| Commit message (Collapse) | Author | Age | Files | Lines |
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With the existing implementation of store_rps_map(), packets are queued
in the receive path on the backlog queues of other CPUs irrespective of
whether they are isolated or not. This could add a latency overhead to
any RT workload that is running on the same CPU.
Ensure that store_rps_map() only uses available housekeeping CPUs for
storing the rps_map.
Signed-off-by: Alex Belits <abelits@marvell.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200625223443.2684-4-nitesh@redhat.com
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pci_call_probe() prevents the nesting of work_on_cpu() for a scenario
where a VF device is probed from work_on_cpu() of the PF.
Replace the cpumask used in pci_call_probe() from all online CPUs to only
housekeeping CPUs. This is to ensure that there are no additional latency
overheads caused due to the pinning of jobs on isolated CPUs.
Signed-off-by: Alex Belits <abelits@marvell.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/20200625223443.2684-3-nitesh@redhat.com
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The current implementation of cpumask_local_spread() does not respect the
isolated CPUs, i.e., even if a CPU has been isolated for Real-Time task,
it will return it to the caller for pinning of its IRQ threads. Having
these unwanted IRQ threads on an isolated CPU adds up to a latency
overhead.
Restrict the CPUs that are returned for spreading IRQs only to the
available housekeeping CPUs.
Signed-off-by: Alex Belits <abelits@marvell.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200625223443.2684-2-nitesh@redhat.com
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There is a report that when uclamp is enabled, a netperf UDP test
regresses compared to a kernel compiled without uclamp.
https://lore.kernel.org/lkml/20200529100806.GA3070@suse.de/
While investigating the root cause, there were no sign that the uclamp
code is doing anything particularly expensive but could suffer from bad
cache behavior under certain circumstances that are yet to be
understood.
https://lore.kernel.org/lkml/20200616110824.dgkkbyapn3io6wik@e107158-lin/
To reduce the pressure on the fast path anyway, add a static key that is
by default will skip executing uclamp logic in the
enqueue/dequeue_task() fast path until it's needed.
As soon as the user start using util clamp by:
1. Changing uclamp value of a task with sched_setattr()
2. Modifying the default sysctl_sched_util_clamp_{min, max}
3. Modifying the default cpu.uclamp.{min, max} value in cgroup
We flip the static key now that the user has opted to use util clamp.
Effectively re-introducing uclamp logic in the enqueue/dequeue_task()
fast path. It stays on from that point forward until the next reboot.
This should help minimize the effect of util clamp on workloads that
don't need it but still allow distros to ship their kernels with uclamp
compiled in by default.
SCHED_WARN_ON() in uclamp_rq_dec_id() was removed since now we can end
up with unbalanced call to uclamp_rq_dec_id() if we flip the key while
a task is running in the rq. Since we know it is harmless we just
quietly return if we attempt a uclamp_rq_dec_id() when
rq->uclamp[].bucket[].tasks is 0.
In schedutil, we introduce a new uclamp_is_enabled() helper which takes
the static key into account to ensure RT boosting behavior is retained.
The following results demonstrates how this helps on 2 Sockets Xeon E5
2x10-Cores system.
nouclamp uclamp uclamp-static-key
Hmean send-64 162.43 ( 0.00%) 157.84 * -2.82%* 163.39 * 0.59%*
Hmean send-128 324.71 ( 0.00%) 314.78 * -3.06%* 326.18 * 0.45%*
Hmean send-256 641.55 ( 0.00%) 628.67 * -2.01%* 648.12 * 1.02%*
Hmean send-1024 2525.28 ( 0.00%) 2448.26 * -3.05%* 2543.73 * 0.73%*
Hmean send-2048 4836.14 ( 0.00%) 4712.08 * -2.57%* 4867.69 * 0.65%*
Hmean send-3312 7540.83 ( 0.00%) 7425.45 * -1.53%* 7621.06 * 1.06%*
Hmean send-4096 9124.53 ( 0.00%) 8948.82 * -1.93%* 9276.25 * 1.66%*
Hmean send-8192 15589.67 ( 0.00%) 15486.35 * -0.66%* 15819.98 * 1.48%*
Hmean send-16384 26386.47 ( 0.00%) 25752.25 * -2.40%* 26773.74 * 1.47%*
The perf diff between nouclamp and uclamp-static-key when uclamp is
disabled in the fast path:
8.73% -1.55% [kernel.kallsyms] [k] try_to_wake_up
0.07% +0.04% [kernel.kallsyms] [k] deactivate_task
0.13% -0.02% [kernel.kallsyms] [k] activate_task
The diff between nouclamp and uclamp-static-key when uclamp is enabled
in the fast path:
8.73% -0.72% [kernel.kallsyms] [k] try_to_wake_up
0.13% +0.39% [kernel.kallsyms] [k] activate_task
0.07% +0.38% [kernel.kallsyms] [k] deactivate_task
Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting")
Reported-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-3-qais.yousef@arm.com
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struct uclamp_rq was zeroed out entirely in assumption that in the first
call to uclamp_rq_inc() they'd be initialized correctly in accordance to
default settings.
But when next patch introduces a static key to skip
uclamp_rq_{inc,dec}() until userspace opts in to use uclamp, schedutil
will fail to perform any frequency changes because the
rq->uclamp[UCLAMP_MAX].value is zeroed at init and stays as such. Which
means all rqs are capped to 0 by default.
Fix it by making sure we do proper initialization at init without
relying on uclamp_rq_inc() doing it later.
Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-2-qais.yousef@arm.com
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For some mysterious reason GCC-4.9 has a 64 byte section alignment for
structures, all other GCC versions (and Clang) tested (including 4.8
and 5.0) are fine with the 32 bytes alignment.
Getting this right is important for the new SCHED_DATA macro that
creates an explicitly ordered array of 'struct sched_class' in the
linker script and expect pointer arithmetic to work.
Fixes: c3a340f7e7ea ("sched: Have sched_class_highest define by vmlinux.lds.h")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200630144905.GX4817@hirez.programming.kicks-ass.net
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While integrating rseq into glibc and replacing glibc's sched_getcpu
implementation with rseq, glibc's tests discovered an issue with
incorrect __rseq_abi.cpu_id field value right after the first time
a newly created process issues sched_setaffinity.
For the records, it triggers after building glibc and running tests, and
then issuing:
for x in {1..2000} ; do posix/tst-affinity-static & done
and shows up as:
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
This is caused by the scheduler invoking __set_task_cpu() directly from
sched_fork() and wake_up_new_task(), thus bypassing rseq_migrate() which
is done by set_task_cpu().
Add the missing rseq_migrate() to both functions. The only other direct
use of __set_task_cpu() is done by init_idle(), which does not involve a
user-space task.
Based on my testing with the glibc test-case, just adding rseq_migrate()
to wake_up_new_task() is sufficient to fix the observed issue. Also add
it to sched_fork() to keep things consistent.
The reason why this never triggered so far with the rseq/basic_test
selftest is unclear.
The current use of sched_getcpu(3) does not typically require it to be
always accurate. However, use of the __rseq_abi.cpu_id field within rseq
critical sections requires it to be accurate. If it is not accurate, it
can cause corruption in the per-cpu data targeted by rseq critical
sections in user-space.
Reported-By: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-By: Florian Weimer <fweimer@redhat.com>
Cc: stable@vger.kernel.org # v4.18+
Link: https://lkml.kernel.org/r/20200707201505.2632-1-mathieu.desnoyers@efficios.com
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The recent commit:
c6e7bd7afaeb ("sched/core: Optimize ttwu() spinning on p->on_cpu")
moved these lines in ttwu():
p->sched_contributes_to_load = !!task_contributes_to_load(p);
p->state = TASK_WAKING;
up before:
smp_cond_load_acquire(&p->on_cpu, !VAL);
into the 'p->on_rq == 0' block, with the thinking that once we hit
schedule() the current task cannot change it's ->state anymore. And
while this is true, it is both incorrect and flawed.
It is incorrect in that we need at least an ACQUIRE on 'p->on_rq == 0'
to avoid weak hardware from re-ordering things for us. This can fairly
easily be achieved by relying on the control-dependency already in
place.
The second problem, which makes the flaw in the original argument, is
that while schedule() will not change prev->state, it will read it a
number of times (arguably too many times since it's marked volatile).
The previous condition 'p->on_cpu == 0' was sufficient because that
indicates schedule() has completed, and will no longer read
prev->state. So now the trick is to make this same true for the (much)
earlier 'prev->on_rq == 0' case.
Furthermore, in order to make the ordering stick, the 'prev->on_rq = 0'
assignment needs to he a RELEASE, but adding additional ordering to
schedule() is an unwelcome proposition at the best of times, doubly so
for mere accounting.
Luckily we can push the prev->state load up before rq->lock, with the
only caveat that we then have to re-read the state after. However, we
know that if it changed, we no longer have to worry about the blocking
path. This gives us the required ordering, if we block, we did the
prev->state load before an (effective) smp_mb() and the p->on_rq store
needs not change.
With this we end up with the effective ordering:
LOAD p->state LOAD-ACQUIRE p->on_rq == 0
MB
STORE p->on_rq, 0 STORE p->state, TASK_WAKING
which ensures the TASK_WAKING store happens after the prev->state
load, and all is well again.
Fixes: c6e7bd7afaeb ("sched/core: Optimize ttwu() spinning on p->on_cpu")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Dave Jones <davej@codemonkey.org.uk>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: https://lkml.kernel.org/r/20200707102957.GN117543@hirez.programming.kicks-ass.net
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Using a mutex for "print this warning only once" is so overdesigned as
to be actively offensive to my sensitive stomach.
Just use "pr_info_once()" that already does this, although in a
(harmlessly) racy manner that can in theory cause the message to be
printed twice if more than one CPU races on that "is this the first
time" test.
[ If somebody really cares about that harmless data race (which sounds
very unlikely indeed), that person can trivially fix printk_once() by
using a simple atomic access, preferably with an optimistic non-atomic
test first before even bothering to treat the pointless "make sure it
is _really_ just once" case.
A mutex is most definitely never the right primitive to use for
something like this. ]
Yes, this is a small and meaningless detail in a code path that hardly
matters. But let's keep some code quality standards here, and not
accept outrageously bad code.
Link: https://lore.kernel.org/lkml/CAHk-=wgV9toS7GU3KmNpj8hCS9SeF+A0voHS8F275_mgLhL4Lw@mail.gmail.com/
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A series of fixes for x86:
- Reset MXCSR in kernel_fpu_begin() to prevent using a stale user
space value.
- Prevent writing MSR_TEST_CTRL on CPUs which are not explicitly
whitelisted for split lock detection. Some CPUs which do not
support it crash even when the MSR is written to 0 which is the
default value.
- Fix the XEN PV fallout of the entry code rework
- Fix the 32bit fallout of the entry code rework
- Add more selftests to ensure that these entry problems don't come
back.
- Disable 16 bit segments on XEN PV. It's not supported because XEN
PV does not implement ESPFIX64"
* tag 'x86-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ldt: Disable 16-bit segments on Xen PV
x86/entry/32: Fix #MC and #DB wiring on x86_32
x86/entry/xen: Route #DB correctly on Xen PV
x86/entry, selftests: Further improve user entry sanity checks
x86/entry/compat: Clear RAX high bits on Xen PV SYSENTER
selftests/x86: Consolidate and fix get/set_eflags() helpers
selftests/x86/syscall_nt: Clear weird flags after each test
selftests/x86/syscall_nt: Add more flag combinations
x86/entry/64/compat: Fix Xen PV SYSENTER frame setup
x86/entry: Move SYSENTER's regs->sp and regs->flags fixups into C
x86/entry: Assert that syscalls are on the right stack
x86/split_lock: Don't write MSR_TEST_CTRL on CPUs that aren't whitelisted
x86/fpu: Reset MXCSR to default in kernel_fpu_begin()
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Xen PV doesn't implement ESPFIX64, so they don't work right. Disable
them. Also print a warning the first time anyone tries to use a
16-bit segment on a Xen PV guest that would otherwise allow it
to help people diagnose this change in behavior.
This gets us closer to having all x86 selftests pass on Xen PV.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/92b2975459dfe5929ecf34c3896ad920bd9e3f2d.1593795633.git.luto@kernel.org
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DEFINE_IDTENTRY_MCE and DEFINE_IDTENTRY_DEBUG were wired up as non-RAW
on x86_32, but the code expected them to be RAW.
Get rid of all the macro indirection for them on 32-bit and just use
DECLARE_IDTENTRY_RAW and DEFINE_IDTENTRY_RAW directly.
Also add a warning to make sure that we only hit the _kernel paths
in kernel mode.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/9e90a7ee8e72fd757db6d92e1e5ff16339c1ecf9.1593795633.git.luto@kernel.org
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On Xen PV, #DB doesn't use IST. It still needs to be correctly routed
depending on whether it came from user or kernel mode.
Get rid of DECLARE/DEFINE_IDTENTRY_XEN -- it was too hard to follow the
logic. Instead, route #DB and NMI through DECLARE/DEFINE_IDTENTRY_RAW on
Xen, and do the right thing for #DB. Also add more warnings to the
exc_debug* handlers to make this type of failure more obvious.
This fixes various forms of corruption that happen when usermode
triggers #DB on Xen PV.
Fixes: 4c0dcd8350a0 ("x86/entry: Implement user mode C entry points for #DB and #MCE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/4163e733cce0b41658e252c6c6b3464f33fdff17.1593795633.git.luto@kernel.org
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Chasing down a Xen bug caused me to realize that the new entry sanity
checks are still fairly weak. Add some more checks.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/881de09e786ab93ce56ee4a2437ba2c308afe7a9.1593795633.git.luto@kernel.org
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Move the clearing of the high bits of RAX after Xen PV joins the SYSENTER
path so that Xen PV doesn't skip it.
Arguably this code should be deleted instead, but that would belong in the
merge window.
Fixes: ffae641f5747 ("x86/entry/64/compat: Fix Xen PV SYSENTER frame setup")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/9d33b3f3216dcab008070f1c28b6091ae7199969.1593795633.git.luto@kernel.org
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There are several copies of get_eflags() and set_eflags() and they all are
buggy. Consolidate them and fix them. The fixes are:
Add memory clobbers. These are probably unnecessary but they make sure
that the compiler doesn't move something past one of these calls when it
shouldn't.
Respect the redzone on x86_64. There has no failure been observed related
to this, but it's definitely a bug.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/982ce58ae8dea2f1e57093ee894760e35267e751.1593191971.git.luto@kernel.org
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Clear the weird flags before logging to improve strace output --
logging results while, say, TF is set does no one any favors.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/907bfa5a42d4475b8245e18b67a04b13ca51ffdb.1593191971.git.luto@kernel.org
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Add EFLAGS.AC to the mix.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/12924e2fe2c5826568b7fc9436d85ca7f5eb1743.1593191971.git.luto@kernel.org
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The SYSENTER frame setup was nonsense. It worked by accident because the
normal code into which the Xen asm jumped (entry_SYSENTER_32/compat) threw
away SP without touching the stack. entry_SYSENTER_compat was recently
modified such that it relied on having a valid stack pointer, so now the
Xen asm needs to invoke it with a valid stack.
Fix it up like SYSCALL: use the Xen-provided frame and skip the bare
metal prologue.
Fixes: 1c3e5d3f60e2 ("x86/entry: Make entry_64_compat.S objtool clean")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lkml.kernel.org/r/947880c41ade688ff4836f665d0c9fcaa9bd1201.1593191971.git.luto@kernel.org
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The SYSENTER asm (32-bit and compat) contains fixups for regs->sp and
regs->flags. Move the fixups into C and fix some comments while at it.
This is a valid cleanup all by itself, and it also simplifies the
subsequent patch that will fix Xen PV SYSENTER.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/fe62bef67eda7fac75b8f3dbafccf571dc4ece6b.1593191971.git.luto@kernel.org
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Now that the entry stack is a full page, it's too easy to regress the
system call entry code and end up on the wrong stack without noticing.
Assert that all system calls (SYSCALL64, SYSCALL32, SYSENTER, and INT80)
are on the right stack and have pt_regs in the right place.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/52059e42bb0ab8551153d012d68f7be18d72ff8e.1593191971.git.luto@kernel.org
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Choo! Choo! All aboard the Split Lock Express, with direct service to
Wreckage!
Skip split_lock_verify_msr() if the CPU isn't whitelisted as a possible
SLD-enabled CPU model to avoid writing MSR_TEST_CTRL. MSR_TEST_CTRL
exists, and is writable, on many generations of CPUs. Writing the MSR,
even with '0', can result in bizarre, undocumented behavior.
This fixes a crash on Haswell when resuming from suspend with a live KVM
guest. Because APs use the standard SMP boot flow for resume, they will
go through split_lock_init() and the subsequent RDMSR/WRMSR sequence,
which runs even when sld_state==sld_off to ensure SLD is disabled. On
Haswell (at least, my Haswell), writing MSR_TEST_CTRL with '0' will
succeed and _may_ take the SMT _sibling_ out of VMX root mode.
When KVM has an active guest, KVM performs VMXON as part of CPU onlining
(see kvm_starting_cpu()). Because SMP boot is serialized, the resulting
flow is effectively:
on_each_ap_cpu() {
WRMSR(MSR_TEST_CTRL, 0)
VMXON
}
As a result, the WRMSR can disable VMX on a different CPU that has
already done VMXON. This ultimately results in a #UD on VMPTRLD when
KVM regains control and attempt run its vCPUs.
The above voodoo was confirmed by reworking KVM's VMXON flow to write
MSR_TEST_CTRL prior to VMXON, and to serialize the sequence as above.
Further verification of the insanity was done by redoing VMXON on all
APs after the initial WRMSR->VMXON sequence. The additional VMXON,
which should VM-Fail, occasionally succeeded, and also eliminated the
unexpected #UD on VMPTRLD.
The damage done by writing MSR_TEST_CTRL doesn't appear to be limited
to VMX, e.g. after suspend with an active KVM guest, subsequent reboots
almost always hang (even when fudging VMXON), a #UD on a random Jcc was
observed, suspend/resume stability is qualitatively poor, and so on and
so forth.
kernel BUG at arch/x86/kvm/x86.c:386!
CPU: 1 PID: 2592 Comm: CPU 6/KVM Tainted: G D
Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014
RIP: 0010:kvm_spurious_fault+0xf/0x20
Call Trace:
vmx_vcpu_load_vmcs+0x1fb/0x2b0
vmx_vcpu_load+0x3e/0x160
kvm_arch_vcpu_load+0x48/0x260
finish_task_switch+0x140/0x260
__schedule+0x460/0x720
_cond_resched+0x2d/0x40
kvm_arch_vcpu_ioctl_run+0x82e/0x1ca0
kvm_vcpu_ioctl+0x363/0x5c0
ksys_ioctl+0x88/0xa0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x4c/0x170
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: dbaba47085b0c ("x86/split_lock: Rework the initialization flow of split lock detection")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200605192605.7439-1-sean.j.christopherson@intel.com
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Previously, kernel floating point code would run with the MXCSR control
register value last set by userland code by the thread that was active
on the CPU core just before kernel call. This could affect calculation
results if rounding mode was changed, or a crash if a FPU/SIMD exception
was unmasked.
Restore MXCSR to the kernel's default value.
[ bp: Carve out from a bigger patch by Petteri, add feature check, add
FNINIT call too (amluto). ]
Signed-off-by: Petteri Aimonen <jpa@git.mail.kapsi.fi>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207979
Link: https://lkml.kernel.org/r/20200624114646.28953-2-bp@alien8.de
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"A set of interrupt chip driver fixes:
- Ensure the atomicity of affinity updates in the GIC driver
- Don't try to sleep in atomic context when waiting for the GICv4.1
to respond. Use polling instead.
- Typo fixes in Kconfig and warnings"
* tag 'irq-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic: Atomically update affinity
irqchip/riscv-intc: Fix a typo in a pr_warn()
irqchip/gic-v4.1: Use readx_poll_timeout_atomic() to fix sleep in atomic
irqchip/loongson-pci-msi: Fix a typo in Kconfig
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git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent
Pull irqchip fixes from Marc Zyngier:
- Fix atomicity of affinity update in the GIC driver
- Don't sleep in atomic when waiting for a GICv4.1 RD to respond
- Fix a couple of typos in user-visible messages
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The GIC driver uses a RMW sequence to update the affinity, and
relies on the gic_lock_irqsave/gic_unlock_irqrestore sequences
to update it atomically.
But these sequences only expand into anything meaningful if
the BL_SWITCHER option is selected, which almost never happens.
It also turns out that using a RMW and locks is just as silly,
as the GIC distributor supports byte accesses for the GICD_TARGETRn
registers, which when used make the update atomic by definition.
Drop the terminally broken code and replace it by a byte write.
Fixes: 04c8b0f82c7d ("irqchip/gic: Make locking a BL_SWITCHER only feature")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Anup originally re-spun his patch set to include this fix, but it was a bit too
late for my PR so I've split it out.
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200611175302.253540-1-palmer@dabbelt.com
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readx_poll_timeout() can sleep if @sleep_us is specified by the caller,
and is therefore unsafe to be used inside the atomic context, which is
this case when we use it to poll the GICR_VPENDBASER.Dirty bit in
irq_set_vcpu_affinity() callback.
Let's convert to its atomic version instead which helps to get the v4.1
board back to life!
Fixes: 96806229ca03 ("irqchip/gic-v4.1: Add support for VPENDBASER's Dirty+Valid signaling")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200605052345.1494-1-yuzenghui@huawei.com
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PCH MSI driver's menuconfig entry was wrong. Fix it.
Fixes: 632dcc2c75ef ("irqchip: Add Loongson PCH MSI controller")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200530121113.1797678-2-jiaxun.yang@flygoat.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rcu fixlet from Thomas Gleixner:
"A single fix for a printk format warning in RCU"
* tag 'core-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcuperf: Fix printk format warning
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git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent
Pull RCU fix from Paul E. McKenney.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Using "%zu" to fix following warning,
kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’:
include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=]
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes frin Masahiro Yamada:
- fix various bugs in xconfig
- fix some issues in cross-compilation using Clang
- fix documentation
* tag 'kbuild-fixes-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
.gitignore: Do not track `defconfig` from `make savedefconfig`
kbuild: make Clang build userprogs for target architecture
kbuild: fix CONFIG_CC_CAN_LINK(_STATIC) for cross-compilation with Clang
kconfig: qconf: parse newer types at debug info
kconfig: qconf: navigate menus on hyperlinks
kconfig: qconf: don't show goback button on splitMode
kconfig: qconf: simplify the goBack() logic
kconfig: qconf: re-implement setSelected()
kconfig: qconf: make debug links work again
kconfig: qconf: make search fully work again on split mode
kconfig: qconf: cleanup includes
docs: kbuild: fix ReST formatting
gcc-plugins: fix gcc-plugins directory path in documentation
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Running `make savedefconfig` creates by default `defconfig`, which is,
currently, on git’s radar, for example, `git status` lists this file as
untracked.
So, add the file to `.gitignore`, so it’s ignored by git.
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Programs added 'userprogs' should be compiled for the target
architecture i.e. the same architecture as the kernel.
GCC does this correctly since the target architecture is implied
by the toolchain prefix.
Clang builds userspace programs always for the host architecture
because the target triple is currently missing.
Fix this.
Fixes: 7f3a59db274c ("kbuild: add infrastructure to build userspace programs")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
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scripts/cc-can-link.sh tests if the compiler can link userspace
programs.
When $(CC) is GCC, it is checked against the target architecture
because the toolchain prefix is specified as a part of $(CC).
When $(CC) is Clang, it is checked against the host architecture
because --target option is missing.
Pass $(CLANG_FLAGS) to scripts/cc-can-link.sh to evaluate the link
capability for the target architecture.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
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There are 3 types that are not parsed by the debug info logic.
Add support for them.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Instead of just changing the helper window to show a
dependency, also navigate to it at the config and menu
widgets.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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the goback button does nothing on splitMode. So, why display
it?
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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The goBack() logic is used only for the configList, as
it only makes sense on singleMode. So, let's simplify the
code.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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The default implementation for setSelected() at QTreeWidgetItem
allows multiple items to be selected.
Well, this should never be possible for the configItem lists.
So, implement a function that will automatically clean any
previous selection. This simplifies the logic somewhat, while
making the selection logic to be applied atomically, avoiding
future issues on that.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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The Qt5 conversion broke support for debug info links.
Restore the behaviour added by changeset
ab45d190fd4a ("kconfig: create links in info window").
The original approach was to pass a pointer for a data struct
via an <a href>. That doesn't sound a good idea, as, if something
gets wrong, the app could crash. So, instead, pass the name of
the symbol, and validate such symbol at the hyperlink handling
logic.
Link: https://lore.kernel.org/lkml/20200628125421.12458086@coco.lan/
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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When the search dialog box finds symbols/menus that match
the search criteria, it presents all results at the window.
Clicking on a search result should make qconf to navigate
to the selected item. This works on singleMode and on
fullMode, but on splitMode, the navigation is broken.
This was partially caused by an incomplete Qt5 conversion
and by the followup patches that restored the original
behavior.
When qconf is on split mode, it has to update both the
config and the menu views. Right now, such logic is broken,
as it is not seeking using the right structures.
On qconf, the screen is split into 3 parts:
+------------+-------+
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+------------+-------+
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| ConfigInfo |
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+--------------------+
On singleMode and on fullMode, the menuView is hidden, and search
updates only the configList (which controls the ConfigView).
On SplitMode, the search logic should detect if the variable is a
leaf or not. If it is a leaf, it should be presented at the menuView,
and both configList and menuList should be updated. Otherwise, just
the configList should be updated.
Link: https://lore.kernel.org/lkml/a98b0f0ebe0c23615a76f1d23f25fd0c84835e6b.camel@redhat.com/
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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The usage of c-like include is deprecated on modern Qt
versions. Use the c++ style includes.
While here, remove uneeded and redundant ones, sorting
them on alphabetic order.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to
*.rst") missed a ReST header and a verbatim file content area.
Signed-off-by: Dov Murik <dovmurik@linux.vnet.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Fix typos "plgins" -> "plugins".
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Four small fixes in three drivers.
The mptfusion one has actually caused user visible issues in certain
kernel configurations"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: mptfusion: Don't use GFP_ATOMIC for larger DMA allocations
scsi: libfc: Skip additional kref updating work event
scsi: libfc: Handling of extra kref
scsi: qla2xxx: Fix a condition in qla2x00_find_all_fabric_devs()
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The mpt fusion driver still uses the legacy PCI DMA API which hardcodes
atomic allocations. This caused the driver to fail to load on some powerpc
VMs with incoherent DMA and small memory sizes. Switch to use the modern
DMA API and sleeping allocations for large allocations instead. This is
not a full cleanup of the PCI DMA API usage yet, but just enough to fix the
regression caused by reducing the default atomic pool size.
Link: https://lore.kernel.org/r/20200624165724.1818496-1-hch@lst.de
Fixes: 3ee06a6d532f ("dma-pool: fix too large DMA pools on medium memory size systems")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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