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Ard Biesheuvel 23e6039404 efi/libstub/x86: Work around page freeing issue in mixed mode
Mixed mode translates calls from the 64-bit kernel into the 32-bit
firmware by wrapping them in a call to a thunking routine that
pushes a 32-bit word onto the stack for each argument passed to the
function, regardless of the argument type. This works surprisingly
well for most services and protocols, with the exception of ones that
take explicit 64-bit arguments.

efi_free() invokes the FreePages() EFI boot service, which takes
a efi_physical_addr_t as its address argument, and this is one of
those 64-bit types. This means that the 32-bit firmware will
interpret the (addr, size) pair as a single 64-bit quantity, and
since it is guaranteed to have the high word set (as size > 0),
it will always fail due to the fact that EFI memory allocations are
always < 4 GB on 32-bit firmware.

So let's fix this by giving the thunking code a little hand, and
pass two values for the address, and a third one for the size.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-21-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-25 10:49:23 +01:00
arch efi/libstub/x86: Work around page freeing issue in mixed mode 2019-12-25 10:49:23 +01:00
block block: fix memleak when __blk_rq_map_user_iov() is failed 2019-12-20 11:52:01 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto tpmdd fixes for Linux v5.5-rc3 2019-12-18 17:17:36 -08:00
Documentation Fixes for 5.5: 2019-12-22 10:59:06 -08:00
drivers efi/libstub/x86: Work around page freeing issue in mixed mode 2019-12-25 10:49:23 +01:00
fs Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-22 17:00:04 -08:00
include efi/libstub: Remove 'sys_table_arg' from all function prototypes 2019-12-25 10:49:23 +01:00
init early init: fix error handling when opening /dev/console 2019-12-17 13:10:11 -08:00
ipc treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
lib Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-12-22 17:00:04 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG 2019-12-17 20:59:59 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
scripts Kbuild fixes for v5.5 2019-12-21 10:49:47 -08:00
security tpmdd fixes for Linux v5.5-rc3 2019-12-18 17:17:36 -08:00
sound sound fixes for 5.5-rc3 2019-12-18 08:54:15 -08:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
usr kbuild: fix 'No such file or directory' warning when cleaning 2019-12-09 10:08:21 +09:00
virt PPC KVM fix for 5.5 2019-12-22 13:18:15 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
COPYING
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS PPC: 2019-12-22 10:26:59 -08:00
Makefile Linux 5.5-rc3 2019-12-22 17:02:23 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.