Commit graph

3 commits

Author SHA1 Message Date
Compostella, Jeremy
5356c32742 efibc: Report more information in the error messages
Report the name of the EFI variable if the value size is too large,
or if efibc_set_variable() fails to allocate the 'struct efivar_entry'
object.

If efibc_set_variable() fails because the 'size' value is too
large, it also reports this value in the error message.

Reported-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1466839230-12781-2-git-send-email-matt@codeblueprint.co.uk
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27 13:06:54 +02:00
Jeremy Compostella
2e121d711a efibc: Fix excessive stack footprint warning
GCC complains about a newly added file for the EFI Bootloader Control:

  drivers/firmware/efi/efibc.c: In function 'efibc_set_variable':
  drivers/firmware/efi/efibc.c:53:1: error: the frame size of 2272 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

The problem is the declaration of a local variable of type struct
efivar_entry, which is by itself larger than the warning limit of 1024
bytes.

Use dynamic memory allocation instead of stack memory for the entry
object.

This patch also fixes a potential buffer overflow.

Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
[ Updated changelog to include GCC error ]
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.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: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-3-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-07 07:06:13 +02:00
Compostella, Jeremy
06f7d4a161 efibc: Add EFI Bootloader Control module
This module installs a reboot callback, such that if reboot() is invoked
with a string argument NNN, "NNN" is copied to the "LoaderEntryOneShot"
EFI variable, to be read by the bootloader.

If the string matches one of the boot labels defined in its configuration,
the bootloader will boot once to that label.  The "LoaderEntryRebootReason"
EFI variable is set with the reboot reason: "reboot", "shutdown".

The bootloader reads this reboot reason and takes particular action
according to its policy.

There are reboot implementations that do "reboot <reason>", such as
Android's reboot command and Upstart's reboot replacement, which pass
the reason as an argument to the reboot syscall.  There is no
platform-agnostic way how those could be modified to pass the reason
to the bootloader, regardless of platform or bootloader.

Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stefan Stanacar <stefan.stanacar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-26-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28 11:34:02 +02:00