linux-stable.git/drivers/firmware/efi, branch v6.14 Linux kernel stable tree efi/libstub: Avoid physical address 0x0 when doing random allocation 2025-03-14T11:21:29+00:00 Ard Biesheuvel ardb@kernel.org 2025-03-14T11:03:33+00:00 cb16dfed0093217a68c0faa9394fa5823927e04c Ben reports spurious EFI zboot failures on a system where physical RAM starts at 0x0. When doing random memory allocation from the EFI stub on such a platform, a random seed of 0x0 (which means no entropy source is available) will result in the allocation to be placed at address 0x0 if sufficient space is available. When this allocation is subsequently passed on to the decompression code, the 0x0 address is mistaken for NULL and the code complains and gives up. So avoid address 0x0 when doing random allocation, and set the minimum address to the minimum alignment. Cc: <stable@vger.kernel.org> Reported-by: Ben Schneider <ben@bens.haus> Tested-by: Ben Schneider <ben@bens.haus> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
Ben reports spurious EFI zboot failures on a system where physical RAM
starts at 0x0. When doing random memory allocation from the EFI stub on
such a platform, a random seed of 0x0 (which means no entropy source is
available) will result in the allocation to be placed at address 0x0 if
sufficient space is available.

When this allocation is subsequently passed on to the decompression
code, the 0x0 address is mistaken for NULL and the code complains and
gives up.

So avoid address 0x0 when doing random allocation, and set the minimum
address to the minimum alignment.

Cc: <stable@vger.kernel.org>
Reported-by: Ben Schneider <ben@bens.haus>
Tested-by: Ben Schneider <ben@bens.haus>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi/mokvar-table: Avoid repeated map/unmap of the same page 2025-02-27T17:25:44+00:00 Ard Biesheuvel ardb@kernel.org 2025-02-27T13:30:22+00:00 e3cf2d91d0583cae70aeb512da87e3ade25ea912 Tweak the logic that traverses the MOKVAR UEFI configuration table to only unmap the entry header and map the next one if they don't live in the same physical page. Link: https://lore.kernel.org/all/8f085931-3e9d-4386-9209-1d6c95616327@uncooperative.org/ Tested-By: Peter Jones <pjones@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
Tweak the logic that traverses the MOKVAR UEFI configuration table to
only unmap the entry header and map the next one if they don't live in
the same physical page.

Link: https://lore.kernel.org/all/8f085931-3e9d-4386-9209-1d6c95616327@uncooperative.org/
Tested-By: Peter Jones <pjones@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi: Don't map the entire mokvar table to determine its size 2025-02-27T17:25:44+00:00 Peter Jones pjones@redhat.com 2025-02-26T20:18:39+00:00 2b90e7ace79774a3540ce569e000388f8d22c9e0 Currently, when validating the mokvar table, we (re)map the entire table on each iteration of the loop, adding space as we discover new entries. If the table grows over a certain size, this fails due to limitations of early_memmap(), and we get a failure and traceback: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:139 __early_ioremap+0xef/0x220 ... Call Trace: <TASK> ? __early_ioremap+0xef/0x220 ? __warn.cold+0x93/0xfa ? __early_ioremap+0xef/0x220 ? report_bug+0xff/0x140 ? early_fixup_exception+0x5d/0xb0 ? early_idt_handler_common+0x2f/0x3a ? __early_ioremap+0xef/0x220 ? efi_mokvar_table_init+0xce/0x1d0 ? setup_arch+0x864/0xc10 ? start_kernel+0x6b/0xa10 ? x86_64_start_reservations+0x24/0x30 ? x86_64_start_kernel+0xed/0xf0 ? common_startup_64+0x13e/0x141 </TASK> ---[ end trace 0000000000000000 ]--- mokvar: Failed to map EFI MOKvar config table pa=0x7c4c3000, size=265187. Mapping the entire structure isn't actually necessary, as we don't ever need more than one entry header mapped at once. Changes efi_mokvar_table_init() to only map each entry header, not the entire table, when determining the table size. Since we're not mapping any data past the variable name, it also changes the code to enforce that each variable name is NUL terminated, rather than attempting to verify it in place. Cc: <stable@vger.kernel.org> Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
Currently, when validating the mokvar table, we (re)map the entire table
on each iteration of the loop, adding space as we discover new entries.
If the table grows over a certain size, this fails due to limitations of
early_memmap(), and we get a failure and traceback:

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:139 __early_ioremap+0xef/0x220
  ...
  Call Trace:
   <TASK>
   ? __early_ioremap+0xef/0x220
   ? __warn.cold+0x93/0xfa
   ? __early_ioremap+0xef/0x220
   ? report_bug+0xff/0x140
   ? early_fixup_exception+0x5d/0xb0
   ? early_idt_handler_common+0x2f/0x3a
   ? __early_ioremap+0xef/0x220
   ? efi_mokvar_table_init+0xce/0x1d0
   ? setup_arch+0x864/0xc10
   ? start_kernel+0x6b/0xa10
   ? x86_64_start_reservations+0x24/0x30
   ? x86_64_start_kernel+0xed/0xf0
   ? common_startup_64+0x13e/0x141
   </TASK>
  ---[ end trace 0000000000000000 ]---
  mokvar: Failed to map EFI MOKvar config table pa=0x7c4c3000, size=265187.

Mapping the entire structure isn't actually necessary, as we don't ever
need more than one entry header mapped at once.

Changes efi_mokvar_table_init() to only map each entry header, not the
entire table, when determining the table size.  Since we're not mapping
any data past the variable name, it also changes the code to enforce
that each variable name is NUL terminated, rather than attempting to
verify it in place.

Cc: <stable@vger.kernel.org>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi/cper: Fix cper_arm_ctx_info alignment 2025-02-23T16:30:05+00:00 Patrick Rudolph patrick.rudolph@9elements.com 2025-02-21T11:15:16+00:00 d6a2d02aa060531607f4a8411ec384470faa2761 According to the UEFI Common Platform Error Record appendix, the processor context information structure is a variable length structure, but "is padded with zeros if the size is not a multiple of 16 bytes". Currently this isn't honoured, causing all but the first structure to be garbage when printed. Thus align the size to be a multiple of 16. Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
According to the UEFI Common Platform Error Record appendix, the
processor context information structure is a variable length structure,
but "is padded with zeros if the size is not a multiple of 16 bytes".

Currently this isn't honoured, causing all but the first structure to
be garbage when printed. Thus align the size to be a multiple of 16.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi/cper: Fix cper_ia_proc_ctx alignment 2025-02-23T16:30:04+00:00 Patrick Rudolph patrick.rudolph@9elements.com 2025-02-21T08:12:42+00:00 174e5e9da4f5946de3d09c32ee56cbbc9d70505b According to the UEFI Common Platform Error Record appendix, the IA32/X64 Processor Context Information Structure is a variable length structure, but "is padded with zeros if the size is not a multiple of 16 bytes". Currently this isn't honoured, causing all but the first structure to be garbage when printed. Thus align the size to be a multiple of 16. Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
According to the UEFI Common Platform Error Record appendix, the
IA32/X64 Processor Context Information Structure is a variable length
structure, but "is padded with zeros if the size is not a multiple
of 16 bytes".

Currently this isn't honoured, causing all but the first structure to
be garbage when printed. Thus align the size to be a multiple of 16.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi: Avoid cold plugged memory for placing the kernel 2025-02-04T13:08:22+00:00 Ard Biesheuvel ardb@kernel.org 2025-02-01T17:21:35+00:00 ba69e0750b0362870294adab09339a0c39c3beaf UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory regions that are 'cold plugged' at boot, i.e., hot pluggable memory that is available from early boot, and described as system RAM by the firmware. Existing loaders and EFI applications running in the boot context will happily use this memory for allocating data structures that cannot be freed or moved at runtime, and this prevents the memory from being unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute should be tested, and memory annotated as such should be avoided for such allocations. In the EFI stub, there are a couple of occurrences where, instead of the high-level AllocatePages() UEFI boot service, a low-level code sequence is used that traverses the EFI memory map and carves out the requested number of pages from a free region. This is needed, e.g., for allocating as low as possible, or for allocating pages at random. While AllocatePages() should presumably avoid special purpose memory and cold plugged regions, this manual approach needs to incorporate this logic itself, in order to prevent the kernel itself from ending up in a hot unpluggable region, preventing it from being unplugged. So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it where appropriate. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory
regions that are 'cold plugged' at boot, i.e., hot pluggable memory that
is available from early boot, and described as system RAM by the
firmware.

Existing loaders and EFI applications running in the boot context will
happily use this memory for allocating data structures that cannot be
freed or moved at runtime, and this prevents the memory from being
unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute
should be tested, and memory annotated as such should be avoided for
such allocations.

In the EFI stub, there are a couple of occurrences where, instead of the
high-level AllocatePages() UEFI boot service, a low-level code sequence
is used that traverses the EFI memory map and carves out the requested
number of pages from a free region. This is needed, e.g., for allocating
as low as possible, or for allocating pages at random.

While AllocatePages() should presumably avoid special purpose memory and
cold plugged regions, this manual approach needs to incorporate this
logic itself, in order to prevent the kernel itself from ending up in a
hot unpluggable region, preventing it from being unplugged.

So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it
where appropriate.

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Merge tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 2025-01-28T20:25:12+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-01-28T20:25:12+00:00 2ab002c755bfa88777e3f2db884d531f3010736c Pull driver core and debugfs updates from Greg KH: "Here is the big set of driver core and debugfs updates for 6.14-rc1. Included in here is a bunch of driver core, PCI, OF, and platform rust bindings (all acked by the different subsystem maintainers), hence the merge conflict with the rust tree, and some driver core api updates to mark things as const, which will also require some fixups due to new stuff coming in through other trees in this merge window. There are also a bunch of debugfs updates from Al, and there is at least one user that does have a regression with these, but Al is working on tracking down the fix for it. In my use (and everyone else's linux-next use), it does not seem like a big issue at the moment. Here's a short list of the things in here: - driver core rust bindings for PCI, platform, OF, and some i/o functions. We are almost at the "write a real driver in rust" stage now, depending on what you want to do. - misc device rust bindings and a sample driver to show how to use them - debugfs cleanups in the fs as well as the users of the fs api for places where drivers got it wrong or were unnecessarily doing things in complex ways. - driver core const work, making more of the api take const * for different parameters to make the rust bindings easier overall. - other small fixes and updates All of these have been in linux-next with all of the aforementioned merge conflicts, and the one debugfs issue, which looks to be resolved "soon"" * tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits) rust: device: Use as_char_ptr() to avoid explicit cast rust: device: Replace CString with CStr in property_present() devcoredump: Constify 'struct bin_attribute' devcoredump: Define 'struct bin_attribute' through macro rust: device: Add property_present() saner replacement for debugfs_rename() orangefs-debugfs: don't mess with ->d_name octeontx2: don't mess with ->d_parent or ->d_parent->d_name arm_scmi: don't mess with ->d_parent->d_name slub: don't mess with ->d_name sof-client-ipc-flood-test: don't mess with ->d_name qat: don't mess with ->d_name xhci: don't mess with ->d_iname mtu3: don't mess wiht ->d_iname greybus/camera - stop messing with ->d_iname mediatek: stop messing with ->d_iname netdevsim: don't embed file_operations into your structs b43legacy: make use of debugfs_get_aux() b43: stop embedding struct file_operations into their objects carl9170: stop embedding file_operations into their objects ... 
Pull driver core and debugfs updates from Greg KH:
 "Here is the big set of driver core and debugfs updates for 6.14-rc1.

  Included in here is a bunch of driver core, PCI, OF, and platform rust
  bindings (all acked by the different subsystem maintainers), hence the
  merge conflict with the rust tree, and some driver core api updates to
  mark things as const, which will also require some fixups due to new
  stuff coming in through other trees in this merge window.

  There are also a bunch of debugfs updates from Al, and there is at
  least one user that does have a regression with these, but Al is
  working on tracking down the fix for it. In my use (and everyone
  else's linux-next use), it does not seem like a big issue at the
  moment.

  Here's a short list of the things in here:

   - driver core rust bindings for PCI, platform, OF, and some i/o
     functions.

     We are almost at the "write a real driver in rust" stage now,
     depending on what you want to do.

   - misc device rust bindings and a sample driver to show how to use
     them

   - debugfs cleanups in the fs as well as the users of the fs api for
     places where drivers got it wrong or were unnecessarily doing
     things in complex ways.

   - driver core const work, making more of the api take const * for
     different parameters to make the rust bindings easier overall.

   - other small fixes and updates

  All of these have been in linux-next with all of the aforementioned
  merge conflicts, and the one debugfs issue, which looks to be resolved
  "soon""

* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  rust: device: Use as_char_ptr() to avoid explicit cast
  rust: device: Replace CString with CStr in property_present()
  devcoredump: Constify 'struct bin_attribute'
  devcoredump: Define 'struct bin_attribute' through macro
  rust: device: Add property_present()
  saner replacement for debugfs_rename()
  orangefs-debugfs: don't mess with ->d_name
  octeontx2: don't mess with ->d_parent or ->d_parent->d_name
  arm_scmi: don't mess with ->d_parent->d_name
  slub: don't mess with ->d_name
  sof-client-ipc-flood-test: don't mess with ->d_name
  qat: don't mess with ->d_name
  xhci: don't mess with ->d_iname
  mtu3: don't mess wiht ->d_iname
  greybus/camera - stop messing with ->d_iname
  mediatek: stop messing with ->d_iname
  netdevsim: don't embed file_operations into your structs
  b43legacy: make use of debugfs_get_aux()
  b43: stop embedding struct file_operations into their objects
  carl9170: stop embedding file_operations into their objects
  ...
efi: libstub: Use '-std=gnu11' to fix build with GCC 15 2025-01-22T11:57:45+00:00 Nathan Chancellor nathan@kernel.org 2025-01-22T01:11:34+00:00 8ba14d9f490aef9fd535c04e9e62e1169eb7a055 GCC 15 changed the default C standard version to C23, which should not have impacted the kernel because it requests the gnu11 standard via '-std=' in the main Makefile. However, the EFI libstub Makefile uses its own set of KBUILD_CFLAGS for x86 without a '-std=' value (i.e., using the default), resulting in errors from the kernel's definitions of bool, true, and false in stddef.h, which are reserved keywords under C23. ./include/linux/stddef.h:11:9: error: expected identifier before ‘false’ 11 | false = 0, ./include/linux/types.h:35:33: error: two or more data types in declaration specifiers 35 | typedef _Bool bool; Set '-std=gnu11' in the x86 cflags to resolve the error and consistently use the same C standard version for the entire kernel. All other architectures reuse KBUILD_CFLAGS from the rest of the kernel, so this issue is not visible for them. Cc: stable@vger.kernel.org Reported-by: Kostadin Shishmanov <kostadinshishmanov@protonmail.com> Closes: https://lore.kernel.org/4OAhbllK7x4QJGpZjkYjtBYNLd_2whHx9oFiuZcGwtVR4hIzvduultkgfAIRZI3vQpZylu7Gl929HaYFRGeMEalWCpeMzCIIhLxxRhq4U-Y=@protonmail.com/ Reported-by: Jakub Jelinek <jakub@redhat.com> Closes: https://lore.kernel.org/Z4467umXR2PZ0M1H@tucnak/ Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
GCC 15 changed the default C standard version to C23, which should not
have impacted the kernel because it requests the gnu11 standard via
'-std=' in the main Makefile. However, the EFI libstub Makefile uses its
own set of KBUILD_CFLAGS for x86 without a '-std=' value (i.e., using
the default), resulting in errors from the kernel's definitions of bool,
true, and false in stddef.h, which are reserved keywords under C23.

  ./include/linux/stddef.h:11:9: error: expected identifier before ‘false’
     11 |         false   = 0,
  ./include/linux/types.h:35:33: error: two or more data types in declaration specifiers
     35 | typedef _Bool                   bool;

Set '-std=gnu11' in the x86 cflags to resolve the error and consistently
use the same C standard version for the entire kernel. All other
architectures reuse KBUILD_CFLAGS from the rest of the kernel, so this
issue is not visible for them.

Cc: stable@vger.kernel.org
Reported-by: Kostadin Shishmanov <kostadinshishmanov@protonmail.com>
Closes: https://lore.kernel.org/4OAhbllK7x4QJGpZjkYjtBYNLd_2whHx9oFiuZcGwtVR4hIzvduultkgfAIRZI3vQpZylu7Gl929HaYFRGeMEalWCpeMzCIIhLxxRhq4U-Y=@protonmail.com/
Reported-by: Jakub Jelinek <jakub@redhat.com>
Closes: https://lore.kernel.org/Z4467umXR2PZ0M1H@tucnak/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi: sysfb_efi: fix W=1 warnings when EFI is not set 2025-01-14T07:35:28+00:00 Randy Dunlap rdunlap@infradead.org 2025-01-07T23:53:09+00:00 19fdc68aa7b90b1d3d600e873a3e050a39e7663d A build with W=1 fails because there are code and data that are not needed or used when CONFIG_EFI is not set. Move the "#ifdef CONFIG_EFI" block to earlier in the source file so that the unused code/data are not built. drivers/firmware/efi/sysfb_efi.c:345:39: warning: ‘efifb_fwnode_ops’ defined but not used [-Wunused-const-variable=] 345 | static const struct fwnode_operations efifb_fwnode_ops = { | ^~~~~~~~~~~~~~~~ drivers/firmware/efi/sysfb_efi.c:238:35: warning: ‘efifb_dmi_swap_width_height’ defined but not used [-Wunused-const-variable=] 238 | static const struct dmi_system_id efifb_dmi_swap_width_height[] __initconst = { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/firmware/efi/sysfb_efi.c:188:35: warning: ‘efifb_dmi_system_table’ defined but not used [-Wunused-const-variable=] 188 | static const struct dmi_system_id efifb_dmi_system_table[] __initconst = { | ^~~~~~~~~~~~~~~~~~~~~~ Fixes: 15d27b15de96 ("efi: sysfb_efi: fix build when EFI is not set") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501071933.20nlmJJt-lkp@intel.com/ Cc: David Rheinsberg <david@readahead.eu> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Javier Martinez Canillas <javierm@redhat.com> Cc: Peter Jones <pjones@redhat.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: Ard Biesheuvel <ardb@kernel.org> Cc: linux-efi@vger.kernel.org Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
A build with W=1 fails because there are code and data that are not
needed or used when CONFIG_EFI is not set. Move the "#ifdef CONFIG_EFI"
block to earlier in the source file so that the unused code/data are
not built.

drivers/firmware/efi/sysfb_efi.c:345:39: warning: ‘efifb_fwnode_ops’ defined but not used [-Wunused-const-variable=]
  345 | static const struct fwnode_operations efifb_fwnode_ops = {
      |                                       ^~~~~~~~~~~~~~~~
drivers/firmware/efi/sysfb_efi.c:238:35: warning: ‘efifb_dmi_swap_width_height’ defined but not used [-Wunused-const-variable=]
  238 | static const struct dmi_system_id efifb_dmi_swap_width_height[] __initconst = {
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/firmware/efi/sysfb_efi.c:188:35: warning: ‘efifb_dmi_system_table’ defined but not used [-Wunused-const-variable=]
  188 | static const struct dmi_system_id efifb_dmi_system_table[] __initconst = {
      |                                   ^~~~~~~~~~~~~~~~~~~~~~

Fixes: 15d27b15de96 ("efi: sysfb_efi: fix build when EFI is not set")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501071933.20nlmJJt-lkp@intel.com/
Cc: David Rheinsberg <david@readahead.eu>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi/libstub: Use __free() helper for pool deallocations 2025-01-14T07:35:27+00:00 Ard Biesheuvel ardb@kernel.org 2024-12-20T11:04:57+00:00 4e23c96b1fe1a13078209394a292efe06767f3a4 Annotate some local buffer allocations as __free(efi_pool) and simplify the associated error handling accordingly. This removes a couple of gotos and simplifies the code. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
Annotate some local buffer allocations as __free(efi_pool) and simplify
the associated error handling accordingly. This removes a couple of
gotos and simplifies the code.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>