tjh.dev
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Pull x86 fixes from Ingo Molnar:
"Last minute x86 fixes:
- Fix a softlockup detector warning and long delays if using ptdump
with KASAN enabled.
- Two more TSC-adjust fixes for interesting firmware interactions.
- Two commits to fix an AMD CPU topology enumeration bug that caused
a measurable gaming performance regression"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/ptdump: Fix soft lockup in page table walker
x86/tsc: Make the TSC ADJUST sanitizing work for tsc_reliable
x86/tsc: Avoid the large time jump when sanitizing TSC ADJUST
x86/CPU/AMD: Fix Zen SMT topology
x86/CPU/AMD: Bring back Compute Unit ID
Pull timer fix from Ingo Molnar:
"Fix a sporadic missed timer hw reprogramming bug that can result in
random delays"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/nohz: Fix possible missing clock reprog after tick soft restart
CONFIG_KASAN=y needs a lot of virtual memory mapped for its shadow.
In that case ptdump_walk_pgd_level_core() takes a lot of time to
walk across all page tables and doing this without
a rescheduling causes soft lockups:
NMI watchdog: BUG: soft lockup - CPU#3 stuck for 23s! [swapper/0:1]
...
Call Trace:
ptdump_walk_pgd_level_core+0x40c/0x550
ptdump_walk_pgd_level_checkwx+0x17/0x20
mark_rodata_ro+0x13b/0x150
kernel_init+0x2f/0x120
ret_from_fork+0x2c/0x40
I guess that this issue might arise even without KASAN on huge machines
with several terabytes of RAM.
Stick cond_resched() in pgd loop to fix this.
Reported-by: Tobias Regnery <tobias.regnery@gmail.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Alexander Potapenko <glider@google.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170210095405.31802-1-aryabinin@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull perf fixes from Ingo Molnar:
"A kernel crash fix plus three tooling fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix crash in perf_event_read()
perf callchain: Reference count maps
perf diff: Fix -o/--order option behavior (again)
perf diff: Fix segfault on 'perf diff -o N' option
ts->next_tick keeps track of the next tick deadline in order to optimize
clock programmation on irq exit and avoid redundant clock device writes.
Now if ts->next_tick missed an update, we may spuriously miss a clock
reprog later as the nohz code is fooled by an obsolete next_tick value.
This is what happens here on a specific path: when we observe an
expired timer from the nohz update code on irq exit, we perform a soft
tick restart which simply fires the closest possible tick without
actually exiting the nohz mode and restoring a periodic state. But we
forget to update ts->next_tick accordingly.
As a result, after the next tick resulting from such soft tick restart,
the nohz code sees a stale value on ts->next_tick which doesn't match
the clock deadline that just expired. If that obsolete ts->next_tick
value happens to collide with the actual next tick deadline to be
scheduled, we may spuriously bypass the clock reprogramming. In the
worst case, the tick may never fire again.
Fix this with a ts->next_tick reset on soft tick restart.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1486485894-29173-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When the TSC is marked reliable then the synchronization check is skipped,
but that also skips the TSC ADJUST sanitizing code. So on a machine with a
wreckaged BIOS the TSC deviation between CPUs might go unnoticed.
Let the TSC adjust sanitizing code run unconditionally and just skip the
expensive synchronization checks when TSC is marked reliable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Olof Johansson <olof@lixom.net>
Link: http://lkml.kernel.org/r/20170209151231.491189912@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull lockdep fix from Ingo Molnar:
"This fixes an ugly lockdep stack trace output regression. (But also
affects other stacktrace users such as kmemleak, KASAN, etc)"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
stacktrace, lockdep: Fix address, newline ugliness
Alexei had his box explode because doing read() on a package
(rapl/uncore) event that isn't currently scheduled in ends up doing an
out-of-bounds load.
Rework the code to more explicitly deal with event->oncpu being -1.
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: David Carrillo-Cisneros <davidcc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: eranian@google.com
Fixes: d6a2f9035bfc ("perf/core: Introduce PMU_EV_CAP_READ_ACTIVE_PKG")
Link: http://lkml.kernel.org/r/20170131102710.GL6515@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull drm fixes from Dave Airlie:
"This should be the final set of drm fixes for 4.10: one vmwgfx boot
fix, one vc4 fix, and a few i915 fixes:
* tag 'drm-fixes-for-v4.10-rc8' of git://people.freedesktop.org/~airlied/linux:
drm: vc4: adapt to new behaviour of drm_crtc.c
drm/i915: Always convert incoming exec offsets to non-canonical
drm/i915: Remove overzealous fence warn on runtime suspend
drm/i915/bxt: Add MST support when do DPLL calculation
drm/i915: don't warn about Skylake CPU - KabyPoint PCH combo
drm/i915: fix i915 running as dom0 under Xen
drm/i915: Flush untouched framebuffers before display on !llc
drm/i915: fix use-after-free in page_flip_completed()
drm/vmwgfx: Fix depth input into drm_mode_legacy_fb_format
Olof reported that on a machine which has a BIOS wreckaged TSC the
timestamps in dmesg are making a large jump because the TSC value is
jumping forward after resetting the TSC ADJUST register to a sane value.
This can be avoided by calling the TSC ADJUST saniziting function before
initializing the per cpu sched clock machinery. That takes the offset into
account and avoid the time jump.
What cannot be avoided is that the 'Firmware Bug' warnings on the secondary
CPUs are printed with the large time offsets because it would be too much
effort and ugly hackery to print those warnings into a buffer and emit them
after the adjustemt on the starting CPUs. It's a firmware bug and should be
fixed in firmware. The weird timestamps are collateral damage and just
illustrate the sillyness of the BIOS folks:
[ 0.397445] smp: Bringing up secondary CPUs ...
[ 0.402100] x86: Booting SMP configuration:
[ 0.406343] .... node #0, CPUs: #1
[1265776479.930667] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -2978888639075328 CPU1: -2978888639183101
[1265776479.944664] TSC ADJUST synchronize: Reference CPU0: 0 CPU1: -2978888639183101
[ 0.508119] #2
[1265776480.032346] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -2978888639075328 CPU2: -2978888639183677
[1265776480.044192] TSC ADJUST synchronize: Reference CPU0: 0 CPU2: -2978888639183677
[ 0.607643] #3
[1265776480.131874] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -2978888639075328 CPU3: -2978888639184530
[1265776480.143720] TSC ADJUST synchronize: Reference CPU0: 0 CPU3: -2978888639184530
[ 0.707108] smp: Brought up 1 node, 4 CPUs
[ 0.711271] smpboot: Total of 4 processors activated (21698.88 BogoMIPS)
Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170209151231.411460506@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull irq fixes from Ingo Molnar:
"Two last minute ARM irqchip driver fixes"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/mxs: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
irqchip/keystone: Fix "scheduling while atomic" on rt
Since KERN_CONT became meaningful again, lockdep stack traces have had
annoying extra newlines, like this:
[ 5.561122] -> #1 (B){+.+...}:
[ 5.561528]
[ 5.561532] [<ffffffff810d8873>] lock_acquire+0xc3/0x210
[ 5.562178]
[ 5.562181] [<ffffffff816f6414>] mutex_lock_nested+0x74/0x6d0
[ 5.562861]
[ 5.562880] [<ffffffffa01aa3c3>] init_btrfs_fs+0x21/0x196 [btrfs]
[ 5.563717]
[ 5.563721] [<ffffffff81000472>] do_one_initcall+0x52/0x1b0
[ 5.564554]
[ 5.564559] [<ffffffff811a3af6>] do_init_module+0x5f/0x209
[ 5.565357]
[ 5.565361] [<ffffffff81122f4d>] load_module+0x218d/0x2b80
[ 5.566020]
[ 5.566021] [<ffffffff81123beb>] SyS_finit_module+0xeb/0x120
[ 5.566694]
[ 5.566696] [<ffffffff816fd241>] entry_SYSCALL_64_fastpath+0x1f/0xc2
That's happening because each printk() call now gets printed on its own
line, and we do a separate call to print the spaces before the symbol.
Fix it by doing the printk() directly instead of using the
print_ip_sym() helper.
Additionally, the symbol address isn't very helpful, so let's get rid of
that, too. The final result looks like this:
[ 5.194518] -> #1 (B){+.+...}:
[ 5.195002] lock_acquire+0xc3/0x210
[ 5.195439] mutex_lock_nested+0x74/0x6d0
[ 5.196491] do_one_initcall+0x52/0x1b0
[ 5.196939] do_init_module+0x5f/0x209
[ 5.197355] load_module+0x218d/0x2b80
[ 5.197792] SyS_finit_module+0xeb/0x120
[ 5.198251] entry_SYSCALL_64_fastpath+0x1f/0xc2
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Fixes: 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines")
Link: http://lkml.kernel.org/r/43b4e114724b2bdb0308fa86cb33aa07d3d67fad.1486510315.git.osandov@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
- Reference count maps in callchains, fixing a SEGFAULT when referencing a
map after it is freed (Krister Johansen)
- Fix segfault on 'perf diff -o N' option (Namhyung Kim)
- Fix 'perf diff -o/--order' option behavior (Namhyung Kim)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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