Add SMBus PCI ID on Intel Tiger Lake PCH-H.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add support for SMBus controller on Intel Emmitsburg PCH. This is the
same IP as used in Cannon Lake and derivatives.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
[wsa: shortened commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

And it has been for a while (since 2012 at least), only it was not
documented. Add it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Make the Microchip at91 driver the first to use the generic GPIO bus
recovery support from the I2C core and discard the driver implementation.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Even if I2C bus GPIO recovery is optional, devm_gpiod_get() can return
-EPROBE_DEFER, so we should at least treat that. This ends up with
i2c_register_adapter() to be able to return -EPROBE_DEFER.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Multiple I2C bus drivers use similar bindings to obtain information needed
for I2C recovery. For example, for platforms using device-tree, the
properties look something like this:

&i2c {
	...
	pinctrl-names = "default", "gpio";
	pinctrl-0 = <&pinctrl_i2c_default>;
	pinctrl-1 = <&pinctrl_i2c_gpio>;
	sda-gpios = <&pio 0 GPIO_ACTIVE_HIGH>;
	scl-gpios = <&pio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
	...
}

For this reason, we can add this common initialization in the core. This
way, other I2C bus drivers will be able to support GPIO recovery just by
providing a pointer to platform's pinctrl and calling i2c_recover_bus()
when SDA is stuck low.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
[wsa: inverted one logic for better readability, minor update to kdoc]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

The I2C GPIO bus recovery properties consist of two GPIOS and one extra
pinctrl state ("gpio" or "recovery"). "recovery" pinctrl state is
considered deprecated and "gpio" should be used instead.
Not all are mandatory for recovery.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Reviewed-by: Rob Herring <robh@kernel.org>
[wsa: kept sorting, minor whitespace change]
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Due to the lockless design of the driver, it is theoretically possible
to access a NULL pointer, if a slave interrupt was running while we were
unregistering the slave. To make this rock solid, disable the interrupt
for a short time while we are clearing the interrupt_enable register.
This patch is purely based on code inspection. The OOPS is super-hard to
trigger because clearing SAR (the address) makes interrupts even more
unlikely to happen as well. While here, reinit SCR to SDBS because this
bit should always be set according to documentation. There is no effect,
though, because the interface is disabled.

Fixes: 7b814d85 ("i2c: rcar: avoid race when unregistering slave client")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

VI I2C is on host1x bus so APB DMA can't be used for Tegra210 VI
I2C and there are no tx and rx dma channels for VI I2C.

So, avoid attempt of requesting DMA channels.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

VI I2C is on host1x bus and is part of VE power domain.

During suspend/resume VE power domain goes through power off/on.

So, controller reset followed by i2c re-initialization is required
after the domain power up.

This patch fixes it.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

tegra_i2c_runtime_resume does not disable prior enabled clocks
properly.

This patch fixes it.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

clk_enable, clk_disable, clk_prepare, and clk_unprepare APIs have
implementation for checking clk pointer not NULL and clock consumers
can safely call these APIs without NULL pointer check.

So, this patch cleans up Tegra i2c driver to remove explicit checks
before these APIs.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Tegra VI I2C is part of VE power domain and typically used for
camera usecases.

VE power domain is not always on and is non-IRQ safe. So, IRQ safe
device cannot be attached to a non-IRQ safe domain as it prevents
powering off the PM domain and generic power domain driver will warn.

Current driver marks all I2C devices as IRQ safe and VI I2C device
does not require IRQ safe as it will not be used for atomic transfers.

This patch has fix to make VI I2C as non-IRQ safe.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Let's rather use its physical parent device to give proper namings and
connections in debugfs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild into master

Pull Kbuild fixes from Masahiro Yamada:

 - do not use non-portable strsep() in a host program

 - fix single target builds for external modules

 - change Clang's --prefix option to make it work for the latest Clang

* tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation
  kbuild: fix single target builds for external modules
  modpost: remove use of non-standard strsep() in HOSTCC code

Merge branch 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into master

Pull parisc fixes from Helge Deller:
 "Two fixes:

   - Add the cmpxchg() function for pointers to u8 values. This fixes a
     kernel linking error when building the tusb1210 driver (from Liam
     Beguin).

   - Add a define for atomic64_set_release() to fix CPU soft lockups
     which happen because of missing unlocks while processing bit
     operations (from John David Anglin)"

* 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Add atomic64_set_release() define to avoid CPU soft lockups
  parisc: add support for cmpxchg on u8 pointers

Merge tag 'char-misc-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc into master

Pull char/misc driver fixes from Greg KH:
 "Here are a few small driver fixes for 5.8-rc7

  They include:

   - habanalabs fixes

   - tiny fpga driver fixes

   - /dev/mem fixup from previous changes

   - interconnect driver fixes

   - binder fix

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  interconnect: msm8916: Fix buswidth of pcnoc_s nodes
  interconnect: Do not skip aggregation for disabled paths
  /dev/mem: Add missing memory barriers for devmem_inode
  binder: Don't use mmput() from shrinker function.
  habanalabs: prevent possible out-of-bounds array access
  fpga: dfl: fix bug in port reset handshake
  fpga: dfl: pci: reduce the scope of variable 'ret'
  habanalabs: set 4s timeout for message to device CPU
  habanalabs: set clock gating per engine
  habanalabs: block WREG_BULK packet on PDMA

Merge tag 'driver-core-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into master

Pull driver core fix from Greg KH:
 "A single driver core fix for 5.8-rc7. It resolves a problem found in
  the previous fix for this code made in 5.8-rc6. Hopefully this is all
  now cleared up, as this seems to be the last of the reported issues in
  this area, and was tested on the problem hardware.

  This patch has been in linux-next with no reported problems"

* tag 'driver-core-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  device property: Avoid NULL pointer dereference in device_get_next_child_node()

Merge tag 'staging-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging into master

Pull staging driver fixes from Greg KH:
 "Five small staging driver fixes for 5.8-rc7 to resolve some reported
  problems:

   - four comedi driver fixes for problems found with them

   - a syzbot-found fix for the wlang-ng driver that resolves a much
     reported problem.

  All of these have been in linux-next with no reported issues"

* tag 'staging-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: wlan-ng: properly check endpoint types
  staging: comedi: addi_apci_1564: check INSN_CONFIG_DIGITAL_TRIG shift
  staging: comedi: addi_apci_1500: check INSN_CONFIG_DIGITAL_TRIG shift
  staging: comedi: addi_apci_1032: check INSN_CONFIG_DIGITAL_TRIG shift
  staging: comedi: ni_6527: fix INSN_CONFIG_DIGITAL_TRIG support

Pull tty/serial/fbcon fixes from Greg KH:
 "Here are some small tty and serial and fbcon fixes for 5.8-rc7 to
  resolve some reported issues.

  The fbcon fix is in here as it was simpler to take it this way (and it
  was acked by the maintainer) as it was related to the vt console fix
  as well, both of which resolve syzbot-found issues in the console
  handling code.

  The other serial driver fixes are for small issues reported in the -rc
  releases.

  All of these have been in linux-next with no reported issues"

* tag 'tty-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: exar: Fix GPIO configuration for Sealevel cards based on XR17V35X
  fbdev: Detect integer underflow at "struct fbcon_ops"->clear_margins.
  serial: 8250_mtk: Fix high-speed baud rates clamping
  serial: 8250: fix null-ptr-deref in serial8250_start_tx()
  serial: tegra: drop bogus NULL tty-port checks
  serial: tegra: fix CREAD handling for PIO
  tty: xilinx_uartps: Really fix id assignment
  vt: Reject zero-sized screen buffer size.

Pull USB fixes from Greg KH:
 "Three small USB XHCI driver fixes for 5.8-rc7.

  They all resolve some minor issues that have been reported on some
  different platforms.

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: tegra: Fix allocation for the FPCI context
  usb: xhci: Fix ASM2142/ASM3142 DMA addressing
  usb: xhci-mtk: fix the failure of bandwidth allocation

Pull SCSI fix from James Bottomley:
 "Small core patch to fix a corner case bug: we forgot to run the queues
  to handle starvation in the error exit from the scsi_queue_rq routine,
  which can lead to hangs on error conditions"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: core: Run queue in case of I/O resource contention failure

Document IIC controller for RZ/G2H (R8A774E1) SoC, which is compatible
with R-Car Gen3 SoC family.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Document i2c controller for RZ/G2H (R8A774E1) SoC, which is compatible
with R-Car Gen3 SoC family.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

When the SSR interrupt is activated, it will detect every STOP condition
on the bus, not only the ones after we have been addressed. So, enable
this interrupt only after we have been addressed, and disable it
otherwise.

Fixes: de20d185 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'riscv-for-linus-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux into master

Pull RISC-V fixes from Palmer Dabbelt:
 "A few more fixes this week:

   - A fix to avoid using SBI calls during kasan initialization, as the
     SBI calls themselves have not been probed yet.

   - Three fixes related to systems with multiple memory regions"

* tag 'riscv-for-linus-5.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Parse all memory blocks to remove unusable memory
  RISC-V: Do not rely on initrd_start/end computed during early dt parsing
  RISC-V: Set maximum number of mapped pages correctly
  riscv: kasan: use local_tlb_flush_all() to avoid uninitialized __sbi_rfence

Merge tag 'x86-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - Fix a section end page alignment assumption that was causing
     crashes

   - Fix ORC unwinding on freshly forked tasks which haven't executed
     yet and which have empty user task stacks

   - Fix the debug.exception-trace=1 sysctl dumping of user stacks,
     which was broken by recent maccess changes"

* tag 'x86-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/dumpstack: Dump user space code correctly again
  x86/stacktrace: Fix reliable check for empty user task stacks
  x86/unwind/orc: Fix ORC for newly forked tasks
  x86, vmlinux.lds: Page-align end of ..page_aligned sections

Merge tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull uprobe fix from Ingo Molnar:
 "Fix an interaction/regression between uprobes based shared library
  tracing & GDB"

* tag 'perf-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression

Merge tag 'timers-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull timer fix from Ingo Molnar:
 "Fix a suspend/resume regression (crash) on TI AM3/AM4 SoC's"

* tag 'timers-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4

Merge tag 'sched-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull scheduler fixes from Ingo Molnar:
 "Fix a race introduced by the recent loadavg race fix, plus add a debug
  check for a hard to debug case of bogus wakeup function flags"

* tag 'sched-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Warn if garbage is passed to default_wake_function()
  sched: Fix race against ptrace_freeze_trace()

Merge tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull EFI fixes from Ingo Molnar:
 "Various EFI fixes:

   - Fix the layering violation in the use of the EFI runtime services
     availability mask in users of the 'efivars' abstraction

   - Revert build fix for GCC v4.8 which is no longer supported

   - Clean up some x86 EFI stub details, some of which are borderline
     bugs that copy around garbage into padding fields - let's fix these
     out of caution.

   - Fix build issues while working on RISC-V support

   - Avoid --whole-archive when linking the stub on arm64"

* tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Revert "efi/x86: Fix build with gcc 4"
  efi/efivars: Expose RT service availability via efivars abstraction
  efi/libstub: Move the function prototypes to header file
  efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds
  efi/libstub/arm64: link stub lib.a conditionally
  efi/x86: Only copy upto the end of setup_header
  efi/x86: Remove unused variables

Pull cifs fix from Steve French:
 "A fix for a recently discovered regression in rename to older servers
  caused by a recent patch"

* tag '5.8-rc6-cifs-fix' of git://git.samba.org/sfrench/cifs-2.6:
  Revert "cifs: Fix the target file was deleted when rename failed."

Pull networking fixes from David Miller:

 1) Fix RCU locaking in iwlwifi, from Johannes Berg.

 2) mt76 can access uninitialized NAPI struct, from Felix Fietkau.

 3) Fix race in updating pause settings in bnxt_en, from Vasundhara
    Volam.

 4) Propagate error return properly during unbind failures in ax88172a,
    from George Kennedy.

 5) Fix memleak in adf7242_probe, from Liu Jian.

 6) smc_drv_probe() can leak, from Wang Hai.

 7) Don't muck with the carrier state if register_netdevice() fails in
    the bonding driver, from Taehee Yoo.

 8) Fix memleak in dpaa_eth_probe, from Liu Jian.

 9) Need to check skb_put_padto() return value in hsr_fill_tag(), from
    Murali Karicheri.

10) Don't lose ionic RSS hash settings across FW update, from Shannon
    Nelson.

11) Fix clobbered SKB control block in act_ct, from Wen Xu.

12) Missing newlink in "tx_timeout" sysfs output, from Xiongfeng Wang.

13) IS_UDPLITE cleanup a long time ago, incorrectly handled
    transformations involving UDPLITE_RECV_CC. From Miaohe Lin.

14) Unbalanced locking in netdevsim, from Taehee Yoo.

15) Suppress false-positive error messages in qed driver, from Alexander
    Lobakin.

16) Out of bounds read in ax25_connect and ax25_sendmsg, from Peilin Ye.

17) Missing SKB release in cxgb4's uld_send(), from Navid Emamdoost.

18) Uninitialized value in geneve_changelink(), from Cong Wang.

19) Fix deadlock in xen-netfront, from Andera Righi.

19) flush_backlog() frees skbs with IRQs disabled, so should use
    dev_kfree_skb_irq() instead of kfree_skb(). From Subash Abhinov
    Kasiviswanathan.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (111 commits)
  drivers/net/wan: lapb: Corrected the usage of skb_cow
  dev: Defer free of skbs in flush_backlog
  qrtr: orphan socket in qrtr_release()
  xen-netfront: fix potential deadlock in xennet_remove()
  flow_offload: Move rhashtable inclusion to the source file
  geneve: fix an uninitialized value in geneve_changelink()
  bonding: check return value of register_netdevice() in bond_newlink()
  tcp: allow at most one TLP probe per flight
  AX.25: Prevent integer overflows in connect and sendmsg
  cxgb4: add missing release on skb in uld_send()
  net: atlantic: fix PTP on AQC10X
  AX.25: Prevent out-of-bounds read in ax25_sendmsg()
  sctp: shrink stream outq when fails to do addstream reconf
  sctp: shrink stream outq only when new outcnt < old outcnt
  AX.25: Fix out-of-bounds read in ax25_connect()
  enetc: Remove the mdio bus on PF probe bailout
  net: ethernet: ti: add NETIF_F_HW_TC hw feature flag for taprio offload
  net: ethernet: ave: Fix error returns in ave_init
  drivers/net/wan/x25_asy: Fix to make it work
  ipvs: fix the connection sync failed in some cases
  ...

Currently, maximum physical memory allowed is equal to -PAGE_OFFSET.
That's why we remove any memory blocks spanning beyond that size. However,
it is done only for memblock containing linux kernel which will not work
if there are multiple memblocks.

Process all memory blocks to figure out how much memory needs to be removed
and remove at the end instead of updating the memblock list in place.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Currently, initrd_start/end are computed during early_init_dt_scan
but used during arch_setup. We will get the following panic if initrd is used
and CONFIG_DEBUG_VIRTUAL is turned on.

[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at arch/riscv/mm/physaddr.c:33!
[    0.000000] Kernel BUG [#1]
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00015-ged0b226fed02 #886
[    0.000000] epc: ffffffe0002058d2 ra : ffffffe0000053f0 sp : ffffffe001001f40
[    0.000000]  gp : ffffffe00106e250 tp : ffffffe001009d40 t0 : ffffffe00107ee28
[    0.000000]  t1 : 0000000000000000 t2 : ffffffe000a2e880 s0 : ffffffe001001f50
[    0.000000]  s1 : ffffffe0001383e8 a0 : ffffffe00c087e00 a1 : 0000000080200000
[    0.000000]  a2 : 00000000010bf000 a3 : ffffffe00106f3c8 a4 : ffffffe0010bf000
[    0.000000]  a5 : ffffffe000000000 a6 : 0000000000000006 a7 : 0000000000000001
[    0.000000]  s2 : ffffffe00106f068 s3 : ffffffe00106f070 s4 : 0000000080200000
[    0.000000]  s5 : 0000000082200000 s6 : 0000000000000000 s7 : 0000000000000000
[    0.000000]  s8 : 0000000080011010 s9 : 0000000080012700 s10: 0000000000000000
[    0.000000]  s11: 0000000000000000 t3 : 000000000001fe30 t4 : 000000000001fe30
[    0.000000]  t5 : 0000000000000000 t6 : ffffffe00107c471
[    0.000000] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[    0.000000] random: get_random_bytes called from print_oops_end_marker+0x22/0x46 with crng_init=0

To avoid the error, initrd_start/end can be computed from phys_initrd_start/size
in setup itself. It also improves the initrd placement by aligning the start
and size with the page size.

Fixes: 76d2a049 ("RISC-V: Init and Halt Code")
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

This patch fixed 2 issues with the usage of skb_cow in LAPB drivers
"lapbether" and "hdlc_x25":

1) After skb_cow fails, kfree_skb should be called to drop a reference
to the skb. But in both drivers, kfree_skb is not called.

2) skb_cow should be called before skb_push so that is can ensure the
safety of skb_push. But in "lapbether", it is incorrectly called after
skb_push.

More details about these 2 issues:

1) The behavior of calling kfree_skb on failure is also the behavior of
netif_rx, which is called by this function with "return netif_rx(skb);".
So this function should follow this behavior, too.

2) In "lapbether", skb_cow is called after skb_push. This results in 2
logical issues:
   a) skb_push is not protected by skb_cow;
   b) An extra headroom of 1 byte is ensured after skb_push. This extra
      headroom has no use in this function. It also has no use in the
      upper-layer function that this function passes the skb to
      (x25_lapb_receive_frame in net/x25/x25_dev.c).
So logically skb_cow should instead be called before skb_push.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IRQs are disabled when freeing skbs in input queue.
Use the IRQ safe variant to free skbs here.

Fixes: 145dd5f9 ("net: flush the softnet backlog in process context")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>