Update properties for newly added Airmont CPU variant.
Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Gayatri Kammela <gayatri.kammela@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190905193020.14707-5-tony.luck@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Add new Airmont variant CPU model to Intel family.
Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Gayatri Kammela <gayatri.kammela@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190905193020.14707-4-tony.luck@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Add the model number/CPUID of atom based Elkhart Lake to the Intel
family.
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190905193020.14707-3-tony.luck@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Add the model numbers/CPUIDs of Tiger Lake mobile and desktop to the
Intel family.
Suggested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190905193020.14707-2-tony.luck@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Correct spelling typos in comments in different files under arch/x86/.

 [ bp: Merge into a single patch, massage. ]
Signed-off-by: Marco Ammon <marco.ammon@fau.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: trivial@kernel.org
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190902102436.27396-1-marco.ammon@fau.de

Conflicts:
	tools/power/x86/turbostat/turbostat.c

Recent turbostat changes conflicted with a pending rename of x86 model names in tip:x86/cpu,
sort it out.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Fix the bogus detection of 32bit user mode for uretprobes which
     caused corruption of the user return address resulting in
     application crashes. In the uprobes handler in_ia32_syscall() is
     obviously always returning false on a 64bit kernel. Use
     user_64bit_mode() instead which works correctly.

   - Prevent large page splitting when ftrace flips RW/RO on the kernel
     text which caused iTLB performance issues. Ftrace wants to be
     converted to text_poke() which avoids the problem, but for now
     allow large page preservation in the static protections check when
     the change request spawns a full large page.

   - Prevent arch_dynirq_lower_bound() from returning 0 when the IOAPIC
     is configured via device tree. In the device tree case the GSI 1:1
     mapping is meaningless therefore the lower bound which protects the
     GSI range on ACPI machines is irrelevant. Return the lower bound
     which the core hands to the function instead of blindly returning 0
     which causes the core to allocate the invalid virtual interupt
     number 0 which in turn prevents all drivers from allocating and
     requesting an interrupt.

   - Remove the bogus initialization of LDR and DFR in the 32bit bigsmp
     APIC driver. That uses physical destination mode where LDR/DFR are
     ignored, but the initialization and the missing clear of LDR caused
     the APIC to be left in a inconsistent state on kexec/reboot.

   - Clear LDR when clearing the APIC registers so the APIC is in a well
     defined state.

   - Initialize variables proper in the find_trampoline_placement()
     code.

   - Silence GCC( build warning for the real mode part of the build"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/cpa: Prevent large page split when ftrace flips RW on kernel text
  x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning
  x86/boot/compressed/64: Fix missing initialization in find_trampoline_placement()
  x86/apic: Include the LDR when clearing out APIC registers
  x86/apic: Do not initialize LDR and DFR for bigsmp
  uprobes/x86: Fix detection of 32-bit user mode
  x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines

Pull perf fixes from Thomas Gleixner:
 "Two fixes for perf x86 hardware implementations:

   - Restrict the period on Nehalem machines to prevent perf from
     hogging the CPU

   - Prevent the AMD IBS driver from overwriting the hardwre controlled
     and pre-seeded reserved bits (0-6) in the count register which
     caused a sample bias for dispatched micro-ops"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/ibs: Fix sample bias for dispatched micro-ops
  perf/x86/intel: Restrict period on Nehalem

Pull turbostat updates from Len Brown:
 "User-space turbostat (and x86_energy_perf_policy) patches.

  They are primarily bug fixes from users"

* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools/power turbostat: update version number
  tools/power turbostat: Add support for Hygon Fam 18h (Dhyana) RAPL
  tools/power turbostat: Fix caller parameter of get_tdp_amd()
  tools/power turbostat: Fix CPU%C1 display value
  tools/power turbostat: do not enforce 1ms
  tools/power turbostat: read from pipes too
  tools/power turbostat: Add Ice Lake NNPI support
  tools/power turbostat: rename has_hsw_msrs()
  tools/power turbostat: Fix Haswell Core systems
  tools/power turbostat: add Jacobsville support
  tools/power turbostat: fix buffer overrun
  tools/power turbostat: fix file descriptor leaks
  tools/power turbostat: fix leak of file descriptor on error return path
  tools/power turbostat: Make interval calculation per thread to reduce jitter
  tools/power turbostat: remove duplicate pc10 column
  tools/power x86_energy_perf_policy: Fix argument parsing
  tools/power: Fix typo in man page
  tools/power/x86: Enable compiler optimisations and Fortify by default
  tools/power x86_energy_perf_policy: Fix "uninitialized variable" warnings at -O2

Today is 19.08.31, at least in some parts of the world.
Signed-off-by: Len Brown <len.brown@intel.com>

Commit 9392bd98 ("tools/power turbostat: Add support for AMD
Fam 17h (Zen) RAPL") and the commit 3316f99a ("tools/power
turbostat: Also read package power on AMD F17h (Zen)") add AMD Fam 17h
RAPL support.

Hygon Family 18h(Dhyana) support RAPL in bit 14 of CPUID 0x80000007 EDX,
and has MSRs RAPL_PWR_UNIT/CORE_ENERGY_STAT/PKG_ENERGY_STAT. So add Hygon
Dhyana Family 18h support for RAPL.

Already tested on Hygon multi-node systems and it shows correct per-core
energy usage and the total package power.
Signed-off-by: Pu Wen <puwen@hygon.cn>
Reviewed-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Len Brown <len.brown@intel.com>

Commit 9392bd98 ("tools/power turbostat: Add support for AMD
Fam 17h (Zen) RAPL") add a function get_tdp_amd(), the parameter is CPU
family. But the rapl_probe_amd() function use wrong model parameter.
Fix the wrong caller parameter of get_tdp_amd() to use family.

Cc: <stable@vger.kernel.org> # v5.1+
Signed-off-by: Pu Wen <puwen@hygon.cn>
Reviewed-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Len Brown <len.brown@intel.com>

In some case C1% will be wrong value, when platform doesn't have MSR for
C1 residency.

For example:
Core    CPU     CPU%c1
-       -       100.00
0       0       100.00
0       2       100.00
1       1       100.00
1       3       100.00

But adding Busy% will fix this
Core    CPU     Busy%   CPU%c1
-       -       99.77   0.23
0       0       99.77   0.23
0       2       99.77   0.23
1       1       99.77   0.23
1       3       99.77   0.23

This issue can be reproduced on most of the recent systems including
Broadwell, Skylake and later.

This is because if we don't select Busy% or Avg_MHz or Bzy_MHz then
mperf value will not be read from MSR, so it will be 0. But this
is required for C1% calculation when MSR for C1 residency is not present.
Same is true for C3, C6 and C7 column selection.

So add another define DO_BIC_READ(), which doesn't depend on user
column selection and use for mperf, C3, C6 and C7 related counters.
So when there is no platform support for C1 residency counters,
we still read these counters, if the CPU has support and user selected
display of CPU%c1.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Turbostat works by taking a snapshot of counters, sleeping, taking another
snapshot, calculating deltas, and printing out the table.

The sleep time is controlled via -i option or by user sending a signal or a
character to stdin. In the latter case, turbostat always adds 1 ms
sleep before it reads the counters, in order to avoid larger imprecisions
in the results in prints.

While the 1 ms delay may be a good idea for a "dumb" user, it is a
problem for an "aware" user. I do thousands and thousands of measurements
over a short period of time (like 2ms), and turbostat unconditionally adds
a 1ms to my interval, so I cannot get what I really need.

This patch removes the unconditional 1ms sleep. This is an expert user
tool, after all, and non-experts will unlikely ever use it in the non-fixed
interval mode anyway, so I think it is OK to remove the 1ms delay.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Commit '47936f94 tools/power turbostat: fix printing on input' make
a valid fix, but it completely disabled piped stdin support, which is
a valuable use-case. Indeed, if stdin is a pipe, turbostat won't read
anything from it, so it becomes impossible to get turbostat output at
user-defined moments, instead of the regular intervals.

There is no reason why this should works for terminals, but not for
pipes. This patch improves the situation. Instead of ignoring pipes, we
read data from them but gracefully handle the EOF case.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

This enables turbostat utility on Ice Lake NNPI SoC.

Link: https://lkml.org/lkml/2019/6/5/1034Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Perhaps if this more descriptive name had been used,
then we wouldn't have had the HSW ULT vs HSW CORE bug,
fixed by the previous commit.
Signed-off-by: Len Brown <len.brown@intel.com>

turbostat: cpu0: msr offset 0x630 read failed: Input/output error

because Haswell Core does not have C8-C10.

Output C8-C10 only on Haswell ULT.

Fixes: f5a4c76a ("tools/power turbostat: consolidate duplicate model numbers")
Reported-by: Prarit Bhargava <prarit@redhat.com>
Suggested-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Jacobsville behaves like Denverton.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

turbostat could be terminated by general protection fault on some latest
hardwares which (for example) support 9 levels of C-states and show 18
"tADDED" lines. That bloats the total output and finally causes buffer
overrun.  So let's extend the buffer to avoid this.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Fix file descriptor leaks by closing fp before return.

Addresses-Coverity-ID: 1444591 ("Resource leak")
Addresses-Coverity-ID: 1444592 ("Resource leak")
Fixes: 5ea7647b ("tools/power turbostat: Warn on bad ACPI LPIT data")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Currently the error return path does not close the file fp and leaks
a file descriptor. Fix this by closing the file.

Fixes: 5ea7647b ("tools/power turbostat: Warn on bad ACPI LPIT data")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Turbostat currently normalizes TSC and other values by dividing by an
interval. This interval is the delta between the start of one global
(all counters on all CPUs) sampling and the start of another. However,
this introduces a lot of jitter into the data.

In order to reduce jitter, the interval calculation should be based on
timestamps taken per thread and close to the start of the thread's
sampling.

Define a per thread time value to hold the delta between samples taken
on the thread.

Use the timestamp taken at the beginning of sampling to calculate the
delta.

Move the thread's beginning timestamp to after the CPU migration to
avoid jitter due to the migration.

Use the global time delta for the average time delta.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Remove the duplicate pc10 column.

Fixes: be0e54c4 ("turbostat: Build-in "Low Power Idle" counters support")
Reported-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Len Brown <len.brown@intel.com>

The -w argument in x86_energy_perf_policy currently triggers an
unconditional segfault.

This is because the argument string reads: "+a:c:dD:E:e:f:m:M:rt:u:vw" and
yet the argument handler expects an argument.

When parse_optarg_string is called with a null argument, we then proceed to
crash in strncmp, not horribly friendly.

The man page describes -w as taking an argument, the long form
(--hwp-window) is correctly marked as taking a required argument, and the
code expects it.

As such, this patch simply marks the short form (-w) as requiring an
argument.
Signed-off-by: Zephaniah E. Loss-Cutler-Hull <zephaniah@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

From context, we mean EPB (Enegry Performance Bias).
Signed-off-by: Matt Lupfer <mlupfer@ddn.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Compiling without optimisations is silly, especially since some
warnings depend on the optimiser.  Use -O2.

Fortify adds warnings for unchecked I/O (among other things), which
seems to be a good idea for user-space code.  Enable that too.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

x86_energy_perf_policy first uses __get_cpuid() to check the maximum
CPUID level and exits if it is too low.  It then assumes that later
calls will succeed (which I think is architecturally guaranteed).  It
also assumes that CPUID works at all (which is not guaranteed on
x86_32).

If optimisations are enabled, gcc warns about potentially
uninitialized variables.  Fix this by adding an exit-on-error after
every call to __get_cpuid() instead of just checking the maximum
level.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

Pull i2c fixes from Wolfram Sang:
 "I2C has a bunch of driver fixes and a core improvement to make the
  on-going API transition more robust"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mediatek: disable zero-length transfers for mt8183
  i2c: iproc: Stop advertising support of SMBUS quick cmd
  MAINTAINERS: i2c mv64xxx: Update documentation path
  i2c: piix4: Fix port selection for AMD Family 16h Model 30h
  i2c: designware: Synchronize IRQs when unregistering slave client
  i2c: i801: Avoid memory leak in check_acpi_smo88xx_device()
  i2c: make i2c_unregister_device() ERR_PTR safe

Pull tracing fixes from Steven Rostedt:
 "Small fixes and minor cleanups for tracing:

   - Make exported ftrace function not static

   - Fix NULL pointer dereference in reading probes as they are created

   - Fix NULL pointer dereference in k/uprobe clean up path

   - Various documentation fixes"

* tag 'trace-v5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Correct kdoc formats
  ftrace/x86: Remove mcount() declaration
  tracing/probe: Fix null pointer dereference
  tracing: Make exported ftrace_set_clr_event non-static
  ftrace: Check for successful allocation of hash
  ftrace: Check for empty hash and comment the race with registering probes
  ftrace: Fix NULL pointer dereference in t_probe_next()

Pull RISC-V fix from Paul Walmsley:
 "One significant fix for 32-bit RISC-V systems:

  Fix the RV32 memory map to prevent userspace from corrupting the
  FIXMAP area. Without this patch, the system can crash very early
  during the boot"

* tag 'riscv/for-v5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: Fix FIXMAP area corruption on RV32 systems

Pull KVM fixes from Radim Krčmář:
 "PPC:
   - Fix bug which could leave locks held in the host on return to a
     guest.

  x86:
   - Prevent infinitely looping emulation of a failing syscall while
     single stepping.

   - Do not crash the host when nesting is disabled"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Don't update RIP or do single-step on faulting emulation
  KVM: x86: hyper-v: don't crash on KVM_GET_SUPPORTED_HV_CPUID when kvm_intel.nested is disabled
  KVM: PPC: Book3S: Fix incorrect guest-to-user-translation error handling

Merge misc mm fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: memcontrol: fix percpu vmstats and vmevents flush
  mm, memcg: do not set reclaim_state on soft limit reclaim
  mailmap: add aliases for Dmitry Safonov
  mm/z3fold.c: fix lock/unlock imbalance in z3fold_page_isolate
  mm, memcg: partially revert "mm/memcontrol.c: keep local VM counters in sync with the hierarchical ones"
  mm/zsmalloc.c: fix build when CONFIG_COMPACTION=n
  mm: memcontrol: flush percpu slab vmstats on kmem offlining

Fix the following kdoc warnings:

kernel/trace/trace.c:1579: warning: Function parameter or member 'tr' not described in 'update_max_tr_single'
kernel/trace/trace.c:1579: warning: Function parameter or member 'tsk' not described in 'update_max_tr_single'
kernel/trace/trace.c:1579: warning: Function parameter or member 'cpu' not described in 'update_max_tr_single'
kernel/trace/trace.c:1776: warning: Function parameter or member 'type' not described in 'register_tracer'
kernel/trace/trace.c:2239: warning: Function parameter or member 'task' not described in 'tracing_record_taskinfo'
kernel/trace/trace.c:2239: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo'
kernel/trace/trace.c:2269: warning: Function parameter or member 'prev' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:2269: warning: Function parameter or member 'next' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:2269: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:3078: warning: Function parameter or member 'ip' not described in 'trace_vbprintk'
kernel/trace/trace.c:3078: warning: Function parameter or member 'fmt' not described in 'trace_vbprintk'
kernel/trace/trace.c:3078: warning: Function parameter or member 'args' not described in 'trace_vbprintk'

Link: http://lkml.kernel.org/r/20190828052549.2472-2-jakub.kicinski@netronome.comSigned-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Commit 562e14f7 ("ftrace/x86: Remove mcount support") removed the
support for using mcount, so we could remove the mcount() declaration
to clean up.

Link: http://lkml.kernel.org/r/20190826170150.10f101ba@xhacker.debianSigned-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

BUG: KASAN: null-ptr-deref in trace_probe_cleanup+0x8d/0xd0
Read of size 8 at addr 0000000000000000 by task syz-executor.0/9746
trace_probe_cleanup+0x8d/0xd0
free_trace_kprobe.part.14+0x15/0x50
alloc_trace_kprobe+0x23e/0x250

Link: http://lkml.kernel.org/r/1565220563-980-1-git-send-email-danielliu861@gmail.com

Fixes: e3dc9f89 ("tracing/probe: Add trace_event_call accesses APIs")
Signed-off-by: Xinpeng Liu <danielliu861@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The function ftrace_set_clr_event is declared static and marked
EXPORT_SYMBOL_GPL(), which is at best an odd combination. Because the
function was decided to be a part of API, this commit removes the static
attribute and adds the declaration to the header.

Link: http://lkml.kernel.org/r/20190704172110.27041-1-efremov@linux.com

Fixes: f45d1225 ("tracing: Kernel access to Ftrace instances")
Reviewed-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Pull crypto fix from Herbert Xu:
 "Fix a potential crash in the ccp driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: ccp - Ignore unconfigured CCP device on suspend/resume

Commit dfe2a77f ("kfifo: fix kfifo_alloc() and kfifo_init()") made
the kfifo code round the number of elements up.  That was good for
__kfifo_alloc(), but it's actually wrong for __kfifo_init().

The difference? __kfifo_alloc() will allocate the rounded-up number of
elements, but __kfifo_init() uses an allocation done by the caller.  We
can't just say "use more elements than the caller allocated", and have
to round down.

The good news? All the normal cases will be using power-of-two arrays
anyway, and most users of kfifo's don't use kfifo_init() at all, but one
of the helper macros to declare a KFIFO that enforce the proper
power-of-two behavior.  But it looks like at least ibmvscsis might be
affected.

The bad news? Will Deacon refers to an old thread and points points out
that the memory ordering in kfifo's is questionable.  See

  https://lore.kernel.org/lkml/20181211034032.32338-1-yuleixzhang@tencent.com/

for more.

Fixes: dfe2a77f ("kfifo: fix kfifo_alloc() and kfifo_init()")
Reported-by: laokz <laokz@foxmail.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>