mm: prevent a warning when casting void* -> enum

I recently build the RISC-V port with LLVM trunk, which has introduced a
new warning when casting from a pointer to an enum of a smaller size.
This patch simply casts to a long in the middle to stop the warning.  I'd
be surprised this is the only one in the kernel, but it's the only one I
saw.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200227211741.83165-1-palmer@dabbelt.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I91f127e3111aad48cbdfd2e63ab90f88047ddfca

defconfig: exynos9610: Re-add dropped Wi-Fi AP options lost
 in R rebase

* Not sure why Motorola removed these but there's 0 hope of
  Wi-Fi AP working without them.
* Note: Motorola stock doesn't have these, oddly.

Change-Id: I545153e75b55bd94fe44f9f318746bed1a2cbb38

drivers: regulator: fix leading whitespace warning

Change-Id: I2d914aee0464a4edd531164908e5c0e611437658

drivers: net: wireless: scsc: don't delete or deactivate AP
 interface in slsi_del_station

* This function is meant for cleaning up going from STA to AP mode
* On latest 18.1 builds deleting/deactivating AP interface causes
  hotspot not to work, hostapd starts up and system says hotspot
  is on, but due to a kernel error (vif type isn't set to AP anymore)
  SSID isn't actually broadcasted and clients can't find nor connect
  to the hotspot
* So let's remove this as removing it doesn't seem to have any
  negative consequences but fixes hotspot, also disable an
  ugly warning caused by this which isn't actually a problem

Change-Id: I5a656fd38697b9be09ecdc5f344bc343458aeaaf

ARM64: configs: kane/troika: disable {ex,v}fat

 * we have sdfat instead

Change-Id: I9e265238f32dace3cd3658c642769c12d5617250

fs: sdfat: Add MODULE_ALIAS_FS for supported filesystems

* This is the proper thing to do for filesystem drivers

Change-Id: I109b201d85e324cc0a72c3fcd09df4a3e1703042
Signed-off-by: Paul Keith <javelinanddart@gmail.com>

fs: sdfat: Add config option to register sdFAT for VFAT

Change-Id: I72ba7a14b56175535884390e8601960b5d8ed1cf
Signed-off-by: Paul Keith <javelinanddart@gmail.com>

fs: sdfat: Add config option to register sdFAT for exFAT

Change-Id: Id57abf0a4bd0b433fecc622eecb383cd4ea29d17
Signed-off-by: Paul Keith <javelinanddart@gmail.com>

fs: Import sdFAT version 2.4.5

From Samsung package version T725XXU2DUD1.

Change-Id: I4e8c3317e03edc44d6ac4248231067da8c4f3873

kbuild: add dtc as dependency on .dtb files

If dtc is rebuilt, we should rebuild .dtb files with the new dtc.

Change-Id: I313ee55506628c0922161541adf293735cb4edae
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>

scripts: Silence all dtc warnings seen with Samsung DTS

It is insane to fix them all, so just ignore.

If needed, can be re-enabled by building with 'W=1'.

Change-Id: Ic56bc08b255342fc19f5872463552be13375cceb

power: supply: s2mu00x: export {CURRENT/VOLTAGE}_MAX to sysfs

Change-Id: I54c775bb80c2151bdc69ea9fb53a48a34327bbef

kane/troika: disable CONFIG_SCSC_LOG_COLLECTION

 * causes random kernel crashes

Change-Id: I5348c4dfba02b1fabb65e124b32f850b8138c197

wireless: scsc: fix CONFIG_SCSC_LOG_COLLECTION ifdefs

Change-Id: I280d122ffa74a201027bcab61208bf6f5a568d89

media: radio: s610: fix indentation warning

input: touchscreen: nt36xxx: fix snprintf warning

Fixes the following clang warning:

../drivers/input/touchscreen/nt36xxx/nt36xxx_mp_ctrlram.c:1293:3: error: 'snprintf' size argument is too large; destination buffer has size 32, $
                snprintf(mpcriteria, PAGE_SIZE, "novatek-mp-criteria-%04X", ts->nvt_pid);
                ^
1 error generated.

Change-Id: Ieb3331a226cb6e183aaac2f22e7e8dccf27af7fc
Signed-off-by: Khusika Dhamar Gusti <mail@khusika.com>

exynos9609: do not mount oem partition

Change-Id: I98ea0ff45d6c3bd300439d93687c98c6deeab2e0

add toggle for disabling newly added USB devices

Based on the public grsecurity patches.

Change-Id: I2cbea91b351cda7d098f4e1aa73dff1acbd23cce
Signed-off-by: Daniel Micay <danielmicay@gmail.com>

kane/troika: disable CONFIG_SCSC_WLAN_KEY_MGMT_OFFLOAD

 * our wpa_supplicant has no support for this

arm64: Add 32-bit sigcontext definition to uapi signcontext.h

The arm64 uapi sigcontext.h can be included by 32-bit userspace
modules.  Since arm and arm64 sigcontext definition are not
compatible, add arm sigcontext definition to arm64 sigcontext.h.

Change-Id: I94109b094f6c8376fdaeb2822d7b26d18ddfb2bc
Signed-off-by: David Ng <dave@codeaurora.org>

gud: fix mobicore initialization

* backported from s9

Change-Id: I48476e899495490ded64a9e173e3daa3c4cdafa0

Android: Add empty Android.mk file

* This prevents inclusion of drivers/staging/greybus/tools/Android.mk
  which will conflict in case we have more than 1 kernel tree in AOSP
  source dir.

Change-Id: I335bca7b6d6463b1ffc673ab5367603347516e13

drivers: soc: cal-if: create new macro to handle NULL return

some of the func have NULL's which will return the size of the pointer instead which is ((void*) 0), because of that we need to make a new macro to set it to 0

Signed-off-by: Michael Benedict <michaelbt@live.com>
Change-Id: I3ab61542330c7b13cd165dfb48d453cff005884d

fimc-is2: fix sizeof pointer use

Change-Id: Ie53e42ab4527647e4435449b738a6b869508160f

sound: soc: codecs: cs35l41: fix variable declaration

Change-Id: Ief5c96b73b59670c71025b879776a50b9b435d38

fimc-is2: fix variable declarations

Change-Id: I99a5c03664346d74fc4fe93278121c52cbe3289c

remove libdss from Makefile

 * what is this even doing?

kane/troika: enable last_kmsg

add kane defconfig

add troika defconfig

implement samsung last_kmsg

tracing: do not leak kernel addresses

This likely breaks tracing tools like trace-cmd.  It logs in the same
format but now addresses are all 0x0.

Bug: 34277115
MOT-CRs-fixed: (CR)

Change-Id: Ifb0d4d2a184bf0d95726de05b1acee0287a375d9
Reviewed-on: https://gerrit.mot.com/1887836
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

arm/config: support for hid-nintendo driver

CTS will test this device so we should enable it in the
kernel config
CTS cases:
run cts -m CtsHardwareTestCases -t
android.hardware.input.cts.tests.NintendoSwitchProTest#testAllKeys
android.hardware.input.cts.tests.NintendoSwitchProTest#testAllMotions

Change-Id: I4c0f9dcb468fbfa629ae82b984ff55dc170a1acc
Signed-off-by: sunyue5 <sunyue5@motorola.com>
Reviewed-on: https://gerrit.mot.com/1839437
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

arm64/defconfig: Disable CONFIG_SCSC_WLAN_WIFI_SHARING

SCSC_WLAN_WIFI_SHARING is to enable APSTA function which means
the device can start wifi hotspot with wifi station enabled.
In this case, wlan1 will be for the AP mode while wlan0 will be
for the STA mode.
Disable this function since we have disabled it in the frameworks

Change-Id: Icd0d10badec991b3235735c0e53de3214368ba87
Signed-off-by: sunyue5 <sunyue5@motorola.com>
Reviewed-on: https://gerrit.mot.com/1825115
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

enable blkio for exynos9610

IO cgroup should be enabled to restrict background IO R/W.

Change-Id: I4736eb38d208a23afb183c27a5d90296e79e5f39
Reviewed-on: https://gerrit.mot.com/1812665
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Guolin Wang <wanggl3@mt.com>
Submit-Approved: Jira Key

arm64/defconfig: sync Q defconfig

1. sync kane defconfig change
2. pick wifi change
RAMEN9610-21775]wlbt: Enable Wifi Configurations in Defconfig.
Enable Wifi Configurations in Defconfi

Change-Id: Iea3d6c430f6b3a039c7124b5fa2a331c15bad27c
Signed-off-by: zhaoxp3 <zhaoxp3@motorola.com>

UPSTREAM: signal: don't silently convert SI_USER signals to non-current pidfd

The current sys_pidfd_send_signal() silently turns signals with explicit
SI_USER context that are sent to non-current tasks into signals with
kernel-generated siGinfo.
This is unlike do_rt_sigqueueinfo(), which returns -EPERM in this case.
If a user actually wants to send a signal with kernel-provided siGinfo,
they can do that with pidfd_send_signal(pidfd, sig, NULL, 0); so allowing
this case is unnecessary.

Instead of silently replacing the siGinfo, just bail out with an error;
this is consistent with other interfaces and avoids special-casing behavior
based on security checks.

Fixes: 3eb39f47934f ("signal: add pidfd_send_signal() syscall")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Christian Brauner <christian@brauner.io>
(cherry picked from commit 556a888a14afe27164191955618990fb3ccc9aad)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_pidfd_send_signal,..) to send SIGKILL
Change-Id: I493af671b82c43bff1425ee24550d2fb9aa6d961
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505848
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796156
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

UPSTREAM: pidfd: add polling support

This patch adds polling support to pidfd.

Android low memory killer (LMK) needs to know when a process dies once
it is sent the kill signal. It does so by checking for the existence of
/proc/pid which is both racy and slow. For example, if a PID is reused
between when LMK sends a kill signal and checks for existence of the
PID, since the wrong PID is now possibly checked for existence.
Using the polling support, LMK will be able to get notified when a process
exists in race-free and fast way, and allows the LMK to do other things
(such as by polling on other fds) while awaiting the process being killed
to die.

For notification to polling processes, we follow the same existing
mechanism in the kernel used when the parent of the task group is to be
notified of a child's death (do_notify_parent). This is precisely when the
tasks waiting on a poll of pidfd are also awakened in this patch.

We have decided to include the waitqueue in struct pid for the following
reasons:
1. The wait queue has to survive for the lifetime of the poll. Including
   it in task_struct would not be option in this case because the task can
   be reaped and destroyed before the poll returns.

2. By including the struct pid for the waitqueue means that during
   de_thread(), the new thread group leader automatically gets the new
   waitqueue/pid even though its task_struct is different.

Appropriate test cases are added in the second patch to provide coverage of
all the cases the patch is handling.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Jonathan Kowalski <bl0pbl33p@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: kernel-team@android.com
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Co-developed-by: Daniel Colascione <dancol@google.com>
Signed-off-by: Daniel Colascione <dancol@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
(cherry picked from commit b53b0b9d9a613c418057f6cb921c2f40a6f78c24)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I02f259d2875bec46b198d580edfbb067f077084e
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505855
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796163
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

BACKPORT: signal: support CLONE_PIDFD with pidfd_send_signal

Let pidfd_send_signal() use pidfds retrieved via CLONE_PIDFD.  With this
patch pidfd_send_signal() becomes independent of procfs.  This fullfils
the request made when we merged the pidfd_send_signal() patchset.  The
pidfd_send_signal() syscall is now always available allowing for it to
be used by users without procfs mounted or even users without procfs
support compiled into the kernel.

Signed-off-by: Christian Brauner <christian@brauner.io>
Co-developed-by: Jann Horn <jannh@google.com>
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from commit 2151ad1b067275730de1b38c7257478cae47d29e)

Conflicts:
        kernel/sys_ni.c

(1. Replaced COND_SYSCALL with cond_syscall.)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I621fe6547397e0e68c560d7da60ef7715deb290c
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505852
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796160
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

UPSTREAM: fork: do not release lock that wasn't taken

Avoid calling cgroup_threadgroup_change_end() without having called
cgroup_threadgroup_change_beGin() first.

During process creation we need to check whether the cgroup we are in
allows us to fork. To perform this check the cgroup needs to guard itself
against threadgroup changes and takes a lock.
Prior to CLONE_PIDFD the cleanup target "bad_fork_free_pid" would also need
to call cgroup_threadgroup_change_end() because said lock had already been
taken.
However, this is not the case anymore with the addition of CLONE_PIDFD. We
are now allocating a pidfd before we check whether the cgroup we're in can
fork and thus prior to taking the lock. So when copy_process() fails at the
right step it would release a lock we haven't taken.
This bug is not even very subtle to be honest. It's just not very clear
from the naming of cgroup_threadgroup_change_{beGin,end}() that a lock is
taken.

Here's the relevant splat:

entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fec849
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000
RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(depth <= 0)
WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052 __lock_release
kernel/locking/lockdep.c:4052 [inline]
WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052
lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 7744 Comm: syz-executor007 Not tainted 5.1.0+ #4
Hardware name: Google Google Compute EnGine/Google Compute EnGine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x172/0x1f0 lib/dump_stack.c:113
  panic+0x2cb/0x65c kernel/panic.c:214
  __warn.cold+0x20/0x45 kernel/panic.c:566
  report_bug+0x263/0x2b0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  fixup_bug arch/x86/kernel/traps.c:174 [inline]
  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
  do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:972
RIP: 0010:__lock_release kernel/locking/lockdep.c:4052 [inline]
RIP: 0010:lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321
Code: 0f 85 a0 03 00 00 8b 35 77 66 08 08 85 f6 75 23 48 c7 c6 a0 55 6b 87
48 c7 c7 40 25 6b 87 4c 89 85 70 ff ff ff e8 b7 a9 eb ff <0f> 0b 4c 8b 85
70 ff ff ff 4c 89 ea 4c 89 e6 4c 89 c7 e8 52 63 ff
RSP: 0018:ffff888094117b48 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 1ffff11012822f6f RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815af236 RDI: ffffed1012822f5b
RBP: ffff888094117c00 R08: ffff888092bfc400 R09: fffffbfff113301d
R10: fffffbfff113301c R11: ffffffff889980e3 R12: ffffffff8a451df8
R13: ffffffff8142e71f R14: ffffffff8a44cc80 R15: ffff888094117bd8
  percpu_up_read.constprop.0+0xcb/0x110 include/linux/percpu-rwsem.h:92
  cgroup_threadgroup_change_end include/linux/cgroup-defs.h:712 [inline]
  copy_process.part.0+0x47ff/0x6710 kernel/fork.c:2222
  copy_process kernel/fork.c:1772 [inline]
  _do_fork+0x25d/0xfd0 kernel/fork.c:2338
  __do_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:240 [inline]
  __se_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:236 [inline]
  __ia32_compat_sys_x86_clone+0xbc/0x140 arch/x86/ia32/sys_ia32.c:236
  do_syscall_32_irqs_on arch/x86/entry/common.c:334 [inline]
  do_fast_syscall_32+0x281/0xd54 arch/x86/entry/common.c:405
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fec849
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000
RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Reported-and-tested-by: syzbot+3286e58549edc479faae@syzkaller.appspotmail.com
Fixes: b3e583825266 ("clone: add CLONE_PIDFD")
Signed-off-by: Christian Brauner <christian@brauner.io>
(cherry picked from commit c3b7112df86b769927a60a6d7175988ca3d60f09)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: Ib9ecb1e5c0c6e2d062b89c25109ec571570eb497
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505853
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796161
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

BACKPORT: clone: add CLONE_PIDFD

This patchset makes it possible to retrieve pid file descriptors at
process creation time by introducing the new flag CLONE_PIDFD to the
clone() system call.  Linus oriGinally suggested to implement this as a
new flag to clone() instead of making it a separate system call.  As
spotted by Linus, there is exactly one bit for clone() left.

CLONE_PIDFD creates file descriptors based on the anonymous inode
implementation in the kernel that will also be used to implement the new
mount api.  They serve as a simple opaque handle on pids.  Logically,
this makes it possible to interpret a pidfd differently, narrowing or
widening the scope of various operations (e.g. signal sending).  Thus, a
pidfd cannot just refer to a tgid, but also a tid, or in theory - given
appropriate flag arguments in relevant syscalls - a process group or
session. A pidfd does not represent a privilege.  This does not imply it
cannot ever be that way but for now this is not the case.

A pidfd comes with additional information in fdinfo if the kernel supports
procfs.  The fdinfo file contains the pid of the process in the callers
pid namespace in the same format as the procfs status file, i.e. "Pid:\t%d".

As suggested by Oleg, with CLONE_PIDFD the pidfd is returned in the
parent_tidptr argument of clone.  This has the advantage that we can
give back the associated pid and the pidfd at the same time.

To remove worries about missing metadata access this patchset comes with
a sample program that illustrates how a combination of CLONE_PIDFD, and
pidfd_send_signal() can be used to gain race-free access to process
metadata through /proc/<pid>.  The sample program can easily be
translated into a helper that would be suitable for inclusion in libc so
that users don't have to worry about writing it themselves.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
Co-developed-by: Jann Horn <jannh@google.com>
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from commit b3e5838252665ee4cfa76b82bdf1198dca81e5be)

Conflicts:
        kernel/fork.c

(1. Replaced proc_pid_ns() with its direct implementation.)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I3c804a92faea686e5bf7f99df893fe3a5d87ddf7
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505851
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796159
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

UPSTREAM: Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from commit dadd2299ab61fc2b55b95b7b3a8f674cdd3b69c9)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I2f97bda4f360d8d05bbb603de839717b3d8067ae
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505850
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796158
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

BACKPORT: pid: add pidfd_open()

This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:

int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);

With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a problem for
Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfds for PID-based processes we enable them to adopt this api.

In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.

Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
(cherry picked from commit 32fcb426ec001cb6d5a4a195091a8486ea77e2df)

Conflicts:
        kernel/pid.c

(1. Replaced PIDTYPE_TGID with PIDTYPE_PID and thread_group_leader() check in pidfd_open() call)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I52a93a73722d7f7754dae05f63b94b4ca4a71a75
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505856
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796165
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

UPSTREAM: pidfd: fix a poll race when setting exit_state

There is a race between reading task->exit_state in pidfd_poll and
writing it after do_notify_parent calls do_notify_pidfd. Expected
sequence of events is:

CPU 0                            CPU 1
------------------------------------------------
exit_notify
  do_notify_parent
    do_notify_pidfd
  tsk->exit_state = EXIT_DEAD
                                  pidfd_poll
                                     if (tsk->exit_state)

However nothing prevents the following sequence:

CPU 0                            CPU 1
------------------------------------------------
exit_notify
  do_notify_parent
    do_notify_pidfd
                                   pidfd_poll
                                      if (tsk->exit_state)
  tsk->exit_state = EXIT_DEAD

This causes a polling task to wait forever, since poll blocks because
exit_state is 0 and the waiting task is not notified again. A stress
test continuously doing pidfd poll and process exits uncovered this bug.

To fix it, we make sure that the task's exit_state is always set before
calling do_notify_pidfd.

Fixes: b53b0b9d9a6 ("pidfd: add polling support")
Cc: kernel-team@android.com
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190717172100.261204-1-joel@joelfernandes.org
[christian@brauner.io: adapt commit message and drop unneeded changes from wait_task_zombie]
Signed-off-by: Christian Brauner <christian@brauner.io>
(cherry picked from commit b191d6491be67cef2b3fa83015561caca1394ab9)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I043e54c9b69f25de88f6f19ae167920af8532de2
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505858
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796167
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

Enable PSI

Change-Id: I02a9d4b95606250a6727479ed1a1be01dd208e50
Signed-off-by: huangzq2 <huangzq2@motorola.com>
Reviewed-on: https://gerrit.mot.com/1796168
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

UPSTREAM: signal: improve comments

Improve the comments for pidfd_send_signal().
First, the comment still referred to a file descriptor for a process as a
"task file descriptor" which stems from way back at the beGinning of the
discussion. Replace this with "pidfd" for consistency.
Second, the wording for the explanation of the arguments to the syscall
was a bit inconsistent, e.g. some used the past tense some used present
tense. Make the wording more consistent.

Signed-off-by: Christian Brauner <christian@brauner.io>
(cherry picked from commit c732327f04a3818f35fa97d07b1d64d31b691d78)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I06c6bdd1dddaeb8ac75a78dd21f9cdd0dc139a4c
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505854
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796162
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

BACKPORT: arch: wire-up pidfd_open()

This wires up the pidfd_open() syscall into all arches at once.

Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Cc: x86@kernel.org
(cherry picked from commit 7615d9e1780e26e0178c93c55b73309a5dc093d7)

Conflicts:

        arch/alpha/kernel/syscalls/syscall.tbl
        arch/arm/tools/syscall.tbl
        arch/ia64/kernel/syscalls/syscall.tbl
        arch/m68k/kernel/syscalls/syscall.tbl
        arch/microblaze/kernel/syscalls/syscall.tbl
        arch/mips/kernel/syscalls/syscall_n32.tbl
        arch/mips/kernel/syscalls/syscall_n64.tbl
        arch/mips/kernel/syscalls/syscall_o32.tbl
        arch/parisc/kernel/syscalls/syscall.tbl
        arch/powerpc/kernel/syscalls/syscall.tbl
        arch/s390/kernel/syscalls/syscall.tbl
        arch/sh/kernel/syscalls/syscall.tbl
        arch/sparc/kernel/syscalls/syscall.tbl
        arch/xtensa/kernel/syscalls/syscall.tbl
        arch/x86/entry/syscalls/syscall_32.tbl
        arch/x86/entry/syscalls/syscall_64.tbl

(1. Skipped syscall.tbl modifications for missing architectures.
 2. Removed __ia32_sys_pidfd_open in arch/x86/entry/syscalls/syscall_32.tbl.
 3. Replaced __x64_sys_pidfd_open with sys_pidfd_open in arch/x86/entry/syscalls/syscall_64.tbl.)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I294aa33dea5ed2662e077340281d7aa0452f7471
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505857
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796166
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

UPSTREAM: signal: use fdget() since we don't allow O_PATH

As stated in the oriGinal commit for pidfd_send_signal() we don't allow
to signal processes through O_PATH file descriptors since it is
semantically equivalent to a write on the pidfd.

We already correctly error out right now and return EBADF if an O_PATH
fd is passed.  This is because we use file->f_op to detect whether a
pidfd is passed and O_PATH fds have their file->f_op set to empty_fops
in do_dentry_open() and thus fail the test.

Thus, there is no regression.  It's just semantically correct to use
fdget() and return an error right from there instead of taking a
reference and returning an error later.

Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jann@thejh.net>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 738a7832d21e3d911fcddab98ce260b79010b461)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_pidfd_send_signal,..) to send SIGKILL
Change-Id: IMontanaeaadf9da371fb2d9caae4df49627760de7229
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505849
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796157
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.c

BACKPORT: signal: add pidfd_send_signal() syscall

The kill() syscall operates on process identifiers (pid). After a process
has exited its pid can be reused by another process. If a caller sends a
signal to a reused pid it will end up signaling the wrong process. This
issue has often Surfaced and there has been a push to address this problem [1].

This patch uses file descriptors (fd) from proc/<pid> as stable handles on
struct pid. Even if a pid is recycled the handle will not change. The fd
can be used to send signals to the process it refers to.
Thus, the new syscall pidfd_send_signal() is introduced to solve this
problem. Instead of pids it operates on process fds (pidfd).

/* prototype and argument /*
long pidfd_send_signal(int pidfd, int sig, siGinfo_t *info, unsigned int flags);

/* syscall number 424 */
The syscall number was chosen to be 424 to align with Arnd's rework in his
y2038 to minimize merge conflicts (cf. [25]).

In addition to the pidfd and signal argument it takes an additional
siGinfo_t and flags argument. If the siGinfo_t argument is NULL then
pidfd_send_signal() is equivalent to kill(<positive-pid>, <signal>). If it
is not NULL pidfd_send_signal() is equivalent to rt_sigqueueinfo().
The flags argument is added to allow for future extensions of this syscall.
It currently needs to be passed as 0. Failing to do so will cause EINVAL.

/* pidfd_send_signal() replaces multiple pid-based syscalls */
The pidfd_send_signal() syscall currently takes on the job of
rt_sigqueueinfo(2) and parts of the functionality of kill(2), Namely, when a
positive pid is passed to kill(2). It will however be possible to also
replace tgkill(2) and rt_tgsigqueueinfo(2) if this syscall is extended.

/* sending signals to threads (tid) and process groups (pgid) */
Specifically, the pidfd_send_signal() syscall does currently not operate on
process groups or threads. This is left for future extensions.
In order to extend the syscall to allow sending signal to threads and
process groups appropriately named flags (e.g. PIDFD_TYPE_PGID, and
PIDFD_TYPE_TID) should be added. This implies that the flags argument will
determine what is signaled and not the file descriptor itself. Put in other
words, grouping in this api is a property of the flags argument not a
property of the file descriptor (cf. [13]). Clarification for this has been
requested by Eric (cf. [19]).
When appropriate extensions through the flags argument are added then
pidfd_send_signal() can additionally replace the part of kill(2) which
operates on process groups as well as the tgkill(2) and
rt_tgsigqueueinfo(2) syscalls.
How such an extension could be implemented has been very roughly sketched
in [14], [15], and [16]. However, this should not be taken as a commitment
to a particular implementation. There might be better ways to do it.
Right now this is intentionally left out to keep this patchset as simple as
possible (cf. [4]).

/* naming */
The syscall had various names throughout iterations of this patchset:
- procfd_signal()
- procfd_send_signal()
- taskfd_send_signal()
In the last round of reviews it was pointed out that given that if the
flags argument decides the scope of the signal instead of different types
of fds it might make sense to either settle for "procfd_" or "pidfd_" as
prefix. The community was willing to accept either (cf. [17] and [18]).
Given that one developer expressed strong preference for the "pidfd_"
prefix (cf. [13]) and with other developers less opinionated about the name
we should settle for "pidfd_" to avoid further bikeshedding.

The  "_send_signal" suffix was chosen to reflect the fact that the syscall
takes on the job of multiple syscalls. It is therefore intentional that the
name is not reminiscent of neither kill(2) nor rt_sigqueueinfo(2). Not the
fomer because it might imply that pidfd_send_signal() is a replacement for
kill(2), and not the latter because it is a hassle to remember the correct
spelling - especially for non-native speakers - and because it is not
descriptive enough of what the syscall actually does. The name
"pidfd_send_signal" makes it very clear that its job is to send signals.

/* zombies */
Zombies can be signaled just as any other process. No special error will be
reported since a zombie state is an unreliable state (cf. [3]). However,
this can be added as an extension through the @flags argument if the need
ever arises.

/* cross-namespace signals */
The patch currently enforces that the signaler and signalee either are in
the same pid namespace or that the signaler's pid namespace is an ancestor
of the signalee's pid namespace. This is done for the sake of simplicity
and because it is unclear to what values certain members of struct
siGinfo_t would need to be set to (cf. [5], [6]).

/* compat syscalls */
It became clear that we would like to avoid adding compat syscalls
(cf. [7]).  The compat syscall handling is now done in kernel/signal.c
itself by adding __copy_siGinfo_from_user_generic() which lets us avoid
compat syscalls (cf. [8]). It should be noted that the addition of
__copy_siGinfo_from_user_any() is caused by a bug in the oriGinal
implementation of rt_sigqueueinfo(2) (cf. 12).
With upcoming rework for syscall handling things might improve
significantly (cf. [11]) and __copy_siGinfo_from_user_any() will not gain
any additional callers.

/* testing */
This patch was tested on x64 and x86.

/* userspace usage */
An asciinema recording for the basic functionality can be found under [9].
With this patch a process can be killed via:

 #define _GNU_SOURCE
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <unistd.h>

 static inline int do_pidfd_send_signal(int pidfd, int sig, siGinfo_t *info,
                                         unsigned int flags)
 {
 #ifdef __NR_pidfd_send_signal
         return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
 #else
         return -ENOSYS;
 #endif
 }

 int main(int argc, char *argv[])
 {
         int fd, ret, saved_errno, sig;

         if (argc < 3)
                 exit(EXIT_FAILURE);

         fd = open(argv[1], O_DIRECTORY | O_CLOEXEC);
         if (fd < 0) {
                 printf("%s - Failed to open \"%s\"\n", strerror(errno), argv[1]);
                 exit(EXIT_FAILURE);
         }

         sig = atoi(argv[2]);

         printf("Sending signal %d to process %s\n", sig, argv[1]);
         ret = do_pidfd_send_signal(fd, sig, NULL, 0);

         saved_errno = errno;
         close(fd);
         errno = saved_errno;

         if (ret < 0) {
                 printf("%s - Failed to send signal %d to process %s\n",
                        strerror(errno), sig, argv[1]);
                 exit(EXIT_FAILURE);
         }

         exit(EXIT_SUCCESS);
 }

/* Q&A
 * Given that it seems the same questions get asked again by people who are
 * late to the party it makes sense to add a Q&A section to the commit
 * message so it's hopefully easier to avoid duplicate threads.
 *
 * For the sake of progress please consider these arguments settled unless
 * there is a new point that desperately needs to be addressed. Please make
 * sure to check the links to the threads in this commit message whether
 * this has not already been covered.
 */
Q-01: (Florian Weimer [20], Andrew Morton [21])
      What happens when the target process has exited?
A-01: Sending the signal will fail with ESRCH (cf. [22]).

Q-02:  (Andrew Morton [21])
       Is the task_struct pinned by the fd?
A-02:  No. A reference to struct pid is kept. struct pid - as far as I
       understand - was created exactly for the reason to not require to
       pin struct task_struct (cf. [22]).

Q-03: (Andrew Morton [21])
      Does the entire procfs directory remain visible? Just one entry
      within it?
A-03: The same thing that happens right now when you hold a file descriptor
      to /proc/<pid> open (cf. [22]).

Q-04: (Andrew Morton [21])
      Does the pid remain reserved?
A-04: No. This patchset guarantees a stable handle not that pids are not
      recycled (cf. [22]).

Q-05: (Andrew Morton [21])
      Do attempts to signal that fd return errors?
A-05: See {Q,A}-01.

Q-06: (Andrew Morton [22])
      Is there a cleaner way of obtaining the fd? Another syscall perhaps.
A-06: Userspace can already trivially retrieve file descriptors from procfs
      so this is something that we will need to support anyway. Hence,
      there's no immediate need to add another syscalls just to make
      pidfd_send_signal() not dependent on the presence of procfs. However,
      adding a syscalls to get such file descriptors is planned for a
      future patchset (cf. [22]).

Q-07: (Andrew Morton [21] and others)
      This fd-for-a-process sounds like a handy thing and people may well
      think up other uses for it in the future, probably unrelated to
      signals. Are the code and the interface designed to permit such
      future applications?
A-07: Yes (cf. [22]).

Q-08: (Andrew Morton [21] and others)
      Now I think about it, why a new syscall? This thing is looking
      rather like an ioctl?
A-08: This has been extensively discussed. It was agreed that a syscall is
      preferred for a variety or reasons. Here are just a few taken from
      prior threads. Syscalls are safer than ioctl()s especially when
      signaling to fds. Processes are a core kernel concept so a syscall
      seems more appropriate. The layout of the syscall with its four
      arguments would require the addition of a custom struct for the
      ioctl() thereby causing at least the same amount or even more
      complexity for userspace than a simple syscall. The new syscall will
      replace multiple other pid-based syscalls (see description above).
      The file-descriptors-for-processes concept introduced with this
      syscall will be extended with other syscalls in the future. See also
      [22], [23] and various other threads already linked in here.

Q-09: (Florian Weimer [24])
      What happens if you use the new interface with an O_PATH descriptor?
A-09:
      pidfds opened as O_PATH fds cannot be used to send signals to a
      process (cf. [2]). Signaling processes through pidfds is the
      equivalent of writing to a file. Thus, this is not an operation that
      operates "purely at the file descriptor level" as required by the
      open(2) manpage. See also [4].

/* References */
[1]:  https://lore.kernel.org/lkml/20181029221037.87724-1-dancol@google.com/
[2]:  https://lore.kernel.org/lkml/874lbtjvtd.fsf@oldenburg2.str.redhat.com/
[3]:  https://lore.kernel.org/lkml/20181204132604.aspfupwjgjx6fhva@brauner.io/
[4]:  https://lore.kernel.org/lkml/20181203180224.fkvw4kajtbvru2ku@brauner.io/
[5]:  https://lore.kernel.org/lkml/20181121213946.GA10795@mail.hallyn.com/
[6]:  https://lore.kernel.org/lkml/20181120103111.etlqp7zop34v6nv4@brauner.io/
[7]:  https://lore.kernel.org/lkml/36323361-90BD-41AF-AB5B-EE0D7BA02C21@amacapital.net/
[8]:  https://lore.kernel.org/lkml/87tvjxp8pc.fsf@xmission.com/
[9]:  https://asciinema.org/a/IQjuCHew6bnq1cr78yuMv16cy
[11]: https://lore.kernel.org/lkml/F53D6D38-3521-4C20-9034-5AF447DF62FF@amacapital.net/
[12]: https://lore.kernel.org/lkml/87zhtjn8ck.fsf@xmission.com/
[13]: https://lore.kernel.org/lkml/871s6u9z6u.fsf@xmission.com/
[14]: https://lore.kernel.org/lkml/20181206231742.xxi4ghn24z4h2qki@brauner.io/
[15]: https://lore.kernel.org/lkml/20181207003124.GA11160@mail.hallyn.com/
[16]: https://lore.kernel.org/lkml/20181207015423.4miorx43l3qhppfz@brauner.io/
[17]: https://lore.kernel.org/lkml/CAGXu5jL8PciZAXvOvCeCU3wKUEB_dU-O3q0tDw4uB_ojMvDEew@mail.gmail.com/
[18]: https://lore.kernel.org/lkml/20181206222746.GB9224@mail.hallyn.com/
[19]: https://lore.kernel.org/lkml/20181208054059.19813-1-christian@brauner.io/
[20]: https://lore.kernel.org/lkml/8736rebl9s.fsf@oldenburg.str.redhat.com/
[21]: https://lore.kernel.org/lkml/20181228152012.dbf0508c2508138efc5f2bbe@linux-foundation.org/
[22]: https://lore.kernel.org/lkml/20181228233725.722tdfgijxcssg76@brauner.io/
[23]: https://lwn.net/Articles/773459/
[24]: https://lore.kernel.org/lkml/8736rebl9s.fsf@oldenburg.str.redhat.com/
[25]: https://lore.kernel.org/lkml/CAK8P3a0ej9NcJM8wXNPbcGUyOUZYX+VLoDFdbenW3s3114oQZw@mail.gmail.com/

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Tycho Andersen <tycho@tycho.ws>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Aleksa Sarai <cyphar@cyphar.com>
(cherry picked from commit 3eb39f47934f9d5a3027fe00d906a45fe3a15fad)

Conflicts:
        arch/x86/entry/syscalls/syscall_32.tbl - trivial manual merge
        arch/x86/entry/syscalls/syscall_64.tbl - trivial manual merge
        include/linux/proc_fs.h - trivial manual merge
        include/linux/syscalls.h - trivial manual merge
        include/uapi/asm-generic/unistd.h - trivial manual merge
        kernel/signal.c - struct kernel_siGinfo does not exist in 4.14
        kernel/sys_ni.c - cond_syscall is used instead of COND_SYSCALL
        arch/x86/entry/syscalls/syscall_32.tbl
        arch/x86/entry/syscalls/syscall_64.tbl

(1. manual merges because of 4.14 differences
 2. change prepare_kill_siGinfo() to use struct siGinfo instead of
kernel_siGinfo
 3. use copy_from_user() instead of copy_siGinfo_from_user() in copy_siGinfo_from_user_any()
 4. replaced COND_SYSCALL with cond_syscall
 5. Removed __ia32_sys_pidfd_send_signal in arch/x86/entry/syscalls/syscall_32.tbl.
 6. Replaced __x64_sys_pidfd_send_signal with sys_pidfd_send_signal in arch/x86/entry/syscalls/syscall_64.tbl.)

Mot-CRs-fixed: (CR)

Bug: 135608568
Test: test program using syscall(__NR_pidfd_send_signal,..) to send SIGKILL
Change-Id: I34da11c63ac8cafb0353d9af24c820cef519ec27
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-on: https://gerrit.mot.com/1505847
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Wang Wang <wangwang1@mt.com>
Reviewed-by: Yonghui Jia <jiayh2@motorola.com>
Submit-Approved: Jira Key
Reviewed-on: https://gerrit.mot.com/1796155
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>

ANDROID: fix binder change in merge of 4.9.188

The 4.9.188 merge was missing the change to the
binder driver associated with the linux-4.9.y
commit 16903f1a5ba7 ("coredump: fix race condition
between mmget_not_zero()/get_task_mm() and core dumping").
It was left out because the android-4.9 binder
driver has been significantly refactored compared
to linux-4.9.y.

This patch applies the missing change from that
patch to the binder driver.

Mot-CRs-fixed: (CR)
CVE-Fixed: CVE-2019-11599
BUG: 131964235

Change-Id: I1402cf3c28f1336da9d942abeb322f71a9b8138b
Signed-off-by: Pachipulusu Bhanu Prakash <bhprakas@motorola.com>
Reviewed-on: https://gerrit.mot.com/1473937
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Revert "(CR) arm64: dts: Keep VCCQ power when S2R mode for Sandisk UFS"

The changed will be effect the APM current, the current will increase about 6mA.

This reverts commit 7eb50b69c6197393012ccc02b97c8ad54c8f6ba3.

Change-Id: I27586d466caa39a9632136b87734fc9447090092
Reviewed-on: https://gerrit.mot.com/1473008
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

arm64: dts: Keep VCCQ power when S2R mode for Sandisk UFS

Change-Id: Ib55c4b86a0608ec3e436dd2b8ae36cb1fd44287e
Reviewed-on: https://gerrit.mot.com/1470812
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

usb:Restore linked_func list in none-secure mode

In none-secure mode, there is still
A low chance of gadget NULL case,
Restore the binded functions list back to
Linked_func list, so next time unbind functions
Could be handled correctly without memory corruption
This is a Samsung platform only issue

Change-Id: Ie46fc52d3eaa6ef60c1a4f6bb83a56229Montana854d
Signed-off-by: a17671 <a17671@motorola.com>
Reviewed-on: https://gerrit.mot.com/1456923
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Revert "(CR) psi:kernel:enable PSI configuration"

This reverts commit 9ea0893bec0beb7328429c222097427d33981714.

Conflicts:
arch/arm64/configs/ext_config/moto-erd9610.config

Change-Id: I8e2c88a7b2c932fa877416564d5cbf294afe0d5a
Reviewed-on: https://gerrit.mot.com/1455315
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

arm64/defconfig: define CONFIG_LOCALVERSION to user

add user defconfig
Change-Id: Ib8113f551270eee70178e9638dabeb8083e5b675
Signed-off-by: zhaoxp3 <zhaoxp3@motorola.com>
Reviewed-on: https://gerrit.mot.com/1453937
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Submit-Approved: Jira Key

Enable process reclaim

Change-Id: Icda8271812c13fa2e4677e42ec38f8a52dd50721
Signed-off-by: huangzq2 <huangzq2@motorola.com>
Reviewed-on: https://gerrit.mot.com/1453732
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: remove get/put_online_cpus call

remove get/put_online_cpus call since it could cause
deadlock in cpu hotplug path. This might cause race
but should be rare and we should be able to correct
that with the next dump.

=======================================================
    Task name: Binder:897_2 pid: 3255 cpu: 0 start: 0xffffffd39e2f5700
    state: 0x2 exit_state: 0x0 stack base: 0xffffff80241f0000 Prio: 116
    Stack:
    [<ffffff9048f3163c>] __switch_to.cfi+0x138
    [<ffffff904a947808>] __schedule+0xb7c
    [<ffffff904a94dbdc>] rwsem_down_read_failed.cfi+0x270
    [<ffffff904900a0a4>] __percpu_down_read.cfi+0x164
    [<ffffff90491bc4e8>] record_stat+0x6c0
    [<ffffff90491bbdfc>] mm_event_end.cfi+0x14c
    [<ffffff904916c280>] try_to_free_pages.cfi+0xaf4
    [<ffffff904914a598>] __alloc_pages_nodemask.cfi+0x9c8
    [<ffffff9049aa6350>] zcomp_cpu_up_prepare.cfi+0x88
    [<ffffff9048f66da8>] cpuhp_invoke_callback+0x378
    [<ffffff9048f664e0>] _cpu_up+0x1bc
    [<ffffff9048f6aadc>] enable_nonboot_cpus.cfi+0x208
    [<ffffff90490135f4>] suspend_devices_and_enter.cfi+0xc20
    [<ffffff9049012844>] pm_suspend.cfi+0xb30
    [<ffffff9049010568>] state_store.cfi+0x94
    [<ffffff904a9339dc>] kobj_attr_store.cfi+0x34
    [<ffffff90492ed9ec>] sysfs_kf_write.cfi+0x64
    [<ffffff90492eb51c>] kernfs_fop_write.cfi+0x1a4
    [<ffffff90491fbf34>] __vfs_write.cfi+0x50
    [<ffffff90491fbd58>] vfs_write.cfi+0xcc
    [<ffffff90491fefd4>] SyS_write.cfi+0xa4
    [<ffffff9048e84080>] el0_svc_naked+0x34

Test: manual suspend/resume test

Mot-CRs-fixed: (CR)

Bug: 132011965
Change-Id: I112ca0d25e825bb4e0e8979d9b4f1d8e6090147f
Signed-off-by: Martin Liu <liumartin@google.com>
(cherry picked from commit 5f419093ab253702847a6b3a8417e47c2acfb652)
Reviewed-on: https://gerrit.mot.com/1453731
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: fix compact_scan

It fixes double counting of COMPACTFREE_SCANNED.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I38ef432ecf44ba94988f5a4ec9c69bcb5d20fdce
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453730
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: synchronize period update interval

Wei pointed out period update is racy so it could make partial
update, which could lose a ton of trace potentially.

To close period_ms race between updating and reading, use rwlock
to reduce contention.
To close vmstat_period_ms between updating and reading,
use vmstat_lock.

This patch has small refactoring, too.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I7f84cff758b533b7881f47889c7662b743bc3c12
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453729
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event supports vmstat

Vmstat is significantly important to investigate MM problem.
We have solved many problmes with it via asking users to get
vmstat data periodically from the device, which manual way is
painful once we release the device or on hard reproducible
scenario.

This patch adds periodic vmstat dump into mm_event. It works
only if there are some events in compaction or reclaim. Thus,
unless there is memory pressure, it doesn't gather any vmstat
data. Default interval between each dump is 1000ms.
Admin can tweak it via

echo 2000 > /sys/kernel/debug/mm_event/vmstat_period_ms

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I4c0e7237d7764c4ea79da00952e5de34ccbe4187
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453728
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: per-process reclaim

These day, there are many platforms available in the embedded market
and they are smarter than kernel which has very limited information
about working set so they want to involve memory management more heavily
like android's lowmemory killer and ashmem or recent many lowmemory
notifier.

One of the simple imaGine scenario about userspace's intelligence is that
platform can manage tasks as forground and background so it would be
better to reclaim background's task pages for end-user's *responsibility*
although it has frequent referenced pages.

This patch adds new knob "reclaim under proc/<pid>/" so task manager
can reclaim any target process anytime, anywhere. It could give another
method to platform for using memory efficiently.

It can avoid process killing for getting free memory, which was really
terrible experience because I lost my best score of game I had ever
after I switch the phone call while I enjoyed the game.

Reclaim file-backed pages only.
echo file > /proc/PID/reclaim
Reclaim anonymous pages only.
echo anon > /proc/PID/reclaim
Reclaim all pages
echo all > /proc/PID/reclaim

Mot-CRs-fixed: (CR)

Bug: 122047783
Change-Id: I2f629f7a43289af114df27044b1d2af4a6e785bc
Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-on: https://gerrit.mot.com/1453727
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: emit tracepoint when rss watermark is hit

Useful to track how rss is chanGing per tgid. Required for the
memory visibility work being done for Android.

OriGinal patch by Tim Murray:
https://partner-android-review.googlesource.com/c/kernel/private/msm-google/+/1081280

Changes from oriGinal patch:
- don't bloat mm_struct
- add some noise reduction to rss tracking

Mot-CRs-fixed: (CR)

Change-Id: Ief904334235ff4380244e5803d7853579e70d202
Signed-off-by: Joel Fernandes <joelaf@google.com>
Reviewed-on: https://gerrit.mot.com/1453726
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
SLTApproved: Slta Waiver
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: add read io stat

Read IO's latency as well as filemap fault could affect system
performance so this patch keeps track it on.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I761b7110339cf1e5ef24530ad32aedd784d00d07
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
Reviewed-on: https://gerrit.mot.com/1453725
Tested-by: Jira Key
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: add special kernel allocation stat

Record the count of special page allocation on the process context.

This patch aims for accounting of special page allocation which
consumed a lot by android system.
At this moment, ION system heap is good candidate(it could cover
other kernel allocation in future).
With that, we could keep tracking burst kernel allocation owner
so that it would be useful to find places caused by lmk, reclaim,
compaction latency.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I5942fd940d98baa2eb814f66b076cb37ecd3b4aa
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453724
Tested-by: Jira Key
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: add swapin stat

Many embedded devices use zram as swap. Compared to storage swap
(e.g. UFS), swapin from zram(ie., decompression) is extremly fast
so it might be not major fault but minor. So this patch provides
swapin latency tracking to distinguish them from storage major
fault.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I1c32430e32a051916ede5219bd5f40a9002652bc
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453723
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: add compaction stat

This patch adds compaction mm_event stat so that we could keep track
latency of compaction as well as count of the event.

Under heavy memory fragmentation, high-order page allocation(e.g.
fork, ION memory allocation) triggers compaction, which is
another major part of latency. Let's track it down, too.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: Ia3da9324f123ba2542863eafaf72024b5351785b
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453722
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: add reclaim stat

This patch adds page reclaim mm_event stat so that we could
keep tracking [avg|max]_latency for the handling the event
as well as count of the event.

Direct reclaim latency is usually a most popular latency source
caused by memory pressure so we need to track it down to hunt
down application's jank problem.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I215c3972f76389404da7c4806a776bf753daac01
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453721
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: add page fault stat

This patch add major and minor fault mm_event stat so that we could
keep tracking [avg|max]_latency for the handling the event
as well as count of the event.

With major fault, we could see how long the IO is delayed. It's very
tightly coupled with application's latency.

With major+minor fault, we could see how many of pages are allocated
for the process in the period. It would help to see memory spike.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I8a4434493e3ec291227961939a24c3d57a18fd5b
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
Reviewed-on: https://gerrit.mot.com/1453720
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: mm_event: make capture period configurable

This patch makes per-process mm event capture inteval configurable.
Default is 500ms but admin can change it by below knob.

/sys/kernel/debug/mm_event/period_ms

The unit is millisecond.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I3b2de3dd5c4a519a2e5e20f1ef0d5f9a4c7afc8a
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453719
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

mm: introduce per-process mm event tracking feature

Linux supports /proc/meminfo and /proc/vmstat stats as memory health metric.
Android uses them too. If user see something goes wrong(e.g., sluggish, jank)
on their system, they can capture and report system state to developers
for debugGing.

It shows memory stat at the moment the bug is captured. However, it’s
not enough to investigate application's jank problem caused by memory
shortage. Because

1. It just shows event count which doesn’t quantify the latency of the
application well. Jank could happen by various reasons and one of simple
scenario is frame drop for a second. App should draw the frame every 16ms
interval. Just number of stats(e.g., allocstall or pgmajfault) couldn't
represnt how many of time the app spends for handling the event.

2. At bugreport, dump with vmstat and meminfo is never helpful because it's
too late to capture the moment when the problem happens.
When the user catch up the problem and try to capture the system state,
the problem has already gone.

3. Although we could capture MM stat at the moment bug happens, it couldn't
be helpful because MM stats are usually very flucuate so we need historical
data rather than one-time snapshot to see MM trend.

To solve above problems, this patch introduces per-process, light-weight,
mm event stat. Basically, it tracks minor/major faults, reclaim and compaction
latency of each process as well as event count and record the data into global
buffer.
To compromise memory overhead, it doesn't record every MM event of the process
to the buffer but just drain accumuated stats every 0.5sec interval to buffer.
If there isn't any event, it just skips the recording.
For latency data, it keeps average/max latency of each event in that period

With that, we could keep useful information with small buffer so that
we couldn't miss precious information any longer although the capture time
is rather late. This patch introduces basic facility of MM event stat.

After all patches in this patchset are applied, outout format is as follows,
dumpstate can use it for VM debugGing in future.

<...>-1665  [001] d...   217.575173: mm_event_record: min_flt count=203 avg_lat=3 max_lat=58
<...>-1665  [001] d...   217.575183: mm_event_record: maj_flt count=1 avg_lat=1994 max_lat=1994
<...>-1665  [001] d...   217.575184: mm_event_record: kern_alloc count=227 avg_lat=0 max_lat=0
<...>-626   [000] d...   217.578096: mm_event_record: kern_alloc count=4 avg_lat=0 max_lat=0
<...>-6547  [000] ....   217.581913: mm_event_record: min_flt count=7 avg_lat=7 max_lat=20
<...>-6547  [000] ....   217.581955: mm_event_record: kern_alloc count=4 avg_lat=0 max_lat=0

This feature uses event trace for output buffer so that we could use all of
general benefit of event trace(e.g., buffer size management, filtering and
so on). To prevent overflow of the ring buffer by other random event race,
highly suggest that create separate instance of tracing
on /sys/kernel/debug/tracing/instances/

I had a concern of adding overhead. Actually, major|compaction/reclaim
are already heavy cost so it should be not a concern. Rather than,
minor fault and kern alloc would be severe so I tested a micro benchmark
to measure minor page fault overhead.

Test scenario is create 40 threads and each of them does minor
page fault for 25M range(ranges are not overwrapped).
I didn't see any noticible regression.

Base:
fault/wsec avg: 758489.8288

minor faults=13123118, major faults=0 ctx switch=139234
    User   System     Wall        fault/wsec
  39.55s   41.73s   17.49s        749995.768
minor faults=13123135, major faults=0 ctx switch=139627
    User   System     Wall        fault/wsec
  34.59s   41.61s   16.95s        773906.976
minor faults=13123061, major faults=0 ctx switch=139254
    User   System     Wall        fault/wsec
  39.03s   41.55s   16.97s        772966.334
minor faults=13123131, major faults=0 ctx switch=139970
    User   System     Wall        fault/wsec
  36.71s   42.12s   17.04s        769941.019
minor faults=13123027, major faults=0 ctx switch=138524
    User   System     Wall        fault/wsec
  42.08s   42.24s   18.08s        725639.047

Base + MM event + event trace enable:
fault/wsec avg: 759626.1488

minor faults=13123488, major faults=0 ctx switch=140303
    User   System     Wall        fault/wsec
  37.66s   42.21s   17.48s        750414.257
minor faults=13123066, major faults=0 ctx switch=138119
    User   System     Wall        fault/wsec
  36.77s   42.14s   17.49s        750010.107
minor faults=13123505, major faults=0 ctx switch=140021
    User   System     Wall        fault/wsec
  38.51s   42.50s   17.54s        748022.219
minor faults=13123431, major faults=0 ctx switch=138517
    User   System     Wall        fault/wsec
  36.74s   41.49s   17.03s        770255.610
minor faults=13122955, major faults=0 ctx switch=137174
    User   System     Wall        fault/wsec
  40.68s   40.97s   16.83s        779428.551

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I4e69c994f47402766481c58ab5ec2071180964b8
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
Reviewed-on: https://gerrit.mot.com/1453718
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

psi:kernel:enable PSI configuration

support Google PSI memory management in lmkd

Change-Id: I437daa54c55c4caa9d8a67ba5bf7ac529d61da87
Reviewed-on: https://gerrit.mot.com/1453674
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

psi:kernel:oom reaper porting into samsung platform

reaper can help to reclaim the memory in time, the knob will be set to true
when init parses the init.rc conf file.

Change-Id: I59f1173c0e46202904da6eeacb2fecc32c53232c

mfd: cs47l35: Update codec reg value.

cirrus vendor patch:
When detected the reg value in the cache is inconsistent with
the value in the hardware, update the hardware reg.

Change-Id: I0aea0c59665f470a8625601ac3abbbd915f8dbee
Signed-off-by: Wen Xie <xiewen3@motorola.com>
Reviewed-on: https://gerrit.mot.com/1452347
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Zhengming Yao <yaozm1@mt.com>
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

usb:Balance the enable/disable in secure mode

Enable/Disable shall be banlanced when USB in secure mode
Otherwise the linked_func and func_list could be messed up
That will cause the unbinding release the wild memory
This is a Samsung platform only issue,kernel panic
Has the following mark:

configfs-gadget gadget:unbind function 'mtp'
configfs-gadget gadget:unbind function 'ptp'

Which shall not happen, since user could not choose
Both mtp and ptp together

Change-Id: I4aba691a0c4180f828c55aad5d63b9162c3f881a
Signed-off-by: a17671 <a17671@motorola.com>
Reviewed-on: https://gerrit.mot.com/1451197
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Revert "Revert "printk: add cpu info into kernel log""

Revert this change since we finally decided not to enable Samsung
CONFIG_PRINTK_PROCESS,
https://gerrit.mot.com/#/c/1435442/ had been abandoned

Change-Id: Ic60281e58b15656199666da976721340cd692dcd
Reviewed-on: https://gerrit.mot.com/1449799
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

fix build error

Change-Id: Icbe77ce94e1ac234eb13753750a8ac7a17c77103

input: update touch usb cable detect report function

as vendor patch, change the report function
in call back function

Change-Id: Id0063704802c0841e14cbd5fbd2dd75a8a71c28e
Signed-off-by: dengwei1 <dengwei1@motorola.com>
Reviewed-on: https://gerrit.mot.com/1449028
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

UPSTREAM: xfrm: Make set-mark default behavior backward compatible

Fixes 9b42c1f, which changed the default route lookup behavior for
tunnel mode SAs in the outbound direction to use the skb mark, whereas
previously mark=0 was used if the output mark was unspecified. In
mark-based routing schemes such as Android’s, this change in default
behavior causes routing loops or lookup failures.

This patch restores the default behavior of using a 0 mark while still
incorporating the skb mark if the SET_MARK (and SET_MARK_MASK) is
specified.

Tested with additions to Android's kernel unit test suite:
https://android-review.googlesource.com/c/kernel/tests/+/860150

Fixes: 9b42c1f ("xfrm: Extend the output_mark to support input direction and masking")
Signed-off-by: Benedict Wong <benedictwong@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
(cherry picked from commit e2612cd496e7b465711d219ea6118893d7253f52)
Bug: 122236988
Test: Passes kernel tests
Change-Id: I1289b5b7b1eb93c6d99a0ba7d28e24c3eb25883d
Signed-off-by: Benedict Wong <benedictwong@google.com>

UPSTREAM: xfrm: Remove xfrmi interface ID from flowi

In order to remove performance impact of having the extra u32 in every
single flowi, this change removes the flowi_xfrm struct, prefering to
take the if_id as a method parameter where needed.

In the inbound direction, if_id is only needed during the
__xfrm_check_policy() function, and the if_id can be determined at that
point based on the skb. As such, xfrmi_decode_session() is only called
with the skb in __xfrm_check_policy().

In the outbound direction, the only place where if_id is needed is the
xfrm_lookup() call in xfrmi_xmit2(). With this change, the if_id is
directly passed into the xfrm_lookup_with_ifid() call. All existing
callers can still call xfrm_lookup(), which uses a default if_id of 0.

This change does not change any behavior of XFRMIs except for improving
overall system performance via flowi size reduction.

This change has been tested against the Android Kernel Networking Tests:

https://android.googlesource.com/kernel/tests/+/master/net/test

Signed-off-by: Benedict Wong <benedictwong@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
(cherry picked from commit bc56b33404599edc412b91933d74b36873e8ea25)
Bug: 113046120
Change-Id: Icd3a1ea08427b91c54a64318d9dbb9acfb5d429a

UPSTREAM: xfrm: Add virtual xfrm interfaces

This patch adds support for virtual xfrm interfaces.
Packets that are routed through such an interface
are guaranteed to be IPsec transformed or dropped.
It is a generic virtual interface that ensures IPsec
transformation, no need to know what happens behind
the interface. This means that we can tunnel IPv4 and
IPv6 through the same interface and support all xfrm
modes (tunnel, transport and beet) on it.

Co-developed-by: Lorenzo Colitti <lorenzo@google.com>
Co-developed-by: Benedict Wong <benedictwong@google.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Benedict Wong <benedictwong@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Shannon Nelson <shannon.nelson@oracle.com>
Tested-by: Benedict Wong <benedictwong@google.com>
Tested-by: Antony Antony <antony@phenome.org>
Reviewed-by: Eyal Birger <eyal.birger@gmail.com>
(cherry picked from commit f203b76d78092faf248db3f851840fbecf80b40e)
Bug: 113046120
Change-Id: I05e8fe1e8a8a4b01886504ce694ddda29e4fbec6

UPSTREAM: xfrm: Add a new lookup key to match xfrm interfaces.

This patch adds the xfrm interface id as a lookup key
for xfrm states and policies. With this we can assign
states and policies to virtual xfrm interfaces.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Shannon Nelson <shannon.nelson@oracle.com>
Acked-by: Benedict Wong <benedictwong@google.com>
Tested-by: Benedict Wong <benedictwong@google.com>
Tested-by: Antony Antony <antony@phenome.org>
Reviewed-by: Eyal Birger <eyal.birger@gmail.com>
(cherry picked from commit 7e6526404adedf079279aa7aa11722deaca8fe2e)
Signed-off-by: Benedict Wong <benedictwong@google.com>
Bug: 113046120
Change-Id: I27d7757a374b0bd5f97c3e723773d6c7470a0717

UPSTREAM: flow: Extend flow informations with xfrm interface id.

Add a new flowi_xfrm structure with informations needed to do
a xfrm lookup. At the moment it keeps the informations about
the new xfrm interface id needed to lookup xfrm interfaces
that are introduced with a followup patch. We need this new
lookup key as other possible keys, like the ifindex is
already part of the xfrm selector and used as a key to
enforce the output device after the transformation in the
policy/state lookup.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Shannon Nelson <shannon.nelson@oracle.com>
Acked-by: Benedict Wong <benedictwong@google.com>
Tested-by: Benedict Wong <benedictwong@google.com>
Tested-by: Antony Antony <antony@phenome.org>
Reviewed-by: Eyal Birger <eyal.birger@gmail.com>
(cherry picked from commit d159ce7957eec306eacda672e5909e26675ca8ef)
Signed-off-by: Benedict Wong <benedictwong@google.com>
Bug: 113046120
Change-Id: I70b520d3cf67cd663e84868b0e7cc45ffa74d080

UPSTREAM: xfrm: Extend the output_mark to support input direction and masking.

We already support setting an output mark at the xfrm_state,
unfortunately this does not support the input direction and
masking the marks that will be applied to the skb. This change
adds support applying a masked value in both directions.

The existing XFRMA_OUTPUT_MARK number is reused for this purpose
and as it is now bi-directional, it is renamed to XFRMA_SET_MARK.

An additional XFRMA_SET_MARK_MASK attribute is added for setting the
mask. If the attribute mask not provided, it is set to 0xffffffff,
keeping the XFRMA_OUTPUT_MARK existing 'full mask' semantics.

Co-developed-by: Tobias Brunner <tobias@strongswan.org>
Co-developed-by: Eyal Birger <eyal.birger@gmail.com>
Co-developed-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
(cherry picked from commit 9b42c1f179a614e11893ae4619f0304a38f481ae)
Signed-off-by: Benedict Wong <benedictwong@google.com>
Bug: 113046120
Change-Id: I582f0b460dc58f01e0c30afb6167725aa337d054

UPSTREAM: xfrm: fix XFRMA_OUTPUT_MARK policy entry

This seems to be an obvious typo, NLA_U32 is type of the attribute, not its
(minimal) length.

Fixes: 077fbac405bf ("net: xfrm: support setting an output mark.")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
(cherry picked from commit e719135881f00c01ca400abb8a5dadaf297a24f9)
Signed-off-by: Benedict Wong <benedictwong@google.com>
Bug: 113046120
Change-Id: I4c1a8de03febfa246b99c7eb67d77f74a1e3ba93

arm64/dts: Set detect headset button twice

arm/dts audio:
Set detect headset button twice to avoid err report.

Change-Id: I6d5ca6f72cfdc7459eb02489edeee432f57dae91
Signed-off-by: Wen Xie <xiewen3@motorola.com>
Reviewed-on: https://gerrit.mot.com/1441697
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

usb:configfs:Set udc_name NULL if attach failed

If the probing of UDC controller failed
udc_name shall be NULL to avoid double unregistration
and the panic
It could happen in some corner case

Change-Id: I2e6e4168a505b86d8f1b57db53be91acc608ee97
Signed-off-by: a17671 <a17671@motorola.com>
Reviewed-on: https://gerrit.mot.com/1438349
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Revert "(CR): wlbt: update pmu sequence"

This reverts commit 4e2e4c5090cd3fad1b24e1fb81e94c8b38867e53.

Change-Id: I062461db80799c48f9119606866b2668a12694fe
Reviewed-on: https://gerrit.mot.com/1437290
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Hua Tan <tanhua1@motorola.com>
Submit-Approved: Jira Key

wlbt: update pmu sequence

Change-Id: I161372cee02d25b312968d4c075acccab6ac23eb
Signed-off-by: Youngsoo <youngss.kim@samsung.com>
Signed-off-by: sunyue5 <sunyue5@motorola.com>
Reviewed-on: https://gerrit.mot.com/1436932
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Hua Tan <tanhua1@motorola.com>
Submit-Approved: Jira Key

Revert "printk: add cpu info into kernel log"

Change-Id: I20b58073db759906e2892e14373148a51e2aef99
Signed-off-by: sunyue5 <sunyue5@motorola.com>
Reviewed-on: https://gerrit.mot.com/1435441
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Zonghua Liu <a17671@motorola.com>
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

kernel:optimize cdp thermal charGing limitation

Optimize cdp thermal
charGing limitation

Change-Id: I1ce95bd96e8f257ab103720609d93842840868d5
Signed-off-by: xuwei9 <xuwei9@mt.com>
Reviewed-on: https://gerrit.mot.com/1435344
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

fimc-is2: fix ITS scene0 test_read_write

update exposure metadata update timing to fix exposure
mismatch for raw and jpg case

Change-Id: I7bf61b8d89da819ce8974e2c7f887c3ed6ed2e3a
Signed-off-by: wangdw10 <wangdw10@mt.com>
Reviewed-on: https://gerrit.mot.com/1433855
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Biming Li <libm1@motorola.com>
Reviewed-by: Dawei Wang <wangdw10@motorola.com>
Reviewed-by: Zhichao Chen <chenzc2@motorola.com>
Submit-Approved: Jira Key

Support APEX on samsung platform

Change-Id: If15e3cc404b4f6cb6b582877a55aa5779cbac5e7
Signed-off-by: huangzq2 <huangzq2@motorola.com>
Reviewed-on: https://gerrit.mot.com/1427696
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Enable zram writeback

Porting zram changes from Google, and enable zram writeback

Change-Id: I1bcb545dd4cdeb7f456d2f609fdb43cd9a822816
Signed-off-by: huangzq2 <huangzq2@motorola.com>
Reviewed-on: https://gerrit.mot.com/1416294
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Guolin Wang <wanggl3@mt.com>
Submit-Approved: Jira Key

config: Enable SCSC_WLAN_ABNORMAL_MULTICAST_PKT_FILTER

Drop pkts whose mac address are unicast and ip address
are multicast. It can optimize wifi power consumption.

Change-Id: I5fcb63783e76a4dae78b8305d6e0fc0a009c1aa7
Signed-off-by: sunyue5 <sunyue5@motorola.com>
Reviewed-on: https://gerrit.mot.com/1415107
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Sensor: sx9325 malloc memory size err.

The parameter of sizeof is the structure pointer,
so the allocation size is 8,which leads memory crossing the boundary.

Change-Id: I04e19739b378a948e6ae681e45bcfdacc07ff16c
Signed-off-by: Wen Xie <xiewen3@motorola.com>
Reviewed-on: https://gerrit.mot.com/1407951
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

oem:add oem partition into avb auth chain

create a node at device tree, the system can auto-mount the oem
partition according to the info in the tree node

Change-Id: I944804b129df5a68d8618cae898363229dfa0620
Reviewed-on: https://gerrit.mot.com/1407728
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

dts: add pm-ignore-notify on mmc

add pm-ignore-notify om mmc
picked up from ODM patch

Change-Id: Ia551e6dac0aac97a945d97dd49eba49427d0e071
Signed-off-by: dengwei1 <dengwei1@motorola.com>
Reviewed-on: https://gerrit.mot.com/1404596
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

Troika : vibrator reset itself when IC hang

check with IC vendor
reset the IC when it hang

Change-Id: I5a169e10a3d9b544ab7b041bf9e2fcad9d672f5b
Signed-off-by: dengwei1 <dengwei1@motorola.com>
Reviewed-on: https://gerrit.mot.com/1400750
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Wei Xu <xuwei9@mt.com>
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
(cherry picked from commit 4455d772f87642258340ba5d913a7b26c4820357)
Reviewed-on: https://gerrit.mot.com/1400777

Troika : vib fix stop delay time

discuss with vendor
Troika  vib fix stop delay time

Change-Id: I6ff5a56adf7990b90e0edabb97907a8cef25d812
Signed-off-by: dengwei1 <dengwei1@motorola.com>
Reviewed-on: https://gerrit.mot.com/1397445
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Wei Xu <xuwei9@mt.com>
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

usb: configfs: skip unregister gadget in secure

There will be gadget driver unregister twice in USB secure
when try to set the UDC to none from userspace, which will cause
kernel panic in 4.9 kernel version, as there is a feature
about pending gadget driver list being added in this version.

As a solution, make sure gadget driver unregister or probe only
once over secure mode entry or usb configure from userspace.

Kernel BUG at ffffff8093067140 [verbose debug info unavailable]
Internal error: Accessing user space memory outside uaccess.h

Change-Id: I89f03afbf9716a95aae37e354cc0cb293b2ea090
Signed-off-by: a17671 <a17671@motorola.com>
Reviewed-on: https://gerrit.mot.com/1376192
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key