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https://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clocksource/events updates from Daniel Lezcano:
- Fix return error code check for the timer-of layer when getting
the base address (Guillaume Ranquet)
- Remove MMIO dependency, add notrace annotation for sched_clock
and increase the timer resolution for the Microchip
PIT64b (Claudiu Beznea)
- Convert DT bindings to yaml for the Tegra timer (David Heidelberg)
- Fix compilation error on architecture other than ARM for the
i.MX TPM (Nathan Chancellor)
- Add support for the event stream scaling for 1GHz counter on
the arch ARM timer (Marc Zyngier)
- Support a higher number of interrupts by the Exynos MCT timer
driver (Alim Akhtar)
- Detect and prevent memory corruption when the specified number
of interrupts in the DTS is greater than the array size in the
code for the Exynos MCT timer (Krzysztof Kozlowski)
- Fix regression from a previous errata fix on the TI DM
timer (Drew Fustini)
- Several fixes and code improvements for the i.MX TPM
driver (Peng Fan)
Link: https://lore.kernel.org/all/a8cd9be9-7d70-80df-2b74-1a8226a215e1@linaro.org
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git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/core
Pull tick/NOHZ updates from Frederic Weisbecker:
- A fix for rare jiffies update stalls that were reported by Paul McKenney
- Tick side cleanups after RCU_FAST_NO_HZ removal
- Handle softirqs on idle more gracefully
Link: https://lore.kernel.org/all/20220307233034.34550-1-frederic@kernel.org
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Instead of using sprintf, use snprintf with buffer size limited to
PAGE_SIZE just like what we have for the rest of the file.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Don't fold line that can fit into 80 char limit. No functional change
in this patch.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This fixes following kernel-doc warning:-
drivers/nvme/target/rdma.c:1722: warning: expecting prototype for nvme_rdma_device_removal(). Prototype was for nvmet_rdma_device_removal() instead
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This fixes following kernel-doc warning:-
drivers/nvme/target/fc.c:1619: warning: expecting prototype for nvme_fc_unregister_targetport(). Prototype was for nvmet_fc_unregister_targetport() instead
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This fixes following kernel-doc warning :-
drivers/nvme/target/fc.c:1365: warning: expecting prototype for nvme_fc_register_targetport(). Prototype was for nvmet_fc_register_targetport() instead
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Put NVMe/TCP sockets in their own class to avoid some lockdep warnings.
Sockets created by nvme-tcp are not exposed to user-space, and will not
trigger certain code paths that the general socket API exposes.
Lockdep complains about a circular dependency between the socket and
filesystem locks, because setsockopt can trigger a page fault with a
socket lock held, but nvme-tcp sends requests on the socket while file
system locks are held.
======================================================
WARNING: possible circular locking dependency detected
5.15.0-rc3 #1 Not tainted
------------------------------------------------------
fio/1496 is trying to acquire lock:
(sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendpage+0x23/0x80
but task is already holding lock:
(&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]
which lock already depends on the new lock.
other info that might help us debug this:
chain exists of:
sk_lock-AF_INET --> sb_internal --> &xfs_dir_ilock_class/5
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&xfs_dir_ilock_class/5);
lock(sb_internal);
lock(&xfs_dir_ilock_class/5);
lock(sk_lock-AF_INET);
*** DEADLOCK ***
6 locks held by fio/1496:
#0: (sb_writers#13){.+.+}-{0:0}, at: path_openat+0x9fc/0xa20
#1: (&inode->i_sb->s_type->i_mutex_dir_key){++++}-{3:3}, at: path_openat+0x296/0xa20
#2: (sb_internal){.+.+}-{0:0}, at: xfs_trans_alloc_icreate+0x41/0xd0 [xfs]
#3: (&xfs_dir_ilock_class/5){+.+.}-{3:3}, at: xfs_ilock+0xcf/0x290 [xfs]
#4: (hctx->srcu){....}-{0:0}, at: hctx_lock+0x51/0xd0
#5: (&queue->send_mutex){+.+.}-{3:3}, at: nvme_tcp_queue_rq+0x33e/0x380 [nvme_tcp]
This annotation lets lockdep analyze nvme-tcp controlled sockets
independently of what the user-space sockets API does.
Link: https://lore.kernel.org/linux-nvme/CAHj4cs9MDYLJ+q+2_GXUK9HxFizv2pxUryUR0toX974M040z7g@mail.gmail.com/
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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The call to nvme_tcp_alloc_queue() fits perfectly in one line without
exceeding 80 char limit for the line.
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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No point in initializing ret variable to 0 in nvme_tcp_start_io_queue()
since it gets overwritten by a call to nvme_tcp_start_queue().
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Use bio_io_error() here since bio_io_error does the same thing.
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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The ANA log buffer can get really large, as it depends on the
controller configuration. So to avoid an out-of-memory issue
during scanning use kvmalloc() instead of the kmalloc().
Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch turns the new SHA driver into a tristate and also allows
compile testing.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Zaibo moved projects and is not looking into crypto stuff.
I am responsible for checking the patches of these modules.
so the maintainers list needs to be updated.
I take care of HPRE, Qian Weili take care of TRNG,
Ye Kai and me take care of SEC2.
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Signed-off-by: Kai Ye <yekai12@huawei.com>
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Zaibo Xu <xuzaibo@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Fix the following W=1 kernel warnings:
crypto/dh.c:311:31: warning: unused function 'dh_safe_prime_dh_alg'
[-Wunused-function]
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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The corresponding API for clk_prepare_enable is clk_disable_unprepare,
other than clk_disable_unprepare.
Fix this by changing clk_disable to clk_disable_unprepare.
Fixes: beca35d05cc2 ("hwrng: nomadik - use clk_prepare_enable()")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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The generate function in struct rng_alg expects that the destination
buffer is completely filled if the function returns 0. qcom_rng_read()
can run into a situation where the buffer is partially filled with
randomness and the remaining part of the buffer is zeroed since
qcom_rng_generate() doesn't check the return value. This issue can
be reproduced by running the following from libkcapi:
kcapi-rng -b 9000000 > OUTFILE
The generated OUTFILE will have three huge sections that contain all
zeros, and this is caused by the code where the test
'val & PRNG_STATUS_DATA_AVAIL' fails.
Let's fix this issue by ensuring that qcom_rng_read() always returns
with a full buffer if the function returns success. Let's also have
qcom_rng_generate() return the correct value.
Here's some statistics from the ent project
(https://www.fourmilab.ch/random/) that shows information about the
quality of the generated numbers:
$ ent -c qcom-random-before
Value Char Occurrences Fraction
0 606748 0.067416
1 33104 0.003678
2 33001 0.003667
...
253 � 32883 0.003654
254 � 33035 0.003671
255 � 33239 0.003693
Total: 9000000 1.000000
Entropy = 7.811590 bits per byte.
Optimum compression would reduce the size
of this 9000000 byte file by 2 percent.
Chi square distribution for 9000000 samples is 9329962.81, and
randomly would exceed this value less than 0.01 percent of the
times.
Arithmetic mean value of data bytes is 119.3731 (127.5 = random).
Monte Carlo value for Pi is 3.197293333 (error 1.77 percent).
Serial correlation coefficient is 0.159130 (totally uncorrelated =
0.0).
Without this patch, the results of the chi-square test is 0.01%, and
the numbers are certainly not random according to ent's project page.
The results improve with this patch:
$ ent -c qcom-random-after
Value Char Occurrences Fraction
0 35432 0.003937
1 35127 0.003903
2 35424 0.003936
...
253 � 35201 0.003911
254 � 34835 0.003871
255 � 35368 0.003930
Total: 9000000 1.000000
Entropy = 7.999979 bits per byte.
Optimum compression would reduce the size
of this 9000000 byte file by 0 percent.
Chi square distribution for 9000000 samples is 258.77, and randomly
would exceed this value 42.24 percent of the times.
Arithmetic mean value of data bytes is 127.5006 (127.5 = random).
Monte Carlo value for Pi is 3.141277333 (error 0.01 percent).
Serial correlation coefficient is 0.000468 (totally uncorrelated =
0.0).
This change was tested on a Nexus 5 phone (msm8974 SoC).
Signed-off-by: Brian Masney <bmasney@redhat.com>
Fixes: ceec5f5b5988 ("crypto: qcom-rng - Add Qcom prng driver")
Cc: stable@vger.kernel.org # 4.19+
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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commit f86c3ed55920 ("drm/mgag200: Split PLL setup into compute and
update functions") introduced a regression for g200wb and g200ew.
The PLLs are not set up properly, and VGA screen stays
black, or displays "out of range" message.
MGA1064_WB_PIX_PLLC_N/M/P was mistakenly replaced with
MGA1064_PIX_PLLC_N/M/P which have different addresses.
Patch tested on a Dell T310 with g200wb
Fixes: f86c3ed55920 ("drm/mgag200: Split PLL setup into compute and update functions")
Cc: stable@vger.kernel.org
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220308174321.225606-1-jfalempe@redhat.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Free shmem backing storage for SGX enclave pages when those are
swapped back into EPC memory
- Prevent do_int3() from being kprobed, to avoid recursion
- Remap setup_data and setup_indirect structures properly when
accessing their members
- Correct the alternatives patching order for modules too
* tag 'x86_urgent_for_v5.17_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sgx: Free backing memory after faulting the enclave page
x86/traps: Mark do_int3() NOKPROBE_SYMBOL
x86/boot: Add setup_indirect support in early_memremap_is_setup_data()
x86/boot: Fix memremap of setup_indirect structures
x86/module: Fix the paravirt vs alternative order
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Rather than waiting a full second in an interruptable waiter before
trying to generate entropy, try to generate entropy first and wait
second. While waiting one second might give an extra second for getting
entropy from elsewhere, we're already pretty late in the init process
here, and whatever else is generating entropy will still continue to
contribute. This has implications on signal handling: we call
try_to_generate_entropy() from wait_for_random_bytes(), and
wait_for_random_bytes() always uses wait_event_interruptible_timeout()
when waiting, since it's called by userspace code in restartable
contexts, where signals can pend. Since try_to_generate_entropy() now
runs first, if a signal is pending, it's necessary for
try_to_generate_entropy() to check for signals, since it won't hit the
wait until after try_to_generate_entropy() has returned. And even before
this change, when entering a busy loop in try_to_generate_entropy(), we
should have been checking to see if any signals are pending, so that a
process doesn't get stuck in that loop longer than expected.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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In order to chip away at the "premature first" problem, we augment our
existing entropy accounting with more frequent reseedings at boot.
The idea is that at boot, we're getting entropy from various places, and
we're not very sure which of early boot entropy is good and which isn't.
Even when we're crediting the entropy, we're still not totally certain
that it's any good. Since boot is the one time (aside from a compromise)
that we have zero entropy, it's important that we shepherd entropy into
the crng fairly often.
At the same time, we don't want a "premature next" problem, whereby an
attacker can brute force individual bits of added entropy. In lieu of
going full-on Fortuna (for now), we can pick a simpler strategy of just
reseeding more often during the first 5 minutes after boot. This is
still bounded by the 256-bit entropy credit requirement, so we'll skip a
reseeding if we haven't reached that, but in case entropy /is/ coming
in, this ensures that it makes its way into the crng rather rapidly
during these early stages.
Ordinarily we reseed if the previous reseeding is 300 seconds old. This
commit changes things so that for the first 600 seconds of boot time, we
reseed if the previous reseeding is uptime / 2 seconds old. That means
that we'll reseed at the very least double the uptime of the previous
reseeding.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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This just puts trace_ext4_fc_commit_start(sb) & ktime_get()
for measuring FC commit time, after the check of whether sb
supports JOURNAL_FAST_COMMIT or not.
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/d53cf3e535924ec0a1eb41a560e96561b0727e7a.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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One should use DECLARE_EVENT_CLASS for similar event types instead of
defining TRACE_EVENT for each event type. This is helpful in reducing
the text section footprint for e.g. [1]
[1]: https://lwn.net/Articles/381064/
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/a019cb46219ef4b30e4d98d7ced7d8819a2fc61d.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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ftrace's __print_symbolic() requires that any enum values used in the
symbol to string translation table be wrapped in a TRACE_DEFINE_ENUM
so that the enum value can be decoded from the ftrace ring buffer by
user space tooling.
This patch also fixes few other problems found in this trace point.
e.g. dereferencing structures in TP_printk which should not be done
at any cost.
Also to avoid checkpatch warnings, this patch removes those
whitespaces/tab stops issues.
Cc: stable@kernel.org
Fixes: aa75f4d3daae ("ext4: main fast-commit commit path")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/b4b9691414c35c62e570b723e661c80674169f9a.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Below commit removed all references of EXT4_FC_COMMIT_FAILED.
commit 0915e464cb274 ("ext4: simplify updating of fast commit stats")
Just remove it since it is not used anymore.
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/c941357e476be07a1138c7319ca5faab7fb80fc6.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Recently I've got a report of BUG_ON trigerring during transaction
commit in ext4_journalled_writepage_callback() because we've spotted a
dirty page without buffers. Add WARN_ON_ONCE to
ext4_journalled_set_page_dirty() to catch the problematic condition
earlier where we have better chance of understanding which code path is
creating dirty data without preparing the page properly. Also update the
comment with current information when we are at it.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220310101832.5645-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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The unit of file system size should be TiB, not PiB
Signed-off-by: lianzhi chang <changlianzhi@uniontech.com>
Link: https://lore.kernel.org/r/20220310014415.29937-1-changlianzhi@uniontech.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Currently mb_optimize_scan scan feature which improves filesystem
performance heavily (when FS is fragmented), seems to be not working
with files with extents (ext4 by default has files with extents).
This patch fixes that and makes mb_optimize_scan feature work
for files with extents.
Below are some performance numbers obtained when allocating a 10M and 100M
file with and w/o this patch on a filesytem with no 1M contiguous block.
<perf numbers>
===============
Workload: dd if=/dev/urandom of=test conv=fsync bs=1M count=10/100
Time taken
=====================================================
no. Size without-patch with-patch Diff(%)
1 10M 0m8.401s 0m5.623s 33.06%
2 100M 1m40.465s 1m14.737s 25.6%
<debug stats>
=============
w/o patch:
mballoc:
reqs: 17056
success: 11407
groups_scanned: 13643
cr0_stats:
hits: 37
groups_considered: 9472
useless_loops: 36
bad_suggestions: 0
cr1_stats:
hits: 11418
groups_considered: 908560
useless_loops: 1894
bad_suggestions: 0
cr2_stats:
hits: 1873
groups_considered: 6913
useless_loops: 21
cr3_stats:
hits: 21
groups_considered: 5040
useless_loops: 21
extents_scanned: 417364
goal_hits: 3707
2^n_hits: 37
breaks: 1873
lost: 0
buddies_generated: 239/240
buddies_time_used: 651080
preallocated: 705
discarded: 478
with patch:
mballoc:
reqs: 12768
success: 11305
groups_scanned: 12768
cr0_stats:
hits: 1
groups_considered: 18
useless_loops: 0
bad_suggestions: 0
cr1_stats:
hits: 5829
groups_considered: 50626
useless_loops: 0
bad_suggestions: 0
cr2_stats:
hits: 6938
groups_considered: 580363
useless_loops: 0
cr3_stats:
hits: 0
groups_considered: 0
useless_loops: 0
extents_scanned: 309059
goal_hits: 0
2^n_hits: 1
breaks: 1463
lost: 0
buddies_generated: 239/240
buddies_time_used: 791392
preallocated: 673
discarded: 446
Fixes: 196e402 (ext4: improve cr 0 / cr 1 group scanning)
Cc: stable@kernel.org
Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com>
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Suggested-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/fc9a48f7f8dcfc83891a8b21f6dd8cdf056ed810.1646732698.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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After moving to the new mount API, mb_optimize_scan mount option
handling was not working as expected due to the parsed value always
being overwritten by default. Refactor and fix this to the expected
behavior described below:
* mb_optimize_scan=1 - On
* mb_optimize_scan=0 - Off
* mb_optimize_scan not passed - On if no. of BGs > threshold else off
* Remounts retain previous value unless we explicitly pass the option
with a new value
Fixes: cebe85d570cf ("ext4: switch to the new mount api")
Cc: stable@kernel.org
Reported-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/c98970fe99f26718586d02e942f293300fb48ef3.1646732698.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Rather than sometimes checking `crng_init < 2`, we should always use the
crng_ready() macro, so that should we change anything later, it's
consistent. Additionally, that macro already has a likely() around it,
which means we don't need to open code our own likely() and unlikely()
annotations.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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The current fast_mix() function is a piece of classic mailing list
crypto, where it just sort of sprung up by an anonymous author without a
lot of real analysis of what precisely it was accomplishing. As an ARX
permutation alone, there are some easily searchable differential trails
in it, and as a means of preventing malicious interrupts, it completely
fails, since it xors new data into the entire state every time. It can't
really be analyzed as a random permutation, because it clearly isn't,
and it can't be analyzed as an interesting linear algebraic structure
either, because it's also not that. There really is very little one can
say about it in terms of entropy accumulation. It might diffuse bits,
some of the time, maybe, we hope, I guess. But for the most part, it
fails to accomplish anything concrete.
As a reminder, the simple goal of add_interrupt_randomness() is to
simply accumulate entropy until ~64 interrupts have elapsed, and then
dump it into the main input pool, which uses a cryptographic hash.
It would be nice to have something cryptographically strong in the
interrupt handler itself, in case a malicious interrupt compromises a
per-cpu fast pool within the 64 interrupts / 1 second window, and then
inside of that same window somehow can control its return address and
cycle counter, even if that's a bit far fetched. However, with a very
CPU-limited budget, actually doing that remains an active research
project (and perhaps there'll be something useful for Linux to come out
of it). And while the abundance of caution would be nice, this isn't
*currently* the security model, and we don't yet have a fast enough
solution to make it our security model. Plus there's not exactly a
pressing need to do that. (And for the avoidance of doubt, the actual
cluster of 64 accumulated interrupts still gets dumped into our
cryptographically secure input pool.)
So, for now we are going to stick with the existing interrupt security
model, which assumes that each cluster of 64 interrupt data samples is
mostly non-malicious and not colluding with an infoleaker. With this as
our goal, we have a few more choices, simply aiming to accumulate
entropy, while discarding the least amount of it.
We know from <https://eprint.iacr.org/2019/198> that random oracles,
instantiated as computational hash functions, make good entropy
accumulators and extractors, which is the justification for using
BLAKE2s in the main input pool. As mentioned, we don't have that luxury
here, but we also don't have the same security model requirements,
because we're assuming that there aren't malicious inputs. A
pseudorandom function instance can approximately behave like a random
oracle, provided that the key is uniformly random. But since we're not
concerned with malicious inputs, we can pick a fixed key, which is not
secret, knowing that "nature" won't interact with a sufficiently chosen
fixed key by accident. So we pick a PRF with a fixed initial key, and
accumulate into it continuously, dumping the result every 64 interrupts
into our cryptographically secure input pool.
For this, we make use of SipHash-1-x on 64-bit and HalfSipHash-1-x on
32-bit, which are already in use in the kernel's hsiphash family of
functions and achieve the same performance as the function they replace.
It would be nice to do two rounds, but we don't exactly have the CPU
budget handy for that, and one round alone is already sufficient.
As mentioned, we start with a fixed initial key (zeros is fine), and
allow SipHash's symmetry breaking constants to turn that into a useful
starting point. Also, since we're dumping the result (or half of it on
64-bit so as to tax our hash function the same amount on all platforms)
into the cryptographically secure input pool, there's no point in
finalizing SipHash's output, since it'll wind up being finalized by
something much stronger. This means that all we need to do is use the
ordinary round function word-by-word, as normal SipHash does.
Simplified, the flow is as follows:
Initialize:
siphash_state_t state;
siphash_init(&state, key={0, 0, 0, 0});
Update (accumulate) on interrupt:
siphash_update(&state, interrupt_data_and_timing);
Dump into input pool after 64 interrupts:
blake2s_update(&input_pool, &state, sizeof(state) / 2);
The result of all of this is that the security model is unchanged from
before -- we assume non-malicious inputs -- yet we now implement that
model with a stronger argument. I would like to emphasize, again, that
the purpose of this commit is to improve the existing design, by making
it analyzable, without changing any fundamental assumptions. There may
well be value down the road in changing up the existing design, using
something cryptographically strong, or simply using a ring buffer of
samples rather than having a fast_mix() at all, or changing which and
how much data we collect each interrupt so that we can use something
linear, or a variety of other ideas. This commit does not invalidate the
potential for those in the future.
For example, in the future, if we're able to characterize the data we're
collecting on each interrupt, we may be able to inch toward information
theoretic accumulators. <https://eprint.iacr.org/2021/523> shows that `s
= ror32(s, 7) ^ x` and `s = ror64(s, 19) ^ x` make very good
accumulators for 2-monotone distributions, which would apply to
timestamp counters, like random_get_entropy() or jiffies, but would not
apply to our current combination of the two values, or to the various
function addresses and register values we mix in. Alternatively,
<https://eprint.iacr.org/2021/1002> shows that max-period linear
functions with no non-trivial invariant subspace make good extractors,
used in the form `s = f(s) ^ x`. However, this only works if the input
data is both identical and independent, and obviously a collection of
address values and counters fails; so it goes with theoretical papers.
Future directions here may involve trying to characterize more precisely
what we actually need to collect in the interrupt handler, and building
something specific around that.
However, as mentioned, the morass of data we're gathering at the
interrupt handler presently defies characterization, and so we use
SipHash for now, which works well and performs well.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
|
When a virtual machine forks, it's important that WireGuard clear
existing sessions so that different plaintexts are not transmitted using
the same key+nonce, which can result in catastrophic cryptographic
failure. To accomplish this, we simply hook into the newly added vmfork
notifier.
As a bonus, it turns out that, like the vmfork registration function,
the PM registration function is stubbed out when CONFIG_PM_SLEEP is not
set, so we can actually just remove the maze of ifdefs, which makes it
really quite clean to support both notifiers at once.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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Drivers such as WireGuard need to learn when VMs fork in order to clear
sessions. This commit provides a simple notifier_block for that, with a
register and unregister function. When no VM fork detection is compiled
in, this turns into a no-op, similar to how the power notifier works.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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We previously rolled our own randomness readiness notifier, which only
has two users in the whole kernel. Replace this with a more standard
atomic notifier block that serves the same purpose with less code. Also
unexport the symbols, because no modules use it, only unconditional
builtins. The only drawback is that it's possible for a notification
handler returning the "stop" code to prevent further processing, but
given that there are only two users, and that we're unexporting this
anyway, that doesn't seem like a significant drawback for the
simplification we receive here.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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Since add_vmfork_randomness() is only called from vmgenid.o, we can
guard it in CONFIG_VMGENID, similarly to how we do with
add_disk_randomness() and CONFIG_BLOCK. If we ever have multiple things
calling into add_vmfork_randomness(), we can add another shared Kconfig
symbol for that, but for now, this is good enough. Even though
add_vmfork_randomess() is a pretty small function, removing it means
that there are only calls to crng_reseed(false) and none to
crng_reseed(true), which means the compiler can constant propagate the
false, removing branches from crng_reseed() and its descendants.
Additionally, we don't even need the symbol to be exported if
CONFIG_VMGENID is not a module, so conditionalize that too.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
|
VM Generation ID is a feature from Microsoft, described at
<https://go.microsoft.com/fwlink/?LinkId=260709>, and supported by
Hyper-V and QEMU. Its usage is described in Microsoft's RNG whitepaper,
<https://aka.ms/win10rng>, as:
If the OS is running in a VM, there is a problem that most
hypervisors can snapshot the state of the machine and later rewind
the VM state to the saved state. This results in the machine running
a second time with the exact same RNG state, which leads to serious
security problems. To reduce the window of vulnerability, Windows
10 on a Hyper-V VM will detect when the VM state is reset, retrieve
a unique (not random) value from the hypervisor, and reseed the root
RNG with that unique value. This does not eliminate the
vulnerability, but it greatly reduces the time during which the RNG
system will produce the same outputs as it did during a previous
instantiation of the same VM state.
Linux has the same issue, and given that vmgenid is supported already by
multiple hypervisors, we can implement more or less the same solution.
So this commit wires up the vmgenid ACPI notification to the RNG's newly
added add_vmfork_randomness() function.
It can be used from qemu via the `-device vmgenid,guid=auto` parameter.
After setting that, use `savevm` in the monitor to save the VM state,
then quit QEMU, start it again, and use `loadvm`. That will trigger this
driver's notify function, which hands the new UUID to the RNG. This is
described in <https://git.qemu.org/?p=qemu.git;a=blob;f=docs/specs/vmgenid.txt>.
And there are hooks for this in libvirt as well, described in
<https://libvirt.org/formatdomain.html#general-metadata>.
Note, however, that the treatment of this as a UUID is considered to be
an accidental QEMU nuance, per
<https://github.com/libguestfs/virt-v2v/blob/master/docs/vm-generation-id-across-hypervisors.txt>,
so this driver simply treats these bytes as an opaque 128-bit binary
blob, as per the spec. This doesn't really make a difference anyway,
considering that's how it ends up when handed to the RNG in the end.
Cc: Alexander Graf <graf@amazon.com>
Cc: Adrian Catangiu <adrian@parity.io>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Tested-by: Souradeep Chakrabarti <souradch.linux@gmail.com> # With Hyper-V's virtual hardware
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
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We create a list of ACPI "PNP" IDs which contains _HID, _CID, and CLS
entries of the respective devices. However, when making structs for
matching, we squeeze those IDs into acpi_device_id, which only has 9
bytes space to store the identifier. The subsystem actually captures the
full length of the IDs, and the modalias has the full length, but this
struct we use for matching is limited. It originally had 16 bytes, but
was changed to only have 9 in 6543becf26ff ("mod/file2alias: make
modalias generation safe for cross compiling"), presumably on the theory
that it would match the ACPI spec so it didn't matter.
Unfortunately, while most people adhere to the ACPI specs, Microsoft
decided that its VM Generation Counter device [1] should only be
identifiable by _CID with a value of "VM_Gen_Counter", which is longer
than 9 characters.
To allow device drivers to match identifiers that exceed the 9 byte
limit, this simply ups the length to 16, just like it was before the
aforementioned commit. Empirical testing indicates that this
doesn't actually increase vmlinux size on 64-bit, because the ulong in
the same struct caused there to be 7 bytes of padding anyway, and when
doing a s/M/Y/g i386_defconfig build, the bzImage only increased by
0.0055%, so negligible.
This patch is a prerequisite to add support for VMGenID in Linux, the
subsequent patch in this series. It has been confirmed to also work on
the udev/modalias side in userspace.
[1] https://download.microsoft.com/download/3/1/C/31CFC307-98CA-4CA5-914C-D9772691E214/VirtualMachineGenerationID.docx
Signed-off-by: Alexander Graf <graf@amazon.com>
Co-developed-by: Jason A. Donenfeld <Jason@zx2c4.com>
[Jason: reworked commit message a bit, went with len=16 approach.]
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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When a VM forks, we must immediately mix in additional information to
the stream of random output so that two forks or a rollback don't
produce the same stream of random numbers, which could have catastrophic
cryptographic consequences. This commit adds a simple API, add_vmfork_
randomness(), for that, by force reseeding the crng.
This has the added benefit of also draining the entropy pool and setting
its timer back, so that any old entropy that was there prior -- which
could have already been used by a different fork, or generally gone
stale -- does not contribute to the accounting of the next 256 bits.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jann Horn <jannh@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
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We leave around these old sysctls for compatibility, and we keep them
"writable" for compatibility, but even after writing, we should keep
reporting the same value. This is consistent with how userspaces tend to
use sysctl_random_write_wakeup_bits, writing to it, and then later
reading from it and using the value.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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This isn't used by anything or anywhere, but we can't delete it due to
compatibility. So at least give it the correct value of what it's
supposed to be instead of a garbage one.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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This topic has come up countless times, and usually doesn't go anywhere.
This time I thought I'd bring it up with a slightly narrower focus,
updated for some developments over the last three years: we finally can
make /dev/urandom always secure, in light of the fact that our RNG is
now always seeded.
Ever since Linus' 50ee7529ec45 ("random: try to actively add entropy
rather than passively wait for it"), the RNG does a haveged-style jitter
dance around the scheduler, in order to produce entropy (and credit it)
for the case when we're stuck in wait_for_random_bytes(). How ever you
feel about the Linus Jitter Dance is beside the point: it's been there
for three years and usually gets the RNG initialized in a second or so.
As a matter of fact, this is what happens currently when people use
getrandom(). It's already there and working, and most people have been
using it for years without realizing.
So, given that the kernel has grown this mechanism for seeding itself
from nothing, and that this procedure happens pretty fast, maybe there's
no point any longer in having /dev/urandom give insecure bytes. In the
past we didn't want the boot process to deadlock, which was
understandable. But now, in the worst case, a second goes by, and the
problem is resolved. It seems like maybe we're finally at a point when
we can get rid of the infamous "urandom read hole".
The one slight drawback is that the Linus Jitter Dance relies on random_
get_entropy() being implemented. The first lines of try_to_generate_
entropy() are:
stack.now = random_get_entropy();
if (stack.now == random_get_entropy())
return;
On most platforms, random_get_entropy() is simply aliased to get_cycles().
The number of machines without a cycle counter or some other
implementation of random_get_entropy() in 2022, which can also run a
mainline kernel, and at the same time have a both broken and out of date
userspace that relies on /dev/urandom never blocking at boot is thought
to be exceedingly low. And to be clear: those museum pieces without
cycle counters will continue to run Linux just fine, and even
/dev/urandom will be operable just like before; the RNG just needs to be
seeded first through the usual means, which should already be the case
now.
On systems that really do want unseeded randomness, we already offer
getrandom(GRND_INSECURE), which is in use by, e.g., systemd for seeding
their hash tables at boot. Nothing in this commit would affect
GRND_INSECURE, and it remains the means of getting those types of random
numbers.
This patch goes a long way toward eliminating a long overdue userspace
crypto footgun. After several decades of endless user confusion, we will
finally be able to say, "use any single one of our random interfaces and
you'll be fine. They're all the same. It doesn't matter." And that, I
think, is really something. Finally all of those blog posts and
disagreeing forums and contradictory articles will all become correct
about whatever they happened to recommend, and along with it, a whole
class of vulnerabilities eliminated.
With very minimal downside, we're finally in a position where we can
make this change.
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Guo Ren <guoren@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: David Laight <David.Laight@aculab.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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|
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tools fixes from Arnaldo Carvalho de Melo:
- Fix event parser error for hybrid systems
- Fix NULL check against wrong variable in 'perf bench' and in the
parsing code
- Update arm64 KVM headers from the kernel sources
- Sync cpufeatures header with the kernel sources
* tag 'perf-tools-fixes-for-v5.17-2022-03-12' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
perf parse: Fix event parser error for hybrid systems
perf bench: Fix NULL check against wrong variable
perf parse-events: Fix NULL check against wrong variable
tools headers cpufeatures: Sync with the kernel sources
tools kvm headers arm64: Update KVM headers from the kernel sources
|
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Pull drm kconfig fix from Dave Airlie:
"Thorsten pointed out this had fallen down the cracks and was in -next
only, I've picked it out, fixed up it's Fixes: line.
- fix regression in Kconfig"
* tag 'drm-fixes-2022-03-12' of git://anongit.freedesktop.org/drm/drm:
drm/panel: Select DRM_DP_HELPER for DRM_PANEL_EDP
|
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The register tracking infrastructure is incomplete, it might lead to
generating incorrect ruleset bytecode, disable it by now given we are
late in the release process.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
|
|
This bug happened on hybrid systems when both cpu_core and cpu_atom
have the same event name such as "UOPS_RETIRED.MS" while their event
terms are different, then during perf stat, the event for cpu_atom
will parse fail and then no output for cpu_atom.
UOPS_RETIRED.MS -> cpu_core/period=0x1e8483,umask=0x4,event=0xc2,frontend=0x8/
UOPS_RETIRED.MS -> cpu_atom/period=0x1e8483,umask=0x1,event=0xc2/
It is because event terms in the "head" of parse_events_multi_pmu_add
will be changed to event terms for cpu_core after parsing UOPS_RETIRED.MS
for cpu_core, then when parsing the same event for cpu_atom, it still
uses the event terms for cpu_core, but event terms for cpu_atom are
different with cpu_core, the event parses for cpu_atom will fail. This
patch fixes it, the event terms should be parsed from the original
event.
This patch can work for the hybrid systems that have the same event
in more than 2 PMUs. It also can work in non-hybrid systems.
Before:
# perf stat -v -e UOPS_RETIRED.MS -a sleep 1
Using CPUID GenuineIntel-6-97-1
UOPS_RETIRED.MS -> cpu_core/period=0x1e8483,umask=0x4,event=0xc2,frontend=0x8/
Control descriptor is not initialized
UOPS_RETIRED.MS: 2737845 16068518485 16068518485
Performance counter stats for 'system wide':
2,737,845 cpu_core/UOPS_RETIRED.MS/
1.002553850 seconds time elapsed
After:
# perf stat -v -e UOPS_RETIRED.MS -a sleep 1
Using CPUID GenuineIntel-6-97-1
UOPS_RETIRED.MS -> cpu_core/period=0x1e8483,umask=0x4,event=0xc2,frontend=0x8/
UOPS_RETIRED.MS -> cpu_atom/period=0x1e8483,umask=0x1,event=0xc2/
Control descriptor is not initialized
UOPS_RETIRED.MS: 1977555 16076950711 16076950711
UOPS_RETIRED.MS: 568684 8038694234 8038694234
Performance counter stats for 'system wide':
1,977,555 cpu_core/UOPS_RETIRED.MS/
568,684 cpu_atom/UOPS_RETIRED.MS/
1.004758259 seconds time elapsed
Fixes: fb0811535e92c6c1 ("perf parse-events: Allow config on kernel PMU events")
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220307151627.30049-1-zhengjun.xing@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
MMAP records that occur after the build-id header is parsed do not have
their build-id set even if the filename matches an entry from the
header. Set the build-id on these dsos as long as the MMAP record
doesn't have its own build-id set.
This fixes an issue with off target analysis where the local version of
a dso is loaded rather than one from ~/.debug via a build-id.
Reported-by: Denis Nikitin <denik@chromium.org>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20220304090956.2048712-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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|
The same three lines also appear a bit earlier in the same file.
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20211015083144.2767725-1-linux@rasmusvillemoes.dk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Julia and the kernel test robot report that the prep handling for this
command inadvertently checks one field twice:
fs/io_uring.c:4338:42-56: duplicated argument to && or ||
Get rid of it.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Fixes: 4f57f06ce218 ("io_uring: add support for IORING_OP_MSG_RING command")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
We did a NULL check after "epollfdp = calloc(...)", but we checked
"epollfd" instead of "epollfdp".
Signed-off-by: Weiguo Li <liwg06@foxmail.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/tencent_B5D64530EB9C7DBB8D2C88A0C790F1489D0A@qq.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|