lockdep: Introduce wait-type checks

Extend lockdep to validate lock wait-type context.

The current wait-types are:

LD_WAIT_FREE, /* wait free, rcu etc.. */
LD_WAIT_SPIN, /* spin loops, raw_spi

lockdep: Introduce wait-type checks

Extend lockdep to validate lock wait-type context.

The current wait-types are:

LD_WAIT_FREE, /* wait free, rcu etc.. */
LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */
LD_WAIT_CONFIG, /* CONFIG_PREEMPT_LOCK, spinlock_t etc.. */
LD_WAIT_SLEEP, /* sleeping locks, mutex_t etc.. */

Where lockdep validates that the current lock (the one being acquired)
fits in the current wait-context (as generated by the held stack).

This ensures that there is no attempt to acquire mutexes while holding
spinlocks, to acquire spinlocks while holding raw_spinlocks and so on. In
other words, its a more fancy might_sleep().

Obviously RCU made the entire ordeal more complex than a simple single
value test because RCU can be acquired in (pretty much) any context and
while it presents a context to nested locks it is not the same as it
got acquired in.

Therefore its necessary to split the wait_type into two values, one
representing the acquire (outer) and one representing the nested context
(inner). For most 'normal' locks these two are the same.

[ To make static initialization easier we have the rule that:
.outer == INV means .outer == .inner; because INV == 0. ]

It further means that its required to find the minimal .inner of the held
stack to compare against the outer of the new lock; because while 'normal'
RCU presents a CONFIG type to nested locks, if it is taken while already
holding a SPIN type it obviously doesn't relax the rules.

Below is an example output generated by the trivial test code:

raw_spin_lock(&foo);
spin_lock(&bar);
spin_unlock(&bar);
raw_spin_unlock(&foo);

[ BUG: Invalid wait context ]
-----------------------------
swapper/0/1 is trying to lock:
ffffc90000013f20 (&bar){....}-{3:3}, at: kernel_init+0xdb/0x187
other info that might help us debug this:
1 lock held by swapper/0/1:
#0: ffffc90000013ee0 (&foo){+.+.}-{2:2}, at: kernel_init+0xd1/0x187

The way to read it is to look at the new -{n,m} part in the lock
description; -{3:3} for the attempted lock, and try and match that up to
the held locks, which in this case is the one: -{2,2}.

This tells that the acquiring lock requires a more relaxed environment than
presented by the lock stack.

Currently only the normal locks and RCU are converted, the rest of the
lockdep users defaults to .inner = INV which is ignored. More conversions
can be done when desired.

The check for spinlock_t nesting is not enabled by default. It's a separate
config option for now as there are known problems which are currently
addressed. The config option allows to identify these problems and to
verify that the solutions found are indeed solving them.

The config switch will be removed and the checks will permanently enabled
once the vast majority of issues has been addressed.

[ bigeasy: Move LD_WAIT_FREE,… out of CONFIG_LOCKDEP to avoid compile
failure with CONFIG_DEBUG_SPINLOCK + !CONFIG_LOCKDEP]
[ tglx: Add the config option ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200321113242.427089655@linutronix.de

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Merge drm-intel-next-queued into gvt-next

Backmerge to pull in
https://patchwork.freedesktop.org/patch/353621/?series=73544&rev=1

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Merge v5.6-rc2 into drm-misc-next

Lyude needs some patches in 5.6-rc2 and we didn't bring drm-misc-next
forward yet, so it looks like a good occasion.

Signed-off-by: Maxime Ripard <maxime@cerno.tec

Merge v5.6-rc2 into drm-misc-next

Lyude needs some patches in 5.6-rc2 and we didn't bring drm-misc-next
forward yet, so it looks like a good occasion.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

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Merge drm/drm-next into drm-intel-next-queued

Moving the base forward since this one was so old.
New base contains fixes that we needed.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflicts

Conflicts:
init/main.c
lib/Kconfig.debug

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'next' into for-linus

Prepare input updates for 5.6 merge window.

Merge tag 'spi-nor/for-5.6' into mtd/next

SPI NOR core changes:
- Add support for TB selection using SR bit 6,
- Add support for few flashes.

Merge tag 'asoc-v5.6' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Updates for v5.6

A pretty big release this time around, a lot of new drivers and both
Mor

Merge tag 'asoc-v5.6' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Updates for v5.6

A pretty big release this time around, a lot of new drivers and both
Morimoto-san and Takashi were doing subsystem wide updates as well:

- Further big refactorings from Morimoto-san simplifying the core
interfaces and moving things to the component level.
- Transition of drivers to managed buffer allocation and removal of
redundant PCM ioctls.
- New driver support for Ingenic JZ4770, Mediatek MT6660, Qualcomm
WCD934x and WSA881x, and Realtek RT700, RT711, RT715, RT1011, RT1015
and RT1308.

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Backmerge v5.5-rc7 into drm-next

msm needs 5.5-rc4, go to the latest.

Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge tag 'v5.5-rc6' into devel

Linux 5.5-rc6

Merge branch 'i2c/for-current' into i2c/for-5.6

Merge tag 'v5.5-rc5' into next

Sync up with mainline to get SPI "delay" API changes.

Merge tag 'block-ioctl-cleanup-5.6' into 5.6/scsi-queue

Pull compat_ioctl cleanup from Arnd. Here's his description:

This series concludes the work I did for linux-5.5 on the compat_ioctl()
cleanup

Merge tag 'block-ioctl-cleanup-5.6' into 5.6/scsi-queue

Pull compat_ioctl cleanup from Arnd. Here's his description:

This series concludes the work I did for linux-5.5 on the compat_ioctl()
cleanup, killing off fs/compat_ioctl.c and block/compat_ioctl.c by moving
everything into drivers.

Overall this would be a reduction both in complexity and line count, but
as I'm also adding documentation the overall number of lines increases
in the end.

My plan was originally to keep the SCSI and block parts separate.
This did not work easily because of interdependencies: I cannot
do the final SCSI cleanup in a good way without first addressing the
CDROM ioctls, so this is one series that I hope could be merged through
either the block or the scsi git trees, or possibly both if you can
pull in the same branch.

The series comes in these steps:

1. clean up the sg v3 interface as suggested by Linus. I have
talked about this with Doug Gilbert as well, and he would
rebase his sg v4 patches on top of "compat: scsi: sg: fix v3
compat read/write interface"

2. Actually moving handlers out of block/compat_ioctl.c and
block/scsi_ioctl.c into drivers, mixed in with cleanup
patches

3. Document how to do this right. I keep getting asked about this,
and it helps to point to some documentation file.

The branch is based on another one that fixes a couple of bugs found
during the creation of this series.

Changes since v3:
https://lore.kernel.org/lkml/20200102145552.1853992-1-arnd@arndb.de/

- Move sr_compat_ioctl fixup to correct patch (Ben Hutchings)
- Add Reviewed-by tags

Changes since v2:
https://lore.kernel.org/lkml/20191217221708.3730997-1-arnd@arndb.de/

- Rebase to v5.5-rc4, which contains the earlier bugfixes
- Fix sr_block_compat_ioctl() error handling bug found by
Ben Hutchings
- Fix idecd_locked_compat_ioctl() compat_ptr() bug
- Don't try to handle HDIO_DRIVE_TASKFILE in drivers/ide
- More documentation improvements

Changes since v1:
https://lore.kernel.org/lkml/20191211204306.1207817-1-arnd@arndb.de/

- move out the bugfixes into a branch for itself
- clean up scsi sg driver further as suggested by Christoph Hellwig
- avoid some ifdefs by moving compat_ptr() out of asm/compat.h
- split out the blkdev_compat_ptr_ioctl function; bug spotted by
Ben Hutchings
- Improve formatting of documentation

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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Merge tag 'cpuidle_psci-v5.5-rc4' of git://git.linaro.org/people/ulf.hansson/linux-pm into arm/drivers

Initial support for hierarchical CPU arrangement, managed by PSCI and its
corresponding cpuidle

Merge tag 'cpuidle_psci-v5.5-rc4' of git://git.linaro.org/people/ulf.hansson/linux-pm into arm/drivers

Initial support for hierarchical CPU arrangement, managed by PSCI and its
corresponding cpuidle driver. This support is based upon using the generic
PM domain, which already supports devices belonging to CPUs.

Finally, these is a DTS patch that enables the hierarchical topology to be
used for the Qcom 410c Dragonboard, which supports the PSCI OS-initiated
mode.

* tag 'cpuidle_psci-v5.5-rc4' of git://git.linaro.org/people/ulf.hansson/linux-pm: (611 commits)
arm64: dts: Convert to the hierarchical CPU topology layout for MSM8916
cpuidle: psci: Add support for PM domains by using genpd
PM / Domains: Introduce a genpd OF helper that removes a subdomain
cpuidle: psci: Support CPU hotplug for the hierarchical model
cpuidle: psci: Manage runtime PM in the idle path
cpuidle: psci: Prepare to use OS initiated suspend mode via PM domains
cpuidle: psci: Attach CPU devices to their PM domains
cpuidle: psci: Add a helper to attach a CPU to its PM domain
cpuidle: psci: Support hierarchical CPU idle states
cpuidle: psci: Simplify OF parsing of CPU idle state nodes
cpuidle: dt: Support hierarchical CPU idle states
of: base: Add of_get_cpu_state_node() to get idle states for a CPU node
firmware: psci: Export functions to manage the OSI mode
dt: psci: Update DT bindings to support hierarchical PSCI states
cpuidle: psci: Align psci_power_state count with idle state count
Linux 5.5-rc4
locks: print unsigned ino in /proc/locks
riscv: export flush_icache_all to modules
riscv: reject invalid syscalls below -1
riscv: fix compile failure with EXPORT_SYMBOL() & !MMU
...

Link: https://lore.kernel.org/r/20200102160820.3572-1-ulf.hansson@linaro.org
Signed-off-by: Olof Johansson <olof@lixom.net>

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Merge tag 'v5.5-rc5' into patchwork

Linux 5.5-rc5

* tag 'v5.5-rc5': (1006 commits)
Linux 5.5-rc5
Documentation: riscv: add patch acceptance guidelines
riscv: prefix IRQ_ macro names with an R

Merge tag 'v5.5-rc5' into patchwork

Linux 5.5-rc5

* tag 'v5.5-rc5': (1006 commits)
Linux 5.5-rc5
Documentation: riscv: add patch acceptance guidelines
riscv: prefix IRQ_ macro names with an RV_ namespace
clocksource: riscv: add notrace to riscv_sched_clock
apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock
hexagon: define ioremap_uc
ocfs2: fix the crash due to call ocfs2_get_dlm_debug once less
ocfs2: call journal flush to mark journal as empty after journal recovery when mount
mm/hugetlb: defer freeing of huge pages if in non-task context
mm/gup: fix memory leak in __gup_benchmark_ioctl
mm/oom: fix pgtables units mismatch in Killed process message
fs/posix_acl.c: fix kernel-doc warnings
hexagon: work around compiler crash
hexagon: parenthesize registers in asm predicates
fs/namespace.c: make to_mnt_ns() static
fs/nsfs.c: include headers for missing declarations
fs/direct-io.c: include fs/internal.h for missing prototype
mm: move_pages: return valid node id in status if the page is already on the target node
memcg: account security cred as well to kmemcg
kcov: fix struct layout for kcov_remote_arg
...

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Merge remote-tracking branch 'net-next/master' into mac80211-next

Merging to get the mac80211 updates that have since propagated
into net-next.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Merge tag 'v5.5-rc3' into devel

Linux 5.5-rc3

Merge tag 'v5.5-rc3' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge 5.5-rc3 into staging-next

We need the staging fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge 5.5-rc3 into tty-next

We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge 5.5-rc3 into usb-next

We need the USB fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Mere overlapping changes in the conflicts here.

Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Ingo Molnar:
"Tone down mutex debugging complaints, and annotate/fix spinloc

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Ingo Molnar:
"Tone down mutex debugging complaints, and annotate/fix spinlock
debugging data accesses for KCSAN"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "locking/mutex: Complain upon mutex API misuse in IRQ contexts"
locking/spinlock/debug: Fix various data races

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locking/spinlock/debug: Fix various data races

This fixes various data races in spinlock_debug. By testing with KCSAN,
it is observable that the console gets spammed with data races reports,
suggest

locking/spinlock/debug: Fix various data races

This fixes various data races in spinlock_debug. By testing with KCSAN,
it is observable that the console gets spammed with data races reports,
suggesting these are extremely frequent.

Example data race report:

read to 0xffff8ab24f403c48 of 4 bytes by task 221 on cpu 2:
debug_spin_lock_before kernel/locking/spinlock_debug.c:85 [inline]
do_raw_spin_lock+0x9b/0x210 kernel/locking/spinlock_debug.c:112
__raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_lock+0x39/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:338 [inline]
get_partial_node.isra.0.part.0+0x32/0x2f0 mm/slub.c:1873
get_partial_node mm/slub.c:1870 [inline]
<snip>

write to 0xffff8ab24f403c48 of 4 bytes by task 167 on cpu 3:
debug_spin_unlock kernel/locking/spinlock_debug.c:103 [inline]
do_raw_spin_unlock+0xc9/0x1a0 kernel/locking/spinlock_debug.c:138
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline]
_raw_spin_unlock_irqrestore+0x2d/0x50 kernel/locking/spinlock.c:191
spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
free_debug_processing+0x1b3/0x210 mm/slub.c:1214
__slab_free+0x292/0x400 mm/slub.c:2864
<snip>

As a side-effect, with KCSAN, this eventually locks up the console, most
likely due to deadlock, e.g. .. -> printk lock -> spinlock_debug ->
KCSAN detects data race -> kcsan_print_report() -> printk lock ->
deadlock.

This fix will 1) avoid the data races, and 2) allow using lock debugging
together with KCSAN.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20191120155715.28089-1-elver@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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Merge branch 'next' into for-linus

Prepare second round of input updates for 5.3 merge window.