Commit

  8117961d98fb2 ("x86/efi: Disregard setup header of loaded image")

dropped the memcopy of the image's setup header into the boot_params
struct provided to the core kernel, on the basis that EFI boot does not
need it and should rely only on a single protocol to interface with the
boot chain. It is also a prerequisite for being able to increase the
section alignment to 4k, which is needed to enable memory protections
when running in the boot services.

So only the setup_header fields that matter to the core kernel are
populated explicitly, and everything else is ignored. One thing was
overlooked, though: the initrd_addr_max field in the setup_header is not
used by the core kernel, but it is used by the EFI stub itself when it
loads the initrd, where its default value of INT_MAX is used as the soft
limit for memory allocation.

This means that, in the old situation, the initrd was virtually always
loaded in the lower 2G of memory, but now, due to initrd_addr_max being
0x0, the initrd may end up anywhere in memory. This should not be an
issue principle, as most systems can deal with this fine. However, it
does appear to tickle some problems in older UEFI implementations, where
the memory ends up being corrupted, resulting in errors when unpacking
the initramfs.

So set the initrd_addr_max field to INT_MAX like it was before.

Fixes: 8117961d98fb2 ("x86/efi: Disregard setup header of loaded image")
Reported-by: Radek Podgorny <radek@podgorny.cz>
Closes: https://lore.kernel.org/all/a99a831a-8ad5-4cb0-bff9-be637311f771@podgorny.cz
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Avoid a type mismatch warning in max() by switching to max_t() and
providing the type explicitly.

Fixes: 3cb4a4827596abc82e ("efi/libstub: fix efi_random_alloc() ...")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Pull EFI fixes from Ard Biesheuvel:

 - Fix logic that is supposed to prevent placement of the kernel image
   below LOAD_PHYSICAL_ADDR

 - Use the firmware stack in the EFI stub when running in mixed mode

 - Clear BSS only once when using mixed mode

 - Check efi.get_variable() function pointer for NULL before trying to
   call it

* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: fix panic in kdump kernel
  x86/efistub: Don't clear BSS twice in mixed mode
  x86/efistub: Call mixed mode boot services on the firmware's stack
  efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address

Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.

Tested with QEMU and OVMF firmware.

Fixes: bad267f9e18f ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Clearing BSS should only be done once, at the very beginning.
efi_pe_entry() is the entrypoint from the firmware, which may not clear
BSS and so it is done explicitly. However, efi_pe_entry() is also used
as an entrypoint by the mixed mode startup code, in which case BSS will
already have been cleared, and doing it again at this point will corrupt
global variables holding the firmware's GDT/IDT and segment selectors.

So make the memset() conditional on whether the EFI stub is running in
native mode.

Fixes: b3810c5a2cc4a666 ("x86/efistub: Clear decompressor BSS in native EFI entrypoint")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Pull fbdev updates from Helge Deller:

 - Allow console fonts up to 64x128 pixels (Samuel Thibault)

 - Prevent division-by-zero in fb monitor code (Roman Smirnov)

 - Drop Renesas ARM platforms from Mobile LCDC framebuffer driver (Geert
   Uytterhoeven)

 - Various code cleanups in viafb, uveafb and mb862xxfb drivers by
   Aleksandr Burakov, Li Zhijian and Michael Ellerman

* tag 'fbdev-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
  fbdev: panel-tpo-td043mtea1: Convert sprintf() to sysfs_emit()
  fbmon: prevent division by zero in fb_videomode_from_videomode()
  fbcon: Increase maximum font width x height to 64 x 128
  fbdev: viafb: fix typo in hw_bitblt_1 and hw_bitblt_2
  fbdev: mb862xxfb: Fix defined but not used error
  fbdev: uvesafb: Convert sprintf/snprintf to sysfs_emit
  fbdev: Restrict FB_SH_MOBILE_LCDC to SuperH

Following warning is sometimes observed while booting my servers:
  [    3.594838] DMA: preallocated 4096 KiB GFP_KERNEL pool for atomic allocations
  [    3.602918] swapper/0: page allocation failure: order:10, mode:0xcc1(GFP_KERNEL|GFP_DMA), nodemask=(null),cpuset=/,mems_allowed=0-1
  ...
  [    3.851862] DMA: preallocated 1024 KiB GFP_KERNEL|GFP_DMA pool for atomic allocation

If 'nokaslr' boot option is set, the warning always happens.

On x86, ZONE_DMA is small zone at the first 16MB of physical address
space. When this problem happens, most of that space seems to be used by
decompressed kernel. Thereby, there is not enough space at DMA_ZONE to
meet the request of DMA pool allocation.

The commit 2f77465b05b1 ("x86/efistub: Avoid placing the kernel below
LOAD_PHYSICAL_ADDR") tried to fix this problem by introducing lower
bound of allocation.

But the fix is not complete.

efi_random_alloc() allocates pages by following steps.
1. Count total available slots ('total_slots')
2. Select a slot ('target_slot') to allocate randomly
3. Calculate a starting address ('target') to be included target_slot
4. Allocate pages, which starting address is 'target'

In step 1, 'alloc_min' is used to offset the starting address of memory
chunk. But in step 3 'alloc_min' is not considered at all.  As the
result, 'target' can be miscalculated and become lower than 'alloc_min'.

When KASLR is disabled, 'target_slot' is always 0 and the problem
happens everytime if the EFI memory map of the system meets the
condition.

Fix this problem by calculating 'target' considering 'alloc_min'.

Cc: linux-efi@vger.kernel.org
Cc: Tom Englund <tomenglund26@gmail.com>
Cc: linux-kernel@vger.kernel.org
Fixes: 2f77465b05b1 ("x86/efistub: Avoid placing the kernel below LOAD_PHYSICAL_ADDR")
Signed-off-by: Kazuma Kondo <kazuma-kondo@nec.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Pull driver core updates from Greg KH:
 "Here is the "big" set of driver core and kernfs changes for 6.9-rc1.

  Nothing all that crazy here, just some good updates that include:

   - automatic attribute group hiding from Dan Williams (he fixed up my
     horrible attempt at doing this.)

   - kobject lock contention fixes from Eric Dumazet

   - driver core cleanups from Andy

   - kernfs rcu work from Tejun

   - fw_devlink changes to resolve some reported issues

   - other minor changes, all details in the shortlog

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

* tag 'driver-core-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (28 commits)
  device: core: Log warning for devices pending deferred probe on timeout
  driver: core: Use dev_* instead of pr_* so device metadata is added
  driver: core: Log probe failure as error and with device metadata
  of: property: fw_devlink: Add support for "post-init-providers" property
  driver core: Add FWLINK_FLAG_IGNORE to completely ignore a fwnode link
  driver core: Adds flags param to fwnode_link_add()
  debugfs: fix wait/cancellation handling during remove
  device property: Don't use "proxy" headers
  device property: Move enum dev_dma_attr to fwnode.h
  driver core: Move fw_devlink stuff to where it belongs
  driver core: Drop unneeded 'extern' keyword in fwnode.h
  firmware_loader: Suppress warning on FW_OPT_NO_WARN flag
  sysfs:Addresses documentation in sysfs_merge_group and sysfs_unmerge_group.
  firmware_loader: introduce __free() cleanup hanler
  platform-msi: Remove usage of the deprecated ida_simple_xx() API
  sysfs: Introduce DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE()
  sysfs: Document new "group visible" helpers
  sysfs: Fix crash on empty group attributes array
  sysfs: Introduce a mechanism to hide static attribute_groups
  sysfs: Introduce a mechanism to hide static attribute_groups
  ...

Pull char/misc and other driver subsystem updates from Greg KH:
 "Here is the big set of char/misc and a number of other driver
  subsystem updates for 6.9-rc1. Included in here are:

   - IIO driver updates, loads of new ones and evolution of existing ones

   - coresight driver updates

   - const cleanups for many driver subsystems

   - speakup driver additions

   - platform remove callback void cleanups

   - mei driver updates

   - mhi driver updates

   - cdx driver updates for MSI interrupt handling

   - nvmem driver updates

   - other smaller driver updates and cleanups, full details in the
    shortlog

  All of these have been in linux-next for a long time with no reported
  issue, other than a build warning for the speakup driver"

The build warning hits clang and is a gcc (and C23) extension, and is
fixed up in the merge.

Link: https://lore.kernel.org/all/20240321134831.GA2762840@dev-arch.thelio-3990X/

* tag 'char-misc-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (279 commits)
  binder: remove redundant variable page_addr
  uio_dmem_genirq: UIO_MEM_DMA_COHERENT conversion
  uio_pruss: UIO_MEM_DMA_COHERENT conversion
  cnic,bnx2,bnx2x: use UIO_MEM_DMA_COHERENT
  uio: introduce UIO_MEM_DMA_COHERENT type
  cdx: add MSI support for CDX bus
  pps: use cflags-y instead of EXTRA_CFLAGS
  speakup: Add /dev/synthu device
  speakup: Fix 8bit characters from direct synth
  parport: sunbpp: Convert to platform remove callback returning void
  parport: amiga: Convert to platform remove callback returning void
  char: xillybus: Convert to platform remove callback returning void
  vmw_balloon: change maintainership
  MAINTAINERS: change the maintainer for hpilo driver
  char: xilinx_hwicap: Fix NULL vs IS_ERR() bug
  hpet: remove hpets::hp_clocksource
  platform: goldfish: move the separate 'default' propery for CONFIG_GOLDFISH
  char: xilinx_hwicap: drop casting to void in dev_set_drvdata
  greybus: move is_gb_* functions out of greybus.h
  greybus: Remove usage of the deprecated ida_simple_xx() API
  ...

Pull more power management updates from Rafael Wysocki:
 "These update the Energy Model to make it prevent errors due to power
  unit mismatches, fix a typo in power management documentation, convert
  one driver to using a platform remove callback returning void, address
  two cpufreq issues (one in the core and one in the DT driver), and
  enable boost support in the SCMI cpufreq driver.

  Specifics:

   - Modify the Energy Model code to bail out and complain if the unit
     of power is not uW to prevent errors due to unit mismatches (Lukasz
     Luba)

   - Make the intel_rapl platform driver use a remove callback returning
     void (Uwe Kleine-König)

   - Fix typo in the suspend and interrupts document (Saravana Kannan)

   - Make per-policy boost flags actually take effect on platforms using
     cpufreq_boost_set_sw() (Sibi Sankar)

   - Enable boost support in the SCMI cpufreq driver (Sibi Sankar)

   - Make the DT cpufreq driver use zalloc_cpumask_var() for allocating
     cpumasks to avoid using unitinialized memory (Marek Szyprowski)"

* tag 'pm-6.9-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: scmi: Enable boost support
  firmware: arm_scmi: Add support for marking certain frequencies as turbo
  cpufreq: dt: always allocate zeroed cpumask
  cpufreq: Fix per-policy boost behavior on SoCs using cpufreq_boost_set_sw()
  Documentation: power: Fix typo in suspend and interrupts doc
  PM: EM: Force device drivers to provide power in uW
  powercap: intel_rapl: Convert to platform remove callback returning void