commit bc8a76a152c5f9ef3b48104154a65a68a8b76946 upstream.

[ Fixes: CVE-2019-14615 ]

Intel ID: PSIRT-TA-201910-001
CVEID: CVE-2019-14615

Intel GPU Hardware prior to Gen11 does not clear EU state
during a context switch. This can result in information
leakage between contexts.

For Gen8 and Gen9, hardware provides a mechanism for
fast cleardown of the EU state, by issuing a PIPE_CONTROL
with bit 27 set. We can use this in a context batch buffer
to explicitly cleardown the state on every context switch.

As this workaround is already in place for gen8, we can borrow
the code verbatim for Gen9.
Signed-off-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NAkeem G Abodunrin <akeem.g.abodunrin@intel.com>
Cc: Kumar Valsan Prathap <prathap.kumar.valsan@intel.com>
Cc: Chris Wilson <chris.p.wilson@intel.com>
Cc: Balestrieri Francesco <francesco.balestrieri@intel.com>
Cc: Bloomfield Jon <jon.bloomfield@intel.com>
Cc: Dutt Sudeep <sudeep.dutt@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 4a9d46a9fe14401f21df69cea97c62396d5fb053 upstream.

[ Fixes: CVE-2019-19077 ]

In bnxt_re_create_srq(), when ib_copy_to_udata() fails allocated memory
should be released by goto fail.

Fixes: 37cb11ac ("RDMA/bnxt_re: Add SRQ support for Broadcom adapters")
Link: https://lore.kernel.org/r/20190910222120.16517-1-navid.emamdoost@gmail.comSigned-off-by: NNavid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 4aa7afb0ee20a97fbf0c5bab3df028d5fb85fdab upstream.

[ Fixes: CVE-2019-19046 ]

In the impelementation of __ipmi_bmc_register() the allocated memory for
bmc should be released in case ida_simple_get() fails.

Fixes: 68e7e50f ("ipmi: Don't use BMC product/dev ids in the BMC name")
Signed-off-by: NNavid Emamdoost <navid.emamdoost@gmail.com>
Message-Id: <20191021200649.1511-1-navid.emamdoost@gmail.com>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 07e6124a1a46b4b5a9b3cacc0c306b50da87abf5 upstream.

[ Fixes: CVE-2020-8648 ]

syzkaller reported this UAF:
BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741
Read of size 1 at addr ffff8880089e40e9 by task syz-executor.1/13184

CPU: 0 PID: 13184 Comm: syz-executor.1 Not tainted 5.4.7 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
...
 kasan_report+0xe/0x20 mm/kasan/common.c:634
 n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741
 tty_ldisc_receive_buf+0xac/0x190 drivers/tty/tty_buffer.c:461
 paste_selection+0x297/0x400 drivers/tty/vt/selection.c:372
 tioclinux+0x20d/0x4e0 drivers/tty/vt/vt.c:3044
 vt_ioctl+0x1bcf/0x28d0 drivers/tty/vt/vt_ioctl.c:364
 tty_ioctl+0x525/0x15a0 drivers/tty/tty_io.c:2657
 vfs_ioctl fs/ioctl.c:47 [inline]

It is due to a race between parallel paste_selection (TIOCL_PASTESEL)
and set_selection_user (TIOCL_SETSEL) invocations. One uses sel_buffer,
while the other frees it and reallocates a new one for another
selection. Add a mutex to close this race.

The mutex takes care properly of sel_buffer and sel_buffer_lth only. The
other selection global variables (like sel_start, sel_end, and sel_cons)
are protected only in set_selection_user. The other functions need quite
some more work to close the races of the variables there. This is going
to happen later.

This likely fixes (I am unsure as there is no reproducer provided) bug
206361 too. It was marked as CVE-2020-8648.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Reported-by: syzbot+59997e8d5cbdc486e6f6@syzkaller.appspotmail.com
References: https://bugzilla.kernel.org/show_bug.cgi?id=206361
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200210081131.23572-2-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 513dc792d6060d5ef572e43852683097a8420f56 upstream.

[ Fixes: CVE-2020-8647, CVE-2020-8649 ]

When syzkaller tests, there is a UAF:
  BUG: KASan: use after free in vgacon_invert_region+0x9d/0x110 at addr
    ffff880000100000
  Read of size 2 by task syz-executor.1/16489
  page:ffffea0000004000 count:0 mapcount:-127 mapping:          (null)
  index:0x0
  page flags: 0xfffff00000000()
  page dumped because: kasan: bad access detected
  CPU: 1 PID: 16489 Comm: syz-executor.1 Not tainted
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    [<ffffffffb119f309>] dump_stack+0x1e/0x20
    [<ffffffffb04af957>] kasan_report+0x577/0x950
    [<ffffffffb04ae652>] __asan_load2+0x62/0x80
    [<ffffffffb090f26d>] vgacon_invert_region+0x9d/0x110
    [<ffffffffb0a39d95>] invert_screen+0xe5/0x470
    [<ffffffffb0a21dcb>] set_selection+0x44b/0x12f0
    [<ffffffffb0a3bfae>] tioclinux+0xee/0x490
    [<ffffffffb0a1d114>] vt_ioctl+0xff4/0x2670
    [<ffffffffb0a0089a>] tty_ioctl+0x46a/0x1a10
    [<ffffffffb052db3d>] do_vfs_ioctl+0x5bd/0xc40
    [<ffffffffb052e2f2>] SyS_ioctl+0x132/0x170
    [<ffffffffb11c9b1b>] system_call_fastpath+0x22/0x27
    Memory state around the buggy address:
     ffff8800000fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00
     ffff8800000fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00 00
    >ffff880000100000: ff ff ff ff ff ff ff ff ff ff ff ff ff
     ff ff ff

It can be reproduce in the linux mainline by the program:
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/ioctl.h>
  #include <linux/vt.h>

  struct tiocl_selection {
    unsigned short xs;      /* X start */
    unsigned short ys;      /* Y start */
    unsigned short xe;      /* X end */
    unsigned short ye;      /* Y end */
    unsigned short sel_mode; /* selection mode */
  };

  #define TIOCL_SETSEL    2
  struct tiocl {
    unsigned char type;
    unsigned char pad;
    struct tiocl_selection sel;
  };

  int main()
  {
    int fd = 0;
    const char *dev = "/dev/char/4:1";

    struct vt_consize v = {0};
    struct tiocl tioc = {0};

    fd = open(dev, O_RDWR, 0);

    v.v_rows = 3346;
    ioctl(fd, VT_RESIZEX, &v);

    tioc.type = TIOCL_SETSEL;
    ioctl(fd, TIOCLINUX, &tioc);

    return 0;
  }

When resize the screen, update the 'vc->vc_size_row' to the new_row_size,
but when 'set_origin' in 'vgacon_set_origin', vgacon use 'vga_vram_base'
for 'vc_origin' and 'vc_visible_origin', not 'vc_screenbuf'. It maybe
smaller than 'vc_screenbuf'. When TIOCLINUX, use the new_row_size to calc
the offset, it maybe larger than the vga_vram_size in vgacon driver, then
bad access.
Also, if set an larger screenbuf firstly, then set an more larger
screenbuf, when copy old_origin to new_origin, a bad access may happen.

So, If the screen size larger than vga_vram, resize screen should be
failed. This alse fix CVE-2020-8649 and CVE-2020-8647.

Linus pointed out that overflow checking seems absent. We're saved by
the existing bounds checks in vc_do_resize() with rather strict
limits:

	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
		return -EINVAL;

Fixes: 0aec4867 ("[PATCH] SVGATextMode fix")
Reference: CVE-2020-8647 and CVE-2020-8649
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
[danvet: augment commit message to point out overflow safety]
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304022429.37738-1-zhangxiaoxu5@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit d0cb50185ae942b03c4327be322055d622dc79f6 upstream.

[ Fixes: CVE-2020-8428 ]

may_create_in_sticky() call is done when we already have dropped the
reference to dir.

Fixes: 30aba665 (namei: allow restricted O_CREAT of FIFOs and regular files)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

commit 8c6de56a42e0c657955e12b882a81ef07d1d073e upstream.

[ Fixes: CVE-2019-3016 ]

kvm_steal_time_set_preempted() may accidentally clear KVM_VCPU_FLUSH_TLB
bit if it is called more than once while VCPU is preempted.

This is part of CVE-2019-3016.

(This bug was also independently discovered by Jim Mattson
<jmattson@google.com>)
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: NJoao Martins <joao.m.martins@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 35a571346a94fb93b5b3b6a599675ef3384bc75c upstream.

[ Fixes: CVE-2020-2732 ]

Consult the 'unconditional IO exiting' and 'use IO bitmaps' VM-execution
controls when checking instruction interception. If the 'use IO bitmaps'
VM-execution control is 1, check the instruction access against the IO
bitmaps to determine if the instruction causes a VM-exit.
Signed-off-by: NOliver Upton <oupton@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit e71237d3ff1abf9f3388337cfebf53b96df2020d upstream.

[ Fixes: CVE-2020-2732 ]

Checks against the IO bitmap are useful for both instruction emulation
and VM-exit reflection. Refactor the IO bitmap checks into a helper
function.
Signed-off-by: NOliver Upton <oupton@google.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 07721feee46b4b248402133228235318199b05ec upstream.

[ Fixes: CVE-2020-2732 ]

vmx_check_intercept is not yet fully implemented. To avoid emulating
instructions disallowed by the L1 hypervisor, refuse to emulate
instructions by default.

Cc: stable@vger.kernel.org
[Made commit, added commit msg - Oliver]
Signed-off-by: NOliver Upton <oupton@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 07447453db3aebb6a0917592f411a7122d12a8b9 upstream linux-next.

When 'CONFIG_DEFERRED_STRUCT_PAGE_INIT' is set, 'pgdatinit' kthread will
initialise the deferred pages with local interrupts disabled. It is
introduced by commit 3a2d7fa8 ("mm: disable interrupts while
initializing deferred pages").

On machine with NCPUS <= 2, the 'pgdatinit' kthread could be bound to
the boot CPU, which could caused the tick timer long time stall, system
jiffies not be updated in time.

The dmesg shown that:

    [    0.197975] node 0 initialised, 32170688 pages in 1ms

Obviously, 1ms is unreasonable.

Now, fix it by restore in the pending interrupts for every 32*1204 pages
(128MB) initialized, give the chance to update the systemd jiffies.
The reasonable demsg shown likes:

    [    1.069306] node 0 initialised, 32203456 pages in 894ms

Link: http://lkml.kernel.org/r/20200311123848.118638-1-shile.zhang@linux.alibaba.com
Fixes: 3a2d7fa8 ("mm: disable interrupts while initializing deferred pages")
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Co-developed-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

This exports the workingset counters, i.e., workingset_refault,
workingset_activate, workingset_restore, and workingset_nodereclaim, to
memory cgroup v1.

The stat collection of these counters is shared between memory cgroup v1
and v2.  What this patch does is just to export them on memory cgroup v1.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit e7a5f1f1cd0008e5ad379270a8657e121eedb669 upstream

Right now in tcp_bpf_recvmsg, sock read data first from sk_receive_queue
if not empty than psock->ingress_msg otherwise. If a FIN packet arrives
and there's also some data in psock->ingress_msg, the data in
psock->ingress_msg will be purged. It is always happen when request to a
HTTP1.0 server like python SimpleHTTPServer since the server send FIN
packet after data is sent out.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: NArika Chen <eaglesora@gmail.com>
Suggested-by: NArika Chen <eaglesora@gmail.com>
Signed-off-by: NLingpeng Chen <forrest0579@gmail.com>
Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200109014833.18951-1-forrest0579@gmail.com
[tonylu: patched modified to match BIG rework between v4.19 and upstream]
Signed-off-by: NTony Lu <tonylu@linux.alibaba.com>
Acked-by: NDust Li <dust.li@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

It enables SRIOV of PCIe devices of Alibaba MOC,
then VFs can be used by other host or VM above on the host.
Signed-off-by: Nliushanghui <liushanghui@linux.alibaba.com>
Reviewed-by: Nluanshi <zhangliguang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

Explicitly abort mem_cgroup_select_bad_process in priority oom if there
is already a task as oom victim without MMF_OOM_SKIP flag set.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>

Since commit e0205ae40f12 ("mm: memcontrol: use CSS_TASK_ITER_PROCS at
mem_cgroup_scan_tasks()") made mem_cgroup_scan_tasks() to check only one
thread from each thread group, we can make cgroup_subsys_state::nr_tasks
to record only the thread group leader, i.e., process, instead of
thread(s). Furthermore, this renames cgroup_subsys_state::nr_tasks to
cgroup_subsys_state::nr_procs.

Fixes: f061cd88 ("alinux: kernel: cgroup: account number of tasks in
the css and its descendants")
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit f168a9a54ec39b3f832c353733898b713b6b5c1f upstream.

Since commit c03cd7738a83 ("cgroup: Include dying leaders with live
threads in PROCS iterations") corrected how CSS_TASK_ITER_PROCS works,
mem_cgroup_scan_tasks() can use CSS_TASK_ITER_PROCS in order to check
only one thread from each thread group.

[penguin-kernel@I-love.SAKURA.ne.jp: remove thread group leader check in oom_evaluate_task()]
  Link: http://lkml.kernel.org/r/1560853257-14934-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Link: http://lkml.kernel.org/r/c763afc8-f0ae-756a-56a7-395f625b95fc@i-love.sakura.ne.jpSigned-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

Assuming that there is a memory cgroup tree as follows:

        A (use_priority_oom=1, limit=2.5G)
       / \
      /   C (priority=3, usage=1.5G)
     B (priority=0, usage=1G)

As task in C (task-c) invokes oom-killer, task in B (task-b) is chosen
and killed, and then task-c returns from mem_cgroup_oom and retries in
try_charge.

If memory page_counter of B has not been reset yet, leading to task-c
invokes oom-killer again, the soft lockup may happen. In this situation,
task-c keeps selecting bad process in B, while the only task-b in B has
already been set PF_EXITING flag, which makes task-b skipped in
css_task_iter_advance.

Finally, task-c selected no bad process in B and keeps retrying, and
task-b is stalled in synchronize_rcu when do_exit, exit_task_namespaces
specifically.

In a nutshell, the new behavior of css_task_iter_advance, i.e., commit
c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS
iterations"), causes priority oom to misbehave.

This fixes the soft lockup by accounting num_oom_skip of the victim
memcg and its parents (sift up to oc->memcg), if no bad process is
chosen from it.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 32b2244a840a90ea94ba42392de5c48d53f521f5 upstream linux-next

When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, applications don't need
to do io completion events polling again, they can rely on io_sq_thread to do
polling work, which can reduce cpu usage and uring_lock contention.

I modify fio io_uring engine codes a bit to evaluate the performance:
static int fio_ioring_getevents(struct thread_data *td, unsigned int min,
                        continue;
                }

-               if (!o->sqpoll_thread) {
+               if (o->sqpoll_thread && o->hipri) {
                        r = io_uring_enter(ld, 0, actual_min,
                                                IORING_ENTER_GETEVENTS);
                        if (r < 0) {

and use "fio  -name=fiotest -filename=/dev/nvme0n1 -iodepth=$depth -thread
-rw=read -ioengine=io_uring  -hipri=1 -sqthread_poll=1  -direct=1 -bs=4k
-size=10G -numjobs=1  -time_based -runtime=120"

original codes
--------------------------------------------------------------------
iodepth       |        4 |        8 |       16 |       32 |       64
bw            | 1133MB/s | 1519MB/s | 2090MB/s | 2710MB/s | 3012MB/s
fio cpu usage |     100% |     100% |     100% |     100% |     100%
--------------------------------------------------------------------

with patch
--------------------------------------------------------------------
iodepth       |        4 |        8 |       16 |       32 |       64
bw            | 1196MB/s | 1721MB/s | 2351MB/s | 2977MB/s | 3357MB/s
fio cpu usage |    63.8% |   74.4%% |    81.1% |    83.7% |    82.4%
--------------------------------------------------------------------
bw improve    |     5.5% |    13.2% |    12.3% |     9.8% |    11.5%
--------------------------------------------------------------------

From above test results, we can see that bw has above 5.5%~13%
improvement, and fio process's cpu usage also drops much. Note this
won't improve io_sq_thread's cpu usage when SETUP_IOPOLL|SETUP_SQPOLL
are both enabled, in this case, io_sq_thread always has 100% cpu usage.
I think this patch will be friendly to applications which will often use
io_uring_wait_cqe() or similar from liburing.
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

commit 3b7436cc9449d5ff7fa1c1fd5bc3edb6402ff5b8 upstream.

For super_90_load, we need to make sure 'desc_nr' less
than MD_SB_DISKS, avoiding invalid memory access of 'sb->disks'.

Fixes: 228fc7d76db6 ("md: avoid invalid memory access for array sb->dev_roles")
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 228fc7d76db68732677230a3c64337908fd298e3 upstream.

we need to gurantee 'desc_nr' valid before access array
of sb->dev_roles.

In addition, we should avoid .load_super always return '0'
when level is LEVEL_MULTIPATH, which is not expected.
Reported-by: Ncoverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1487373 ("Memory - illegal accesses")
Fixes: 6a5cb53aaa4e ("md: no longer compare spare disk superblock events in super_load")
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit 6a5cb53aaa4ef515ddeffa04ce18b771121127b4 upstream.

We have a test case as follow:

  mdadm -CR /dev/md1 -l 1 -n 4 /dev/sd[a-d] \
	--assume-clean --bitmap=internal
  mdadm -S /dev/md1
  mdadm -A /dev/md1 /dev/sd[b-c] --run --force

  mdadm --zero /dev/sda
  mdadm /dev/md1 -a /dev/sda

  echo offline > /sys/block/sdc/device/state
  echo offline > /sys/block/sdb/device/state
  sleep 5
  mdadm -S /dev/md1

  echo running > /sys/block/sdb/device/state
  echo running > /sys/block/sdc/device/state
  mdadm -A /dev/md1 /dev/sd[a-c] --run --force

When we readd /dev/sda to the array, it started to do recovery.
After offline the other two disks in md1, the recovery have
been interrupted and superblock update info cannot be written
to the offline disks. While the spare disk (/dev/sda) can continue
to update superblock info.

After stopping the array and assemble it, we found the array
run fail, with the follow kernel message:

[  172.986064] md: kicking non-fresh sdb from array!
[  173.004210] md: kicking non-fresh sdc from array!
[  173.022383] md/raid1:md1: active with 0 out of 4 mirrors
[  173.022406] md1: failed to create bitmap (-5)
[  173.023466] md: md1 stopped.

Since both sdb and sdc have the value of 'sb->events' smaller than
that in sda, they have been kicked from the array. However, the only
remained disk sda is in 'spare' state before stop and it cannot be
added to conf->mirrors[] array. In the end, raid array assemble
and run fail.

In fact, we can use the older disk sdb or sdc to assemble the array.
That means we should not choose the 'spare' disk as the fresh disk in
analyze_sbs().

To fix the problem, we do not compare superblock events when it is
a spare disk, as same as validate_super.
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit c42d3240990814eec1e4b2b93fa0487fc4873aed upstream.

Mdadm expects that setting drive as faulty will fail with -EBUSY only if
this operation will cause RAID to be failed. If this happens, it will
try to stop the array. Currently -EBUSY might also be returned if rdev
is in the middle of the removal process - for example there is a race
with mdmon that already requested the drive to be failed/removed.

If rdev does not contain mddev, return -ENODEV instead, so the caller
can distinguish between those two cases and behave accordingly.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NPawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

commit ee37d7314a32ab6809eacc3389bad0406c69a81f upstream.

[Symptom]

Resync thread hang when new added disk faulty during replacing.

[Root Cause]

In raid10_sync_request(), we expect to issue a bio with callback
end_sync_read(), and a bio with callback end_sync_write().

In normal situation, we will add resyncing sectors into
mddev->recovery_active when raid10_sync_request() returned, and sub
resynced sectors from mddev->recovery_active when end_sync_write()
calls end_sync_request().

If new added disk, which are replacing the old disk, is set faulty,
there is a race condition:
    1. In the first rcu protected section, resync thread did not detect
       that mreplace is set faulty and pass the condition.
    2. In the second rcu protected section, mreplace is set faulty.
    3. But, resync thread will prepare the read object first, and then
       check the write condition.
    4. It will find that mreplace is set faulty and do not have to
       prepare write object.
This cause we add resync sectors but never sub it.

[How to Reproduce]

This issue can be easily reproduced by the following steps:
    mdadm -C /dev/md0 --assume-clean -l 10 -n 4 /dev/sd[abcd]
    mdadm /dev/md0 -a /dev/sde
    mdadm /dev/md0 --replace /dev/sdd
    sleep 1
    mdadm /dev/md0 -f /dev/sde

[How to Fix]

This issue can be fixed by using local variables to record the result
of test conditions. Once the conditions are satisfied, we can make sure
that we need to issue a bio for read and a bio for write.

Previous 'commit 24afd80d ("md/raid10: handle recovery of
replacement devices.")' will also check whether bio is NULL, but leave
the comment saying that it is a pointless test. So we remove this dummy
check.
Reported-by: NAlex Chen <alexchen@synology.com>
Reviewed-by: NAllen Peng <allenpeng@synology.com>
Reviewed-by: NBingJing Chang <bingjingc@synology.com>
Signed-off-by: NAlex Wu <alexwu@synology.com>
Signed-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

The memcg background async page reclaim, a.k.a, memcg kswapd, is
implemented with a dedicated unbound workqueue currently.

However, memcg kswapd will run too frequently, resulting in high
overhead, page cache thrashing, frequent dirty page writeback, etc., due
to improper memcg memory.wmark_ratio, unreasonable memcg memor capacity,
or even abnormal memcg memory usage.

We need to find out the problematic memcg(s) where memcg kswapd
introduces significant overhead.

This records the latency of each run of memcg kswapd work, and then
aggregates into the exstat of per memcg.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 22782b3f9bb8ae21c710e2880db21bc729771e92 upstream

After commit 61cb5758d3c4 ("cpuidle: Add cpuidle.governor= command
line parameter") new cpuidle governors are not added to the list
of available governors, so governor selection via sysfs doesn't
work as expected (even though it is rarely used anyway).

Fix that by making cpuidle_register_governor() add new governors to
cpuidle_governors again.

Fixes: 61cb5758d3c4 ("cpuidle: Add cpuidle.governor= command line parameter")
Reported-by: NKees Cook <keescook@chromium.org>
Cc: 5.0+ <stable@vger.kernel.org> # 5.0+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NMichael Wang <yun.wang@linux.alibaba.com>

commit 2d5ba19bdfef4dd06add144eb04287ee98409f75 upstream

Add an MSRs which allows the guest to disable
host polling (specifically the cpuidle-haltpoll,
when performing polling in the guest, disables
host side polling).
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>
Acked-by: NMichael Wang <yun.wang@linux.alibaba.com>

commit ef2e78ddadbb939ce79553b10dee0131d65d8f3e upstream.

Just like we do for WFE trapping, it can be useful to turn off
WFI trapping when the physical CPU is not oversubscribed (that
is, the vcpu is the only runnable process on this CPU) *and*
that we're using direct injection of interrupts.

The conditions are reevaluated on each vcpu_load(), ensuring that
we don't switch to this mode on a busy system.

On a GICv4 system, this has the effect of reducing the generation
of doorbell interrupts to zero when the right conditions are
met, which is a huge improvement over the current situation
(where the doorbells are screaming if the CPU ever hits a
blocking WFI).
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NZenghui Yu <yuzenghui@huawei.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Link: https://lore.kernel.org/r/20191107160412.30301-3-maz@kernel.orgSigned-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 5bd90b0989731520f2cdcfbbe467f1271f3cc803 upstream.

In order to find out whether a vcpu is likely to be the target of
VLPIs (and to further optimize the way we deal with those), let's
track the number of VLPIs a vcpu can receive.

This gets implemented with an atomic variable that gets incremented
or decremented on map, unmap and move of a VLPI.
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NZenghui Yu <yuzenghui@huawei.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Link: https://lore.kernel.org/r/20191107160412.30301-2-maz@kernel.orgSigned-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 8e01d9a396e6db153d94a6004e6473d9ff251a6a upstream.

When the VHE code was reworked, a lot of the vgic stuff was moved around,
but the GICv4 residency code did stay untouched, meaning that we come
in and out of residency on each flush/sync, which is obviously suboptimal.

To address this, let's move things around a bit:

- Residency entry (flush) moves to vcpu_load
- Residency exit (sync) moves to vcpu_put
- On blocking (entry to WFI), we "put"
- On unblocking (exit from WFI), we "load"

Because these can nest (load/block/put/load/unblock/put, for example),
we now have per-VPE tracking of the residency state.

Additionally, vgic_v4_put gains a "need doorbell" parameter, which only
gets set to true when blocking because of a WFI. This allows a finer
control of the doorbell, which now also gets disabled as soon as
it gets signaled.
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191027144234.8395-2-maz@kernel.orgSigned-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit e80634a75aba90e7485cd1fdb463fcac5d45f14d upstream

Skylake logs some additional useful information in per-channel
registers in addition the the architectural status/addr/misc
logged in the machine check bank.

Pick up this information and add it to the EDAC log:

	retry_rd_err_[five 32-bit register values]

Sorry, no definitions for these registers. OEMs and DIMM vendors
will be able to use them to isolate which cells in the DIMM are
causing problems.

	correrrcnt[per rank corrected error counts]

Note that if additional errors are logged while these registers are
being read, you may see a jumble of values some from earlier errors,
others from later errors (since the registers report the most recent
logged error). The correrrcnt registers provide error counts per possible
rank. If these counts only change by one since the previous error logged
for this channel, then it is safe to assume that the registers logged
provide a coherent view of one error.

With this change EDAC logs look like this:

EDAC MC4: 1 CE memory read error on CPU_SrcID#2_MC#0_Chan#1_DIMM#0 (channel:1 slot:0 page:0x8f26018 offset:0x0 grain:32 syndrome:0x0 -  err_code:0x0101:0x0091 socket:2 imc:0 rank:0 bg:0 ba:0 row:0x1f880 col:0x200 retry_rd_err_log[0001a209 00000000 00000001 04800001 0001f880] correrrcnt[0001 0000 0000 0000 0000 0000 0000 0000])
Acked-by: NAristeu Rozanski <aris@redhat.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: Nzhaobing <zhaobing@linux.alibaba.com>
Reviewed-by: Nluanshi <zhangliguang@linux.alibaba.com>

commit b1ba55cf1cfb9f3e0e00d743534684a25bf66d28 upstream

To pick the changes from:

  1a4e58cce84e ("mm: introduce MADV_PAGEOUT")
  9c276cc65a58 ("mm: introduce MADV_COLD")

That result in these changes in the tools:

  $ tools/perf/trace/beauty/madvise_behavior.sh > before
  $ cp include/uapi/asm-generic/mman-common.h tools/include/uapi/asm-generic/mman-common.h
  $ git diff
  diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
  index 63b1f506ea67..c160a5354eb6 100644
  --- a/tools/include/uapi/asm-generic/mman-common.h
  +++ b/tools/include/uapi/asm-generic/mman-common.h
  @@ -67,6 +67,9 @@
   #define MADV_WIPEONFORK 18             /* Zero memory on fork, child only */
   #define MADV_KEEPONFORK 19             /* Undo MADV_WIPEONFORK */

  +#define MADV_COLD      20              /* deactivate these pages */
  +#define MADV_PAGEOUT   21              /* reclaim these pages */
  +
   /* compatibility flags */
   #define MAP_FILE       0

  $ tools/perf/trace/beauty/madvise_behavior.sh > after
  $ diff -u before after
  --- before	2019-09-27 11:29:43.346320100 -0300
  +++ after	2019-09-27 11:30:03.838570439 -0300
  @@ -16,6 +16,8 @@
   	[17] = "DODUMP",
   	[18] = "WIPEONFORK",
   	[19] = "KEEPONFORK",
  +	[20] = "COLD",
  +	[21] = "PAGEOUT",
   	[100] = "HWPOISON",
   	[101] = "SOFT_OFFLINE",
   };
  $

I.e. now when madvise gets those behaviours as args, it will be able to
translate from the number to a human readable string.

This addresses the following perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/mman-common.h' differs from latest version at 'include/uapi/asm-generic/mman-common.h'
  diff -u tools/include/uapi/asm-generic/mman-common.h include/uapi/asm-generic/mman-common.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-n40y6c4sa49p29q6sl8w3ufx@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 82072962973008201b817fae1896512977dd5083 upstream

Recently, I hit the following issue when running upstream.

  kernel BUG at mm/vmscan.c:1521!
  invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 0 PID: 23385 Comm: syz-executor.6 Not tainted 5.4.0-rc4+ #1
  RIP: 0010:shrink_page_list+0x12b6/0x3530 mm/vmscan.c:1521
  Call Trace:
   reclaim_pages+0x499/0x800 mm/vmscan.c:2188
   madvise_cold_or_pageout_pte_range+0x58a/0x710 mm/madvise.c:453
   walk_pmd_range mm/pagewalk.c:53 [inline]
   walk_pud_range mm/pagewalk.c:112 [inline]
   walk_p4d_range mm/pagewalk.c:139 [inline]
   walk_pgd_range mm/pagewalk.c:166 [inline]
   __walk_page_range+0x45a/0xc20 mm/pagewalk.c:261
   walk_page_range+0x179/0x310 mm/pagewalk.c:349
   madvise_pageout_page_range mm/madvise.c:506 [inline]
   madvise_pageout+0x1f0/0x330 mm/madvise.c:542
   madvise_vma mm/madvise.c:931 [inline]
   __do_sys_madvise+0x7d2/0x1600 mm/madvise.c:1113
   do_syscall_64+0x9f/0x4c0 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

madvise_pageout() accesses the specified range of the vma and isolates
them, then runs shrink_page_list() to reclaim its memory.  But it also
isolates the unevictable pages to reclaim.  Hence, we can catch the
cases in shrink_page_list().

The root cause is that we scan the page tables instead of specific LRU
list.  and so we need to filter out the unevictable lru pages from our
end.

Link: http://lkml.kernel.org/r/1572616245-18946-1-git-send-email-zhongjiang@huawei.com
Fixes: 1a4e58cce84e ("mm: introduce MADV_PAGEOUT")
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit d616d5126503967bf365db0711ee3c78b356efe9 upstream

There are many common parts between MADV_COLD and MADV_PAGEOUT.
This patch factor them out to save code duplication.

Link: http://lkml.kernel.org/r/20190726023435.214162-6-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 1a4e58cce84ee88129d5d49c064bd2852b481357 upstream

When a process expects no accesses to a certain memory range for a long
time, it could hint kernel that the pages can be reclaimed instantly but
data should be preserved for future use.  This could reduce workingset
eviction so it ends up increasing performance.

This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall.
MADV_PAGEOUT can be used by a process to mark a memory range as not
expected to be used for a long time so that kernel reclaims *any LRU*
pages instantly.  The hint can help kernel in deciding which pages to
evict proactively.

A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit
intentionally because it's automatically bounded by PMD size.  If PMD
size(e.g., 256) makes some trouble, we could fix it later by limit it to
SWAP_CLUSTER_MAX[1].

- man-page material

MADV_PAGEOUT (since Linux x.x)

Do not expect access in the near future so pages in the specified
regions could be reclaimed instantly regardless of memory pressure.
Thus, access in the range after successful operation could cause
major page fault but never lose the up-to-date contents unlike
MADV_DONTNEED. Pages belonging to a shared mapping are only processed
if a write access is allowed for the calling process.

MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or
VM_PFNMAP pages.

[1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/

[minchan@kernel.org: clear PG_active on MADV_PAGEOUT]
  Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com
[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: Nkbuild test robot <lkp@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 9c276cc65a58faf98be8e56962745ec99ab87636 upstream

Patch series "Introduce MADV_COLD and MADV_PAGEOUT", v7.

- Background

The Android terminology used for forking a new process and starting an app
from scratch is a cold start, while resuming an existing app is a hot
start.  While we continually try to improve the performance of cold
starts, hot starts will always be significantly less power hungry as well
as faster so we are trying to make hot start more likely than cold start.

To increase hot start, Android userspace manages the order that apps
should be killed in a process called ActivityManagerService.
ActivityManagerService tracks every Android app or service that the user
could be interacting with at any time and translates that into a ranked
list for lmkd(low memory killer daemon).  They are likely to be killed by
lmkd if the system has to reclaim memory.  In that sense they are similar
to entries in any other cache.  Those apps are kept alive for
opportunistic performance improvements but those performance improvements
will vary based on the memory requirements of individual workloads.

- Problem

Naturally, cached apps were dominant consumers of memory on the system.
However, they were not significant consumers of swap even though they are
good candidate for swap.  Under investigation, swapping out only begins
once the low zone watermark is hit and kswapd wakes up, but the overall
allocation rate in the system might trip lmkd thresholds and cause a
cached process to be killed(we measured performance swapping out vs.
zapping the memory by killing a process.  Unsurprisingly, zapping is 10x
times faster even though we use zram which is much faster than real
storage) so kill from lmkd will often satisfy the high zone watermark,
resulting in very few pages actually being moved to swap.

- Approach

The approach we chose was to use a new interface to allow userspace to
proactively reclaim entire processes by leveraging platform information.
This allowed us to bypass the inaccuracy of the kernel’s LRUs for pages
that are known to be cold from userspace and to avoid races with lmkd by
reclaiming apps as soon as they entered the cached state.  Additionally,
it could provide many chances for platform to use much information to
optimize memory efficiency.

To achieve the goal, the patchset introduce two new options for madvise.
One is MADV_COLD which will deactivate activated pages and the other is
MADV_PAGEOUT which will reclaim private pages instantly.  These new
options complement MADV_DONTNEED and MADV_FREE by adding non-destructive
ways to gain some free memory space.  MADV_PAGEOUT is similar to
MADV_DONTNEED in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed immediately; MADV_COLD is similar
to MADV_FREE in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed when memory pressure rises.

This patch (of 5):

When a process expects no accesses to a certain memory range, it could
give a hint to kernel that the pages can be reclaimed when memory pressure
happens but data should be preserved for future use.  This could reduce
workingset eviction so it ends up increasing performance.

This patch introduces the new MADV_COLD hint to madvise(2) syscall.
MADV_COLD can be used by a process to mark a memory range as not expected
to be used in the near future.  The hint can help kernel in deciding which
pages to evict early during memory pressure.

It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves

	active file page -> inactive file LRU
	active anon page -> inacdtive anon LRU

Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file
LRU's head because MADV_COLD is a little bit different symantic.
MADV_FREE means it's okay to discard when the memory pressure because the
content of the page is *garbage* so freeing such pages is almost zero
overhead since we don't need to swap out and access afterward causes just
minor fault.  Thus, it would make sense to put those freeable pages in
inactive file LRU to compete other used-once pages.  It makes sense for
implmentaion point of view, too because it's not swapbacked memory any
longer until it would be re-dirtied.  Even, it could give a bonus to make
them be reclaimed on swapless system.  However, MADV_COLD doesn't mean
garbage so reclaiming them requires swap-out/in in the end so it's bigger
cost.  Since we have designed VM LRU aging based on cost-model, anonymous
cold pages would be better to position inactive anon's LRU list, not file
LRU.  Furthermore, it would help to avoid unnecessary scanning if system
doesn't have a swap device.  Let's start simpler way without adding
complexity at this moment.  However, keep in mind, too that it's a caveat
that workloads with a lot of pages cache are likely to ignore MADV_COLD on
anonymous memory because we rarely age anonymous LRU lists.

* man-page material

MADV_COLD (since Linux x.x)

Pages in the specified regions will be treated as less-recently-accessed
compared to pages in the system with similar access frequencies.  In
contrast to MADV_FREE, the contents of the region are preserved regardless
of subsequent writes to pages.

MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP
pages.

[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: Nkbuild test robot <lkp@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 8940b34a4e082ae11498ddae8432f2ac07685d1c upstream

The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
as default.  It is for preventing to reclaim dirty pages when CMA try to
migrate pages.  Strictly speaking, we don't need it because CMA didn't
allow to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.

Moreover, it has a problem to prevent anonymous pages's swap out even
though force_reclaim = true in shrink_page_list on upcoming patch.  So
this patch makes references's default value to PAGEREF_RECLAIM and rename
force_reclaim with ignore_references to make it more clear.

This is a preparatory work for next patch.

Link: http://lkml.kernel.org/r/20190726023435.214162-3-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 4541a8bb13a86e504416a13360c8dc64d2fd612a upstream

Laura reported that the perf build failed in fedora when we got a glibc
that provides gettid(), which I reproduced using fedora rawhide with the
glibc-devel-2.29.9000-26.fc31.x86_64 package.

Add a feature check to avoid providing a gettid() helper in such
systems.

On a fedora rawhide system with this patch applied we now get:

  [root@7a5f55352234 perf]# grep gettid /tmp/build/perf/FEATURE-DUMP
  feature-gettid=1
  [root@7a5f55352234 perf]# cat /tmp/build/perf/feature/test-gettid.make.output
  [root@7a5f55352234 perf]# ldd /tmp/build/perf/feature/test-gettid.bin
          linux-vdso.so.1 (0x00007ffc6b1f6000)
          libc.so.6 => /lib64/libc.so.6 (0x00007f04e0a74000)
          /lib64/ld-linux-x86-64.so.2 (0x00007f04e0c47000)
  [root@7a5f55352234 perf]# nm /tmp/build/perf/feature/test-gettid.bin | grep -w gettid
                   U gettid@@GLIBC_2.30
  [root@7a5f55352234 perf]#

While on a fedora:29 system:

  [acme@quaco perf]$ grep gettid /tmp/build/perf/FEATURE-DUMP
  feature-gettid=0
  [acme@quaco perf]$ cat /tmp/build/perf/feature/test-gettid.make.output
  test-gettid.c: In function ‘main’:
  test-gettid.c:8:9: error: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Werror=implicit-function-declaration]
    return gettid();
           ^~~~~~
           getgid
  cc1: all warnings being treated as errors
  [acme@quaco perf]$
Reported-by: NLaura Abbott <labbott@redhat.com>
Tested-by: NLaura Abbott <labbott@redhat.com>
Acked-by: NJiri Olsa &lt;jolsa@kernel.org&gt;Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lkml.kernel.org/n/tip-yfy3ch53agmklwu9o7rlgf9c@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Nluanshi <zhangliguang@linux.alibaba.com>
Reviewed-by: NAlex Shi <alex.shi@linux.alibaba.com>

For some workloads whose io activities are mostly random, context
readahead feature can introduce unnecessary io read operations, which
will impact app's performance. Context readahead's algorithm is
straightforward and not that smart.

This patch adds "/proc/sys/vm/enable_context_readahead" to control
whether to disable or enable this feature. Currently we enable context
readahead default, user can echo 0 to /proc/sys/vm/enable_context_readahead
to disable context readahead.

We also have tested mongodb's performance in 'random point select' case,
With context readahead enabled:
  mongodb eps 12409
With context readahead disabled:
  mongodb eps 14443
About 16% performance improvement.
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

Now hookers has been support in arm64, add the Kconfig depend for
arm64, otherwise it won't be built.
Signed-off-by: NZou Cao <zoucao@linux.alibaba.com>
Acked-by: NXunlei Pang <xlpang@linux.alibaba.com>