Arnd reports that commit

  9302c1bb8e47 ("efi/libstub: Rewrite file I/O routine")

reworks the file I/O routines in a way that triggers the following
warning:

  drivers/firmware/efi/libstub/file.c:240:1: warning: the frame size
            of 1200 bytes is larger than 1024 bytes [-Wframe-larger-than=]

We can work around this issue dropping an instance of efi_char16_t[256]
from the stack frame, and reusing the 'filename' field of the file info
struct that we use to obtain file information from EFI (which contains
the file name even though we already know it since we used it to open
the file in the first place)

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-8-ardb@kernel.org

Commit

  d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary")

tries to avoid relocating the kernel in the EFI stub as far as possible.

However, when systemd-boot is used to boot a unified kernel image [1],
the image is constructed by embedding the bzImage as a .linux section in
a PE executable that contains a small stub loader from systemd that will
call the EFI stub handover entry, together with additional sections and
potentially an initrd. When this image is constructed, by for example
dracut, the initrd is placed after the bzImage without ensuring that at
least init_size bytes are available for the bzImage. If the kernel is
not relocated by the EFI stub, this could result in the compressed
kernel's startup code in head_{32,64}.S overwriting the initrd.

To prevent this, unconditionally relocate the kernel if the EFI stub was
entered via the handover entry point.

[1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images

Fixes: d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary")
Reported-by: Sergey Shatunov <me@prok.pw>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200406180614.429454-2-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200409130434.6736-5-ardb@kernel.org

Commit

  3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")

removed the .bss section from the bzImage.

However, while a PE loader is required to zero-initialize the .bss
section before calling the PE entry point, the EFI handover protocol
does not currently document any requirement that .bss be initialized by
the bootloader prior to calling the handover entry.

When systemd-boot is used to boot a unified kernel image [1], the image
is constructed by embedding the bzImage as a .linux section in a PE
executable that contains a small stub loader from systemd together with
additional sections and potentially an initrd. As the .bss section
within the bzImage is no longer explicitly present as part of the file,
it is not initialized before calling the EFI handover entry.
Furthermore, as the size of the embedded .linux section is only the size
of the bzImage file itself, the .bss section's memory may not even have
been allocated.

In particular, this can result in efi_disable_pci_dma being true even
when it was not specified via the command line or configuration option,
which in turn causes crashes while booting on some systems.

To avoid issues, place all EFI stub global variables into the .data
section instead of .bss. As of this writing, only boolean flags for a
few command line arguments and the sys_table pointer were in .bss and
will now move into the .data section.

[1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images

Fixes: 3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")
Reported-by: Sergey Shatunov <me@prok.pw>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200406180614.429454-1-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200409130434.6736-4-ardb@kernel.org

The pointer hdr is being assigned a value that is never read and
it is being updated later with a new value. The assignment is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200402102537.503103-1-colin.king@canonical.com
Link: https://lore.kernel.org/r/20200409130434.6736-3-ardb@kernel.org

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200311072145.5001-1-tiwai@suse.de
Link: https://lore.kernel.org/r/20200409130434.6736-2-ardb@kernel.org

Pull sound fixes from Takashi Iwai:
 "A collection of small fixes gathered since the previous update.

  ALSA core:
   - Regression fix for OSS PCM emulation

  ASoC:
   - Trivial fixes in reg bit mask ops, DAPM, DPCM and topology
   - Lots of fixes for Intel-based devices
   - Minor fixes for AMD, STM32, Qualcomm, Realtek

  Others:
   - Fixes for the bugs in mixer handling in HD-audio and ice1724
     drivers that were caught by the recent kctl validator
   - New quirks for HD-audio and USB-audio

  Also this contains a fix for EDD firmware fix, which slipped from
  anyone's hands"

* tag 'sound-fix-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (35 commits)
  ALSA: hda: Add driver blacklist
  ALSA: usb-audio: Add mixer workaround for TRX40 and co
  ALSA: hda/realtek - Add quirk for MSI GL63
  ALSA: ice1724: Fix invalid access for enumerated ctl items
  ALSA: hda: Fix potential access overflow in beep helper
  ASoC: cs4270: pull reset GPIO low then high
  ALSA: hda/realtek - Add HP new mute led supported for ALC236
  ALSA: hda/realtek - Add supported new mute Led for HP
  ASoC: rt5645: Add platform-data for Medion E1239T
  ASoC: Intel: bytcr_rt5640: Add quirk for MPMAN MPWIN895CL tablet
  ASoC: stm32: sai: Add missing cleanup
  ALSA: usb-audio: Add registration quirk for Kingston HyperX Cloud Alpha S
  ASoC: Intel: atom: Fix uninitialized variable compiler warning
  ASoC: Intel: atom: Check drv->lock is locked in sst_fill_and_send_cmd_unlocked
  ASoC: Intel: atom: Take the drv->lock mutex before calling sst_send_slot_map()
  ASoC: SOF: Turn "firmware boot complete" message into a dbg message
  ALSA: usb-audio: Add Pioneer DJ DJM-250MK2 quirk
  ALSA: pcm: oss: Fix regression by buffer overflow fix (again)
  ALSA: pcm: oss: Fix regression by buffer overflow fix
  edd: Use scnprintf() for avoiding potential buffer overflow
  ...

Pull arm64 fixes from Catalin Marinas:

 - Ensure that the compiler and linker versions are aligned so that ld
   doesn't complain about not understanding a .note.gnu.property section
   (emitted when pointer authentication is enabled).

 - Force -mbranch-protection=none when the feature is not enabled, in
   case a compiler may choose a different default value.

 - Remove CONFIG_DEBUG_ALIGN_RODATA. It was never in defconfig and
   rarely enabled.

 - Fix checking 16-bit Thumb-2 instructions checking mask in the
   emulation of the SETEND instruction (it could match the bottom half
   of a 32-bit Thumb-2 instruction).

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: armv8_deprecated: Fix undef_hook mask for thumb setend
  arm64: remove CONFIG_DEBUG_ALIGN_RODATA feature
  arm64: Always force a branch protection mode when the compiler has one
  arm64: Kconfig: ptrauth: Add binutils version check to fix mismatch
  init/kconfig: Add LD_VERSION Kconfig

Pull ARM driver updates from Arnd Bergmann:
 "These are the usual updates for SoC specific device drivers and
  related subsystems that don't have their own top-level maintainers:

   - ARM SCMI/SCPI updates to allow pluggable transport layers

   - TEE subsystem cleanups

   - A new driver for the Amlogic secure power domain controller

   - Various driver updates for the NXP Layerscape DPAA2, NXP i.MX SCU
     and TI OMAP2+ sysc drivers.

   - Qualcomm SoC driver updates, including a new library module for
     "protection domain" notifications

   - Lots of smaller bugfixes and cleanups in other drivers"

* tag 'arm-drivers-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (70 commits)
  soc: fsl: qe: fix sparse warnings for ucc_slow.c
  soc: fsl: qe: ucc_slow: remove 0 assignment for kzalloc'ed structure
  soc: fsl: qe: fix sparse warnings for ucc_fast.c
  soc: fsl: qe: fix sparse warnings for qe_ic.c
  soc: fsl: qe: fix sparse warnings for ucc.c
  soc: fsl: qe: fix sparse warning for qe_common.c
  soc: fsl: qe: fix sparse warnings for qe.c
  soc: qcom: Fix QCOM_APR dependencies
  soc: qcom: pdr: Avoid uninitialized use of found in pdr_indication_cb
  soc: imx: drop COMPILE_TEST for IMX_SCU_SOC
  firmware: imx: add COMPILE_TEST for IMX_SCU driver
  soc: imx: gpc: fix power up sequencing
  soc: imx: increase build coverage for imx8m soc driver
  soc: qcom: apr: Add avs/audio tracking functionality
  dt-bindings: soc: qcom: apr: Add protection domain bindings
  soc: qcom: Introduce Protection Domain Restart helpers
  devicetree: bindings: firmware: add ipq806x to qcom_scm
  memory: tegra: Correct debugfs clk rate-range on Tegra124
  memory: tegra: Correct debugfs clk rate-range on Tegra30
  memory: tegra: Correct debugfs clk rate-range on Tegra20
  ...

Pull ARM SoC updates from Arnd Bergmann:
 "The code changes are mostly for 32-bit platforms and include:

   - Lots of updates for the Nvidia Tegra platform, including cpuidle,
     pmc, and dt-binding changes

   - Microchip at91 power management updates for the recently added
     sam9x60 SoC

   - Treewide setup_irq deprecation by afzal mohammed

   - STMicroelectronics stm32 gains earlycon support

   - Renesas platforms with Cortex-A9 can now use the global timer

   - Some TI OMAP2+ platforms gain cpuidle support

   - Various cleanups for the i.MX6 and Orion platforms, as well as
     Kconfig files across all platforms"

* tag 'arm-soc-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (75 commits)
  ARM: qcom: Add support for IPQ40xx
  ARM: mmp: replace setup_irq() by request_irq()
  ARM: cns3xxx: replace setup_irq() by request_irq()
  ARM: spear: replace setup_irq() by request_irq()
  ARM: ep93xx: Replace setup_irq() by request_irq()
  ARM: iop32x: replace setup_irq() by request_irq()
  arm: mach-dove: Mark dove_io_desc as __maybe_unused
  ARM: orion: replace setup_irq() by request_irq()
  ARM: debug: stm32: add UART early console support for STM32MP1
  ARM: debug: stm32: add UART early console support for STM32H7
  ARM: debug: stm32: add UART early console configuration for STM32F7
  ARM: debug: stm32: add UART early console configuration for STM32F4
  cpuidle: tegra: Disable CC6 state if LP2 unavailable
  cpuidle: tegra: Squash Tegra114 driver into the common driver
  cpuidle: tegra: Squash Tegra30 driver into the common driver
  cpuidle: Refactor and move out NVIDIA Tegra20 driver into drivers/cpuidle
  ARM: tegra: cpuidle: Remove unnecessary memory barrier
  ARM: tegra: cpuidle: Make abort_flag atomic
  ARM: tegra: cpuidle: Handle case where secondary CPU hangs on entering LP2
  ARM: tegra: Make outer_disable() open-coded
  ...

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char/misc/other driver patches for 5.7-rc1.

  Lots of things in here, and it's later than expected due to some
  reverts to resolve some reported issues. All is now clean with no
  reported problems in linux-next.

  Included in here is:
   - interconnect updates
   - mei driver updates
   - uio updates
   - nvmem driver updates
   - soundwire updates
   - binderfs updates
   - coresight updates
   - habanalabs updates
   - mhi new bus type and core
   - extcon driver updates
   - some Kconfig cleanups
   - other small misc driver cleanups and updates

  As mentioned, all have been in linux-next for a while, and with the
  last two reverts, all is calm and good"

* tag 'char-misc-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (174 commits)
  Revert "driver core: platform: Initialize dma_parms for platform devices"
  Revert "amba: Initialize dma_parms for amba devices"
  amba: Initialize dma_parms for amba devices
  driver core: platform: Initialize dma_parms for platform devices
  bus: mhi: core: Drop the references to mhi_dev in mhi_destroy_device()
  bus: mhi: core: Initialize bhie field in mhi_cntrl for RDDM capture
  bus: mhi: core: Add support for reading MHI info from device
  misc: rtsx: set correct pcr_ops for rts522A
  speakup: misc: Use dynamic minor numbers for speakup devices
  mei: me: add cedar fork device ids
  coresight: do not use the BIT() macro in the UAPI header
  Documentation: provide IBM contacts for embargoed hardware
  nvmem: core: remove nvmem_sysfs_get_groups()
  nvmem: core: use is_bin_visible for permissions
  nvmem: core: use device_register and device_unregister
  nvmem: core: add root_only member to nvmem device struct
  extcon: axp288: Add wakeup support
  extcon: Mark extcon_get_edev_name() function as exported symbol
  extcon: palmas: Hide error messages if gpio returns -EPROBE_DEFER
  dt-bindings: extcon: usbc-cros-ec: convert extcon-usbc-cros-ec.txt to yaml format
  ...