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1,089,026 commits

Author SHA1 Message Date
Zqiang
c2cf0767e9 rcu: Avoid running boost kthreads on isolated CPUs
When the boost kthreads are created on systems with nohz_full CPUs,
the cpus_allowed_ptr is set to housekeeping_cpumask(HK_FLAG_KTHREAD).
However, when the rcu_boost_kthread_setaffinity() is called, the original
affinity will be changed and these kthreads can subsequently run on
nohz_full CPUs.  This commit makes rcu_boost_kthread_setaffinity()
restrict these boost kthreads to housekeeping CPUs.

Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:25:20 -08:00
Zhouyi Zhou
17ea371882 rcu: Improve tree_plugin.h comments and add code cleanups
This commit cleans up some comments and code in kernel/rcu/tree_plugin.h.

Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:25:20 -08:00
Changbin Du
2407a64f80 rcu: in_irq() cleanup
This commit replaces the obsolete and ambiguous macro in_irq() with its
shiny new in_hardirq() equivalent.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:25:20 -08:00
Chun-Hung Tseng
24ba53017e rcu: Replace ________p1 and _________p1 with __UNIQUE_ID(rcu)
This commit replaces both ________p1 and _________p1 with __UNIQUE_ID(rcu),
and also adjusts the callers of the affected macros.

__UNIQUE_ID(rcu) will generate unique variable names during compilation,
which eliminates the need of ________p1 and _________p1 (both having 4
occurrences prior to the code change).  This also avoids the variable
name shadowing issue, or at least makes those wishing to cause shadowing
problems work much harder to do so.

The same idea is used for the min/max macros (commit 589a978 and commit
e9092d0).

Signed-off-by: Jim Huang <jserv@ccns.ncku.edu.tw>
Signed-off-by: Chun-Hung Tseng <henrybear327@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:25:20 -08:00
Paul E. McKenney
bc849e9192 rcu: Move rcu_needs_cpu() to tree.c
Now that RCU_FAST_NO_HZ is no more, there is but one implementation of
the rcu_needs_cpu() function.  This commit therefore moves this function
from kernel/rcu/tree_plugin.c to kernel/rcu/tree.c.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:24:47 -08:00
Paul E. McKenney
e2c73a6860 rcu: Remove the RCU_FAST_NO_HZ Kconfig option
All of the uses of CONFIG_RCU_FAST_NO_HZ=y that I have seen involve
systems with RCU callbacks offloaded.  In this situation, all that this
Kconfig option does is slow down idle entry/exit with an additional
allways-taken early exit.  If this is the only use case, then this
Kconfig option nothing but an attractive nuisance that needs to go away.

This commit therefore removes the RCU_FAST_NO_HZ Kconfig option.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:24:47 -08:00
Paul E. McKenney
24eab6e1ff torture: Remove RCU_FAST_NO_HZ from rcu scenarios
All of the rcu scenarios that mentioning CONFIG_RCU_FAST_NO_HZ disable it.
But this Kconfig option is disabled by default, so this commit removes
the pointless "CONFIG_RCU_FAST_NO_HZ=n" lines from these scenarios.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:24:47 -08:00
Paul E. McKenney
f04cbe651b torture: Remove RCU_FAST_NO_HZ from rcuscale and refscale scenarios
All of the rcuscale and refscale scenarios that mention the Kconfig option
CONFIG_RCU_FAST_NO_HZ disable it.  But this Kconfig option is disabled by
default, so this commit removes the pointless "CONFIG_RCU_FAST_NO_HZ=n"
lines from these scenarios.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:24:46 -08:00
Akira Yokosawa
5861dad198 doc: RCU: Avoid 'Symbol' font-family in SVG figures
On Ubuntu Focal, strings in some of SVG files under
Documentation/RCU/Design can not be rendered properly when
converted to PDF.

Ubuntu releases since Focal and Debian bullseye have trouble
with "Symbol" font-family in SVG files.

As those strings are mostly API names such as "READ_ONCE()",
"WRITE_ONCE(), "rcu_read_lock()", and so on, using a generic
monospace font-family should be a good alternative.

Substitute the font-family name by a simple sed pattern:

    's/Symbol/monospace/g'

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:23:14 -08:00
NeilBrown
7c0be9f890 doc: Add refcount analogy to What is RCU
The reader-writer-lock analogy is a useful way to think about RCU, but
it is not always applicable.  It is useful to have other analogies to
work with, and particularly to emphasise that no single analogy is
perfect.

This patch add a "RCU as reference count" to the "what is RCU" document.

See https://lwn.net/Articles/872559/

[ paulmck: Apply Akira Yokosawa feedback. ]
Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:23:06 -08:00
Paul E. McKenney
db4cb76861 doc: Remove obsolete kernel-per-CPU-kthreads RCU_FAST_NO_HZ advice
This document advises building with both CONFIG_NO_HZ=y and
CONFIG_RCU_FAST_NO_HZ=y.  However, CONFIG_NO_HZ=y offloads callbacks from
all nohz_full CPUs, and CPUs with offloaded callbacks do not benefit from
CONFIG_RCU_FAST_NO_HZ=y.  Quite the opposite: CONFIG_RCU_FAST_NO_HZ=y
simply adds a bit of idle entry/exit overhead.

This commit therefore changes that advice to only CONFIG_NO_HZ=y.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:23:06 -08:00
Waiman Long
1a5620671a clocksource: Reduce the default clocksource_watchdog() retries to 2
With the previous patch, there is an extra watchdog read in each retry.
Now the total number of clocksource reads is increased to 4 per iteration.
In order to avoid increasing the clock skew check overhead, the default
maximum number of retries is reduced from 3 to 2 to maintain the same 12
clocksource reads in the worst case.

Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:22:29 -08:00
Waiman Long
c86ff8c55b clocksource: Avoid accidental unstable marking of clocksources
Since commit db3a34e174 ("clocksource: Retry clock read if long delays
detected") and commit 2e27e793e2 ("clocksource: Reduce clocksource-skew
threshold"), it is found that tsc clocksource fallback to hpet can
sometimes happen on both Intel and AMD systems especially when they are
running stressful benchmarking workloads. Of the 23 systems tested with
a v5.14 kernel, 10 of them have switched to hpet clock source during
the test run.

The result of falling back to hpet is a drastic reduction of performance
when running benchmarks. For example, the fio performance tests can
drop up to 70% whereas the iperf3 performance can drop up to 80%.

4 hpet fallbacks happened during bootup. They were:

  [    8.749399] clocksource: timekeeping watchdog on CPU13: hpet read-back delay of 263750ns, attempt 4, marking unstable
  [   12.044610] clocksource: timekeeping watchdog on CPU19: hpet read-back delay of 186166ns, attempt 4, marking unstable
  [   17.336941] clocksource: timekeeping watchdog on CPU28: hpet read-back delay of 182291ns, attempt 4, marking unstable
  [   17.518565] clocksource: timekeeping watchdog on CPU34: hpet read-back delay of 252196ns, attempt 4, marking unstable

Other fallbacks happen when the systems were running stressful
benchmarks. For example:

  [ 2685.867873] clocksource: timekeeping watchdog on CPU117: hpet read-back delay of 57269ns, attempt 4, marking unstable
  [46215.471228] clocksource: timekeeping watchdog on CPU8: hpet read-back delay of 61460ns, attempt 4, marking unstable

Commit 2e27e793e2 ("clocksource: Reduce clocksource-skew threshold"),
changed the skew margin from 100us to 50us. I think this is too small
and can easily be exceeded when running some stressful workloads on a
thermally stressed system.  So it is switched back to 100us.

Even a maximum skew margin of 100us may be too small in for some systems
when booting up especially if those systems are under thermal stress. To
eliminate the case that the large skew is due to the system being too
busy slowing down the reading of both the watchdog and the clocksource,
an extra consecutive read of watchdog clock is being done to check this.

The consecutive watchdog read delay is compared against
WATCHDOG_MAX_SKEW/2. If the delay exceeds the limit, we assume that
the system is just too busy. A warning will be printed to the console
and the clock skew check is skipped for this round.

Fixes: db3a34e174 ("clocksource: Retry clock read if long delays detected")
Fixes: 2e27e793e2 ("clocksource: Reduce clocksource-skew threshold")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:22:29 -08:00
Paul E. McKenney
8c0abfd6d2 rcutorture: Add CONFIG_PREEMPT_DYNAMIC=n to tiny scenarios
With CONFIG_PREEMPT_DYNAMIC=y, the kernel builds with CONFIG_PREEMPTION=y
because preemption can be enabled at runtime.  This prevents any tests
of Tiny RCU or Tiny SRCU from running correctly.  This commit therefore
explicitly sets CONFIG_PREEMPT_DYNAMIC=n for those scenarios.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:20:58 -08:00
Umesh Nerlige Ramappa
2a67b18e67 drm/i915/pmu: Fix synchronization of PMU callback with reset
Since the PMU callback runs in irq context, it synchronizes with gt
reset using the reset count. We could run into a case where the PMU
callback could read the reset count before it is updated. This has a
potential of corrupting the busyness stats.

In addition to the reset count, check if the reset bit is set before
capturing busyness.

In addition save the previous stats only if you intend to update them.

v2:
- The 2 reset counts captured in the PMU callback can end up being the
  same if they were captured right after the count is incremented in the
  reset flow. This can lead to a bad busyness state. Ensure that reset
  is not in progress when the initial reset count is captured.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211108211057.68783-1-umesh.nerlige.ramappa@intel.com
2021-11-30 17:08:07 -08:00
Andrii Nakryiko
e30c8fd310 Merge branch 'Apply suggestions for typeless/weak ksym series'
Kumar Kartikeya says:

====================

Three commits addressing comments for the typeless/weak ksym set. No functional
change intended. Hopefully this is simpler to read for kfunc as well.
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-11-30 15:48:15 -08:00
Kumar Kartikeya Dwivedi
d995816b77 libbpf: Avoid reload of imm for weak, unresolved, repeating ksym
Alexei pointed out that we can use BPF_REG_0 which already contains imm
from move_blob2blob computation. Note that we now compare the second
insn's imm, but this should not matter, since both will be zeroed out
for the error case for the insn populated earlier.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211122235733.634914-4-memxor@gmail.com
2021-11-30 15:48:15 -08:00
Kumar Kartikeya Dwivedi
0270090d39 libbpf: Avoid double stores for success/failure case of ksym relocations
Instead, jump directly to success case stores in case ret >= 0, else do
the default 0 value store and jump over the success case. This is better
in terms of readability. Readjust the code for kfunc relocation as well
to follow a similar pattern, also leads to easier to follow code now.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211122235733.634914-3-memxor@gmail.com
2021-11-30 15:48:14 -08:00
Kumar Kartikeya Dwivedi
d4efb17086 bpf: Change bpf_kallsyms_lookup_name size type to ARG_CONST_SIZE_OR_ZERO
Andrii mentioned in [0] that switching to ARG_CONST_SIZE_OR_ZERO lets
user avoid having to prove that string size at runtime is not zero and
helps with not having to supress clang optimizations.

  [0]: https://lore.kernel.org/bpf/CAEf4BzZa_vhXB3c8atNcTS6=krQvC25H7K7c3WWZhM=27ro=Wg@mail.gmail.com

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211122235733.634914-2-memxor@gmail.com
2021-11-30 15:48:14 -08:00
Alexandre Belloni
a478c433d7 rtc: da9063: switch to RTC_FEATURE_UPDATE_INTERRUPT
Stop using uie_unsupported and clear RTC_FEATURE_UPDATE_INTERRUPT instead.
Also, let the core know that the alarm will truncate seconds as it only has
a minute resolution.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Link: https://lore.kernel.org/r/20211109234750.107115-1-alexandre.belloni@bootlin.com
2021-12-01 00:24:03 +01:00
Rikard Falkeborn
4946f15e8c genirq/generic_chip: Constify irq_generic_chip_ops
The only usage of irq_generic_chip_ops is to pass its address to
irq_domain_add_linear() which takes a pointer to const struct
irq_domain_ops. Make it const to allow the compiler to put it in
read-only memory.

[ tglx: Fixed subject prefix ]

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20211130214043.1257585-1-rikard.falkeborn@gmail.com
2021-12-01 00:15:07 +01:00
Marco Elver
52d0b8b187 x86/fpu/signal: Initialize sw_bytes in save_xstate_epilog()
save_sw_bytes() did not fully initialize sw_bytes, which caused KMSAN
to report an infoleak (see below).
Initialize sw_bytes explicitly to avoid this.

KMSAN report follows:

=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user ./include/linux/instrumented.h:121
BUG: KMSAN: kernel-infoleak in __copy_to_user ./include/linux/uaccess.h:154
BUG: KMSAN: kernel-infoleak in save_xstate_epilog+0x2df/0x510 arch/x86/kernel/fpu/signal.c:127
 instrument_copy_to_user ./include/linux/instrumented.h:121
 __copy_to_user ./include/linux/uaccess.h:154
 save_xstate_epilog+0x2df/0x510 arch/x86/kernel/fpu/signal.c:127
 copy_fpstate_to_sigframe+0x861/0xb60 arch/x86/kernel/fpu/signal.c:245
 get_sigframe+0x656/0x7e0 arch/x86/kernel/signal.c:296
 __setup_rt_frame+0x14d/0x2a60 arch/x86/kernel/signal.c:471
 setup_rt_frame arch/x86/kernel/signal.c:781
 handle_signal arch/x86/kernel/signal.c:825
 arch_do_signal_or_restart+0x417/0xdd0 arch/x86/kernel/signal.c:870
 handle_signal_work kernel/entry/common.c:149
 exit_to_user_mode_loop+0x1f6/0x490 kernel/entry/common.c:173
 exit_to_user_mode_prepare kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290
 syscall_exit_to_user_mode+0x7e/0xc0 kernel/entry/common.c:302
 do_syscall_64+0x60/0xd0 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x44/0xae ??:?

Local variable sw_bytes created at:
 save_xstate_epilog+0x80/0x510 arch/x86/kernel/fpu/signal.c:121
 copy_fpstate_to_sigframe+0x861/0xb60 arch/x86/kernel/fpu/signal.c:245

Bytes 20-47 of 48 are uninitialized
Memory access of size 48 starts at ffff8880801d3a18
Data copied to user address 00007ffd90e2ef50
=====================================================

Link: https://lore.kernel.org/all/CAG_fn=V9T6OKPonSjsi9PmWB0hMHFC=yawozdft8i1-MSxrv=w@mail.gmail.com/
Fixes: 53599b4d54 ("x86/fpu/signal: Prepare for variable sigframe length")
Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lkml.kernel.org/r/20211126124746.761278-1-glider@google.com
2021-11-30 15:13:47 -08:00
Marc Ferland
1c1b3098ae rtc: pcf85063: add i2c_device_id name matching support
The pcf85063 driver regsitration currently supports the "compatible"
property type of matching (for DT).

This patch adds "matching by name" support to the driver by defining
an i2c_device_id table and setting the id_table parameter in the
i2c_driver struct.

This will, for example, make the driver easier to instantiate on
systems where CONFIG_OF is not enabled (x86 in my case).

Signed-off-by: Marc Ferland <ferlandm@amotus.ca>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211116164733.17149-1-ferlandm@amotus.ca
2021-12-01 00:07:25 +01:00
Mark Rutland
985faa7868 powerpc: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-11-mark.rutland@arm.com
2021-12-01 00:06:44 +01:00
Mark Rutland
08b0af5b2a powerpc: Avoid discarding flags in system_call_exception()
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Thus, when setting flags we must use
an atomic operation rather than a plain read-modify-write sequence, as a
plain read-modify-write may discard flags which are concurrently set by a
remote thread, e.g.

	// task A			// task B
	tmp = A->thread_info.flags;
					set_tsk_thread_flag(A, NEWFLAG_B);
	tmp |= NEWFLAG_A;
	A->thread_info.flags = tmp;

arch/powerpc/kernel/interrupt.c's system_call_exception() sets
_TIF_RESTOREALL in the thread info flags with a read-modify-write, which
may result in other flags being discarded.

Elsewhere in the file it uses clear_bits() to atomically remove flag bits,
so use set_bits() here for consistency with those.

There may be reasons (e.g. instrumentation) that prevent the use of
set_thread_flag() and clear_thread_flag() here, which would otherwise be
preferable.

Fixes: ae7aaecc3f ("powerpc/64s: system call rfscv workaround for TM bugs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Eirik Fuller <efuller@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Link: https://lore.kernel.org/r/20211129130653.2037928-10-mark.rutland@arm.com
2021-12-01 00:06:44 +01:00
Mark Rutland
4ea7ce0a79 openrisc: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: https://lore.kernel.org/r/20211129130653.2037928-9-mark.rutland@arm.com
2021-12-01 00:06:44 +01:00
Mark Rutland
e538c58491 microblaze: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-8-mark.rutland@arm.com
2021-12-01 00:06:44 +01:00
Mark Rutland
342b380878 arm64: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20211129130653.2037928-7-mark.rutland@arm.com
2021-12-01 00:06:44 +01:00
Mark Rutland
050e22bfc4 ARM: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/20211129130653.2037928-6-mark.rutland@arm.com
2021-12-01 00:06:43 +01:00
Mark Rutland
7fb2b24bb5 alpha: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Link: https://lore.kernel.org/r/20211129130653.2037928-5-mark.rutland@arm.com
2021-12-01 00:06:43 +01:00
Mark Rutland
0569b24513 sched: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

The READ_ONCE(ti->flags) .. cmpxchg(ti->flags) loop in
set_nr_if_polling() is left as-is for clarity.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-4-mark.rutland@arm.com
2021-12-01 00:06:43 +01:00
Mark Rutland
6ce895128b entry: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-3-mark.rutland@arm.com
2021-12-01 00:06:43 +01:00
Mark Rutland
dca99fb643 x86: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-12-mark.rutland@arm.com
2021-12-01 00:06:43 +01:00
Mark Rutland
7ad639840a thread_info: Add helpers to snapshot thread flags
In <linux/thread_info.h> there are helpers to manipulate individual thread
flags, but where code wants to check several flags at once, it must open
code reading current_thread_info()->flags and operating on a snapshot.

As some flags can be set remotely it's necessary to use READ_ONCE() to get
a consistent snapshot even when IRQs are disabled, but some code forgets to
do this. Generally this is unlike to cause a problem in practice, but it is
somewhat unsound, and KCSAN will legitimately warn that there is a data
race.

To make it easier to do the right thing, and to highlight that concurrent
modification is possible, add new helpers to snapshot the flags, which
should be used in preference to plain reads. Subsequent patches will move
existing code to use the new helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-2-mark.rutland@arm.com
2021-12-01 00:06:43 +01:00
Camel Guo
f601aa7930 rtc: rs5c372: Add RTC_VL_READ, RTC_VL_CLR ioctls
In order to make it possible to get battery voltage status, this commit
adds RTC_VL_READ, RTC_VL_CLR ioctl commands to rtc-rs5c372.

Signed-off-by: Camel Guo <camelg@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211111083625.10216-1-camel.guo@axis.com
2021-12-01 00:05:42 +01:00
Kirill A. Shutemov
c494eb366d x86/sev-es: Use insn_decode_mmio() for MMIO implementation
Switch SEV implementation to insn_decode_mmio(). The helper is going
to be used by TDX too.

No functional changes.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20211130184933.31005-5-kirill.shutemov@linux.intel.com
2021-11-30 14:53:30 -08:00
Kirill A. Shutemov
70a81f99e4 x86/insn-eval: Introduce insn_decode_mmio()
In preparation for sharing MMIO instruction decode between SEV-ES and
TDX, factor out the common decode into a new insn_decode_mmio() helper.

For regular virtual machine, MMIO is handled by the VMM and KVM
emulates instructions that caused MMIO. But, this model doesn't work
for a secure VMs (like SEV or TDX) as VMM doesn't have access to the
guest memory and register state. So, for TDX or SEV VMM needs
assistance in handling MMIO. It induces exception in the guest. Guest
has to decode the instruction and handle it on its own.

The code is based on the current SEV MMIO implementation.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20211130184933.31005-4-kirill.shutemov@linux.intel.com
2021-11-30 14:53:19 -08:00
Kirill A. Shutemov
d5ec1877df x86/insn-eval: Introduce insn_get_modrm_reg_ptr()
The helper returns a pointer to the register indicated by
ModRM byte.

It's going to replace vc_insn_get_reg() in the SEV MMIO
implementation. TDX MMIO implementation will also use it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20211130184933.31005-3-kirill.shutemov@linux.intel.com
2021-11-30 14:53:04 -08:00
Kirill A. Shutemov
23ef731e43 x86/insn-eval: Handle insn_get_opcode() failure
is_string_insn() calls insn_get_opcode() that can fail, but does not
handle the failure.

is_string_insn() interface does not allow to communicate an error to the
caller.

Push insn_get_opcode() to the only non-static user of is_string_insn()
and fail it early if insn_get_opcode() fails.

[ dhansen: fix tabs-versus-spaces breakage ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20211130184933.31005-2-kirill.shutemov@linux.intel.com
2021-11-30 14:52:26 -08:00
Florian Westphal
28b78ecffe netfilter: bridge: add support for pppoe filtering
This makes 'bridge-nf-filter-pppoe-tagged' sysctl work for
bridged traffic.

Looking at the original commit it doesn't appear this ever worked:

 static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb,
[..]
        if (skb->protocol == htons(ETH_P_8021Q)) {
                skb_pull(skb, VLAN_HLEN);
                skb->network_header += VLAN_HLEN;
+       } else if (skb->protocol == htons(ETH_P_PPP_SES)) {
+               skb_pull(skb, PPPOE_SES_HLEN);
+               skb->network_header += PPPOE_SES_HLEN;
        }
 [..]
	NF_HOOK(... POST_ROUTING, ...)

... but the adjusted offsets are never restored.

The alternative would be to rip this code out for good,
but otoh we'd have to keep this anyway for the vlan handling
(which works because vlan tag info is in the skb, not the packet
 payload).

Reported-and-tested-by: Amish Chana <amish@3g.co.za>
Fixes: 516299d2f5 ("[NETFILTER]: bridge-nf: filter bridged IPv4/IPv6 encapsulated in pppoe traffic")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 23:37:55 +01:00
Pablo Neira Ayuso
f87b9464d1 netfilter: nft_fwd_netdev: Support egress hook
Allow packet redirection to another interface upon egress.

[lukas: set skb_iif, add commit message, original patch from Pablo. ]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 23:37:16 +01:00
Florian Westphal
b43c2793f5 netfilter: nfnetlink_queue: silence bogus compiler warning
net/netfilter/nfnetlink_queue.c:601:36: warning: variable 'ctinfo' is
uninitialized when used here [-Wuninitialized]
   if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)

ctinfo is only uninitialized if ct == NULL.  Init it to 0 to silence this.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 23:15:11 +01:00
Bernard Zhao
632cb151ca netfilter: ctnetlink: remove useless type conversion to bool
dying is bool, the type conversion to true/false value is not
needed.

Signed-off-by: Bernard Zhao <bernard@vivo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 23:11:03 +01:00
Tony Luck
7d697f0d57 x86/cpu: Drop spurious underscore from RAPTOR_LAKE #define
Convention for all the other "lake" CPUs is all one word.

So s/RAPTOR_LAKE/RAPTORLAKE/

Fixes: fbdb5e8f29 ("x86/cpu: Add Raptor Lake to Intel family")
Reported-by: Rui Zhang <rui.zhang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20211119170832.1034220-1-tony.luck@intel.com
2021-11-30 14:05:48 -08:00
Florian Westphal
c5fc837bf9 netfilter: nf_queue: remove leftover synchronize_rcu
Its no longer needed after commit 8702997074
("netfilter: nf_queue: move hookfn registration out of struct net").

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 22:50:43 +01:00
Kirill A. Shutemov
6da5175dbe x86/paravirt: Fix build PARAVIRT_XXL=y without XEN_PV
Kernel fails to compile with PARAVIRT_XXL=y if XEN_PV is not enabled:

	ld.lld: error: undefined symbol: xen_iret

It happens because INTERRUPT_RETURN defined to use xen_iret if
CONFIG_PARAVIRT_XXL enabled regardless of CONFIG_XEN_PV.

The issue is not visible in the current kernel because CONFIG_XEN_PV is
the only user of CONFIG_PARAVIRT_XXL and there's no way to enable them
separately.

Rework code to define INTERRUPT_RETURN based on CONFIG_XEN_PV, not
CONFIG_PARAVIRT_XXL.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lkml.kernel.org/r/20211130185533.32658-1-kirill.shutemov@linux.intel.com
2021-11-30 13:50:26 -08:00
Kees Cook
4be1dbb75c netfilter: conntrack: Use memset_startat() to zero struct nf_conn
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() to avoid confusing memset() about writing beyond
the target struct member.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 22:49:29 +01:00
GuoYong Zheng
fc5e0352cc ipvs: remove unused variable for ip_vs_new_dest
The dest variable is not used after ip_vs_new_dest anymore in
ip_vs_add_dest, do not need pass it to ip_vs_new_dest, remove it.

Signed-off-by: GuoYong Zheng <zhenggy@chinatelecom.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-11-30 22:46:08 +01:00
Ondrej Jirman
02fe0fbd8a i2c: rk3x: Handle a spurious start completion interrupt flag
In a typical read transfer, start completion flag is being set after
read finishes (notice ipd bit 4 being set):

trasnfer poll=0
i2c start
rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10
i2c read
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b
i2c stop
rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 33

This causes I2C transfer being aborted in polled mode from a stop completion
handler:

trasnfer poll=1
i2c start
rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10
i2c read
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 0
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b
i2c stop
rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 13
i2c stop
rk3x-i2c fdd40000.i2c: unexpected irq in STOP: 0x10

Clearing the START flag after read fixes the issue without any obvious
side effects.

This issue was dicovered on RK3566 when adding support for powering
off the RK817 PMIC.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-11-30 22:38:15 +01:00
Wolfram Sang
1071d1ad31 Revert "i2c: designware-pci: Add support for Fast Mode Plus and High Speed Mode"
This reverts commit e8578547ce. Drivers
should read these values from ACPI tables.

Reported-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-11-30 22:32:47 +01:00