) to be set that
  is examined by SafeSetID code and nothing else in the kernel.

  The changes to SafeSetID internally allow for setting up GID
  transition security policies, as already existed for UIDs"

* tag 'safesetid-5.10' of git://github.com/micah-morton/linux:
  LSM: SafeSetID: Fix warnings reported by test bot
  LSM: SafeSetID: Add GID security policy handling
  LSM: Signal to SafeSetID when setting group IDs
2020-10-25 10:45:26 -07:00
Linus Torvalds
91f28da8c9 random32: make prandom_u32() less predictable
This is the cleanup of the latest series of prandom_u32 experimentations
 consisting in using SipHash instead of Tausworthe to produce the randoms
 used by the network stack. The changes to the files were kept minimal,
 and the controversial commit that used to take noise from the fast_pool
 (f227e3ec3b) was reverted. Instead, a dedicated "net_rand_noise" per_cpu
 variable is fed from various sources of activities (networking, scheduling)
 to perturb the SipHash state using fast, non-trivially predictable data,
 instead of keeping it fully deterministic. The goal is essentially to make
 any occasional memory leakage or brute-force attempt useless.
 
 The resulting code was verified to be very slightly faster on x86_64 than
 what is was with the controversial commit above, though this remains barely
 above measurement noise. It was also tested on i386 and arm, and build-
 tested only on arm64.
 
 The whole discussion around this is archived here:
   https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJflHDtAAoJEE44bZycYXAvxXUP/A9aKCaSnJUgYi/0Fa507bi9
 yJkNs6cotQfzmG8GznQWdG2mdsviqI/d08UdIHD9JHKoin3wcT4+0So546pCw9BR
 tlrHnFcRnqEqXFLggnqkKnnIgGNNTppMDSi96BplNoXYXAMRjjvKW9Vl94lU2Abk
 a+aOOJRu4Vzj/5tRT3fkg/ldN6YGZ6nbqVkzd0WAwuYYIj1VSYUSkLgKc65n+4Xp
 ISnVWObeHJ+tnBRDVudTaUNYi7T3QvCF9glZZlFUVBDQbTRSqjMBSUmnBnOg1mhO
 Q5nY6xrfTi/0i39+/wOUUOTaxe7YggymibQfN+Y26w1rPO45RkvORiPKvXlfZWaI
 a3wh1TMoDAptrW9VXiO9pJv6a4xC16c7FyyTnGkP4jP+HTFdgmgixoNmPKrBxuEZ
 X8O+HOSf155j057aECMivk8bIj4FfLmYt2ciWqRZTVCwu9uK29AJSMx0SphTmYQ0
 p0HaJ8mHKnFVViX9n+YOPRfZDIRGH1zTOxzPhEkzuX8vx/4uiXsbp/ILxg0uZ913
 DgMk1rzzBlZsL7QqJQnf9JM810pFcU/PI7Y7PKaGKz3ntkJT2WV7gMeg+Wwv9254
 pPccvffYzdbtJAHgj+If8lHwixE33u5RscXqjpxIWLPcKTOLQNIf+6bRQ86sA+Kq
 Vbza8sDu6IWhvApCGLmB
 =KHhI
 -----END PGP SIGNATURE-----

Merge tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom

Pull random32 updates from Willy Tarreau:
 "Make prandom_u32() less predictable.

  This is the cleanup of the latest series of prandom_u32
  experimentations consisting in using SipHash instead of Tausworthe to
  produce the randoms used by the network stack.

  The changes to the files were kept minimal, and the controversial
  commit that used to take noise from the fast_pool (f227e3ec3b) was
  reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
  fed from various sources of activities (networking, scheduling) to
  perturb the SipHash state using fast, non-trivially predictable data,
  instead of keeping it fully deterministic. The goal is essentially to
  make any occasional memory leakage or brute-force attempt useless.

  The resulting code was verified to be very slightly faster on x86_64
  than what is was with the controversial commit above, though this
  remains barely above measurement noise. It was also tested on i386 and
  arm, and build- tested only on arm64"

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/

* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
  random32: add a selftest for the prandom32 code
  random32: add noise from network and scheduling activity
  random32: make prandom_u32() output unpredictable
2020-10-25 10:40:08 -07:00
Linus Torvalds
1b307ac870 dma-mapping fixes for 5.10:
- document the new document dma_{alloc,free}_pages API
  - two fixups for the dma-mapping.h split
 -----BEGIN PGP SIGNATURE-----
 
 iQI/BAABCgApFiEEgdbnc3r/njty3Iq9D55TZVIEUYMFAl+UN1ELHGhjaEBsc3Qu
 ZGUACgkQD55TZVIEUYPhkg//QLMwY4Lib1IPdeYR4k/UE2E4YtPjQghucNHXDkrd
 jjV5tvGPfNDOEKeCOamivTcOmc3E+jFhQFjpHplqd4OjsfZT3EyXaopdX/qN1Bbo
 JIib0WAAxO1N2MRhEPJzGAsCkMPT32Q52/ka1QUOmr1E8VPrKhU4T9+FnTbj1rgF
 HbMk+PdV4+HP53CvK+aaOfNHqJqQoTBeCx9xebybAjxIBCI+LedRwC7haV4Zz6tg
 xSp9cW0Ztdp9U7u1dOO4gEqnL/fNk3+RWF5iwtyCi96uYmguV+/vAqpWMyej97q5
 2Dx0jTQvj0FhnPug9asydadjtUqkzfRCSDGv4TybeHT/OZJEGAwkdJG7V/5PwGOg
 VCMpqi/WRIDPnUtN3OY4IZFigbyb4wJ6MOO/hvXagC7Lc2+z9ZhuUKUjSsV90LoT
 2a4xwm9M1JAglYbhGvLl5cjzmDSdCFXuGYlJ18lRZx7d4cGi34hAqq3WfqqteHm+
 IRfeAaWN7N+W8PgzGaDqfUVDrGNVZ7eo02kVicaJFCdJE5ecS3rUbyU8uVjhX7Sl
 h8zwBs8/5hFIKLCWUBiT+UBmvWXbG/a0plRh/vIvJ8lk4m4+kwdTRwgngpSkb3G/
 ytAJPZTeI7r75zkwxTHPE01Khf8/qWJ3cdv97PpQH+7mlo4J0XUr5ssmiQ7DAHuu
 jjo=
 =0N7Y
 -----END PGP SIGNATURE-----

Merge tag 'dma-mapping-5.10-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - document the new dma_{alloc,free}_pages() API

 - two fixups for the dma-mapping.h split

* tag 'dma-mapping-5.10-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: document dma_{alloc,free}_pages
  dma-mapping: move more functions to dma-map-ops.h
  ARM/sa1111: add a missing include of dma-map-ops.h
2020-10-24 12:17:05 -07:00
Willy Tarreau
3744741ada random32: add noise from network and scheduling activity
With the removal of the interrupt perturbations in previous random32
change (random32: make prandom_u32() output unpredictable), the PRNG
has become 100% deterministic again. While SipHash is expected to be
way more robust against brute force than the previous Tausworthe LFSR,
there's still the risk that whoever has even one temporary access to
the PRNG's internal state is able to predict all subsequent draws till
the next reseed (roughly every minute). This may happen through a side
channel attack or any data leak.

This patch restores the spirit of commit f227e3ec3b ("random32: update
the net random state on interrupt and activity") in that it will perturb
the internal PRNG's statee using externally collected noise, except that
it will not pick that noise from the random pool's bits nor upon
interrupt, but will rather combine a few elements along the Tx path
that are collectively hard to predict, such as dev, skb and txq
pointers, packet length and jiffies values. These ones are combined
using a single round of SipHash into a single long variable that is
mixed with the net_rand_state upon each invocation.

The operation was inlined because it produces very small and efficient
code, typically 3 xor, 2 add and 2 rol. The performance was measured
to be the same (even very slightly better) than before the switch to
SipHash; on a 6-core 12-thread Core i7-8700k equipped with a 40G NIC
(i40e), the connection rate dropped from 556k/s to 555k/s while the
SYN cookie rate grew from 5.38 Mpps to 5.45 Mpps.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin <lkml@sdf.org>
Cc: Amit Klein <aksecurity@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2020-10-24 20:21:57 +02:00