Dan Carpenter [Wed, 10 Aug 2016 23:27:38 +0000 (16:27 -0700)]
rapidio: dereferencing an error pointer
Original patch: https://lkml.org/lkml/2016/8/4/32
If riocm_ch_alloc() fails then we end up dereferencing the error
pointer.
The problem is that we're not unwinding in the reverse order from how we
allocate things so it gets confusing. I've changed this around so now
"ch" is NULL when we are done with it after we call riocm_put_channel().
That way we can check if it's NULL and avoid calling riocm_put_channel()
on it twice.
I renamed err_nodev to err_put_new_ch so that it better reflects what
the goto does.
Then because we had flipping things around, it means we don't neeed to
initialize the pointers to NULL and we can remove an if statement and
pull things in an indent level.
Dan Williams [Wed, 10 Aug 2016 22:59:09 +0000 (15:59 -0700)]
tools/testing/nvdimm: fix SIGTERM vs hotplug crash
The unit tests crash when hotplug races the previous probe. This race
requires that the loading of the nfit_test module be terminated with
SIGTERM, and the module to be unloaded while the ars scan is still
running.
In contrast to the normal nfit driver, the unit test calls
acpi_nfit_init() twice to simulate hotplug, whereas the nominal case
goes through the acpi_nfit_notify() event handler. The
acpi_nfit_notify() path is careful to flush the previous region
registration before servicing the hotplug event. The unit test was
missing this guarantee.
Robin Murphy [Wed, 10 Aug 2016 12:02:17 +0000 (14:02 +0200)]
ARM: dts: realview: Fix PBX-A9 cache description
Clearly QEMU is very permissive in how its PL310 model may be set up,
but the real hardware turns out to be far more particular about things
actually being correct. Fix up the DT description so that the real
thing actually boots:
- The arm,data-latency and arm,tag-latency properties need 3 cells to
be valid, otherwise we end up retaining the default 8-cycle latencies
which leads pretty quickly to lockup.
- The arm,dirty-latency property is only relevant to L210/L220, so get
rid of it.
- The cache geometry override also leads to lockup and/or general
misbehaviour. Irritatingly, the manual doesn't state the actual PL310
configuration, but based on the boardfile code and poking registers
from the Boot Monitor, it would seem to be 8 sets of 16KB ways.
With that, we can successfully boot to enjoy the fun of mismatched FPUs...
c90bb7b enabled the high speed UARTs of the Jetson TK1. Due to a merge
quirk, wrong addresses were introduced. Fix it and use the correct
addresses.
Thierry let me know, that there is another patch (b5896f67ab3c in
linux-next) in preparation which removes all the '0,' prefixes of unit
addresses on Tegra124 and is planned to go upstream in 4.8, so
this patch will get reverted then.
But for the moment, this patch is necessary to fix current misbehaviour.
Arnd Bergmann [Thu, 9 Jun 2016 07:50:28 +0000 (09:50 +0200)]
ARM: hide mach-*/ include for ARM_SINGLE_ARMV7M
The machine specific header files are exported for traditional
platforms, but not for the ones that use ARCH_MULTIPLATFORM, as
they could conflict with one another.
In case of ARM_SINGLE_ARMV7M, we end up also exporting them,
but that appears to be a mistake, and we should treat it the
same way as ARCH_MULTIPLATFORM here.
'make W=1' warns about this because it passes -Wmissing-includes
to gcc and the directories are not actually present.
Arnd Bergmann [Wed, 8 Jun 2016 14:21:19 +0000 (16:21 +0200)]
ARM: don't include removed directories
Three platforms used to have header files in include/mach that
are now all gone, but the removed directories are still being
included, which leads to -Wmissing-include-dirs warnings.
Linus Torvalds [Wed, 10 Aug 2016 18:16:03 +0000 (11:16 -0700)]
Merge branch 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Some fixes for btrfs send/recv and fsync from Filipe and Robbie Ko.
Bonus points to Filipe for already having xfstests in place for many
of these"
* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: remove unused function btrfs_add_delayed_qgroup_reserve()
Btrfs: improve performance on fsync against new inode after rename/unlink
Btrfs: be more precise on errors when getting an inode from disk
Btrfs: send, don't bug on inconsistent snapshots
Btrfs: send, avoid incorrect leaf accesses when sending utimes operations
Btrfs: send, fix invalid leaf accesses due to incorrect utimes operations
Btrfs: send, fix warning due to late freeing of orphan_dir_info structures
Btrfs: incremental send, fix premature rmdir operations
Btrfs: incremental send, fix invalid paths for rename operations
Btrfs: send, add missing error check for calls to path_loop()
Btrfs: send, fix failure to move directories with the same name around
Btrfs: add missing check for writeback errors on fsync
Linus Torvalds [Wed, 10 Aug 2016 18:07:47 +0000 (11:07 -0700)]
Merge tag 'metag-for-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag
Pull metag architecture fix from James Hogan:
"A single fix for a boot crash since a commit in the merge window.
Metag was unusual in calling show_mem() early, before setup_per_cpu_pageset(),
which is no longer safe. It doesn't add much value to the log, so the
fix just drops the call"
* tag 'metag-for-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
metag: Drop show_mem() from mem_init()
The Memory Protection Keys "rights register" (PKRU) is
XSAVE-managed, and is saved/restored along with the FPU state.
When kernel code accesses FPU regsisters, it does a delicate
dance with preempt. Otherwise, the context switching code can
get confused as to whether the most up-to-date state is in the
registers themselves or in the XSAVE buffer.
But, PKRU is not a normal FPU register. Using it does not
generate the normal device-not-available (#NM) exceptions which
means we can not manage it lazily, and the kernel completley
disallows using lazy mode when it is enabled.
The dance with preempt *only* occurs when managing the FPU
lazily. Since we never manage PKRU lazily, we do not have to do
the dance with preempt; we can access it directly. Doing it
this way saves a ton of complicated code (and is faster too).
Further, the XSAVES reenabling failed to patch a bit of code
in fpu__xfeature_set_state() the checked for compacted buffers.
That check caused fpu__xfeature_set_state() to silently refuse to
work when the kernel is using compacted XSAVE buffers. This
broke execute-only and future pkey_mprotect() support when using
compact XSAVE buffers.
But, removing fpu__xfeature_set_state() gets rid of this issue,
in addition to the nice cleanup and speedup.
This fixes the same thing as a fix that Sai posted:
https://lkml.org/lkml/2016/7/25/637
The fix that he posted is a much more obviously correct, but I
think we should just do this instead.
x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables
Building an X86_64 kernel with W=1 throws a total of 9,948 lines of warnings of
this form for both 32-bit and 64-bit syscall tables. Given that the entire rest
of the build for my config only generates 8,375 lines of output, this is a big
reduction in the warnings generated.
The warnings follow this pattern:
./arch/x86/include/generated/asm/syscalls_32.h:885:21: warning: initialized field overwritten [-Woverride-init]
__SYSCALL_I386(379, compat_sys_pwritev2, )
^
arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386'
#define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
^~~
./arch/x86/include/generated/asm/syscalls_32.h:885:21: note: (near initialization for 'ia32_sys_call_table[379]')
__SYSCALL_I386(379, compat_sys_pwritev2, )
^
arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386'
#define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
Since we intentionally build the syscall tables this way, ignore that one
warning in the two files.
Mike Travis [Mon, 1 Aug 2016 18:40:53 +0000 (13:40 -0500)]
x86/platform/UV: Fix kernel panic running RHEL kdump kernel on UV systems
The latest UV kernel support panics when RHEL7 kexec's the kdump kernel
to make a dumpfile. This patch fixes the problem by turning off all UV
support if NUMA is off.
Mike Travis [Mon, 1 Aug 2016 18:40:52 +0000 (13:40 -0500)]
x86/platform/UV: Fix problem with UV4 BIOS providing incorrect PXM values
There are some circumstances where the UV4 BIOS cannot provide the
correct Proximity Node values to associate with specific Sockets and
Physical Nodes. The decision was made to remove these values from BIOS
and for the kernel to get these values from the standard ACPI tables.
Mike Travis [Mon, 1 Aug 2016 18:40:50 +0000 (13:40 -0500)]
x86/platform/UV: Fix problem with UV4 Socket IDs not being contiguous
The UV4 Socket IDs are not guaranteed to equate to Node values which
can cause the GAM (Global Addressable Memory) table lookups to fail.
Fix this by using an independent index into the GAM table instead of
the Socket ID to reference the base address.
Usually current->mm (and therefore mm->pgd) stays the same during the
lifetime of a task so it does not matter if a task gets preempted during
the read and write of the CR3.
But then, there is this scenario on x86-UP:
TaskA is in do_exit() and exit_mm() sets current->mm = NULL followed by:
At this point current->mm is NULL but current->active_mm still points to
the "old" mm.
Let's preempt taskA _after_ native_read_cr3() by taskB. TaskB has its
own mm so CR3 has changed.
Now preempt back to taskA. TaskA has no ->mm set so it borrows taskB's
mm and so CR3 remains unchanged. Once taskA gets active it continues
where it was interrupted and that means it writes its old CR3 value
back. Everything is fine because userland won't need its memory
anymore.
Now the fun part:
Let's preempt taskA one more time and get back to taskB. This
time switch_mm() won't do a thing because oldmm (->active_mm)
is the same as mm (as per context_switch()). So we remain
with a bad CR3 / PGD and return to userland.
The next thing that happens is handle_mm_fault() with an address for
the execution of its code in userland. handle_mm_fault() realizes that
it has a PTE with proper rights so it returns doing nothing. But the
CPU looks at the wrong PGD and insists that something is wrong and
faults again. And again. And one more time…
This pagefault circle continues until the scheduler gets tired of it and
puts another task on the CPU. It gets little difficult if the task is a
RT task with a high priority. The system will either freeze or it gets
fixed by the software watchdog thread which usually runs at RT-max prio.
But waiting for the watchdog will increase the latency of the RT task
which is no good.
Fix this by disabling preemption across the critical code section.
Takashi Iwai [Thu, 4 Aug 2016 20:38:36 +0000 (22:38 +0200)]
ALSA: hda - Manage power well properly for resume
For SKL and later Intel chips, we control the power well per codec
basis via link_power callback since the commit [03b135cebc47: ALSA:
hda - remove dependency on i915 power well for SKL].
However, there are a few exceptional cases where the gfx registers are
accessed from the audio driver: namely the wakeup override bit
toggling at (both system and runtime) resume. This seems causing a
kernel warning when accessed during the power well down (and likely
resulting in the bogus register accesses).
This patch puts the proper power up / down sequence around the resume
code so that the wakeup bit is fiddled properly while the power is
up. (The other callback, sync_audio_rate, is used only in the PCM
callback, so it's guaranteed in the power-on.)
Also, by this proper power up/down, the instantaneous flip of wakeup
bit in the resume callback that was introduced by the commit
[033ea349a7cd: ALSA: hda - Fix Skylake codec timeout] becomes
superfluous, as snd_hdac_display_power() already does it. So we can
clean it up together.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96214 Fixes: 03b135cebc47 ('ALSA: hda - remove dependency on i915 power well for SKL') Cc: <[email protected]> # v4.2+ Tested-by: Hans de Goede <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
Nicholas Piggin [Tue, 9 Aug 2016 12:17:29 +0000 (22:17 +1000)]
powerpc/vdso: Fix build rules to rebuild vdsos correctly
When using if_changed, we need to add FORCE as a dependency (see
Documentation/kbuild/makefiles.txt) otherwise we don't get command line
change checking amongst other things. This has resulted in vdsos not
being rebuilt when switching between big and little endian.
The vdso64/32ld commands have to be changed around to avoid pulling
FORCE into the linker command line (code copied from x86).
powerpc/Makefile: Use cflags-y/aflags-y for setting endian options
When we introduced the little endian support, we added the endian flags
to CC directly using override. I don't know the history of why we did
that, I suspect no one does.
Although this mostly works, it has one bug, which is that CROSS32CC
doesn't get -mbig-endian. That means when the compiler is little endian
by default and the user is building big endian, vdso32 is incorrectly
compiled as little endian and the kernel fails to build.
Instead we can add the endian flags to cflags-y/aflags-y, and then
append those to KBUILD_CFLAGS/KBUILD_AFLAGS.
This has the advantage of being 1) less ugly, 2) the documented way of
adding flags in the arch Makefile and 3) it fixes building vdso32 with a
LE toolchain.
Thomas Garnier [Tue, 9 Aug 2016 17:11:05 +0000 (10:11 -0700)]
x86/mm/KASLR: Increase BRK pages for KASLR memory randomization
Default implementation expects 6 pages maximum are needed for low page
allocations. If KASLR memory randomization is enabled, the worse case
of e820 layout would require 12 pages (no large pages). It is due to the
PUD level randomization and the variable e820 memory layout.
This bug was found while doing extensive testing of KASLR memory
randomization on different type of hardware.
Thomas Garnier [Tue, 9 Aug 2016 17:11:04 +0000 (10:11 -0700)]
x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomization
Initialize KASLR memory randomization after max_pfn is initialized. Also
ensure the size is rounded up. It could create problems on machines
with more than 1Tb of memory on certain random addresses.
This was caused by a stupid typo in a patch that should have been
a simple rename to move around contents of a header file, but
accidentally wrote zeroes into the rtc rather than reading from
it:
463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h")
x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text
Dmitry Vyukov has reported unexpected KASAN stackdepot growth:
https://github.com/google/kasan/issues/36
... which is caused by the APIC handlers not being present in .irqentry.text:
When building with CONFIG_FUNCTION_GRAPH_TRACER=y or CONFIG_KASAN=y, put the
APIC interrupt handlers into the .irqentry.text section. This is needed
because both KASAN and function graph tracer use __irqentry_text_start and
__irqentry_text_end to determine whether a function is an IRQ entry point.
In this case, lock holder inserts the pv_node of queue head into the
hash table and set _Q_SLOW_VAL unnecessary. This patch avoids it by
restoring/setting vcpu_hashed state after failing adaptive locking
spinning.
pan xinhui [Mon, 18 Jul 2016 09:47:39 +0000 (17:47 +0800)]
locking/qrwlock: Fix write unlock bug on big endian systems
This patch aims to get rid of endianness in queued_write_unlock(). We
want to set __qrwlock->wmode to NULL, however the address is not
&lock->cnts in big endian machine. That causes queued_write_unlock()
write NULL to the wrong field of __qrwlock.
So implement __qrwlock_write_byte() which returns the correct
__qrwlock->wmode address.
fixed a problem whereby clock_nanosleep() followed by clock_gettime() could
allow a task to wake early. It addressed the problem by calling the scheduling
classes update_curr() when the cputimer starts.
Said change induced a considerable performance regression on the syscalls
times() and clock_gettimes(CLOCK_PROCESS_CPUTIME_ID). There are some
debuggers and applications that monitor their own performance that
accidentally depend on the performance of these specific calls.
This patch mitigates the performace loss by prefetching data in the CPU
cache, as stalls due to cache misses appear to be where most time is spent
in our benchmarks.
Here are the performance gain of this patch over v4.7-rc7 on a Sandy Bridge
box with 32 logical cores and 2 NUMA nodes. The test is repeated with a
variable number of threads, from 2 to 4*num_cpus; the results are in
seconds and correspond to the average of 10 runs; the percentage gain is
computed with (before-after)/before so a positive value is an improvement
(it's faster). The improvement varies between a few percents for 5-20
threads and more than 10% for 2 or >20 threads.
pound_clock_gettime and pound_clock_gettime are two benchmarks included in
the MMTests framework. They launch a given number of threads which
repeatedly call times() or clock_gettimes(). The results above can be
reproduced with cloning MMTests from github.com and running the "poundtime"
workload:
The above will run "poundtime" measuring the kernel currently running on
the machine; Once a new kernel is installed and the machine rebooted,
running again
$ cd mmtests
$ ./run-mmtests.sh --run-monitor $(uname -r)
will produce results to compare with. A comparison table will be output
with:
$ cd mmtests/work/log
$ ../../compare-kernels.sh
the table will contain a lot of entries; grepping for "Amean" (as in
"arithmetic mean") will give the tables presented above. The source code
for the two benchmarks is reported at the end of this changelog for
clairity.
The cache misses addressed by this patch were found using a combination of
`perf top`, `perf record` and `perf annotate`. The incriminated lines were
found to be
struct sched_entity *curr = cfs_rq->curr;
and
delta_exec = now - curr->exec_start;
in the function update_curr() from kernel/sched/fair.c. This patch
prefetches the data from memory just before update_curr is called in the
interested execution path.
A comparison of the total number of cycles before and after the patch
follows; the data is obtained using `perf stat -r 10 -ddd <program>`
running over the same sequence of number of threads used above (a positive
gain is an improvement):
As a final note, the following shows the evolution of performance figures
in the "poundtime" benchmark and pinpoints commit 6e998916dfe3
("sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency") as a
major source of degradation, mostly unaddressed to this day (figures
expressed in seconds).
Current code in cpudeadline.c has a bug in re-heapifying when adding a
new element at the end of the heap, because a deadline value of 0 is
temporarily set in the new elem, then cpudl_change_key() is called
with the actual elem deadline as param.
However, the function compares the new deadline to set with the one
previously in the elem, which is 0. So, if current absolute deadlines
grew so much to have negative values as s64, the comparison in
cpudl_change_key() makes the wrong decision. Instead, as from
dl_time_before(), the kernel should handle correctly abs deadlines
wrap-arounds.
This patch fixes the problem with a minimally invasive change that
forces cpudl_change_key() to heapify up in this case.
The underlying problem is that there is an optimization in
perf_cgroup_sched_{in,out}() that skips the switch of cgroup events
if the old and new cgroups in a task switch are the same.
This optimization interacts with the current code in two ways
that cause a CPU context's cgroup (cpuctx->cgrp) to be NULL even if a
cgroup event matches the current task. These are:
1. On creation of the first cgroup event in a CPU: In current code,
cpuctx->cpu is only set in perf_cgroup_sched_in, but due to the
aforesaid optimization, perf_cgroup_sched_in will run until the next
cgroup switches in that CPU. This may happen late or never happen,
depending on system's number of cgroups, CPU load, etc.
2. On deletion of the last cgroup event in a cpuctx: In list_del_event,
cpuctx->cgrp is set NULL. Any new cgroup event will not be sched in
because cpuctx->cgrp == NULL until a cgroup switch occurs and
perf_cgroup_sched_in is executed (updating cpuctx->cgrp).
This patch fixes both problems by setting cpuctx->cgrp in list_add_event,
mirroring what list_del_event does when removing a cgroup event from CPU
context, as introduced in:
commit 68cacd29167b ("perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()")
With this patch, cpuctx->cgrp is always set/clear when installing/removing
the first/last cgroup event in/from the CPU context. With cpuctx->cgrp
correctly set, event_filter_match works as intended when events are
sched in/out.
Vegard Nossum reported that perf fuzzing generates a NULL
pointer dereference crash:
> Digging a bit deeper into this, it seems the event itself is getting
> created by perf_event_open() and it gets added to the pmu_event_list
> through:
>
> perf_event_open()
> - perf_event_alloc()
> - account_event()
> - account_pmu_sb_event()
> - attach_sb_event()
>
> so at this point the event is being attached but its ->ctx is still
> NULL. It seems like ->ctx is set just a bit later in
> perf_event_open(), though.
>
> But before that, __schedule() comes along and creates a stack trace
> similar to the one above:
>
> __schedule()
> - __perf_event_task_sched_out()
> - perf_iterate_sb()
> - perf_iterate_sb_cpu()
> - event_filter_match()
> - perf_cgroup_match()
> - __get_cpu_context()
> - (dereference ctx which is NULL)
>
> So I guess the question is... should the event be attached (= put on
> the list) before ->ctx gets set? Or should the cgroup code check for a
> NULL ->ctx?
The latter seems like the simplest solution. Moving the list-add later
creates a bit of a mess.
x86/timers/apic: Inform TSC deadline clockevent device about recalibration
This patch eliminates a source of imprecise APIC timer interrupts,
which imprecision may result in double interrupts or even late
interrupts.
The TSC deadline clockevent devices' configuration and registration
happens before the TSC frequency calibration is refined in
tsc_refine_calibration_work().
This results in the TSC clocksource and the TSC deadline clockevent
devices being configured with slightly different frequencies: the former
gets the refined one and the latter are configured with the inaccurate
frequency detected earlier by means of the "Fast TSC calibration using PIT".
Within the APIC code, introduce the notifier function
lapic_update_tsc_freq() which reconfigures all per-CPU TSC deadline
clockevent devices with the current tsc_khz.
Call it from the TSC code after TSC calibration refinement has happened.
x86/timers/apic: Fix imprecise timer interrupts by eliminating TSC clockevents frequency roundoff error
I noticed the following bug/misbehavior on certain Intel systems: with a
single task running on a NOHZ CPU on an Intel Haswell, I recognized
that I did not only get the one expected local_timer APIC interrupt, but
two per second at minimum. (!)
Further tracing showed that the first one precedes the programmed deadline
by up to ~50us and hence, it did nothing except for reprogramming the TSC
deadline clockevent device to trigger shortly thereafter again.
The reason for this is imprecise calibration, the timeout we program into
the APIC results in 'too short' timer interrupts. The core (hr)timer code
notices this (because it has a precise ktime source and sees the short
interrupt) and fixes it up by programming an additional very short
interrupt period.
This is obviously suboptimal.
The reason for the imprecise calibration is twofold, and this patch
fixes the first reason:
In setup_APIC_timer(), the registered clockevent device's frequency
is calculated by first dividing tsc_khz by TSC_DIVISOR and multiplying
it with 1000 afterwards:
(tsc_khz / TSC_DIVISOR) * 1000
The multiplication with 1000 is done for converting from kHz to Hz and the
division by TSC_DIVISOR is carried out in order to make sure that the final
result fits into an u32.
However, with the order given in this calculation, the roundoff error
introduced by the division gets magnified by a factor of 1000 by the
following multiplication.
To fix it, reversing the order of the division and the multiplication a la:
(tsc_khz * 1000) / TSC_DIVISOR
... reduces the roundoff error already.
Furthermore, if TSC_DIVISOR divides 1000, associativity holds:
and thus, the roundoff error even vanishes and the whole operation can be
carried out within 32 bits.
The powers of two that divide 1000 are 2, 4 and 8. A value of 8 for
TSC_DIVISOR still allows for TSC frequencies up to
2^32 / 10^9ns * 8 = 34.4GHz which is way larger than anything to expect
in the next years.
Thus we also replace the current TSC_DIVISOR value of 32 by 8. Reverse
the order of the divison and the multiplication in the calculation of
the registered clockevent device's frequency.
We cannot do those initializations from apply_feature_fixups() as
this function runs in a very restricted environment on 32-bit where
the kernel isn't running at its linked address and the PTRRELOC()
macro must be used for any global accesss.
Instead, split them into a separtate steup_feature_keys() function
which is called in a more suitable spot on ppc32.
Fixes: 309b315b6ec6 ("powerpc: Call jump_label_init() in apply_feature_fixups()") Reported-and-tested-by: Christian Kujau <[email protected]> Signed-off-by: Benjamin Herrenschmidt <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
powerpc: Print the kernel load address at the end of prom_init()
This makes it easier to debug crashes that happen very early before
the kernel takes over Open Firmware by allowing us to relate the OF
reported crashing addresses to offsets within the kernel.
Cyril Bur [Wed, 10 Aug 2016 05:44:46 +0000 (15:44 +1000)]
powerpc/ptrace: Fix coredump since ptrace TM changes
Commit 8d460f6156cd ("powerpc/process: Add the function
flush_tmregs_to_thread") added flush_tmregs_to_thread() and included
the assumption that it would only be called for a task which is not
current.
Although this is correct for ptrace, when generating a core dump, some
of the routines which call flush_tmregs_to_thread() are called. This
leads to a WARNing such as:
Not expecting ptrace on self: TM regs may be incorrect
------------[ cut here ]------------
WARNING: CPU: 123 PID: 7727 at arch/powerpc/kernel/process.c:1088 flush_tmregs_to_thread+0x78/0x80
CPU: 123 PID: 7727 Comm: libvirtd Not tainted 4.8.0-rc1-gcc6x-g61e8a0d #1
task: c000000fe631b600 task.stack: c000000fe63b0000
NIP: c00000000001a1a8 LR: c00000000001a1a4 CTR: c000000000717780
REGS: c000000fe63b3420 TRAP: 0700 Not tainted (4.8.0-rc1-gcc6x-g61e8a0d)
MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28004222 XER: 20000000
...
NIP [c00000000001a1a8] flush_tmregs_to_thread+0x78/0x80
LR [c00000000001a1a4] flush_tmregs_to_thread+0x74/0x80
Call Trace:
flush_tmregs_to_thread+0x74/0x80 (unreliable)
vsr_get+0x64/0x1a0
elf_core_dump+0x604/0x1430
do_coredump+0x5fc/0x1200
get_signal+0x398/0x740
do_signal+0x54/0x2b0
do_notify_resume+0x98/0xb0
ret_from_except_lite+0x70/0x74
So fix flush_tmregs_to_thread() to detect the case where it is called on
current, and a transaction is active, and in that case flush the TM regs
to the thread_struct.
This patch also moves flush_tmregs_to_thread() into ptrace.c as it is
only called from that file.
Fixes: 8d460f6156cd ("powerpc/process: Add the function flush_tmregs_to_thread") Signed-off-by: Cyril Bur <[email protected]>
[mpe: Flesh out change log] Signed-off-by: Michael Ellerman <[email protected]>
Commit 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic()
based on copy_tofrom_user()") introduced a bug when destination
address is odd and initial csum is not null
In that (rare) case the initial csum value has to be rotated one byte
as well as the resulting value is
This patch also fixes related comments
Fixes: 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
Frederic Barrat [Mon, 8 Aug 2016 09:57:48 +0000 (11:57 +0200)]
cxl: Set psl_fir_cntl to production environment value
Switch the setting of psl_fir_cntl from debug to production
environment recommended value. It mostly affects the PSL behavior when
an error is raised in psl_fir1/2.
mm, writeback: flush plugged IO in wakeup_flusher_threads()
I've found funny live-lock between raid10 barriers during resync and
memory controller hard limits. Inside mpage_readpages() task holds on to
its plug bio which blocks the barrier in raid10. Its memory cgroup have
no free memory thus the task goes into reclaimer but all reclaimable
pages are dirty and cannot be written because raid10 is rebuilding and
stuck on the barrier.
Common flush of such IO in schedule() never happens, because the caller
doesn't go to sleep.
Lock is 'live' because changing memory limit or killing tasks which
holds that stuck bio unblock whole progress.
That was what happened in 3.18.x but I see no difference in upstream
logic. Theoretically this might happen even without memory cgroup.
Ingo Molnar [Tue, 9 Aug 2016 19:11:00 +0000 (21:11 +0200)]
Merge tag 'perf-urgent-for-mingo-20160809' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
User visible fixes:
- Fix the lookup for a kernel module in 'perf probe', fixing for instance, the
erroneous return of "[raid10]" when looking for "[raid1]" (Konstantin Khlebnikov)
- Disable counters in a group before reading them in 'perf stat', to avoid skew (Mark Rutland)
- Fix adding probes to function aliases in systems using kaslr (Masami Hiramatsu)
- Trip libtraceevent trace_seq buffers, removing unnecessary memory usage that could
bring a system using tracepoint events with 'perf top' to a crawl, as the trace_seq
buffers start at a whooping 4 KB, which is very rarely used in perf's usecases,
so realloc it to the really used space as a last measure after using libtraceevent
functions to format the fields of tracepoint events (Arnaldo Carvalho de Melo)
- Fix 'perf probe' location when using DWARF on ppc64le (Ravi Bangoria)
- Allow specifying signedness casts to a 'perf probe' variable, to shorten
the number of steps to see signed values that otherwise would always appear
as hex values (Naohiro Aota)
Documentation fixes:
- Add 'bpf-output' field to 'perf script' usage message (Brendan Gregg)
Infrastructure fixes:
- Sync kernel header files: cpufeatures.h, {disabled,required}-features.h,
bpf.h and vmx.h, so that we get a clean build, without warnings about files
being different from the kernel counterparts.
A verification of the need or desirability of changes in tools/ based on what
was done in the kernel changesets was made and documented in the respective
file sync changesets (Arnaldo Carvalho de Melo)
Geert Uytterhoeven reports:
"This change seems to have an (unintendent?) side-effect.
Before, pr_*() calls without a trailing newline characters would be
printed with a newline character appended, both on the console and in
the output of the dmesg command.
After this commit, no new line character is appended, and the output
of the next pr_*() call of the same type may be appended, like in:
- Truncating RAM at 0x0000000040000000-0x00000000c0000000 to -0x0000000070000000
- Ignoring RAM at 0x0000000200000000-0x0000000240000000 (!CONFIG_HIGHMEM)
+ Truncating RAM at 0x0000000040000000-0x00000000c0000000 to -0x0000000070000000Ignoring RAM at 0x0000000200000000-0x0000000240000000 (!CONFIG_HIGHMEM)"
Joe Perches says:
"No, that is not intentional.
The newline handling code inside vprintk_emit is a bit involved and
for now I suggest a revert until this has all the same behavior as
earlier"
Linus Torvalds [Tue, 9 Aug 2016 17:34:09 +0000 (10:34 -0700)]
Merge tag 'trace-v4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Fix tick_stop tracepoint symbols for user export.
Luiz Capitulino noticed that the tick_stop tracepoint wasn't being
parsed properly by the tracing user space tools.
This was due to the TRACE_DEFINE_ENUM() being set to a define, when it
should have been set to the enum itself. The define was of the MASK
that used the BIT to shift. The BIT was the enum and by adding that,
everything gets converted nicely. The MASK is still kept just in case
it gets converted to an enum in the future"
* tag 'trace-v4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix tick_stop tracepoint symbols for user export
Linus Torvalds [Tue, 9 Aug 2016 17:30:07 +0000 (10:30 -0700)]
Merge tag 'gcc-plugin-infrastructure-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull gcc plugin improvements from Kees Cook:
"Several fixes/improvements for the gcc plugin infrastructure:
- fix a problem with gcc plugins interfering with cc-option tests.
- abort more gracefully when gcc plugin headers or compiler support
is missing.
- improve the gcc plugin rule generation to be more dynamic, pass
arguments, and build from subdirectories"
* tag 'gcc-plugin-infrastructure-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
gcc-plugins: Add support for plugin subdirectories
gcc-plugins: Automate make rule generation
gcc-plugins: Add support for passing plugin arguments
gcc-plugins: abort builds cleanly when not supported
kbuild: no gcc-plugins during cc-option tests
Linus Torvalds [Tue, 9 Aug 2016 17:20:21 +0000 (10:20 -0700)]
Merge tag 'drm-fixes-for-4.8-rc2' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"This contains a bunch of amdgpu fixes, and some i915 regression fixes.
It also contains some fixes for an older regression with some EDID
changes and some 6bpc panels.
Then there are the lockdep, cirrus and rcar-du regression fixes from
this window"
* tag 'drm-fixes-for-4.8-rc2' of git://people.freedesktop.org/~airlied/linux:
drm/cirrus: Fix NULL pointer dereference when registering the fbdev
drm/edid: Set 8 bpc color depth for displays with "DFP 1.x compliant TMDS".
drm/i915/dp: Revert "drm/i915/dp: fall back to 18 bpp when sink capability is unknown"
drm/edid: Add 6 bpc quirk for display AEO model 0.
drm: Paper over locking inversion after registration rework
drm: rcar-du: Link HDMI encoder with bridge
drm/ttm: Wait for a BO to become idle before unbinding it from GTT
drm/i915/fbdev: Check for the framebuffer before use
drm/amdgpu: update golden setting of polaris10
drm/amdgpu: update golden setting of stoney
drm/amdgpu: update golden setting of polaris11
drm/amdgpu: update golden setting of carrizo
drm/amdgpu: update golden setting of iceland
drm/amd/amdgpu: change pptable output format from ASCII to binary
drm/amdgpu/ci: add mullins to default case for smc ucode
drm/amdgpu/gmc7: add missing mullins case
drm/i915: Never fully mask the the EI up rps interrupt on SNB/IVB
drm/i915: Wait up to 3ms for the pcu to ack the cdclk change request on SKL
mm: memcontrol: only mark charged pages with PageKmemcg
To distinguish non-slab pages charged to kmemcg we mark them PageKmemcg,
which sets page->_mapcount to -512. Currently, we set/clear PageKmemcg
in __alloc_pages_nodemask()/free_pages_prepare() for any page allocated
with __GFP_ACCOUNT, including those that aren't actually charged to any
cgroup, i.e. allocated from the root cgroup context. To avoid overhead
in case cgroups are not used, we only do that if memcg_kmem_enabled() is
true. The latter is set iff there are kmem-enabled memory cgroups
(online or offline). The root cgroup is not considered kmem-enabled.
As a result, if a page is allocated with __GFP_ACCOUNT for the root
cgroup when there are kmem-enabled memory cgroups and is freed after all
kmem-enabled memory cgroups were removed, e.g.
# no memory cgroups has been created yet, create one
mkdir /sys/fs/cgroup/memory/test
# run something allocating pages with __GFP_ACCOUNT, e.g.
# a program using pipe
dmesg | tail
# remove the memory cgroup
rmdir /sys/fs/cgroup/memory/test
we'll get bad page state bug complaining about page->_mapcount != -1:
BUG: Bad page state in process swapper/0 pfn:1fd945c
page:ffffea007f651700 count:0 mapcount:-511 mapping: (null) index:0x0
flags: 0x1000000000000000()
To avoid that, let's mark with PageKmemcg only those pages that are
actually charged to and hence pin a non-root memory cgroup.
Fixes: 4949148ad433 ("mm: charge/uncharge kmemcg from generic page allocator paths") Reported-and-tested-by: Eric Dumazet <[email protected]> Signed-off-by: Vladimir Davydov <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
Marc Zyngier [Tue, 19 Jul 2016 14:39:02 +0000 (15:39 +0100)]
drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property
Patch 19a469a58720 ("drivers/perf: arm-pmu: Handle per-interrupt
affinity mask") added support for partitionned PPI setups, but
inadvertently broke setups using SPIs without the "interrupt-affinity"
property (which is the case for UP platforms).
This patch restore the broken functionnality by testing whether the
interrupt is percpu or not instead of relying on the using_spi flag
that really means "SPI *and* interrupt-affinity property".
Sudeep Holla [Wed, 3 Aug 2016 17:08:55 +0000 (18:08 +0100)]
drivers/perf: arm-pmu: convert arm_pmu_mutex to spinlock
arm_pmu_mutex is never held long and we don't want to sleep while the
lock is being held as it's executed in the context of hotplug notifiers.
So it can be converted to a simple spinlock instead.
Without this patch we get the following warning:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/2
no locks held by swapper/2/0.
irq event stamp: 381314
hardirqs last enabled at (381313): _raw_spin_unlock_irqrestore+0x7c/0x88
hardirqs last disabled at (381314): cpu_die+0x28/0x48
softirqs last enabled at (381294): _local_bh_enable+0x28/0x50
softirqs last disabled at (381293): irq_enter+0x58/0x78
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.7.0 #12
Call trace:
dump_backtrace+0x0/0x220
show_stack+0x24/0x30
dump_stack+0xb4/0xf0
___might_sleep+0x1d8/0x1f0
__might_sleep+0x5c/0x98
mutex_lock_nested+0x54/0x400
arm_perf_starting_cpu+0x34/0xb0
cpuhp_invoke_callback+0x88/0x3d8
notify_cpu_starting+0x78/0x98
secondary_start_kernel+0x108/0x1a8
This patch converts the mutex to spinlock to eliminate the above
warnings. This constraints pmu->reset to be non-blocking call which is
the case with all the ARM PMU backends.
Ravi Bangoria [Tue, 9 Aug 2016 06:23:25 +0000 (01:23 -0500)]
perf probe ppc64le: Fix probe location when using DWARF
Powerpc has Global Entry Point and Local Entry Point for functions. LEP
catches call from both the GEP and the LEP. Symbol table of ELF contains
GEP and Offset from which we can calculate LEP, but debuginfo does not
have LEP info.
Currently, perf prioritize symbol table over dwarf to probe on LEP for
ppc64le. But when user tries to probe with function parameter, we fall
back to using dwarf(i.e. GEP) and when function called via LEP, probe
will never hit.
For second case, perf probed on GEP. So when function will be called via
LEP, probe won't hit.
$ sudo ./perf record -a -e probe:do_sys_open ls
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.195 MB perf.data ]
To resolve this issue, let's not prioritize symbol table, let perf
decide what it wants to use. Perf is already converting GEP to LEP when
it uses symbol table. When perf uses debuginfo, let it find LEP offset
form symbol table. This way we fall back to probe on LEP for all cases.
$ sudo ./perf record -a -e probe:do_sys_open ls
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.197 MB perf.data (11 samples) ]
toops: Sync tools/include/uapi/linux/bpf.h with the kernel
The way we're using kernel headers in tools/ now, with a copy that is
made to the same path prefixed by "tools/" plus checking if that copy
got stale, i.e. if the kernel counterpart changed, helps in keeping
track with new features that may be useful for tools to exploit.
For instance, looking at all the changes to bpf.h since it was last
copied to tools/include brings this to toolers' attention:
Need to investigate this one to check how to run a program via perf, setting up
a BPF event, that will take advantage of the way perf already calls clang/LLVM,
sets up the event and runs the workload in a single command line, helping in
debugging such semi cooperative programs:
96ae52279594 ("bpf: Add bpf_probe_write_user BPF helper to be called in tracers")
This one needs further investigation about using the feature it improves
in 'perf trace' to do some tcpdumpin' mixed with syscalls, tracepoints,
probe points, callgraphs, etc:
555c8a8623a3 ("bpf: avoid stack copy and use skb ctx for event output")
Add tracing just packets that are related to some container to that mix:
Naohiro Aota [Tue, 9 Aug 2016 02:40:08 +0000 (11:40 +0900)]
perf probe: Support signedness casting
The 'perf probe' tool detects a variable's type and use the detected
type to add a new probe. Then, kprobes prints its variable in
hexadecimal format if the variable is unsigned and prints in decimal if
it is signed.
We sometimes want to see unsigned variable in decimal format (i.e.
sector_t or size_t). In that case, we need to investigate the variable's
size manually to specify just signedness.
This patch add signedness casting support. By specifying "s" or "u" as a
type, perf-probe will investigate variable size as usual and use the
specified signedness.
E.g. without this:
$ perf probe -a 'submit_bio bio->bi_iter.bi_sector'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector)
You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
$ cat trace_pipe|head
dbench-9692 [003] d..1 971.096633: submit_bio: (submit_bio+0x0/0x140) bi_sector=0x3a3d00
dbench-9692 [003] d..1 971.096685: submit_bio: (submit_bio+0x0/0x140) bi_sector=0x1a3d80
dbench-9692 [003] d..1 971.096687: submit_bio: (submit_bio+0x0/0x140) bi_sector=0x3a3d80
...
// need to investigate the variable size
$ perf probe -a 'submit_bio bio->bi_iter.bi_sector:s64'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector:s64)
You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
With this:
// just use "s" to cast its signedness
$ perf probe -v -a 'submit_bio bio->bi_iter.bi_sector:s'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector:s)
You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
$ cat trace_pipe|head
dbench-9689 [001] d..1 1212.391237: submit_bio: (submit_bio+0x0/0x140) bi_sector=128
dbench-9689 [001] d..1 1212.391252: submit_bio: (submit_bio+0x0/0x140) bi_sector=131072
dbench-9697 [006] d..1 1212.398611: submit_bio: (submit_bio+0x0/0x140) bi_sector=30208
This commit also update perf-probe.txt to describe "types". Most parts
are based on existing documentation: Documentation/trace/kprobetrace.txt
Committer note:
Testing using 'perf trace':
# perf probe -a 'submit_bio bio->bi_iter.bi_sector'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector)
[root@jouet ~]# perf probe -a 'submit_bio bio->bi_iter.bi_sector:s'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector:s)
User space tools have no idea how to parse "TICK_DEP_BIT_SCHED" or the other
symbols used to do the bit shifting. The reason is that the conversion was
done with using the TICK_DEP_MASK_* symbols which are just macros that
convert to the BIT shift itself (with the exception of NONE, which was
converted properly, because it doesn't use bits, and is defined as zero).
The TICK_DEP_BIT_* needs to be denoted by TRACE_DEFINE_ENUM() in order to
have this properly converted for user space tools to parse this event.
Mark Rutland [Tue, 9 Aug 2016 13:04:29 +0000 (14:04 +0100)]
perf stat: Avoid skew when reading events
When we don't have a tracee (i.e. we're attaching to a task or CPU),
counters can still be running after our workload finishes, and can still
be running as we read their values. As we read events one-by-one, there
can be arbitrary skew between values of events, even within a group.
This means that ratios within an event group are not reliable.
This skew can be seen if measuring a group of identical events, e.g:
# perf stat -a -C0 -e '{cycles,cycles}' sleep 1
To avoid this, we must stop groups from counting before we read the
values of any constituent events. This patch adds and makes use of a new
disable_counters() helper, which disables group leaders (and thus each
group as a whole). This mirrors the use of enable_counters() for
starting event groups in the absence of a tracee.
Closing a group leader splits the group, and without a disabled group
leader the newly split events will begin counting. Thus to ensure counts
are reliable we must defer closing group leaders until all counts have
been read. To do so this patch removes the event closing logic from the
read_counters() helper, explicitly closes the events using
perf_evlist__close(), which also aids legibility.
If module is "module" then dso->short_name is "[module]". Substring
comparing is't enough: "raid10" matches to "[raid1]". This patch also
checks terminating zero in module name.
perf probe: Adjust map->reloc offset when finding kernel symbol from map
Adjust map->reloc offset for the unmapped address when finding
alternative symbol address from map, because KASLR can relocate the
kernel symbol address.
The same adjustment has been done when finding appropriate kernel symbol
address from map which was introduced by commit f90acac75713 ("perf
probe: Find given address from offline dwarf")
When we use libtraceevent to format trace event fields into printable
strings to use in hist entries it is important to trim it from the
default 4 KiB it starts with to what is really used, to reduce the
memory footprint, so use realloc(seq.buffer, seq.len + 1) when returning
the seq.buffer formatted with the fields contents.
James Hogan [Fri, 5 Aug 2016 11:08:36 +0000 (12:08 +0100)]
metag: Drop show_mem() from mem_init()
The recent commit 599d0c954f91 ("mm, vmscan: move LRU lists to node"),
changed memory management code so that show_mem() is no longer safe to
call prior to setup_per_cpu_pageset(), as pgdat->per_cpu_nodestats will
still be NULL. This causes an oops on metag due to the call to
show_mem() from mem_init():
This wasn't a problem before with zone_reclaimable() as zone_pcp_init()
was already setting zone->pageset to &boot_pageset, via setup_arch() and
paging_init(), which happens before mm_init():
There only ever have been two host implementations of the old
s390-virtio (pre-ccw) transport: the experimental kuli userspace,
and qemu. As qemu switched its default to ccw with 2.4 (with most
users having used ccw well before that) and removed the old transport
entirely in 2.6, s390-virtio probably hasn't been in active use for
quite some time and is therefore likely to bitrot.
Let's start the slow march towards removing the code by deprecating
it.
Note that this also deprecates the early virtio console code, which
has been causing trouble in the guest without being wired up in any
relevant hypervisor code.
In case the registration of the hvc tty never happens AND the kernel
thinks that hvc0 is the preferred console we should keep the early
printk function to avoid a kernel panic due to code being removed.
Minfei Huang [Tue, 9 Aug 2016 08:39:20 +0000 (16:39 +0800)]
virtio_blk: Fix a slient kernel panic
We do a lot of memory allocation in function init_vq, and don't handle
the allocation failure properly. Then this function will return 0,
although initialization fails due to lacking memory. At that moment,
kernel will panic in guest machine, if virtio is used to drive disk.
To fix this bug, we should take care of allocation failure, and return
correct value to let caller know what happen.
Wei Yongjun [Tue, 2 Aug 2016 14:16:31 +0000 (14:16 +0000)]
virtio: fix memory leak in virtqueue_add()
When using the indirect buffers feature, 'desc' is allocated in
virtqueue_add() but isn't freed before leaving on a ring full error,
causing a memory leak.
For example, it seems rather clear that this can trigger
with virtio net if mergeable buffers are not used.
Kefeng Wang [Tue, 9 Aug 2016 02:30:49 +0000 (10:30 +0800)]
arm64: Support hard limit of cpu count by nr_cpus
Enable the hard limit of cpu count by set boot options nr_cpus=x
on arm64, and make a minor change about message when total number
of cpu exceeds the limit.
powerpc/pnv/pci: Fix incorrect PE reservation attempt on some 64-bit BARs
The generic allocation code may sometimes decide to assign a prefetchable
64-bit BAR to the M32 window. In fact it may also decide to allocate
a 64-bit non-prefetchable BAR to the M64 one ! So using the resource
flags as a test to decide which window was used for PE allocation is
just wrong and leads to insane PE numbers.
Instead, compare the addresses to figure it out.
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
[mpe: Rename the function as agreed by Ben & Gavin] Signed-off-by: Michael Ellerman <[email protected]>
powerpc/book3s: Fix MCE console messages for unrecoverable MCE.
When machine check occurs with MSR(RI=0), it means MC interrupt is
unrecoverable and kernel goes down to panic path. But the console
message still shows it as recovered. This patch fixes the MCE console
messages.
Fixes: 36df96f8acaf ("powerpc/book3s: Decode and save machine check event.") Signed-off-by: Mahesh Salgaonkar <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
The tick_nohz_stop_sched_tick() routine is not properly
canceling the sched timer when nothing is pending, because
get_next_timer_interrupt() is no longer returning KTIME_MAX in
that case. This causes periodic interrupts when none are needed.
When determining the next interrupt time, we first use
__next_timer_interrupt() to get the first expiring timer in the
timer wheel. If no timer is found, we return the base clock value
plus NEXT_TIMER_MAX_DELTA to indicate there is no timer in the
timer wheel.
Back in get_next_timer_interrupt(), we set the "expires" value
by converting the timer wheel expiry (in ticks) to a nsec value.
But we don't want to do this if the timer wheel expiry value
indicates no timer; we want to return KTIME_MAX.
Prior to commit 500462a9de65 ("timers: Switch to a non-cascading
wheel") we checked base->active_timers to see if any timers
were active, and if not, we didn't touch the expiry value and so
properly returned KTIME_MAX. Now we don't have active_timers.
To fix this, we now just check the timer wheel expiry value to
see if it is "now + NEXT_TIMER_MAX_DELTA", and if it is, we don't
try to compute a new value based on it, but instead simply let the
KTIME_MAX value in expires remain.
Marc Zyngier [Wed, 13 Jul 2016 16:18:33 +0000 (17:18 +0100)]
genirq/msi: Make sure PCI MSIs are activated early
Bharat Kumar Gogada reported issues with the generic MSI code, where the
end-point ended up with garbage in its MSI configuration (both for the vector
and the message).
It turns out that the two MSI paths in the kernel are doing slightly different
things:
And it turns out that end-points are allowed to latch the content of the MSI
configuration registers as soon as MSIs are enabled. In Bharat's case, the
end-point ends up using whatever was there already, which is not what you
want.
In order to make things converge, we introduce a new MSI domain flag
(MSI_FLAG_ACTIVATE_EARLY) that is unconditionally set for PCI/MSI. When set,
this flag forces the programming of the end-point as soon as the MSIs are
allocated.
A consequence of this is that we have an extra activate in irq_startup, but
that should be without much consequence.
tglx:
- Several people reported a VMWare regression with PCI/MSI-X passthrough. It
turns out that the patch also cures that issue.
- We need to have a look at the MSI disable interrupt path, where we write
the msg to all zeros without disabling MSI in the PCI device. Is that
correct?
powerpc/pci: Fix endian bug in fixed PHB numbering
The recent commit 63a72284b159 ("powerpc/pci: Assign fixed PHB number
based on device-tree properties"), added code to read a 64-bit property
from the device tree, and if not found read a 32-bit property (reg).
There was a bug in the 32-bit case, on big endian machines, due to the
use of the 64-bit value to read the 32-bit property. The cast of &prop
means we end up writing to the high 32-bit of prop, leaving the low
32-bits containing whatever junk was on the stack.
If that junk value was non-zero, and < MAX_PHBS, we would end up using
it as the PHB id. This results in users seeing what appear to be random
PHB ids.
Fix it by reading into a u32 property and then assigning that to the
u64 value, letting the CPU do the correct conversions for us.
Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties") Signed-off-by: Michael Ellerman <[email protected]>
powerpc/eeh: Switch to conventional PCI address output in EEH log
This is a very minor/trivial fix for the output of PCI address on EEH
logs. The PCI address on "OF node" field currently is using ":" as a
separator for the function, but the usual separator is ".". This patch
changes the separator to dot, so the PCI address is printed as usual.
Andrew Donnellan [Thu, 28 Jul 2016 05:39:41 +0000 (15:39 +1000)]
cxl: Fix NULL dereference in cxl_context_init() on PowerVM guests
Commit f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in
Mellanox CX4") added a "min_pe" field to struct cxl_service_layer_ops,
to allow us to work around a Mellanox CX-4 hardware limitation.
When allocating the PE number in cxl_context_init(), we read from
ctx->afu->adapter->native->sl_ops->min_pe to get the minimum PE number.
Unsurprisingly, in a PowerVM guest ctx->afu->adapter->native is NULL,
and guests don't have a cxl_service_layer_ops struct anywhere.
Move min_pe from struct cxl_service_layer_ops to struct cxl so it's
accessible in both native and PowerVM environments. For the Mellanox
CX-4, set the min_pe value in set_sl_ops().
cxl: Use fixed width predefined types in data structure.
This patch fixes a regression introduced by commit b810253bd934 ("cxl:
Add mechanism for delivering AFU driver specific events").
It changes the type u8 to __u8 in the uapi header cxl.h, because the
former is a kernel internal type, and may not be defined in userland
build environments, in particular when cross-compiling libcxl on x86_64
linux machines (RHEL6.7 and Ubuntu 16.04).
This patch also changes the size of the field data_size, and makes it
constant, to support 32-bit userland applications running on big-endian
ppc64 kernels transparently.
mpe: This is an ABI change, however the ABI was only added during the
4.8 merge window so has never been part of a released kernel - therefore
we give ourselves permission to change it.
Fixes: b810253bd934 ("cxl: Add mechanism for delivering AFU driver specific events") Signed-off-by: Philippe Bergheaud <[email protected]> Reviewed-by: Frederic Barrat <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
Guenter Roeck [Sat, 6 Aug 2016 22:54:12 +0000 (15:54 -0700)]
powerpc/vdso: Add missing include file
Some powerpc builds fail with the following buld error.
In file included from ./arch/powerpc/include/asm/mmu_context.h:11:0,
from arch/powerpc/kernel/vdso.c:28:
arch/powerpc/include/asm/cputhreads.h: In function 'get_tensr':
arch/powerpc/include/asm/cputhreads.h:101:2: error:
implicit declaration of function 'cpu_has_feature'
Fixes: b92a226e5284 ("powerpc: Move cpu_has_feature() to a separate file") Signed-off-by: Guenter Roeck <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
powerpc: Fix unused function warning 'lmb_to_memblock'
This patch fixes the following warning:
arch/powerpc/platforms/pseries/hotplug-memory.c:323:29: error: 'lmb_to_memblock' defined but not used [-Werror=unused-function]
static struct memory_block *lmb_to_memblock(struct of_drconf_cell *lmb)
^~~~~~~~~~~~~~~
The only consumer of this function is 'dlpar_remove_lmb', which is
enabled with CONFIG_MEMORY_HOTREMOVE, so move it into the same
ifdef block.
powerpc/powernv: Fix MCE handler to avoid trashing CR0/CR1 registers.
The current implementation of MCE early handling modifies CR0/1 registers
without saving its old values. Fix this by moving early check for
powersaving mode to machine_check_handle_early().
The power architecture 2.06 or later allows the possibility of getting
machine check while in nap/sleep/winkle. The last bit of HSPRG0 is set
to 1, if thread is woken up from winkle. Hence, clear the last bit of
HSPRG0 (r13) before MCE handler starts using it as paca pointer.
Also, the current code always puts the thread into nap state irrespective
of whatever idle state it woke up from. Fix that by looking at
paca->thread_idle_state and put the thread back into same state where it
came from.
Fixes: 1c51089f777b ("powerpc/book3s: Return from interrupt if coming from evil context.") Reported-by: Paul Mackerras <[email protected]> Signed-off-by: Mahesh Salgaonkar <[email protected]> Reviewed-by: Shreyas B. Prabhu <[email protected]> Signed-off-by: Michael Ellerman <[email protected]>
ALSA: usb-audio: Add a sample rate quirk for Creative Live! Cam Socialize HD (VF0610)
VF0610 does not support reading the sample rate which leads to many
lines of "cannot get freq at ep 0x82". This patch adds the USB ID
(0x041E:4080) to snd_usb_get_sample_rate_quirk() list.
projects / linux.git / log