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Currently, if rcu_barrier() returns too soon, the test waits 100ms and
then does another instance of the test. However, if rcu_barrier() were
to have waited for more than 100ms too short a time, this could cause
the test's rcu_head structures to be reused while they were still on
RCU's callback lists. This can result in knock-on errors that obscure
the original rcu_barrier() test failure.
This commit therefore adds code that attempts to wait until all of
the test's callbacks have been invoked. Of course, if RCU completely
lost track of the corresponding rcu_head structures, this wait could be
forever. This commit therefore also complains if this attempted recovery
takes more than one second, and it also gives up when the test ends.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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Currently, rcu_torture_barrier_cbs() posts callbacks from whatever CPU
it is running on, which means that all these kthreads might well be
posting from the same CPU, which would drastically reduce the effectiveness
of this test. This commit therefore uses IPIs to make the callbacks be
posted from the corresponding CPU (given by local variable myid).
If the IPI fails (which can happen if the target CPU is offline or does
not exist at all), the callback is posted on whatever CPU is currently
running.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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During changes to kfree_rcu() code, we often check the amount of free
memory. As an alternative to checking this manually, this commit adds a
measurement in the test itself. It measures four times during the test
for available memory, digitally filters these measurements to produce a
running average with a weight of 0.5, and compares this digitally filtered
value with the amount of available memory at the beginning of the test.
Something like the following is printed at the end of the run:
Total time taken by all kfree'ers: 6369738407 ns, loops: 10000, batches: 764, memory footprint: 216MB
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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The rcutorture global variable rcu_torture_current is accessed locklessly,
so it must use the RCU pointer load/store primitives. This commit
therefore adds several that were missed.
This data race was reported by KCSAN. Not appropriate for backporting due
to failure being unlikely and due to this being used only by rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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The rcutorture rcu_torture_count and rcu_torture_batch per-CPU variables
are read locklessly, so this commit adds the READ_ONCE() to a load in
order to avoid various types of compiler vandalism^Woptimization.
This data race was reported by KCSAN. Not appropriate for backporting
due to failure being unlikely and due to this being rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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The rcu_fwd_cb_nodelay variable suppresses excessively long read-side
delays while carrying out an rcutorture forward-progress test. As such,
it is accessed both by readers and updaters, and most of the accesses
therefore use *_ONCE(). Except for one in rcu_read_delay(), which this
commit fixes.
This data race was reported by KCSAN. Not appropriate for backporting
due to this being rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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The ->rtort_pipe_count field in the rcu_torture structure checks for
too-short grace periods, and is therefore read by rcutorture's readers
while being updated by rcutorture's writers. This commit therefore
adds the needed READ_ONCE() and WRITE_ONCE() invocations.
This data race was reported by KCSAN. Not appropriate for backporting
due to failure being unlikely and due to this being rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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In theory, RCU-hotplug operations are supposed to work as soon as there
is more than one CPU online. However, in practice, in normal production
there is no way to make them happen until userspace is up and running.
Besides which, on smaller systems, rcutorture doesn't start doing hotplug
operations until 30 seconds after the start of boot, which on most
systems also means the better part of 30 seconds after the end of boot.
This commit therefore provides a new torture.disable_onoff_at_boot kernel
boot parameter that suppresses CPU-hotplug torture operations until
about the time that init is spawned.
Of course, if you know of a need for boottime CPU-hotplug operations,
then you should avoid passing this argument to any of the torture tests.
You might also want to look at the splats linked to below.
Link: https://lore.kernel.org/lkml/20191206185208.GA25636@paulmck-ThinkPad-P72/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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In normal production, an excessively long wait on a grace period
(synchronize_rcu(), for example) at boottime is often just as bad
as at any other time. In fact, given the desire for fast boot, any
sort of long wait at boot is a bad idea. However, heavy rcutorture
testing on large hyperthreaded systems can generate such long waits
during boot as a matter of course. This commit therefore causes
the rcupdate.rcu_cpu_stall_suppress_at_boot kernel boot parameter to
suppress reporting of bootime bad-sequence warning due to excessively
long grace-period waits.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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In normal production, an RCU CPU stall warning at boottime is often
just as bad as at any other time. In fact, given the desire for fast
boot, any sort of long-term stall at boot is a bad idea. However,
heavy rcutorture testing on large hyperthreaded systems can generate
boottime RCU CPU stalls as a matter of course. This commit therefore
provides a kernel boot parameter that suppresses reporting of boottime
RCU CPU stall warnings and similarly of rcutorture writer stalls.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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During boot, CPU hotplug is often disabled, for example by PCI probing.
On large systems that take substantial time to boot, this can result
in spurious RCU_HOTPLUG errors. This commit therefore forgives any
boottime -EBUSY CPU-hotplug failures by adjusting counters to pretend
that the corresponding attempt never happened. A non-splat record
of the failed attempt is emitted to the console with the added string
"(-EBUSY forgiven during boot)".
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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Additional rcutorture aggression can result in, believe it or not,
boot times in excess of three minutes on large hyperthreaded systems.
This is long enough for rcutorture to decide to do some callback flooding,
which seems a bit excessive given that userspace cannot have started
until long after boot, and it is userspace that does the real-world
callback flooding. Worse yet, because Tiny RCU lacks forward-progress
functionality, the looping-in-the-kernel tests can also be problematic
during early boot.
This commit therefore causes rcutorture to hold off on callback
flooding until about the time that init is spawned, and the same
for looping-in-the-kernel tests for Tiny RCU.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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Some larger systems can take in excess of 50 seconds to complete their
early boot initcalls prior to spawing init. This does not in any way
help the forward-progress judgments of built-in rcutorture (when
rcutorture is built as a module, the insmod or modprobe command normally
cannot happen until some time after boot completes). This commit
therefore suppresses such complaints until about the time that init
is spawned.
This also includes a fix to a stupid error located by kbuild test robot.
[ paulmck: Apply kbuild test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ paulmck: Fix to nohz_full slow-expediting recovery logic, per bpetkov. ]
[ paulmck: Restrict splat to CONFIG_PREEMPT_RT=y kernels and simplify. ]
Tested-by: Borislav Petkov <bp@alien8.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
- fix randconfig to generate a sane .config
- rename hostprogs-y / always to hostprogs / always-y, which are more
natual syntax.
- optimize scripts/kallsyms
- fix yes2modconfig and mod2yesconfig
- make multiple directory targets ('make foo/ bar/') work
* tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: make multiple directory targets work
kconfig: Invalidate all symbols after changing to y or m.
kallsyms: fix type of kallsyms_token_table[]
scripts/kallsyms: change table to store (strcut sym_entry *)
scripts/kallsyms: rename local variables in read_symbol()
kbuild: rename hostprogs-y/always to hostprogs/always-y
kbuild: fix the document to use extra-y for vmlinux.lds
kconfig: fix broken dependency in randconfig-generated .config
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for X86:
- Ensure that the PIT is set up when the local APIC is disable or
configured in legacy mode. This is caused by an ordering issue
introduced in the recent changes which skip PIT initialization when
the TSC and APIC frequencies are already known.
- Handle malformed SRAT tables during early ACPI parsing which caused
an infinite loop anda boot hang.
- Fix a long standing race in the affinity setting code which affects
PCI devices with non-maskable MSI interrupts. The problem is caused
by the non-atomic writes of the MSI address (destination APIC id)
and data (vector) fields which the device uses to construct the MSI
message. The non-atomic writes are mandated by PCI.
If both fields change and the device raises an interrupt after
writing address and before writing data, then the MSI block
constructs a inconsistent message which causes interrupts to be
lost and subsequent malfunction of the device.
The fix is to redirect the interrupt to the new vector on the
current CPU first and then switch it over to the new target CPU.
This allows to observe an eventually raised interrupt in the
transitional stage (old CPU, new vector) to be observed in the APIC
IRR and retriggered on the new target CPU and the new vector.
The potential spurious interrupts caused by this are harmless and
can in the worst case expose a buggy driver (all handlers have to
be able to deal with spurious interrupts as they can and do happen
for various reasons).
- Add the missing suspend/resume mechanism for the HYPERV hypercall
page which prevents resume hibernation on HYPERV guests. This
change got lost before the merge window.
- Mask the IOAPIC before disabling the local APIC to prevent
potentially stale IOAPIC remote IRR bits which cause stale
interrupt lines after resume"
* tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Mask IOAPIC entries when disabling the local APIC
x86/hyperv: Suspend/resume the hypercall page for hibernation
x86/apic/msi: Plug non-maskable MSI affinity race
x86/boot: Handle malformed SRAT tables during early ACPI parsing
x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP fixes from Thomas Gleixner:
"Two fixes for the SMP related functionality:
- Make the UP version of smp_call_function_single() match SMP
semantics when called for a not available CPU. Instead of emitting
a warning and assuming that the function call target is CPU0,
return a proper error code like the SMP version does.
- Remove a superfluous check in smp_call_function_many_cond()"
* tag 'smp-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smp/up: Make smp_call_function_single() match SMP semantics
smp: Remove superfluous cond_func check in smp_call_function_many_cond()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"A set of fixes and improvements for the perf subsystem:
Kernel fixes:
- Install cgroup events to the correct CPU context to prevent a
potential list double add
- Prevent an integer underflow in the perf mlock accounting
- Add a missing prototype for arch_perf_update_userpage()
Tooling:
- Add a missing unlock in the error path of maps__insert() in perf
maps.
- Fix the build with the latest libbfd
- Fix the perf parser so it does not delete parse event terms, which
caused a regression for using perf with the ARM CoreSight as the
sink configuration was missing due to the deletion.
- Fix the double free in the perf CPU map merging test case
- Add the missing ustring support for the perf probe command"
* tag 'perf-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf maps: Add missing unlock to maps__insert() error case
perf probe: Add ustring support for perf probe command
perf: Make perf able to build with latest libbfd
perf test: Fix test case Merge cpu map
perf parse: Copy string to perf_evsel_config_term
perf parse: Refactor 'struct perf_evsel_config_term'
kernel/events: Add a missing prototype for arch_perf_update_userpage()
perf/cgroups: Install cgroup events to correct cpuctx
perf/core: Fix mlock accounting in perf_mmap()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"Two small fixes for the time(r) subsystem:
- Handle a subtle race between the clocksource watchdog and a
concurrent clocksource watchdog stop/start sequence correctly to
prevent a timer double add bug.
- Fix the file path for the core time namespace file"
* tag 'timers-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource: Prevent double add_timer_on() for watchdog_timer
MAINTAINERS: Correct path to time namespace source file
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull interrupt fixes from Thomas Gleixner:
"A set of fixes for the interrupt subsystem:
- Provision only ACPI enabled redistributors on GICv3
- Use the proper command colums when building the INVALL command for
the GICv3-ITS
- Ensure the allocation of the L2 vPE table for GICv4.1
- Correct the GICv4.1 VPROBASER programming so it uses the proper
size
- A set of small GICv4.1 tidy up patches
- Configuration cleanup for C-SKY interrupt chip
- Clarify the function documentation for irq_set_wake() to document
that the wakeup functionality is orthogonal to the irq
disable/enable mechanism"
* tag 'irq-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3-its: Rename VPENDBASER/VPROPBASER accessors
irqchip/gic-v3-its: Remove superfluous WARN_ON
irqchip/gic-v4.1: Drop 'tmp' in inherit_vpe_l1_table_from_rd()
irqchip/gic-v4.1: Ensure L2 vPE table is allocated at RD level
irqchip/gic-v4.1: Set vpe_l1_base for all redistributors
irqchip/gic-v4.1: Fix programming of GICR_VPROPBASER_4_1_SIZE
genirq: Clarify that irq wake state is orthogonal to enable/disable
irqchip/gic-v3-its: Reference to its_invall_cmd descriptor when building INVALL
irqchip: Some Kconfig cleanup for C-SKY
irqchip/gic-v3: Only provision redistributors that are enabled in ACPI
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Pull networking fixes from David Miller:
1) Unbalanced locking in mwifiex_process_country_ie, from Brian Norris.
2) Fix thermal zone registration in iwlwifi, from Andrei
Otcheretianski.
3) Fix double free_irq in sgi ioc3 eth, from Thomas Bogendoerfer.
4) Use after free in mptcp, from Florian Westphal.
5) Use after free in wireguard's root_remove_peer_lists, from Eric
Dumazet.
6) Properly access packets heads in bonding alb code, from Eric
Dumazet.
7) Fix data race in skb_queue_len(), from Qian Cai.
8) Fix regression in r8169 on some chips, from Heiner Kallweit.
9) Fix XDP program ref counting in hv_netvsc, from Haiyang Zhang.
10) Certain kinds of set link netlink operations can cause a NULL deref
in the ipv6 addrconf code. Fix from Eric Dumazet.
11) Don't cancel uninitialized work queue in drop monitor, from Ido
Schimmel.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (84 commits)
net: thunderx: use proper interface type for RGMII
mt76: mt7615: fix max_nss in mt7615_eeprom_parse_hw_cap
bpf: Improve bucket_log calculation logic
selftests/bpf: Test freeing sockmap/sockhash with a socket in it
bpf, sockhash: Synchronize_rcu before free'ing map
bpf, sockmap: Don't sleep while holding RCU lock on tear-down
bpftool: Don't crash on missing xlated program instructions
bpf, sockmap: Check update requirements after locking
drop_monitor: Do not cancel uninitialized work item
mlxsw: spectrum_dpipe: Add missing error path
mlxsw: core: Add validation of hardware device types for MGPIR register
mlxsw: spectrum_router: Clear offload indication from IPv6 nexthops on abort
selftests: mlxsw: Add test cases for local table route replacement
mlxsw: spectrum_router: Prevent incorrect replacement of local table routes
net: dsa: microchip: enable module autoprobe
ipv6/addrconf: fix potential NULL deref in inet6_set_link_af()
dpaa_eth: support all modes with rate adapting PHYs
net: stmmac: update pci platform data to use phy_interface
net: stmmac: xgmac: fix missing IFF_MULTICAST checki in dwxgmac2_set_filter
net: stmmac: fix missing IFF_MULTICAST check in dwmac4_set_filter
...
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs file system parameter updates from Al Viro:
"Saner fs_parser.c guts and data structures. The system-wide registry
of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
the horror switch() in fs_parse() that would have to grow another case
every time something got added to that system-wide registry.
New syntax types can be added by filesystems easily now, and their
namespace is that of functions - not of system-wide enum members. IOW,
they can be shared or kept private and if some turn out to be widely
useful, we can make them common library helpers, etc., without having
to do anything whatsoever to fs_parse() itself.
And we already get that kind of requests - the thing that finally
pushed me into doing that was "oh, and let's add one for timeouts -
things like 15s or 2h". If some filesystem really wants that, let them
do it. Without somebody having to play gatekeeper for the variants
blessed by direct support in fs_parse(), TYVM.
Quite a bit of boilerplate is gone. And IMO the data structures make a
lot more sense now. -200LoC, while we are at it"
* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
tmpfs: switch to use of invalfc()
cgroup1: switch to use of errorfc() et.al.
procfs: switch to use of invalfc()
hugetlbfs: switch to use of invalfc()
cramfs: switch to use of errofc() et.al.
gfs2: switch to use of errorfc() et.al.
fuse: switch to use errorfc() et.al.
ceph: use errorfc() and friends instead of spelling the prefix out
prefix-handling analogues of errorf() and friends
turn fs_param_is_... into functions
fs_parse: handle optional arguments sanely
fs_parse: fold fs_parameter_desc/fs_parameter_spec
fs_parser: remove fs_parameter_description name field
add prefix to fs_context->log
ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
new primitive: __fs_parse()
switch rbd and libceph to p_log-based primitives
struct p_log, variants of warnf() et.al. taking that one instead
teach logfc() to handle prefices, give it saner calling conventions
get rid of cg_invalf()
...
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Daniel Borkmann says:
====================
pull-request: bpf 2020-02-07
The following pull-request contains BPF updates for your *net* tree.
We've added 15 non-merge commits during the last 10 day(s) which contain
a total of 12 files changed, 114 insertions(+), 31 deletions(-).
The main changes are:
1) Various BPF sockmap fixes related to RCU handling in the map's tear-
down code, from Jakub Sitnicki.
2) Fix macro state explosion in BPF sk_storage map when calculating its
bucket_log on allocation, from Martin KaFai Lau.
3) Fix potential BPF sockmap update race by rechecking socket's established
state under lock, from Lorenz Bauer.
4) Fix crash in bpftool on missing xlated instructions when kptr_restrict
sysctl is set, from Toke Høiland-Jørgensen.
5) Fix i40e's XSK wakeup code to return proper error in busy state and
various misc fixes in xdpsock BPF sample code, from Maciej Fijalkowski.
6) Fix the way modifiers are skipped in BTF in the verifier while walking
pointers to avoid program rejection, from Alexei Starovoitov.
7) Fix Makefile for runqslower BPF tool to i) rebuild on libbpf changes and
ii) to fix undefined reference linker errors for older gcc version due to
order of passed gcc parameters, from Yulia Kartseva and Song Liu.
8) Fix a trampoline_count BPF kselftest warning about missing braces around
initializer, from Andrii Nakryiko.
9) Fix up redundant "HAVE" prefix from large INSN limit kernel probe in
bpftool, from Michal Rostecki.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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There's some confusion around if an irq that's disabled with disable_irq()
can still wake the system from sleep states such as "suspend to RAM".
Clarify this in the kernel documentation for irq_set_irq_wake() so that
it's clear that an irq can be disabled and still wake the system if it has
been marked for wakeup.
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lkml.kernel.org/r/20200206191521.94559-1-swboyd@chromium.org
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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The former contains nothing but a pointer to an array of the latter...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Unused now.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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pointless alias for invalf()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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In CONFIG_SMP=y kernels, smp_call_function_single() returns -ENXIO when
invoked for a non-existent CPU. In contrast, in CONFIG_SMP=n kernels,
a splat is emitted and smp_call_function_single() otherwise silently
ignores its "cpu" argument, instead pretending that the caller intended
to have something happen on CPU 0. Given that there is now code that
expects smp_call_function_single() to return an error if a bad CPU was
specified, this difference in semantics needs to be addressed.
Bring the semantics of the CONFIG_SMP=n version of
smp_call_function_single() into alignment with its CONFIG_SMP=y
counterpart.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200205143409.GA7021@paulmck-ThinkPad-P72
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git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb fix from Daniel Thompson:
"One of the simplifications added for 5.6-rc1 has caused build
regressions on some platforms (it was reported for sparc64).
This fixes it with a revert"
* tag 'kgdb-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
Revert "kdb: Get rid of confusing diag msg from "rd" if current task has no regs"
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regs"
This reverts commit bbfceba15f8d1260c328a254efc2b3f2deae4904.
When DBG_MAX_REG_NUM is zero then a number of symbols are conditionally
defined. It is therefore not possible to check it using C expressions.
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Acked-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added new "bootconfig".
This looks for a file appended to initrd to add boot config options,
and has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and kprobe
events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
bootconfig: Show the number of nodes on boot message
tools/bootconfig: Show the number of bootconfig nodes
bootconfig: Add more parse error messages
bootconfig: Use bootconfig instead of boot config
ftrace: Protect ftrace_graph_hash with ftrace_sync
ftrace: Add comment to why rcu_dereference_sched() is open coded
tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
tracing: Annotate ftrace_graph_hash pointer with __rcu
bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
tracing: Use seq_buf for building dynevent_cmd string
tracing: Remove useless code in dynevent_arg_pair_add()
tracing: Remove check_arg() callbacks from dynevent args
tracing: Consolidate some synth_event_trace code
tracing: Fix now invalid var_ref_vals assumption in trace action
tracing: Change trace_boot to use synth_event interface
tracing: Move tracing selftests to bottom of menu
tracing: Move mmio tracer config up with the other tracers
tracing: Move tracing test module configs together
tracing: Move all function tracing configs together
tracing: Documentation for in-kernel synthetic event API
...
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As function_graph tracer can run when RCU is not "watching", it can not be
protected by synchronize_rcu() it requires running a task on each CPU before
it can be freed. Calling schedule_on_each_cpu(ftrace_sync) needs to be used.
Link: https://lore.kernel.org/r/20200205131110.GT2935@paulmck-ThinkPad-P72
Cc: stable@vger.kernel.org
Fixes: b9b0c831bed26 ("ftrace: Convert graph filter to use hash tables")
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Because the function graph tracer can execute in sections where RCU is not
"watching", the rcu_dereference_sched() for the has needs to be open coded.
This is fine because the RCU "flavor" of the ftrace hash is protected by
its own RCU handling (it does its own little synchronization on every CPU
and does not rely on RCU sched).
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Fix following instances of sparse error
kernel/trace/ftrace.c:5667:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5813:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5868:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5870:25: error: incompatible types in comparison
Use rcu_dereference_protected to dereference the newly annotated pointer.
Link: http://lkml.kernel.org/r/20200205055701.30195-1-frextrite@gmail.com
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Fix following instances of sparse error
kernel/trace/ftrace.c:5664:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5785:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5864:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5866:25: error: incompatible types in comparison
Use rcu_dereference_protected to access the __rcu annotated pointer.
Link: http://lkml.kernel.org/r/20200201072703.17330-1-frextrite@gmail.com
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs recursive removal updates from Al Viro:
"We have quite a few places where synthetic filesystems do an
equivalent of 'rm -rf', with varying amounts of code duplication,
wrong locking, etc. That really ought to be a library helper.
Only debugfs (and very similar tracefs) are converted here - I have
more conversions, but they'd never been in -next, so they'll have to
wait"
* 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems
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kallsyms_token_table[] only contains ASCII characters. It should be
char instead of u8.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
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The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.
Conversion rule is:
llseek => proc_lseek
unlocked_ioctl => proc_ioctl
xxx => proc_xxx
delete ".owner = THIS_MODULE" line
[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix the way modifiers are skipped while walking pointers. Otherwise second
level dereferences of 'const struct foo *' will be rejected by the verifier.
Fixes: 9e15db66136a ("bpf: Implement accurate raw_tp context access via BTF")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200201000314.261392-1-ast@kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb updates from Daniel Thompson:
"Everything for kgdb this time around is either simplifications or
clean ups.
In particular Douglas Anderson's modifications to the backtrace
machine in the *last* dev cycle have enabled Doug to tidy up some MIPS
specific backtrace code and stop sharing certain data structures
across the kernel. Note that The MIPS folks were on Cc: for the MIPS
patch and reacted positively (but without an explicit Acked-by).
Doug also got rid of the implicit switching between tasks and register
sets during some but not of kdb's backtrace actions (because the
implicit switching was either confusing for users, pointless or both).
Finally there is a coverity fix and patch to replace open coded
console traversal with the proper helper function"
* tag 'kgdb-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kdb: Use for_each_console() helper
kdb: remove redundant assignment to pointer bp
kdb: Get rid of confusing diag msg from "rd" if current task has no regs
kdb: Gid rid of implicit setting of the current task / regs
kdb: kdb_current_task shouldn't be exported
kdb: kdb_current_regs should be private
MIPS: kdb: Remove old workaround for backtracing on other CPUs
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The dynevent_cmd commands that build up the command string don't need
to do that themselves - there's a seq_buf facility that does pretty
much the same thing those command are doing manually, so use it
instead.
Link: http://lkml.kernel.org/r/eb8a6e835c964d0ab8a38cbf5ffa60746b54a465.1580506712.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The final addition to q is unnecessary, since q isn't ever used
afterwards.
Link: http://lkml.kernel.org/r/7880a1268217886cdba7035526650195668da856.1580506712.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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It's kind of strange to have check_arg() callbacks as part of the arg
objects themselves; it makes more sense to just pass these in when the
args are added instead.
Remove the check_arg() callbacks from those objects which also means
removing the check_arg() args from the init functions, adding them to
the add functions and fixing up existing callers.
Link: http://lkml.kernel.org/r/c7708d6f177fcbe1a36b6e4e8e150907df0fa5d2.1580506712.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Kernel crashes inside QEMU/KVM are observed:
kernel BUG at kernel/time/timer.c:1154!
BUG_ON(timer_pending(timer) || !timer->function) in add_timer_on().
At the same time another cpu got:
general protection fault: 0000 [#1] SMP PTI of poinson pointer 0xdead000000000200 in:
__hlist_del at include/linux/list.h:681
(inlined by) detach_timer at kernel/time/timer.c:818
(inlined by) expire_timers at kernel/time/timer.c:1355
(inlined by) __run_timers at kernel/time/timer.c:1686
(inlined by) run_timer_softirq at kernel/time/timer.c:1699
Unfortunately kernel logs are badly scrambled, stacktraces are lost.
Printing the timer->function before the BUG_ON() pointed to
clocksource_watchdog().
The execution of clocksource_watchdog() can race with a sequence of
clocksource_stop_watchdog() .. clocksource_start_watchdog():
expire_timers()
detach_timer(timer, true);
timer->entry.pprev = NULL;
raw_spin_unlock_irq(&base->lock);
call_timer_fn
clocksource_watchdog()
clocksource_watchdog_kthread() or
clocksource_unbind()
spin_lock_irqsave(&watchdog_lock, flags);
clocksource_stop_watchdog();
del_timer(&watchdog_timer);
watchdog_running = 0;
spin_unlock_irqrestore(&watchdog_lock, flags);
spin_lock_irqsave(&watchdog_lock, flags);
clocksource_start_watchdog();
add_timer_on(&watchdog_timer, ...);
watchdog_running = 1;
spin_unlock_irqrestore(&watchdog_lock, flags);
spin_lock(&watchdog_lock);
add_timer_on(&watchdog_timer, ...);
BUG_ON(timer_pending(timer) || !timer->function);
timer_pending() -> true
BUG()
I.e. inside clocksource_watchdog() watchdog_timer could be already armed.
Check timer_pending() before calling add_timer_on(). This is sufficient as
all operations are synchronized by watchdog_lock.
Fixes: 75c5158f70c0 ("timekeeping: Update clocksource with stop_machine")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/158048693917.4378.13823603769948933793.stgit@buzz
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Evan tracked down a subtle race between the update of the MSI message and
the device raising an interrupt internally on PCI devices which do not
support MSI masking. The update of the MSI message is non-atomic and
consists of either 2 or 3 sequential 32bit wide writes to the PCI config
space.
- Write address low 32bits
- Write address high 32bits (If supported by device)
- Write data
When an interrupt is migrated then both address and data might change, so
the kernel attempts to mask the MSI interrupt first. But for MSI masking is
optional, so there exist devices which do not provide it. That means that
if the device raises an interrupt internally between the writes then a MSI
message is sent built from half updated state.
On x86 this can lead to spurious interrupts on the wrong interrupt
vector when the affinity setting changes both address and data. As a
consequence the device interrupt can be lost causing the device to
become stuck or malfunctioning.
Evan tried to handle that by disabling MSI accross an MSI message
update. That's not feasible because disabling MSI has issues on its own:
If MSI is disabled the PCI device is routing an interrupt to the legacy
INTx mechanism. The INTx delivery can be disabled, but the disablement is
not working on all devices.
Some devices lose interrupts when both MSI and INTx delivery are disabled.
Another way to solve this would be to enforce the allocation of the same
vector on all CPUs in the system for this kind of screwed devices. That
could be done, but it would bring back the vector space exhaustion problems
which got solved a few years ago.
Fortunately the high address (if supported by the device) is only relevant
when X2APIC is enabled which implies interrupt remapping. In the interrupt
remapping case the affinity setting is happening at the interrupt remapping
unit and the PCI MSI message is programmed only once when the PCI device is
initialized.
That makes it possible to solve it with a two step update:
1) Target the MSI msg to the new vector on the current target CPU
2) Target the MSI msg to the new vector on the new target CPU
In both cases writing the MSI message is only changing a single 32bit word
which prevents the issue of inconsistency.
After writing the final destination it is necessary to check whether the
device issued an interrupt while the intermediate state #1 (new vector,
current CPU) was in effect.
This is possible because the affinity change is always happening on the
current target CPU. The code runs with interrupts disabled, so the
interrupt can be detected by checking the IRR of the local APIC. If the
vector is pending in the IRR then the interrupt is retriggered on the new
target CPU by sending an IPI for the associated vector on the target CPU.
This can cause spurious interrupts on both the local and the new target
CPU.
1) If the new vector is not in use on the local CPU and the device
affected by the affinity change raised an interrupt during the
transitional state (step #1 above) then interrupt entry code will
ignore that spurious interrupt. The vector is marked so that the
'No irq handler for vector' warning is supressed once.
2) If the new vector is in use already on the local CPU then the IRR check
might see an pending interrupt from the device which is using this
vector. The IPI to the new target CPU will then invoke the handler of
the device, which got the affinity change, even if that device did not
issue an interrupt
3) If the new vector is in use already on the local CPU and the device
affected by the affinity change raised an interrupt during the
transitional state (step #1 above) then the handler of the device which
uses that vector on the local CPU will be invoked.
expose issues in device driver interrupt handlers which are not prepared to
handle a spurious interrupt correctly. This not a regression, it's just
exposing something which was already broken as spurious interrupts can
happen for a lot of reasons and all driver handlers need to be able to deal
with them.
Reported-by: Evan Green <evgreen@chromium.org>
Debugged-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Evan Green <evgreen@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87imkr4s7n.fsf@nanos.tec.linutronix.de
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The synth_event trace code contains some almost identical functions
and some small functions that are called only once - consolidate the
common code into single functions and fold in the small functions to
simplify the code overall.
Link: http://lkml.kernel.org/r/d1c8d8ad124a653b7543afe801d38c199ca5c20e.1580506712.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Pull updates from Andrew Morton:
"Most of -mm and quite a number of other subsystems: hotfixes, scripts,
ocfs2, misc, lib, binfmt, init, reiserfs, exec, dma-mapping, kcov.
MM is fairly quiet this time. Holidays, I assume"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
kcov: ignore fault-inject and stacktrace
include/linux/io-mapping.h-mapping: use PHYS_PFN() macro in io_mapping_map_atomic_wc()
execve: warn if process starts with executable stack
reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()
init/main.c: fix misleading "This architecture does not have kernel memory protection" message
init/main.c: fix quoted value handling in unknown_bootoption
init/main.c: remove unnecessary repair_env_string in do_initcall_level
init/main.c: log arguments and environment passed to init
fs/binfmt_elf.c: coredump: allow process with empty address space to coredump
fs/binfmt_elf.c: coredump: delete duplicated overflow check
fs/binfmt_elf.c: coredump: allocate core ELF header on stack
fs/binfmt_elf.c: make BAD_ADDR() unlikely
fs/binfmt_elf.c: better codegen around current->mm
fs/binfmt_elf.c: don't copy ELF header around
fs/binfmt_elf.c: fix ->start_code calculation
fs/binfmt_elf.c: smaller code generation around auxv vector fill
lib/find_bit.c: uninline helper _find_next_bit()
lib/find_bit.c: join _find_next_bit{_le}
uapi: rename ext2_swab() to swab() and share globally in swab.h
lib/scatterlist.c: adjust indentation in __sg_alloc_table
...
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git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu:
"Summary of modules changes for the 5.6 merge window:
- Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings
to indicate to the linker that it can perform string deduplication
(i.e., duplicate strings are reduced to a single copy in the string
table). This means any repeated namespace string would be merged to
just one entry in __ksymtab_strings.
- Various code cleanups and small fixes (fix small memleak in error
path, improve moduleparam docs, silence rcu warnings, improve error
logging)"
* tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module.h: Annotate mod_kallsyms with __rcu
module: avoid setting info->name early in case we can fall back to info->mod->name
modsign: print module name along with error message
kernel/module: Fix memleak in module_add_modinfo_attrs()
export.h: reduce __ksymtab_strings string duplication by using "MS" section flags
moduleparam: fix kerneldoc
modules: lockdep: Suppress suspicious RCU usage warning
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Don't instrument 3 more files that contain debugging facilities and
produce large amounts of uninteresting coverage for every syscall.
The following snippets are sprinkled all over the place in kcov traces
in a debugging kernel. We already try to disable instrumentation of
stack unwinding code and of most debug facilities. I guess we did not
use fault-inject.c at the time, and stacktrace.c was somehow missed (or
something has changed in kernel/configs). This change both speeds up
kcov (kernel doesn't need to store these PCs, user-space doesn't need to
process them) and frees trace buffer capacity for more useful coverage.
should_fail
lib/fault-inject.c:149
fail_dump
lib/fault-inject.c:45
stack_trace_save
kernel/stacktrace.c:124
stack_trace_consume_entry
kernel/stacktrace.c:86
stack_trace_consume_entry
kernel/stacktrace.c:89
... a hundred frames skipped ...
stack_trace_consume_entry
kernel/stacktrace.c:93
stack_trace_consume_entry
kernel/stacktrace.c:86
Link: http://lkml.kernel.org/r/20200116111449.217744-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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