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Author SHA1 Message Date
Ard Biesheuvel 618ab2e3c1 efi: Don't attempt to map RCI2 config table if it doesn't exist
[ Upstream commit a470552ee8 ]

Commit:

  1c5fecb612 ("efi: Export Runtime Configuration Interface table to sysfs")

... added support for a Dell specific UEFI configuration table, but
failed to take into account that mapping the table should not be
attempted unless the table actually exists. If it doesn't exist,
the code usually fails silently unless pr_debug() prints are
enabled. However, on 32-bit PAE x86, the splat below is produced due
to the attempt to map the placeholder value EFI_INVALID_TABLE_ADDR
which we use for non-existing UEFI configuration tables, and which
equals ULONG_MAX.

   memremap attempted on mixed range 0x00000000ffffffff size: 0x1e
   WARNING: CPU: 1 PID: 1 at kernel/iomem.c:81 memremap+0x1a3/0x1c0
   Modules linked in:
   CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.4.2-smp-mine #1
   Hardware name: Hewlett-Packard HP Z400 Workstation/0B4Ch, BIOS 786G3 v03.61 03/05/2018
   EIP: memremap+0x1a3/0x1c0
  ...
   Call Trace:
    ? map_properties+0x473/0x473
    ? efi_rci2_sysfs_init+0x2c/0x154
    ? map_properties+0x473/0x473
    ? do_one_initcall+0x49/0x1d4
    ? parse_args+0x1e8/0x2a0
    ? do_early_param+0x7a/0x7a
    ? kernel_init_freeable+0x139/0x1c2
    ? rest_init+0x8e/0x8e
    ? kernel_init+0xd/0xf2
    ? ret_from_fork+0x2e/0x38

Fix this by checking whether the table exists before attempting to map it.

Reported-by: Richard Narron <comet.berkeley@gmail.com>
Tested-by: Richard Narron <comet.berkeley@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Fixes: 1c5fecb612 ("efi: Export Runtime Configuration Interface table to sysfs")
Link: https://lkml.kernel.org/r/20191210090945.11501-2-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09 10:20:07 +01:00
Ben Dooks 1ed121e616 efi: Make unexported efi_rci2_sysfs_init() static
The efi_rci2_sysfs_init() is not used outside of rci2-table.c so
make it static to silence the following Sparse warning:

  drivers/firmware/efi/rci2-table.c:79:12: warning: symbol 'efi_rci2_sysfs_init' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Matthew Garrett <mjg59@google.com>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Talbert <swt@techie.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Link: https://lkml.kernel.org/r/20191002165904.8819-7-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-07 15:24:36 +02:00
Narendra K 1c5fecb612 efi: Export Runtime Configuration Interface table to sysfs
System firmware advertises the address of the 'Runtime
Configuration Interface table version 2 (RCI2)' via
an EFI Configuration Table entry. This code retrieves the RCI2
table from the address and exports it to sysfs as a binary
attribute 'rci2' under /sys/firmware/efi/tables directory.
The approach adopted is similar to the attribute 'DMI' under
/sys/firmware/dmi/tables.

RCI2 table contains BIOS HII in XML format and is used to populate
BIOS setup page in Dell EMC OpenManage Server Administrator tool.
The BIOS setup page contains BIOS tokens which can be configured.

Signed-off-by: Narendra K <Narendra.K@dell.com>
Reviewed-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2019-08-08 11:10:25 +03:00