Interrupt handler processes multiple message write requests one after
another, till the driver message queue is drained.  However if driver
encounters a read message without preceding START, it stops the I2C
transfer as it is an invalid condition for the controller.  At least the
comment describes a requirement "the controller forces us to send a new
START when we change direction".  This stop results in clearing the
message queue (i2c->msg = NULL).

The code however immediately jumped back to label "retry_write" which
dereferenced the "i2c->msg" making it a possible NULL pointer
dereference.

The Coverity analysis:
1. Condition !is_msgend(i2c), taking false branch.
   if (!is_msgend(i2c)) {

2. Condition !is_lastmsg(i2c), taking true branch.
   } else if (!is_lastmsg(i2c)) {

3. Condition i2c->msg->flags & 1, taking true branch.
   if (i2c->msg->flags & I2C_M_RD) {

4. write_zero_model: Passing i2c to s3c24xx_i2c_stop, which sets i2c->msg to NULL.
   s3c24xx_i2c_stop(i2c, -EINVAL);

5. Jumping to label retry_write.
   goto retry_write;

6. var_deref_model: Passing i2c to is_msgend, which dereferences null i2c->msg.
   if (!is_msgend(i2c)) {"

All previous calls to s3c24xx_i2c_stop() in this interrupt service
routine are followed by jumping to end of function (acknowledging
the interrupt and returning).  This seems a reasonable choice also here
since message buffer was entirely emptied.

Addresses-Coverity: Explicit null dereferenced
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

The i2c controller driver do dma reset after transfer timeout,
but sometimes dma reset will trigger an unexpected DMA_ERR irq.
It will cause the i2c controller to continuously send interrupts
to the system and cause soft lock-up. So we need to disable i2c
start_en and clear intr_stat to stop i2c controller before dma
reset when transfer timeout.

Fixes: aafced67("i2c: mediatek: move dma reset before i2c reset")
Signed-off-by: NQii Wang <qii.wang@mediatek.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Now that the i2c-i801 driver supports interrupts, setting the KILL bit
in a attempt to recover from a timed out transaction triggers an
interrupt. Unfortunately, the interrupt handler (i801_isr) is not
prepared for this situation and will try to process the interrupt as
if it was signaling the end of a successful transaction. In the case
of a block transaction, this can result in an out-of-range memory
access.

This condition was reproduced several times by syzbot:
https://syzkaller.appspot.com/bug?extid=ed71512d469895b5b34e
https://syzkaller.appspot.com/bug?extid=8c8dedc0ba9e03f6c79e
https://syzkaller.appspot.com/bug?extid=c8ff0b6d6c73d81b610e
https://syzkaller.appspot.com/bug?extid=33f6c360821c399d69eb
https://syzkaller.appspot.com/bug?extid=be15dc0b1933f04b043a
https://syzkaller.appspot.com/bug?extid=b4d3fd1dfd53e90afd79

So disable interrupts while trying to reset the bus. Interrupts will
be enabled again for the following transaction.

Fixes: 636752bc ("i2c-i801: Enable IRQ for SMBus transactions")
Reported-by: syzbot+b4d3fd1dfd53e90afd79@syzkaller.appspotmail.com
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

The P2040/P2041 has an erratum where the normal i2c recovery mechanism
does not work. Implement the alternative recovery mechanism documented
in the P2040 Chip Errata Rev Q.
Signed-off-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

The i2c controllers on the P1010 have an erratum where the documented
scheme for i2c bus recovery will not work (A-004447). A different
mechanism is needed which is documented in the P1010 Chip Errata Rev L.
Signed-off-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

The i2c controllers on the P2040/P2041 have an erratum where the
documented scheme for i2c bus recovery will not work (A-004447). A
different mechanism is needed which is documented in the P2040 Chip
Errata Rev Q (latest available at the time of writing).
Signed-off-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Document the fsl,i2c-erratum-a004447 flag which indicates the presence
of an i2c erratum on some QorIQ SoCs.
Signed-off-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-stm32f4.c:321: warning: expecting prototype for stm32f4_i2c_write_ byte()(). Prototype was for stm32f4_i2c_write_byte() instead
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NAlain Volmat <alain.volmat@foss.st.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-st.c:531: warning: expecting prototype for st_i2c_handle_write(). Prototype was for st_i2c_handle_read() instead
 drivers/i2c/busses/i2c-st.c:566: warning: expecting prototype for st_i2c_isr(). Prototype was for st_i2c_isr_thread() instead

Fix the "enmpty" typo while here.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NAlain Volmat <alain.volmat@foss.st.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-pnx.c:147: warning: Function parameter or member 'alg_data' not described in 'i2c_pnx_start'
 drivers/i2c/busses/i2c-pnx.c:147: warning: Excess function parameter 'adap' description in 'i2c_pnx_start'
 drivers/i2c/busses/i2c-pnx.c:202: warning: Function parameter or member 'alg_data' not described in 'i2c_pnx_stop'
 drivers/i2c/busses/i2c-pnx.c:202: warning: Excess function parameter 'adap' description in 'i2c_pnx_stop'
 drivers/i2c/busses/i2c-pnx.c:231: warning: Function parameter or member 'alg_data' not described in 'i2c_pnx_master_xmit'
 drivers/i2c/busses/i2c-pnx.c:231: warning: Excess function parameter 'adap' description in 'i2c_pnx_master_xmit'
 drivers/i2c/busses/i2c-pnx.c:301: warning: Function parameter or member 'alg_data' not described in 'i2c_pnx_master_rcv'
 drivers/i2c/busses/i2c-pnx.c:301: warning: Excess function parameter 'adap' description in 'i2c_pnx_master_rcv'
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-ocores.c:253: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/i2c/busses/i2c-ocores.c:267: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/i2c/busses/i2c-ocores.c:299: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/i2c/busses/i2c-ocores.c:347: warning: expecting prototype for It handles an IRQ(). Prototype was for ocores_process_polling() instead
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-eg20t.c:151: warning: bad line:                          PCH i2c controller
 drivers/i2c/busses/i2c-eg20t.c:369: warning: Function parameter or member 'msgs' not described in 'pch_i2c_writebytes'
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-designware-master.c:176: warning: expecting prototype for i2c_dw_init(). Prototype was for i2c_dw_init_master() instead
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-cadence.c:157: warning: expecting prototype for enum cdns_i2c_slave_mode. Prototype was for enum cdns_i2c_slave_state instead
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-ali1563.c:24: warning: expecting prototype for i2c(). Prototype was for ALI1563_MAX_TIMEOUT() instead
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/muxes/i2c-arb-gpio-challenge.c:43: warning: Function parameter or member 'muxc' not described in 'i2c_arbitrator_select'
 drivers/i2c/muxes/i2c-arb-gpio-challenge.c:43: warning: Function parameter or member 'chan' not described in 'i2c_arbitrator_select'
 drivers/i2c/muxes/i2c-arb-gpio-challenge.c:86: warning: Function parameter or member 'muxc' not described in 'i2c_arbitrator_deselect'
 drivers/i2c/muxes/i2c-arb-gpio-challenge.c:86: warning: Function parameter or member 'chan' not described in 'i2c_arbitrator_deselect'
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NDouglas Anderson <dianders@chromium.org>
Acked-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-nomadik.c:184: warning: Function parameter or member 'timeout' not described in 'nmk_i2c_dev'
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

When switching the Gen3 SoCs to the new clock calculation formulas, the
match entry for RZ/G2E added in commit 51243b73 ("i2c:
sh_mobile: Add support for r8a774c0 (RZ/G2E)") was forgotten.

Fixes: e8a27567 ("i2c: sh_mobile: use new clock calculation formulas for Gen3")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NFabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

The HiSilicon Kunpeng I2C controller driver relies on ACPI to probe for
its presence.  Hence add a dependency on ACPI, to prevent asking the
user about this driver when configuring a kernel without ACPI firmware
support.

Fixes: d62fbdb9 ("i2c: add support for HiSilicon I2C controller")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NYicong Yang <yangyicong@hisilicon.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

The last user of new_fwnode was removed, leading to:

    drivers/i2c/busses/i2c-icy.c: In function ‘icy_probe’:
    drivers/i2c/busses/i2c-icy.c:126:24: warning: unused variable ‘new_fwnode’ [-Wunused-variable]
      126 |  struct fwnode_handle *new_fwnode;
	  |                        ^~~~~~~~~~

Fixes: dd7a3710 ("i2c: icy: Constify the software node")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NMax Staudt <max@enpas.org>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

There is a spelling mistake in an error message string, fix it.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NAkash Asthana <akashast@codeaurora.org>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Pull perf fixes from Thomas Gleixner:
 "Two perf fixes:

   - Do not check the LBR_TOS MSR when setting up unrelated LBR MSRs as
     this can cause malfunction when TOS is not supported

   - Allocate the LBR XSAVE buffers along with the DS buffers upfront
     because allocating them when adding an event can deadlock"

* tag 'perf-urgent-2021-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/lbr: Remove cpuc->lbr_xsave allocation from atomic context
  perf/x86: Avoid touching LBR_TOS MSR for Arch LBR

Pull locking fixes from Thomas Gleixner:
 "Two locking fixes:

   - Invoke the lockdep tracepoints in the correct place so the ordering
     is correct again

   - Don't leave the mutex WAITER bit stale when the last waiter is
     dropping out early due to a signal as that forces all subsequent
     lock operations needlessly into the slowpath until it's cleaned up
     again"

* tag 'locking-urgent-2021-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: clear MUTEX_FLAGS if wait_list is empty due to signal
  locking/lockdep: Correct calling tracepoints

Pull irq fixes from Thomas Gleixner:
 "A few fixes for irqchip drivers:

   - Allocate interrupt descriptors correctly on Mainstone PXA when
     SPARSE_IRQ is enabled; otherwise the interrupt association fails

   - Make the APPLE AIC chip driver depend on APPLE

   - Remove redundant error output on devm_ioremap_resource() failure"

* tag 'irq-urgent-2021-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Remove redundant error printing
  irqchip/apple-aic: APPLE_AIC should depend on ARCH_APPLE
  ARM: PXA: Fix cplds irqdesc allocation when using legacy mode

Pull x86 fixes from Borislav Petkov:

 - Fix how SEV handles MMIO accesses by forwarding potential page faults
   instead of killing the machine and by using the accessors with the
   exact functionality needed when accessing memory.

 - Fix a confusion with Clang LTO compiler switches passed to the it

 - Handle the case gracefully when VMGEXIT has been executed in
   userspace

* tag 'x86_urgent_for_v5.13_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev-es: Use __put_user()/__get_user() for data accesses
  x86/sev-es: Forward page-faults which happen during emulation
  x86/sev-es: Don't return NULL from sev_es_get_ghcb()
  x86/build: Fix location of '-plugin-opt=' flags
  x86/sev-es: Invalidate the GHCB after completing VMGEXIT
  x86/sev-es: Move sev_es_put_ghcb() in prep for follow on patch

Pull powerpc fixes from Michael Ellerman:

 - Fix breakage of strace (and other ptracers etc.) when using the new
   scv ABI (Power9 or later with glibc >= 2.33).

 - Fix early_ioremap() on 64-bit, which broke booting on some machines.

Thanks to Dmitry V. Levin, Nicholas Piggin, Alexey Kardashevskiy, and
Christophe Leroy.

* tag 'powerpc-5.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls
  powerpc/64s/syscall: Use pt_regs.trap to distinguish syscall ABI difference between sc and scv syscalls
  powerpc: Fix early setup to make early_ioremap() work

Merge tag 'kbuild-fixes-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix short log indentation for tools builds

 - Fix dummy-tools to adjust to the latest stackprotector check

* tag 'kbuild-fixes-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: dummy-tools: adjust to stricter stackprotector check
  scripts/jobserver-exec: Fix a typo ("envirnoment")
  tools build: Fix quiet cmd indentation

Merge misc fixes from Andrew Morton:
 "10 patches.

  Subsystems affected by this patch series: mm (pagealloc, gup, kasan,
  and userfaultfd), ipc, selftests, watchdog, bitmap, procfs, and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  userfaultfd: hugetlbfs: fix new flag usage in error path
  lib: kunit: suppress a compilation warning of frame size
  proc: remove Alexey from MAINTAINERS
  linux/bits.h: fix compilation error with GENMASK
  watchdog: reliable handling of timestamps
  kasan: slab: always reset the tag in get_freepointer_safe()
  tools/testing/selftests/exec: fix link error
  ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry
  Revert "mm/gup: check page posion status for coredump."
  mm/shuffle: fix section mismatch warning

In commit d6995da3 ("hugetlb: use page.private for hugetlb specific
page flags") the use of PagePrivate to indicate a reservation count
should be restored at free time was changed to the hugetlb specific flag
HPageRestoreReserve.  Changes to a userfaultfd error path as well as a
VM_BUG_ON() in remove_inode_hugepages() were overlooked.

Users could see incorrect hugetlb reserve counts if they experience an
error with a UFFDIO_COPY operation.  Specifically, this would be the
result of an unlikely copy_huge_page_from_user error.  There is not an
increased chance of hitting the VM_BUG_ON.

Link: https://lkml.kernel.org/r/20210521233952.236434-1-mike.kravetz@oracle.com
Fixes: d6995da3 ("hugetlb: use page.private for hugetlb specific page flags")
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NMina Almasry <almasry.mina@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/bitfield_kunit.c: In function `test_bitfields_constants':
lib/bitfield_kunit.c:93:1: warning: the frame size of 7456 bytes is larger than 2048 bytes [-Wframe-larger-than=]
 }
 ^

As the description of BITFIELD_KUNIT in lib/Kconfig.debug, it "Only useful
for kernel devs running the KUnit test harness, and not intended for
inclusion into a production build".  Therefore, it is not worth modifying
variable 'test_bitfields_constants' to clear this warning.  Just suppress
it.

Link: https://lkml.kernel.org/r/20210518094533.7652-1-thunder.leizhen@huawei.comSigned-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

People Cc me and I don't have time.

Link: https://lkml.kernel.org/r/YKarMxHJBIhMHQIh@localhost.localdomainSigned-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

GENMASK() has an input check which uses __builtin_choose_expr() to
enable a compile time sanity check of its inputs if they are known at
compile time.

However, it turns out that __builtin_constant_p() does not always return
a compile time constant [0].  It was thought this problem was fixed with
gcc 4.9 [1], but apparently this is not the case [2].

Switch to use __is_constexpr() instead which always returns a compile time
constant, regardless of its inputs.

Link: https://lore.kernel.org/lkml/42b4342b-aefc-a16a-0d43-9f9c0d63ba7a@rasmusvillemoes.dk [0]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19449 [1]
Link: https://lore.kernel.org/lkml/1ac7bbc2-45d9-26ed-0b33-bf382b8d858b@I-love.SAKURA.ne.jp [2]
Link: https://lkml.kernel.org/r/20210511203716.117010-1-rikard.falkeborn@gmail.comSigned-off-by: NRikard Falkeborn <rikard.falkeborn@gmail.com>
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 9bf3bc94 ("watchdog: cleanup handling of false positives")
tried to handle a virtual host stopped by the host a more
straightforward and cleaner way.

But it introduced a risk of false softlockup reports.  The virtual host
might be stopped at any time, for example between
kvm_check_and_clear_guest_paused() and is_softlockup().  As a result,
is_softlockup() might read the updated jiffies and detects a softlockup.

A solution might be to put back kvm_check_and_clear_guest_paused() after
is_softlockup() and detect it.  But it would put back the cycle that
complicates the logic.

In fact, the handling of all the timestamps is not reliable.  The code
does not guarantee when and how many times the timestamps are read.  For
example, "period_ts" might be touched anytime also from NMI and re-read in
is_softlockup().  It works just by chance.

Fix all the problems by making the code even more explicit.

1. Make sure that "now" and "period_ts" timestamps are read only once.
   They might be changed at anytime by NMI or when the virtual guest is
   stopped by the host.  Note that "now" timestamp does this implicitly
   because "jiffies" is marked volatile.

2. "now" time must be read first.  The state of "period_ts" will
   decide whether it will be used or the period will get restarted.

3. kvm_check_and_clear_guest_paused() must be called before reading
   "period_ts".  It touches the variable when the guest was stopped.

As a result, "now" timestamp is used only when the watchdog was not
touched and the guest not stopped in the meantime.  "period_ts" is
restarted in all other situations.

Link: https://lkml.kernel.org/r/YKT55gw+RZfyoFf7@alley
Fixes: 9bf3bc94 ("watchdog: cleanup handling of false positives")
Signed-off-by: NPetr Mladek <pmladek@suse.com>
Reported-by: NSergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: NSergey Senozhatsky <senozhatsky@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With CONFIG_DEBUG_PAGEALLOC enabled, the kernel should also untag the
object pointer, as done in get_freepointer().

Failing to do so reportedly leads to SLUB freelist corruptions that
manifest as boot-time crashes.

Link: https://lkml.kernel.org/r/20210514072228.534418-1-glider@google.comSigned-off-by: NAlexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Elliot Berman <eberman@codeaurora.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the link error by adding '-static':

  gcc -Wall  -Wl,-z,max-page-size=0x1000 -pie load_address.c -o /home/yang/linux/tools/testing/selftests/exec/load_address_4096
  /usr/bin/ld: /tmp/ccopEGun.o: relocation R_AARCH64_ADR_PREL_PG_HI21 against symbol `stderr@@GLIBC_2.17' which may bind externally can not be used when making a shared object; recompile with -fPIC
  /usr/bin/ld: /tmp/ccopEGun.o(.text+0x158): unresolvable R_AARCH64_ADR_PREL_PG_HI21 relocation against symbol `stderr@@GLIBC_2.17'
  /usr/bin/ld: final link failed: bad value
  collect2: error: ld returned 1 exit status
  make: *** [Makefile:25: tools/testing/selftests/exec/load_address_4096] Error 1

Link: https://lkml.kernel.org/r/20210514092422.2367367-1-yangyingliang@huawei.com
Fixes: 206e22f0 ("tools/testing/selftests: add self-test for verifying load alignment")
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Cc: Chris Kennelly <ckennelly@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

do_mq_timedreceive calls wq_sleep with a stack local address.  The
sender (do_mq_timedsend) uses this address to later call pipelined_send.

This leads to a very hard to trigger race where a do_mq_timedreceive
call might return and leave do_mq_timedsend to rely on an invalid
address, causing the following crash:

  RIP: 0010:wake_q_add_safe+0x13/0x60
  Call Trace:
   __x64_sys_mq_timedsend+0x2a9/0x490
   do_syscall_64+0x80/0x680
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f5928e40343

The race occurs as:

1. do_mq_timedreceive calls wq_sleep with the address of `struct
   ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it
   holds a valid `struct ext_wait_queue *` as long as the stack has not
   been overwritten.

2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and
   do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call
   __pipelined_op.

3. Sender calls __pipelined_op::smp_store_release(&this->state,
   STATE_READY).  Here is where the race window begins.  (`this` is
   `ewq_addr`.)

4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it
   will see `state == STATE_READY` and break.

5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed
   to be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's
   stack.  (Although the address may not get overwritten until another
   function happens to touch it, which means it can persist around for an
   indefinite time.)

6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a
   `struct ext_wait_queue *`, and uses it to find a task_struct to pass to
   the wake_q_add_safe call.  In the lucky case where nothing has
   overwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.
   In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a
   bogus address as the receiver's task_struct causing the crash.

do_mq_timedsend::__pipelined_op() should not dereference `this` after
setting STATE_READY, as the receiver counterpart is now free to return.
Change __pipelined_op to call wake_q_add_safe on the receiver's
task_struct returned by get_task_struct, instead of dereferencing `this`
which sits on the receiver's stack.

As Manfred pointed out, the race potentially also exists in
ipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare.  Fix
those in the same way.

Link: https://lkml.kernel.org/r/20210510102950.12551-1-varad.gautam@suse.com
Fixes: c5b2cbdb ("ipc/mqueue.c: update/document memory barriers")
Fixes: 8116b54e ("ipc/sem.c: document and update memory barriers")
Fixes: 0d97a82b ("ipc/msg.c: update and document memory barriers")
Signed-off-by: NVarad Gautam <varad.gautam@suse.com>
Reported-by: NMatthias von Faber <matthias.vonfaber@aox-tech.de>
Acked-by: NDavidlohr Bueso <dbueso@suse.de>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While reviewing [1] I came across commit d3378e86 ("mm/gup: check
page posion status for coredump.") and noticed that this patch is broken
in two ways.  First it doesn't really prevent hwpoison pages from being
dumped because hwpoison pages can be marked asynchornously at any time
after the check.  Secondly, and more importantly, the patch introduces a
ref count leak because get_dump_page takes a reference on the page which
is not released.

It also seems that the patch was merged incorrectly because there were
follow up changes not included as well as discussions on how to address
the underlying problem [2]

Therefore revert the original patch.

Link: http://lkml.kernel.org/r/20210429122519.15183-4-david@redhat.com [1]
Link: http://lkml.kernel.org/r/57ac524c-b49a-99ec-c1e4-ef5027bfb61b@redhat.com [2]
Link: https://lkml.kernel.org/r/20210505135407.31590-1-mhocko@kernel.org
Fixes: d3378e86 ("mm/gup: check page posion status for coredump.")
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Aili Yao <yaoaili@kingsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

clang sometimes decides not to inline shuffle_zone(), but it calls a
__meminit function.  Without the extra __meminit annotation we get this
warning:

  WARNING: modpost: vmlinux.o(.text+0x2a86d4): Section mismatch in reference from the function shuffle_zone() to the function .meminit.text:__shuffle_zone()
  The function shuffle_zone() references
  the function __meminit __shuffle_zone().
  This is often because shuffle_zone lacks a __meminit
  annotation or the annotation of __shuffle_zone is wrong.

shuffle_free_memory() did not show the same problem in my tests, but it
could happen in theory as well, so mark both as __meminit.

Link: https://lkml.kernel.org/r/20210514135952.2928094-1-arnd@kernel.orgSigned-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NNathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull block fixes from Jens Axboe:

 - Fix BLKRRPART and deletion race (Gulam, Christoph)

 - NVMe pull request (Christoph):
      - nvme-tcp corruption and timeout fixes (Sagi Grimberg, Keith
        Busch)
      - nvme-fc teardown fix (James Smart)
      - nvmet/nvme-loop memory leak fixes (Wu Bo)"

* tag 'block-5.13-2021-05-22' of git://git.kernel.dk/linux-block:
  block: fix a race between del_gendisk and BLKRRPART
  block: prevent block device lookups at the beginning of del_gendisk
  nvme-fc: clear q_live at beginning of association teardown
  nvme-tcp: rerun io_work if req_list is not empty
  nvme-tcp: fix possible use-after-completion
  nvme-loop: fix memory leak in nvme_loop_create_ctrl()
  nvmet: fix memory leak in nvmet_alloc_ctrl()