Michael Weiser reported that he got this error during a kexec rebooting:

  esrt: Unsupported ESRT version 2904149718861218184.

The ESRT memory stays in EFI boot services data, and it was reserved
in kernel via efi_mem_reserve().  The initial purpose of the reservation
is to reuse the EFI boot services data across kexec reboot. For example
the BGRT image data and some ESRT memory like Michael reported.

But although the memory is reserved it is not updated in the X86 E820 table,
and kexec_file_load() iterates system RAM in the IO resource list to find places
for kernel, initramfs and other stuff. In Michael's case the kexec loaded
initramfs overwrote the ESRT memory and then the failure happened.

Since kexec_file_load() depends on the E820 table being updated, just fix this
by updating the reserved EFI boot services memory as reserved type in E820.

Originally any memory descriptors with EFI_MEMORY_RUNTIME attribute are
bypassed in the reservation code path because they are assumed as reserved.

But the reservation is still needed for multiple kexec reboots,
and it is the only possible case we come here thus just drop the code
chunk, then everything works without side effects.

On my machine the ESRT memory sits in an EFI runtime data range, it does
not trigger the problem, but I successfully tested with BGRT instead.
both kexec_load() and kexec_file_load() work and kdump works as well.

[ mingo: Edited the changelog. ]

Reported-by: Michael Weiser <michael@weiser.dinsnail.net>
Tested-by: Michael Weiser <michael@weiser.dinsnail.net>
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kexec@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204075233.GA10520@dhcp-128-65.nay.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull MFD updates from Lee Jones:
 "Core Frameworks:
   - Add support for a "resource managed strongly uncachable ioremap"
     call
   - Provide a collection of MFD helper macros
   - Remove mfd_clone_cell() from MFD core
   - Add NULL de-reference protection in MFD core
   - Remove superfluous function fd_platform_add_cell() from MFD core
   - Honour Device Tree's request to disable a device

  New Drivers:
   - Add support for MediaTek MT6323 PMIC

  New Device Support:
   - Add support for Gemini Lake to Intel LPSS PCI
   - Add support for Cherry Trail Crystal Cover PMIC to Intel SoC PMIC
     CRC
   - Add support for PM{I}8950 to Qualcomm SPMI PMIC
   - Add support for U8420 to ST-Ericsson DB8500
   - Add support for Comet Lake PCH-H to Intel LPSS PCI

  New Functionality:
   - Add support for requested supply clocks; madera-core

  Fix-ups:
   - Lower interrupt priority; rk808
   - Use provided helpers (macros, group functions, defines); rk808,
     ipaq-micro, ab8500-core, db8500-prcmu, mt6397-core, cs5535-mfd
   - Only allocate IRQs on request; max77620
   - Use simplified API; arizona-core
   - Remove redundant and/or duplicated code; wm8998-tables, arizona,
     syscon
   - Device Tree binding fix-ups; madera, max77650, max77693
   - Remove mfd_cell->id abuse hack; cs5535-mfd
   - Remove only user of mfd_clone_cell(); cs5535-mfd
   - Make resources static; rohm-bd70528

  Bug Fixes:
   - Fix product ID for RK818; rk808
   - Fix Power Key; rk808
   - Fix booting on the BananaPi; mt6397-core
   - Endian fix-ups; twl.h
   - Fix static error checker warnings; ti_am335x_tscadc"

* tag 'mfd-next-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (47 commits)
  Revert "mfd: syscon: Set name of regmap_config"
  mfd: ti_am335x_tscadc: Fix static checker warning
  mfd: bd70528: Staticize bit value definitions
  mfd: mfd-core: Honour Device Tree's request to disable a child-device
  dt-bindings: mfd: max77693: Fix missing curly brace
  mfd: intel-lpss: Add Intel Comet Lake PCH-H PCI IDs
  mfd: db8500-prcmu: Support U8420-sysclk firmware
  dt-bindings: mfd: max77650: Convert the binding document to yaml
  mfd: mfd-core: Move pdev->mfd_cell creation back into mfd_add_device()
  mfd: mfd-core: Remove usage counting for .{en,dis}able() call-backs
  x86: olpc-xo1-sci: Remove invocation of MFD's .enable()/.disable() call-backs
  x86: olpc-xo1-pm: Remove invocation of MFD's .enable()/.disable() call-backs
  mfd: mfd-core: Remove mfd_clone_cell()
  mfd: mfd-core: Protect against NULL call-back function pointer
  mfd: cs5535-mfd: Register clients using their own dedicated MFD cell entries
  mfd: cs5535-mfd: Request shared IO regions centrally
  mfd: cs5535-mfd: Remove mfd_cell->id hack
  mfd: cs5535-mfd: Use PLATFORM_DEVID_* defines and tidy error message
  mfd: intel_soc_pmic_crc: Add "cht_crystal_cove_pmic" cell to CHT cells
  mfd: madera: Add support for requesting the supply clocks
  ...

Pull ACPI updates from Rafael Wysocki:
 "These update the ACPICA code in the kernel to upstream revision
  20191018, add support for EFI specific purpose memory, update the ACPI
  EC driver to make it work on systems with hardware-reduced ACPI,
  improve ACPI-based device enumeration for some platforms, rework the
  lid blacklist handling in the button driver and add more lid quirks to
  it, unify ACPI _HID/_UID matching, fix assorted issues and clean up
  the code and documentation.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20191018
     including:
      * Fixes for Clang warnings (Bob Moore)
      * Fix for possible overflow in get_tick_count() (Bob Moore)
      * Introduction of acpi_unload_table() (Bob Moore)
      * Debugger and utilities updates (Erik Schmauss)
      * Fix for unloading tables loaded via configfs (Nikolaus Voss)

   - Add support for EFI specific purpose memory to optionally allow
     either application-exclusive or core-kernel-mm managed access to
     differentiated memory (Dan Williams)

   - Fix and clean up processing of the HMAT table (Brice Goglin, Qian
     Cai, Tao Xu)

   - Update the ACPI EC driver to make it work on systems with
     hardware-reduced ACPI (Daniel Drake)

   - Always build in support for the Generic Event Device (GED) to allow
     one kernel binary to work both on systems with full hardware ACPI
     and hardware-reduced ACPI (Arjan van de Ven)

   - Fix the table unload mechanism to unregister platform devices
     created when the given table was loaded (Andy Shevchenko)

   - Rework the lid blacklist handling in the button driver and add more
     lid quirks to it (Hans de Goede)

   - Improve ACPI-based device enumeration for some platforms based on
     Intel BayTrail SoCs (Hans de Goede)

   - Add an OpRegion driver for the Cherry Trail Crystal Cove PMIC and
     prevent handlers from being registered for unhandled PMIC OpRegions
     (Hans de Goede)

   - Unify ACPI _HID/_UID matching (Andy Shevchenko)

   - Clean up documentation and comments (Cao jin, James Pack, Kacper
     Piwiński)"

* tag 'acpi-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  ACPI: OSI: Shoot duplicate word
  ACPI: HMAT: use %u instead of %d to print u32 values
  ACPI: NUMA: HMAT: fix a section mismatch
  ACPI: HMAT: don't mix pxm and nid when setting memory target processor_pxm
  ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device
  ACPI: NUMA: HMAT: Register HMAT at device_initcall level
  device-dax: Add a driver for "hmem" devices
  dax: Fix alloc_dax_region() compile warning
  lib: Uplevel the pmem "region" ida to a global allocator
  x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP
  arm/efi: EFI soft reservation to memblock
  x86/efi: EFI soft reservation to E820 enumeration
  efi: Common enable/disable infrastructure for EFI soft reservation
  x86/efi: Push EFI_MEMMAP check into leaf routines
  efi: Enumerate EFI_MEMORY_SP
  ACPI: NUMA: Establish a new drivers/acpi/numa/ directory
  ACPICA: Update version to 20191018
  ACPICA: debugger: remove leading whitespaces when converting a string to a buffer
  ACPICA: acpiexec: initialize all simple types and field units from user input
  ACPICA: debugger: add field unit support for acpi_db_get_next_token
  ...

Pull x86 asm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Cross-arch changes to move the linker sections for NOTES and
     EXCEPTION_TABLE into the RO_DATA area, where they belong on most
     architectures. (Kees Cook)

   - Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to
     trap jumps into the middle of those padding areas instead of
     sliding execution. (Kees Cook)

   - A thorough cleanup of symbol definitions within x86 assembler code.
     The rather randomly named macros got streamlined around a
     (hopefully) straightforward naming scheme:

        SYM_START(name, linkage, align...)
        SYM_END(name, sym_type)

        SYM_FUNC_START(name)
        SYM_FUNC_END(name)

        SYM_CODE_START(name)
        SYM_CODE_END(name)

        SYM_DATA_START(name)
        SYM_DATA_END(name)

     etc - with about three times of these basic primitives with some
     label, local symbol or attribute variant, expressed via postfixes.

     No change in functionality intended. (Jiri Slaby)

   - Misc other changes, cleanups and smaller fixes"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
  x86/entry/64: Remove pointless jump in paranoid_exit
  x86/entry/32: Remove unused resume_userspace label
  x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o
  m68k: Convert missed RODATA to RO_DATA
  x86/vmlinux: Use INT3 instead of NOP for linker fill bytes
  x86/mm: Report actual image regions in /proc/iomem
  x86/mm: Report which part of kernel image is freed
  x86/mm: Remove redundant address-of operators on addresses
  xtensa: Move EXCEPTION_TABLE to RO_DATA segment
  powerpc: Move EXCEPTION_TABLE to RO_DATA segment
  parisc: Move EXCEPTION_TABLE to RO_DATA segment
  microblaze: Move EXCEPTION_TABLE to RO_DATA segment
  ia64: Move EXCEPTION_TABLE to RO_DATA segment
  h8300: Move EXCEPTION_TABLE to RO_DATA segment
  c6x: Move EXCEPTION_TABLE to RO_DATA segment
  arm64: Move EXCEPTION_TABLE to RO_DATA segment
  alpha: Move EXCEPTION_TABLE to RO_DATA segment
  x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment
  x86/vmlinux: Actually use _etext for the end of the text segment
  vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA
  ...

Pull x86 platform updates from Ingo Molnar:
 "UV platform updates (with a 'hubless' variant) and Jailhouse updates
  for better UART support"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/jailhouse: Only enable platform UARTs if available
  x86/jailhouse: Improve setup data version comparison
  x86/platform/uv: Account for UV Hubless in is_uvX_hub Ops
  x86/platform/uv: Check EFI Boot to set reboot type
  x86/platform/uv: Decode UVsystab Info
  x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files
  x86/platform/uv: Setup UV functions for Hubless UV Systems
  x86/platform/uv: Add return code to UV BIOS Init function
  x86/platform/uv: Return UV Hubless System Type
  x86/platform/uv: Save OEM_ID from ACPI MADT probe

Pull printk updates from Petr Mladek:

 - Allow to print symbolic error names via new %pe modifier.

 - Use pr_warn() instead of the remaining pr_warning() calls. Fix
   formatting of the related lines.

 - Add VSPRINTF entry to MAINTAINERS.

* tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits)
  checkpatch: don't warn about new vsprintf pointer extension '%pe'
  MAINTAINERS: Add VSPRINTF
  tools lib api: Renaming pr_warning to pr_warn
  ASoC: samsung: Use pr_warn instead of pr_warning
  lib: cpu_rmap: Use pr_warn instead of pr_warning
  trace: Use pr_warn instead of pr_warning
  dma-debug: Use pr_warn instead of pr_warning
  vgacon: Use pr_warn instead of pr_warning
  fs: afs: Use pr_warn instead of pr_warning
  sh/intc: Use pr_warn instead of pr_warning
  scsi: Use pr_warn instead of pr_warning
  platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning
  platform/x86: asus-laptop: Use pr_warn instead of pr_warning
  platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning
  oprofile: Use pr_warn instead of pr_warning
  of: Use pr_warn instead of pr_warning
  macintosh: Use pr_warn instead of pr_warning
  idsn: Use pr_warn instead of pr_warning
  ide: Use pr_warn instead of pr_warning
  crypto: n2: Use pr_warn instead of pr_warning
  ...

IO regions are now requested and released by this device's parent.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

IO regions are now requested and released by this device's parent.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

Given that EFI_MEMORY_SP is platform BIOS policy decision for marking
memory ranges as "reserved for a specific purpose" there will inevitably
be scenarios where the BIOS omits the attribute in situations where it
is desired. Unlike other attributes if the OS wants to reserve this
memory from the kernel the reservation needs to happen early in init. So
early, in fact, that it needs to happen before e820__memblock_setup()
which is a pre-requisite for efi_fake_memmap() that wants to allocate
memory for the updated table.

Introduce an x86 specific efi_fake_memmap_early() that can search for
attempts to set EFI_MEMORY_SP via efi_fake_mem and update the e820 table
accordingly.

The KASLR code that scans the command line looking for user-directed
memory reservations also needs to be updated to consider
"efi_fake_mem=nn@ss:0x40000" requests.

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose".

The proposed Linux behavior for specific purpose memory is that it is
reserved for direct-access (device-dax) by default and not available for
any kernel usage, not even as an OOM fallback.  Later, through udev
scripts or another init mechanism, these device-dax claimed ranges can
be reconfigured and hot-added to the available System-RAM with a unique
node identifier. This device-dax management scheme implements "soft" in
the "soft reserved" designation by allowing some or all of the
reservation to be recovered as typical memory. This policy can be
disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with
efi=nosoftreserve.

This patch introduces 2 new concepts at once given the entanglement
between early boot enumeration relative to memory that can optionally be
reserved from the kernel page allocator by default. The new concepts
are:

- E820_TYPE_SOFT_RESERVED: Upon detecting the EFI_MEMORY_SP
  attribute on EFI_CONVENTIONAL memory, update the E820 map with this
  new type. Only perform this classification if the
  CONFIG_EFI_SOFT_RESERVE=y policy is enabled, otherwise treat it as
  typical ram.

- IORES_DESC_SOFT_RESERVED: Add a new I/O resource descriptor for
  a device driver to search iomem resources for application specific
  memory. Teach the iomem code to identify such ranges as "Soft Reserved".

Note that the comment for do_add_efi_memmap() needed refreshing since it
seemed to imply that the efi map might overflow the e820 table, but that
is not an issue as of commit 7b6e4ba3cb1f "x86/boot/e820: Clean up the
E820_X_MAX definition" that removed the 128 entry limit for
e820__range_add().

A follow-on change integrates parsing of the ACPI HMAT to identify the
node and sub-range boundaries of EFI_MEMORY_SP designated memory. For
now, just identify and reserve memory of this type.

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>