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The WnR bit in the HSR/ESR_EL2 indicates whether a data abort was
generated by a read or a write instruction. For stage 2 data aborts
generated by a stage 1 translation table walk (i.e. the actual page
table access faults at EL2), the WnR bit therefore reports whether the
instruction generating the walk was a load or a store, *not* whether the
page table walker was reading or writing the entry.
For page tables marked as read-only at stage 2 (e.g. due to KSM merging
them with the tables from another guest), this could result in livelock,
where a page table walk generated by a load instruction attempts to
set the access flag in the stage 1 descriptor, but fails to trigger
CoW in the host since only a read fault is reported.
This patch modifies the arm64 kvm_vcpu_dabt_iswrite function to
take into account stage 2 faults in stage 1 walks. Since DBM cannot be
disabled at EL2 for CPUs that implement it, we assume that these faults
are always causes by writes, avoiding the livelock situation at the
expense of occasional, spurious CoWs.
We could, in theory, do a bit better by checking the guest TCR
configuration and inspecting the page table to see why the PTE faulted.
However, I doubt this is measurable in practice, and the threat of
livelock is real.
Cc: <stable@vger.kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Although I am leaving Synopsys, I would like to keep working with the linux
kernel community and help in what you might find useful. For that I am
sending this patch to change my contact e-mail.
Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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It turns out we need to ping the watchdog hardware on resume when we
re-program it. Otherwise this causes inadvertent reset to trigger
right after the resume is complete.
Fixes: 058dfc767008 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Usually a validity intercept is a programming error of the host
because of invalid entries in the state description.
We can get a validity intercept if the mode of the runtime
instrumentation control block is wrong. As the host does not know
which modes are valid, this can be used by userspace to trigger
a WARN.
Instead of printing a WARN let's return an error to userspace as
this can only happen if userspace provides a malformed initial
value (e.g. on migration). The kernel should never warn on bogus
input. Instead let's log it into the s390 debug feature.
While at it, let's return -EINVAL for all validity intercepts as
this will trigger an error in QEMU like
error: kvm run failed Invalid argument
PSW=mask 0404c00180000000 addr 000000000063c226 cc 00
R00=000000000000004f R01=0000000000000004 R02=0000000000760005 R03=000000007fe0a000
R04=000000000064ba2a R05=000000049db73dd0 R06=000000000082c4b0 R07=0000000000000041
R08=0000000000000002 R09=000003e0804042a8 R10=0000000496152c42 R11=000000007fe0afb0
[...]
This will avoid an endless loop of validity intercepts.
Cc: stable@vger.kernel.org # v4.5+
Fixes: c6e5f166373a ("KVM: s390: implement the RI support of guest")
Acked-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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'best' is always less or equals to 'pos', so `best - pos' returns
a negative value which is then getting casted to `unsigned int'
and passed to __cpufreq_driver_target()->acpi_cpufreq_target()
for policy->freq_table selection. This results in
BUG: unable to handle kernel paging request at ffff881019b469f8
IP: [<ffffffffa00356c1>] acpi_cpufreq_target+0x4f/0x190 [acpi_cpufreq]
PGD 267f067
PUD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 6 PID: 70 Comm: kworker/6:1 Not tainted 4.9.0-rc1-next-20161017-dbg-dirty
Workqueue: events dbs_work_handler
task: ffff88041b808000 task.stack: ffff88041b810000
RIP: 0010:[<ffffffffa00356c1>] [<ffffffffa00356c1>] acpi_cpufreq_target+0x4f/0x190 [acpi_cpufreq]
RSP: 0018:ffff88041b813c60 EFLAGS: 00010282
RAX: ffff880419b46a00 RBX: ffff88041b848400 RCX: ffff880419b20f80
RDX: 00000000001dff38 RSI: 00000000ffffffff RDI: ffff88041b848400
RBP: ffff88041b813cb0 R08: 0000000000000006 R09: 0000000000000040
R10: ffffffff8207f9e0 R11: ffffffff8173595b R12: 0000000000000000
R13: ffff88041f1dff38 R14: 0000000000262900 R15: 0000000bfffffff4
FS: 0000000000000000(0000) GS:ffff88041f000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff881019b469f8 CR3: 000000041a2d3000 CR4: 00000000001406e0
Stack:
ffff88041b813cb0 ffffffff813347f9 ffff88041b813ca0 ffffffff81334663
ffff88041f1d4bc0 ffff88041b848400 0000000000000000 0000000000000000
0000000000262900 0000000000000000 ffff88041b813d00 ffffffff813355dc
Call Trace:
[<ffffffff813347f9>] ? cpufreq_freq_transition_begin+0xf1/0xfc
[<ffffffff81334663>] ? get_cpu_idle_time+0x97/0xa6
[<ffffffff813355dc>] __cpufreq_driver_target+0x3b6/0x44e
[<ffffffff81336ca3>] cs_dbs_timer+0x11a/0x135
[<ffffffff81336fda>] dbs_work_handler+0x39/0x62
[<ffffffff81057823>] process_one_work+0x280/0x4a5
[<ffffffff81058719>] worker_thread+0x24f/0x397
[<ffffffff810584ca>] ? rescuer_thread+0x30b/0x30b
[<ffffffff81418380>] ? nl80211_get_key+0x29/0x36a
[<ffffffff8105d2b7>] kthread+0xfc/0x104
[<ffffffff8107ceea>] ? put_lock_stats.isra.9+0xe/0x20
[<ffffffff8105d1bb>] ? kthread_create_on_node+0x3f/0x3f
[<ffffffff814b2092>] ret_from_fork+0x22/0x30
Code: 56 4d 6b ff 0c 41 55 41 54 53 48 83 ec 28 48 8b 15 ad 1e 00 00 44 8b 41
08 48 8b 87 c8 00 00 00 49 89 d5 4e 03 2c c5 80 b2 78 81 <46> 8b 74 38 04 45
3b 75 00 75 11 31 c0 83 39 00 0f 84 1c 01 00
RIP [<ffffffffa00356c1>] acpi_cpufreq_target+0x4f/0x190 [acpi_cpufreq]
RSP <ffff88041b813c60>
CR2: ffff881019b469f8
---[ end trace 16d9fc7a17897d37 ]---
[ rjw: In some cases this bug may also cause incorrect frequencies to
be selected by cpufreq governors. ]
Fixes: 899bb6642f2a (cpufreq: skip invalid entries when searching the frequency)
Link: http://marc.info/?l=linux-kernel&m=147672030714331&w=2
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reported-and-tested-by: Jörg Otte <jrg.otte@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.8+ <stable@vger.kernel.org> # 4.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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All the lines printed by mem_init are independent, with each ending with
a newline. While they logically form a large block, none are actually
continuations of previous lines.
The kernel-side printk code and the userspace demsg tool differ in their
handling of KERN_CONT following a newline, and while this isn't always a
problem kernel-side, it does cause difficulty for userspace. Using
pr_cont causes the userspace tool to not print line prefix (e.g.
timestamps) even when following a newline, mis-aligning the output and
making it harder to read, e.g.
[ 0.000000] Virtual kernel memory layout:
[ 0.000000] modules : 0xffff000000000000 - 0xffff000008000000 ( 128 MB)
vmalloc : 0xffff000008000000 - 0xffff7dffbfff0000 (129022 GB)
.text : 0xffff000008080000 - 0xffff0000088b0000 ( 8384 KB)
.rodata : 0xffff0000088b0000 - 0xffff000008c50000 ( 3712 KB)
.init : 0xffff000008c50000 - 0xffff000008d50000 ( 1024 KB)
.data : 0xffff000008d50000 - 0xffff000008e25200 ( 853 KB)
.bss : 0xffff000008e25200 - 0xffff000008e6bec0 ( 284 KB)
fixed : 0xffff7dfffe7fd000 - 0xffff7dfffec00000 ( 4108 KB)
PCI I/O : 0xffff7dfffee00000 - 0xffff7dffffe00000 ( 16 MB)
vmemmap : 0xffff7e0000000000 - 0xffff800000000000 ( 2048 GB maximum)
0xffff7e0000000000 - 0xffff7e0026000000 ( 608 MB actual)
memory : 0xffff800000000000 - 0xffff800980000000 ( 38912 MB)
[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=6, Nodes=1
Fix this by using pr_notice consistently for all lines, which both the
kernel and userspace are happy with.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Recently in commit 4bcc595ccd80decb ("printk: reinstate KERN_CONT for
printing continuation lines"), the behaviour of printk changed w.r.t.
KERN_CONT. Now, KERN_CONT is mandatory to continue existing lines.
Without this, prefixes are inserted, making output illegible, e.g.
[ 1007.069010] pc : [<ffff00000871898c>] lr : [<ffff000008718948>] pstate: 40000145
[ 1007.076329] sp : ffff000008d53ec0
[ 1007.079606] x29: ffff000008d53ec0 [ 1007.082797] x28: 0000000080c50018
[ 1007.086160]
[ 1007.087630] x27: ffff000008e0c7f8 [ 1007.090820] x26: ffff80097631ca00
[ 1007.094183]
[ 1007.095653] x25: 0000000000000001 [ 1007.098843] x24: 000000ea68b61cac
[ 1007.102206]
... or when dumped with the userpace dmesg tool, which has slightly
different implicit newline behaviour. e.g.
[ 1007.069010] pc : [<ffff00000871898c>] lr : [<ffff000008718948>] pstate: 40000145
[ 1007.076329] sp : ffff000008d53ec0
[ 1007.079606] x29: ffff000008d53ec0
[ 1007.082797] x28: 0000000080c50018
[ 1007.086160]
[ 1007.087630] x27: ffff000008e0c7f8
[ 1007.090820] x26: ffff80097631ca00
[ 1007.094183]
[ 1007.095653] x25: 0000000000000001
[ 1007.098843] x24: 000000ea68b61cac
[ 1007.102206]
We can't simply always use KERN_CONT for lines which may or may not be
continuations. That causes line prefixes (e.g. timestamps) to be
supressed, and the alignment of all but the first line will be broken.
For even more fun, we can't simply insert some dummy empty-string printk
calls, as GCC warns for an empty printk string, and even if we pass
KERN_DEFAULT explcitly to silence the warning, the prefix gets swallowed
unless there is an additional part to the string.
Instead, we must manually iterate over pairs of registers, which gives
us the legible output we want in either case, e.g.
[ 169.771790] pc : [<ffff00000871898c>] lr : [<ffff000008718948>] pstate: 40000145
[ 169.779109] sp : ffff000008d53ec0
[ 169.782386] x29: ffff000008d53ec0 x28: 0000000080c50018
[ 169.787650] x27: ffff000008e0c7f8 x26: ffff80097631de00
[ 169.792913] x25: 0000000000000001 x24: 00000027827b2cf4
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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gcc 7 warns:
arch/x86/kvm/ioapic.c: In function 'kvm_ioapic_reset':
arch/x86/kvm/ioapic.c:597:2: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]
And it is right. Memset whole array using sizeof operator.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[Added x86 subject tag]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
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When CONFIG_CPU_FREQ is not set, int cpu is unused and gcc rightfully
warns about it:
arch/x86/kvm/x86.c: In function ‘kvm_timer_init’:
arch/x86/kvm/x86.c:5697:6: warning: unused variable ‘cpu’ [-Wunused-variable]
int cpu;
^~~
But since it is used only in the CONFIG_CPU_FREQ block, simply move it
there, thus squashing the warning too.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
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GNU ld used to set the ELF file type to ET_DYN for PIE executables, which
is the same file type used for shared libraries. However, this was changed
recently, and now PIE executables are emitted as ET_EXEC instead.
The distinction is only relevant for ELF loaders, and so there is little
reason to care about the difference when building the kernel, which is
why the change has gone unnoticed until now.
However, debuggers do use the ELF binary, and expect ET_EXEC type files
to appear in memory at the exact offset described in the ELF metadata.
This means source level debugging is no longer possible when KASLR is in
effect or when executing the stub.
So add the -shared LD option when building with CONFIG_RELOCATABLE=y. This
forces the ELF file type to be set to ET_DYN (which is what you get when
building with binutils 2.24 and earlier anyway), and has no other ill
effects.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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The suspend/resume path in kernel/sleep.S, as used by cpu-idle, does not
save/restore PSTATE. As a result of this cpufeatures that were detected
and have bits in PSTATE get lost when we resume from idle.
UAO gets set appropriately on the next context switch. PAN will be
re-enabled next time we return from user-space, but on a preemptible
kernel we may run work accessing user space before this point.
Add code to re-enable theses two features in __cpu_suspend_exit().
We re-use uao_thread_switch() passing current.
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Commit 338d4f49d6f7 ("arm64: kernel: Add support for Privileged Access
Never") enabled PAN by enabling the 'SPAN' feature-bit in SCTLR_EL1.
This means the PSTATE.PAN bit won't be set until the next return to the
kernel from userspace. On a preemptible kernel we may schedule work that
accesses userspace on a CPU before it has done this.
Now that cpufeature enable() calls are scheduled via stop_machine(), we
can set PSTATE.PAN from the cpu_enable_pan() call.
Add WARN_ON_ONCE(in_interrupt()) to check the PSTATE value we updated
is not immediately discarded.
Reported-by: Tony Thompson <anthony.thompson@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
[will: fixed typo in comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
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The enable() call for a cpufeature/errata is called using on_each_cpu().
This issues a cross-call IPI to get the work done. Implicitly, this
stashes the running PSTATE in SPSR when the CPU receives the IPI, and
restores it when we return. This means an enable() call can never modify
PSTATE.
To allow PAN to do this, change the on_each_cpu() call to use
stop_machine(). This schedules the work on each CPU which allows
us to modify PSTATE.
This involves changing the protype of all the enable() functions.
enable_cpu_capabilities() is called during boot and enables the feature
on all online CPUs. This path now uses stop_machine(). CPU features for
hotplug'd CPUs are enabled by verify_local_cpu_features() which only
acts on the local CPU, and can already modify the running PSTATE as it
is called from secondary_start_kernel().
Reported-by: Tony Thompson <anthony.thompson@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Commit 7dd01aef0557 ("arm64: trap userspace "dc cvau" cache operation on
errata-affected core") adds code to execute cache maintenance instructions
in the kernel on behalf of userland on CPUs with certain ARM CPU errata.
It turns out that the address hasn't been checked to be a valid user
space address, allowing userland to clean cache lines in kernel space.
Fix this by introducing an address check before executing the
instructions on behalf of userland.
Since the address doesn't come via a syscall parameter, we can't just
reject tagged pointers and instead have to remove the tag when checking
against the user address limit.
Cc: <stable@vger.kernel.org>
Fixes: 7dd01aef0557 ("arm64: trap userspace "dc cvau" cache operation on errata-affected core")
Reported-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[will: rework commit message + replace access_ok with max_user_addr()]
Signed-off-by: Will Deacon <will.deacon@arm.com>
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The pixel clock should not be on if the CRTC is not in use, hence
move clock enable/disable calls into CRTC callbacks.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-By: Meng Yi <meng.yi@nxp.com>
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Do not schedule a transfer of mode settings early. Modes should
get applied on on CRTC enable where we also enable the pixel clock.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-By: Meng Yi <meng.yi@nxp.com>
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There is no need to explicitly initiate a register transfer and
turn off the DCU after initializing the plane registers. In fact,
this is harmful and leads to unnecessary flickers if the DCU has
been left on by the bootloader.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-By: Meng Yi <meng.yi@nxp.com>
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Do not use encoder disable/enable callbacks to control bypass
mode as this seems to mess with the signals not liked by
displays. This also makes more sense since the encoder is
already defined to be parallel RGB/LVDS at creation time.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-By: Meng Yi <meng.yi@nxp.com>
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A bugfix introduced a harmless warning for update_open_stateid:
fs/nfs/nfs4proc.c:1548:2: error: missing braces around initializer [-Werror=missing-braces]
Removing the zero in the initializer will do the right thing here
and initialize the entire structure to zero.
Fixes: 1393d9612ba0 ("NFSv4: Fix a race when updating an open_stateid")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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Ported over from nvme-cli.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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This makes life easier for nvme-cli and we don't really need the uuid
type anyway to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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Import a few updates to nvme.h from nvme-cli. This mostly includes a few
new fields and error codes, but also a few renames that so far are only
used in user space. Also one field is moved from an array of two le64
values to one of 16 u8 values so that we can more easily access it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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NVMe 1.2.1 specification adds a tertiary element to the version number.
This updates the macro and its callers to include the final number and
fixup a single place in nvmet where the version was generated manually.
Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
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We have a fairly common pattern where you print several things as
continuations on one single line in a loop, and then at the end you do
printk(KERN_CONT "\n");
to flush the buffered output.
But if the output was flushed by something else (concurrent printk
activity, or just system logging), we don't want that final flushing to
just print an empty line.
So just suppress empty continuation lines when they couldn't be merged
into the line they are a continuation of.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' argument from access_process_vm() and replaces
it with 'gup_flags' as use of this function previously silently implied
FOLL_FORCE, whereas after this patch callers explicitly pass this flag.
We make this explicit as use of FOLL_FORCE can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' argument from access_remote_vm() and replaces
it with 'gup_flags' as use of this function previously silently implied
FOLL_FORCE, whereas after this patch callers explicitly pass this flag.
We make this explicit as use of FOLL_FORCE can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' argument from __access_remote_vm() and replaces
it with 'gup_flags' as use of this function previously silently implied
FOLL_FORCE, whereas after this patch callers explicitly pass this flag.
We make this explicit as use of FOLL_FORCE can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' and 'force' from get_user_pages_remote() and
replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in
callers as use of this flag can result in surprising behaviour (and
hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' and 'force' from get_vaddr_frames() and
replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in
callers as use of this flag can result in surprising behaviour (and
hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the 'write' and 'force' use from get_user_pages_locked()
and replaces them with 'gup_flags' to make the use of FOLL_FORCE
explicit in callers as use of this flag can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Writing the outer loop of an LL/SC sequence using do {...} while
constructs potentially allows the compiler to hoist memory accesses
between the STXR and the branch back to the LDXR. On CPUs that do not
guarantee forward progress of LL/SC loops when faced with memory
accesses to the same ERG (up to 2k) between the failed STXR and the
branch back, we may end up livelocking.
This patch avoids this issue in our percpu atomics by rewriting the
outer loop as part of the LL/SC inline assembly block.
Cc: <stable@vger.kernel.org>
Fixes: f97fc810798c ("arm64: percpu: Implement this_cpu operations")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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If a CPU does not implement a global monitor for certain memory types,
then userspace can attempt a kernel DoS by issuing SWP instructions
targetting the problematic memory (for example, a framebuffer mapped
with non-cacheable attributes).
The SWP emulation code protects against these sorts of attacks by
checking for pending signals and potentially rescheduling when the STXR
instruction fails during the emulation. Whilst this is good for avoiding
livelock, it harms emulation of legitimate SWP instructions on CPUs
where forward progress is not guaranteed if there are memory accesses to
the same reservation granule (up to 2k) between the failing STXR and
the retry of the LDXR.
This patch solves the problem by retrying the STXR a bounded number of
times (4) before breaking out of the LL/SC loop and looking for
something else to do.
Cc: <stable@vger.kernel.org>
Fixes: bd35a4adc413 ("arm64: Port SWP/SWPB emulation support from arm")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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A scheduler performance regression has been reported by Joseph Salisbury,
which he bisected back to:
3d30544f0212 ("sched/fair: Apply more PELT fixes)
The regression triggers when several levels of task groups are involved
(read: SystemD) and cpu_possible_mask != cpu_present_mask.
The root cause is that group entity's load (tg_child->se[i]->avg.load_avg)
is initialized to scale_load_down(se->load.weight). During the creation of
a child task group, its group entities on possible CPUs are attached to
parent's cfs_rq (tg_parent) and their loads are added to the parent's load
(tg_parent->load_avg) with update_tg_load_avg().
But only the load on online CPUs will then be updated to reflect real load,
whereas load on other CPUs will stay at the initial value.
The result is a tg_parent->load_avg that is higher than the real load, the
weight of group entities (tg_parent->se[i]->load.weight) on online CPUs is
smaller than it should be, and the task group gets a less running time than
what it could expect.
( This situation can be detected with /proc/sched_debug. The ".tg_load_avg"
of the task group will be much higher than sum of ".tg_load_avg_contrib"
of online cfs_rqs of the task group. )
The load of group entities don't have to be intialized to something else
than 0 because their load will increase when an entity is attached.
Reported-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org> # 4.8.x
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: joonwoop@codeaurora.org
Fixes: 3d30544f0212 ("sched/fair: Apply more PELT fixes)
Link: http://lkml.kernel.org/r/1476881123-10159-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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MIPS KVM uses user memory accessors but mips.c doesn't directly include
uaccess.h, so include it now.
This wasn't too much of a problem before v4.9-rc1 as asm/module.h
included asm/uaccess.h, however since commit 29abfbd9cbba ("mips:
separate extable.h, switch module.h to it") this is no longer the case.
This resulted in build failures when trace points were disabled, as
trace/define_trace.h includes trace/trace_events.h only ifdef
TRACEPOINTS_ENABLED, which goes on to include asm/uaccess.h via a couple
of other headers.
Fixes: 29abfbd9cbba ("mips: separate extable.h, switch module.h to it")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
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Signed-off-by: Rich Felker <dalias@libc.org>
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Signed-off-by: Rich Felker <dalias@libc.org>
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This removes the 'write' and 'force' use from get_user_pages_unlocked()
and replaces them with 'gup_flags' to make the use of FOLL_FORCE
explicit in callers as use of this flag can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the redundant 'write' and 'force' parameters from
__get_user_pages_unlocked() to make the use of FOLL_FORCE explicit in
callers as use of this flag can result in surprising behaviour (and
hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This removes the redundant 'write' and 'force' parameters from
__get_user_pages_locked() to make the use of FOLL_FORCE explicit in
callers as use of this flag can result in surprising behaviour (and
hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is an ancient bug that was actually attempted to be fixed once
(badly) by me eleven years ago in commit 4ceb5db9757a ("Fix
get_user_pages() race for write access") but that was then undone due to
problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug").
In the meantime, the s390 situation has long been fixed, and we can now
fix it by checking the pte_dirty() bit properly (and do it better). The
s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement
software dirty bits") which made it into v3.9. Earlier kernels will
have to look at the page state itself.
Also, the VM has become more scalable, and what used a purely
theoretical race back then has become easier to trigger.
To fix it, we introduce a new internal FOLL_COW flag to mark the "yes,
we already did a COW" rather than play racy games with FOLL_WRITE that
is very fundamental, and then use the pte dirty flag to validate that
the FOLL_COW flag is still valid.
Reported-and-tested-by: Phil "not Paul" Oester <kernel@linuxace.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dell XPS 13 (and maybe some others) uses a GPIO (CPU_GP_1) during suspend
to explicitly disable USB touchscreen interrupt. This is done to prevent
situation where the lid is closed the touchscreen is left functional.
The pinctrl driver (wrongly) assumes it owns all pins which are owned by
host and not locked down. It is perfectly fine for BIOS to use those pins
as it is also considered as host in this context.
What happens is that when the lid of Dell XPS 13 is closed, the BIOS
configures CPU_GP_1 low disabling the touchscreen interrupt. During resume
we restore all host owned pins to the known state which includes CPU_GP_1
and this overwrites what the BIOS has programmed there causing the
touchscreen to fail as no interrupts are reaching the CPU anymore.
Fix this by restoring only those pins we know are explicitly requested by
the kernel one way or other.
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=176361
Reported-by: AceLan Kao <acelan.kao@canonical.com>
Tested-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Initialize the spinlock before using it.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.8.0-dwc-bisect #4
Hardware name: Intel Corp. VALLEYVIEW C0 PLATFORM/BYT-T FFD8, BIOS BLAKFF81.X64.0088.R10.1403240443 FFD8_X64_R_2014_13_1_00 03/24/2014
0000000000000000 ffff8800788ff770 ffffffff8133d597 0000000000000000
0000000000000000 ffff8800788ff7e0 ffffffff810cfb9e 0000000000000002
ffff8800788ff7d0 ffffffff8205b600 0000000000000002 ffff8800788ff7f0
Call Trace:
[<ffffffff8133d597>] dump_stack+0x67/0x90
[<ffffffff810cfb9e>] register_lock_class+0x52e/0x540
[<ffffffff810d2081>] __lock_acquire+0x81/0x16b0
[<ffffffff810cede1>] ? save_trace+0x41/0xd0
[<ffffffff810d33b2>] ? __lock_acquire+0x13b2/0x16b0
[<ffffffff810cf05a>] ? __lock_is_held+0x4a/0x70
[<ffffffff810d3b1a>] lock_acquire+0xba/0x220
[<ffffffff8136f1fe>] ? byt_gpio_get_direction+0x3e/0x80
[<ffffffff81631567>] _raw_spin_lock_irqsave+0x47/0x60
[<ffffffff8136f1fe>] ? byt_gpio_get_direction+0x3e/0x80
[<ffffffff8136f1fe>] byt_gpio_get_direction+0x3e/0x80
[<ffffffff813740a9>] gpiochip_add_data+0x319/0x7d0
[<ffffffff81631723>] ? _raw_spin_unlock_irqrestore+0x43/0x70
[<ffffffff8136fe3b>] byt_pinctrl_probe+0x2fb/0x620
[<ffffffff8142fb0c>] platform_drv_probe+0x3c/0xa0
...
Based on the diff it looks like the problem was introduced in
commit 71e6ca61e826 ("pinctrl: baytrail: Register pin control handling")
but I wasn't able to verify that empirically as the parent commit
just oopsed when I tried to boot it.
Cc: Cristina Ciocan <cristina.ciocan@intel.com>
Cc: stable@vger.kernel.org
Fixes: 71e6ca61e826 ("pinctrl: baytrail: Register pin control handling")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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The SPI1 function was associated with the wrong pins: The functions that
those pins provide is either an SPI debug or passthrough function
coupled to SPI1. Make the SPI1 mux function configure the relevant pins
and associate new SPI1DEBUG and SPI1PASSTHRU functions with the pins
that were already defined.
The notation used in the datasheet's multi-function pin table for the SoC is
often creative: in this case the SYS* signals are enabled by a single bit,
which is nothing unusual on its own, but in this case the bit was also
participating in a multi-bit bitfield and therefore represented multiple
functions. This fact was overlooked in the original patch.
Fixes: 56e57cb6c07f (pinctrl: Add pinctrl-aspeed-g5 driver)
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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This prevented C20 from successfully being muxed as GPIO.
Fixes: 56e57cb6c07f (pinctrl: Add pinctrl-aspeed-g5 driver)
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Fixes simple typos in the initial commit. There is no behavioural
change.
Fixes: 56e57cb6c07f (pinctrl: Add pinctrl-aspeed-g5 driver)
Reported-by: Xo Wang <xow@google.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Consider a scenario with one pin P that has two signals A and B, where A
is defined to be higher priority than B: That is, if the mux IP is in a
state that would consider both A and B to be active on P, then A will be
the active signal.
To instead configure B as the active signal we must configure the mux so
that A is inactive. The mux state for signals can be described by
logical operations on one or more bits from one or more registers (a
"signal expression"), which in some cases leads to aliased mux states for
a particular signal. Further, signals described by multi-bit bitfields
often do not only need to record the states that would make them active
(the "enable" expressions), but also the states that makes them inactive
(the "disable" expressions). All of this combined leads to four possible
states for a signal:
1. A signal is active with respect to an "enable" expression
2. A signal is not active with respect to an "enable" expression
3. A signal is inactive with respect to a "disable" expression
4. A signal is not inactive with respect to a "disable" expression
In the case of P, if we are looking to activate B without explicitly
having configured A it's enough to consider A inactive if all of A's
"enable" signal expressions evaluate to "not active". If any evaluate to
"active" then the corresponding "disable" states must be applied so it
becomes inactive.
For example, on the AST2400 the pins composing GPIO bank H provide
signals ROMD8 through ROMD15 (high priority) and those for UART6 (low
priority). The mux states for ROMD8 through ROMD15 are aliased, i.e.
there are two mux states that result in the respective signals being
configured:
A. SCU90[6]=1
B. Strap[4,1:0]=100
Further, the second mux state is a 3-bit bitfield that explicitly
defines the enabled state but the disabled state is implicit, i.e. if
Strap[4,1:0] is not exactly "100" then ROMD8 through ROMD15 are not
considered active. This requires the mux function evaluation logic to
use approach 2. above, however the existing code was using approach 3.
The problem was brought to light on the Palmetto machines where the
strap register value is 0x120ce416, and prevented GPIO requests in bank
H from succeeding despite the hardware being in a position to allow
them.
Fixes: 318398c09a8d ("pinctrl: Add core pinctrl support for Aspeed SoCs")
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Fixes the following sparse warning:
fs/ceph/xattr.c:19:28: warning:
symbol 'ceph_other_xattr_handler' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
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