This patch reworks the UEFI anti-bricking code, including an effective
reversion of cc5a080c and 31ff2f20. It turns out that calling
QueryVariableInfo() from boot services results in some firmware
implementations jumping to physical addresses even after entering virtual
mode, so until we have 1:1 mappings for UEFI runtime space this isn't
going to work so well.
Reverting these gets us back to the situation where we'd refuse to create
variables on some systems because they classify deleted variables as "used"
until the firmware triggers a garbage collection run, which they won't do
until they reach a lower threshold. This results in it being impossible to
install a bootloader, which is unhelpful.
Feedback from Samsung indicates that the firmware doesn't need more than
5KB of storage space for its own purposes, so that seems like a reasonable
threshold. However, there's still no guarantee that a platform will attempt
garbage collection merely because it drops below this threshold. It seems
that this is often only triggered if an attempt to write generates a
genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to
create a variable larger than the remaining space. This should fail, but if
it somehow succeeds we can then immediately delete it.
I've tested this on the UEFI machines I have available, but I don't have
a Samsung and so can't verify that it avoids the bricking problem.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ]
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
That will be better initial the value of DataSize to zero for the input of
GetVariable(), otherwise we will feed a random value. The debug log of input
DataSize like this:
...
[ 195.915612] EFI Variables Facility v0.08 2004-May-17
[ 195.915819] efi: size: 18446744071581821342
[ 195.915969] efi: size': 18446744071581821342
[ 195.916324] efi: size: 18446612150714306560
[ 195.916632] efi: size': 18446612150714306560
[ 195.917159] efi: size: 18446612150714306560
[ 195.917453] efi: size': 18446612150714306560
...
The size' is value that was returned by BIOS.
After applied this patch:
[ 82.442042] EFI Variables Facility v0.08 2004-May-17
[ 82.442202] efi: size: 0
[ 82.442360] efi: size': 1039
[ 82.443828] efi: size: 0
[ 82.444127] efi: size': 2616
[ 82.447057] efi: size: 0
[ 82.447356] efi: size': 5832
...
Found on Acer Aspire V3 BIOS, it will not return the size of data if we input a
non-zero DataSize.
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
Pull x86/efi changes from Peter Anvin:
"The bulk of these changes are cleaning up the efivars handling and
breaking it up into a tree of files. There are a number of fixes as
well.
The entire changeset is pretty big, but most of it is code movement.
Several of these commits are quite new; the history got very messed up
due to a mismerge with the urgent changes for rc8 which completely
broke IA64, and so Ingo requested that we rebase it to straighten it
out."
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: remove "kfree(NULL)"
efi: locking fix in efivar_entry_set_safe()
efi, pstore: Read data from variable store before memcpy()
efi, pstore: Remove entry from list when erasing
efi, pstore: Initialise 'entry' before iterating
efi: split efisubsystem from efivars
efivarfs: Move to fs/efivarfs
efivars: Move pstore code into the new EFI directory
efivars: efivar_entry API
efivars: Keep a private global pointer to efivars
efi: move utf16 string functions to efi.h
x86, efi: Make efi_memblock_x86_reserve_range more readable
efivarfs: convert to use simple_open()
Pull x86 platform changes from Ingo Molnar:
"Small fixes and cleanups all over the map"
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/setup: Drop unneeded include <asm/dmi.h>
x86/olpc/xo1/sci: Don't call input_free_device() after input_unregister_device()
x86/platform/intel/mrst: Remove cast for kmalloc() return value
x86/platform/uv: Replace kmalloc() & memset with kzalloc()
Using this parameter one can disable the storage_size/2 check if
he is really sure that the UEFI does sane gc and fulfills the spec.
This parameter is useful if a devices uses more than 50% of the
storage by default.
The Intel DQSW67 desktop board is such a sucker for exmaple.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Fixes build with CONFIG_EFI_VARS=m which was broken after the commit
"x86, efivars: firmware bug workarounds should be in platform code".
Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
EFI implementations distinguish between space that is actively used by a
variable and space that merely hasn't been garbage collected yet. Space
that hasn't yet been garbage collected isn't available for use and so isn't
counted in the remaining_space field returned by QueryVariableInfo().
Combined with commit 68d9298 this can cause problems. Some implementations
don't garbage collect until the remaining space is smaller than the maximum
variable size, and as a result check_var_size() will always fail once more
than 50% of the variable store has been used even if most of that space is
marked as available for garbage collection. The user is unable to create
new variables, and deleting variables doesn't increase the remaining space.
The problem that 68d9298 was attempting to avoid was one where certain
platforms fail if the actively used space is greater than 50% of the
available storage space. We should be able to calculate that by simply
summing the size of each available variable and subtracting that from
the total storage space. With luck this will fix the problem described in
https://bugzilla.kernel.org/show_bug.cgi?id=55471 without permitting
damage to occur to the machines 68d9298 was attempting to fix.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
EFI variables can be flagged as being accessible only within boot services.
This makes it awkward for us to figure out how much space they use at
runtime. In theory we could figure this out by simply comparing the results
from QueryVariableInfo() to the space used by all of our variables, but
that fails if the platform doesn't garbage collect on every boot. Thankfully,
calling QueryVariableInfo() while still inside boot services gives a more
reliable answer. This patch passes that information from the EFI boot stub
up to the efi platform code.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Some EFI implementations return always a MaximumVariableSize of 0,
check against max_size only if it is non-zero.
My Intel DQ67SW desktop board has such an implementation.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Let's not burden ia64 with checks in the common efivars code that we're not
writing too much data to the variable store. That kind of thing is an x86
firmware bug, plain and simple.
efi_query_variable_store() provides platforms with a wrapper in which they can
perform checks and workarounds for EFI variable storage bugs.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Every 11 minutes ntp attempts to update the x86 rtc with the current
system time. Currently, the x86 code only updates the rtc if the system
time is within +/-15 minutes of the current value of the rtc. This
was done originally to avoid setting the RTC if the RTC was in localtime
mode (common with Windows dualbooting). Other architectures do a full
synchronization and now that we have better infrastructure to detect
when the RTC is in localtime, there is no reason that x86 should be
software limited to a 30 minute window.
This patch changes the behavior of the kernel to do a full synchronization
(year, month, day, hour, minute, and second) of the rtc when ntp requests
a synchronization between the system time and the rtc.
I've used the RTC library functions in this patchset as they do all the
required bounds checking.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: x86@kernel.org
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: linux-efi@vger.kernel.org
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
[jstultz: Tweak commit message, fold in build fix found by fengguang
Also add select RTC_LIB to X86, per new dependency, as found by prarit]
Signed-off-by: John Stultz <john.stultz@linaro.org>
So basically this function copies EFI memmap stuff from boot_params into
the EFI memmap descriptor and reserves memory for it. Make it much more
readable.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Matthew Garret <mjg59@srcf.ucam.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Pull x86/EFI changes from Peter Anvin:
- Improve the initrd handling in the EFI boot stub by allowing forward
slashes in the pathname - from Chun-Yi Lee.
- Cleanup code duplication in the EFI mixed kernel/firmware code - from
Satoru Takeuchi.
- efivarfs bug fixes for more strict filename validation, with lots of
input from Al Viro.
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, efi: remove duplicate code in setup_arch() by using, efi_is_native()
efivarfs: guid part of filenames are case-insensitive
efivarfs: Validate filenames much more aggressively
efivarfs: Use sizeof() instead of magic number
x86, efi: Allow slash in file path of initrd
Pull more x86 fixes from Peter Anvin:
"Additional x86 fixes. Three of these patches are pure documentation,
two are pretty trivial; the remaining one fixes boot problems on some
non-BIOS machines."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Make sure we can boot in the case the BDA contains pure garbage
x86, efi: Mark disable_runtime as __initdata
x86, doc: Fix incorrect comment about 64-bit code segment descriptors
doc, kernel-parameters: Document 'console=hvc<n>'
doc, xen: Mention 'earlyprintk=xen' in the documentation.
ACPI: Overriding ACPI tables via initrd only works with an initrd and on X86
Pull x86 fixes from Ingo Molnar.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/pageattr: Prevent PSE and GLOABL leftovers to confuse pmd/pte_present and pmd_huge
Revert "x86, mm: Make spurious_fault check explicitly check explicitly check the PRESENT bit"
x86/mm/numa: Don't check if node is NUMA_NO_NODE
x86, efi: Make "noefi" really disable EFI runtime serivces
x86/apic: Fix parsing of the 'lapic' cmdline option
Pull x86 mm changes from Peter Anvin:
"This is a huge set of several partly interrelated (and concurrently
developed) changes, which is why the branch history is messier than
one would like.
The *really* big items are two humonguous patchsets mostly developed
by Yinghai Lu at my request, which completely revamps the way we
create initial page tables. In particular, rather than estimating how
much memory we will need for page tables and then build them into that
memory -- a calculation that has shown to be incredibly fragile -- we
now build them (on 64 bits) with the aid of a "pseudo-linear mode" --
a #PF handler which creates temporary page tables on demand.
This has several advantages:
1. It makes it much easier to support things that need access to data
very early (a followon patchset uses this to load microcode way
early in the kernel startup).
2. It allows the kernel and all the kernel data objects to be invoked
from above the 4 GB limit. This allows kdump to work on very large
systems.
3. It greatly reduces the difference between Xen and native (Xen's
equivalent of the #PF handler are the temporary page tables created
by the domain builder), eliminating a bunch of fragile hooks.
The patch series also gets us a bit closer to W^X.
Additional work in this pull is the 64-bit get_user() work which you
were also involved with, and a bunch of cleanups/speedups to
__phys_addr()/__pa()."
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits)
x86, mm: Move reserving low memory later in initialization
x86, doc: Clarify the use of asm("%edx") in uaccess.h
x86, mm: Redesign get_user with a __builtin_choose_expr hack
x86: Be consistent with data size in getuser.S
x86, mm: Use a bitfield to mask nuisance get_user() warnings
x86/kvm: Fix compile warning in kvm_register_steal_time()
x86-32: Add support for 64bit get_user()
x86-32, mm: Remove reference to alloc_remap()
x86-32, mm: Remove reference to resume_map_numa_kva()
x86-32, mm: Rip out x86_32 NUMA remapping code
x86/numa: Use __pa_nodebug() instead
x86: Don't panic if can not alloc buffer for swiotlb
mm: Add alloc_bootmem_low_pages_nopanic()
x86, 64bit, mm: hibernate use generic mapping_init
x86, 64bit, mm: Mark data/bss/brk to nx
x86: Merge early kernel reserve for 32bit and 64bit
x86: Add Crash kernel low reservation
x86, kdump: Remove crashkernel range find limit for 64bit
memblock: Add memblock_mem_size()
x86, boot: Not need to check setup_header version for setup_data
...
Matthew Garrett
Lee, Chun-Yi
Linus Torvalds
Matt Fleming
David Howells
Thomas Gleixner
Wei Yongjun
H. Peter Anvin
Richard Weinberger
Sergey Vlasov
Prarit Bhargava
Zhang Yanfei
Alexandru Gheorghiu
Borislav Petkov