There are some circumstances that call for trying to write an EFI
variable in a non-blocking way. One such scenario is when writing pstore
data in efi_pstore_write() via the pstore_dump() kdump callback.
Now that we have an EFI runtime spinlock we need a way of aborting if
there is contention instead of spinning, since when writing pstore data
from the kdump callback, the runtime lock may already be held by the CPU
that's running the callback if we crashed in the middle of an EFI
variable operation.
The situation is sufficiently special that a new EFI variable operation
is warranted.
Introduce ->set_variable_nonblocking() for this use case. It is an
optional EFI backend operation, and need only be implemented by those
backends that usually acquire locks to serialize access to EFI
variables, as is the case for virt_efi_set_variable() where we now grab
the EFI runtime spinlock.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
At the moment, there are three architectures debug-printing the EFI memory
map at initialization: x86, ia64, and arm64. They all use different format
strings, plus the EFI memory type and the EFI memory attributes are
similarly hard to decode for a human reader.
Introduce a helper __init function that formats the memory type and the
memory attributes in a unified way, to a user-provided character buffer.
The array "memory_type_name" is copied from the arm64 code, temporarily
duplicating it. The (otherwise optional) braces around each string literal
in the initializer list are dropped in order to match the kernel coding
style more closely. The element size is tightened from 32 to 20 bytes
(maximum actual string length + 1) so that we can derive the field width
from the element size.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[ Dropped useless 'register' keyword, which compiler will ignore ]
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Add the following macro from the UEFI spec, for completeness:
EFI_MEMORY_UCE Memory cacheability attribute: The memory region
supports being configured as not cacheable, exported,
and supports the "fetch and add" semaphore mechanism.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
noefi param can be used for arches other than X86 later, thus move it
out of x86 platform code.
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We need a way to customize the behaviour of the EFI boot stub, in
particular, we need a way to disable the "chunking" workaround, used
when reading files from the EFI System Partition.
One of my machines doesn't cope well when reading files in 1MB chunks to
a buffer above the 4GB mark - it appears that the "chunking" bug
workaround triggers another firmware bug. This was only discovered with
commit 4bf7111f50 ("x86/efi: Support initrd loaded above 4G"), and
that commit is perfectly valid. The symptom I observed was a corrupt
initrd rather than any kind of crash.
efi= is now used to specify EFI parameters in two very different
execution environments, the EFI boot stub and during kernel boot.
There is also a slight performance optimization by enabling efi=nochunk,
but that's offset by the fact that you're more likely to run into
firmware issues, at least on x86. This is the rationale behind leaving
the workaround enabled by default.
Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're
using the current value of 1MB.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This patch does two things. It passes EFI run time mappings to second
kernel in bootparams efi_info. Second kernel parse this info and create
new mappings in second kernel. That means mappings in first and second
kernel will be same. This paves the way to enable EFI in kexec kernel.
This patch also prepares and passes EFI setup data through bootparams.
This contains bunch of information about various tables and their
addresses.
These information gathering and passing has been written along the lines
of what current kexec-tools is doing to make kexec work with UEFI.
[akpm@linux-foundation.org: s/get_efi/efi_get/g, per Matt]
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The comment describing how struct efivars->lock is used hasn't been
updated in sync with the code. Fix it.
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
efi_set_rtc_mmss() is never used to set RTC due to bugs found
on many EFI platforms. It is set directly by mach_set_rtc_mmss().
Hence, remove unused efi_set_rtc_mmss() function.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Introduce EFI_PARAVIRT flag. If it is set then kernel runs
on EFI platform but it has not direct control on EFI stuff
like EFI runtime, tables, structures, etc. If not this means
that Linux Kernel has direct access to EFI infrastructure
and everything runs as usual.
This functionality is used in Xen dom0 because hypervisor
has full control on EFI stuff and all calls from dom0 to
EFI must be requested via special hypercall which in turn
executes relevant EFI code in behalf of dom0.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
It appears that the BayTrail-T class of hardware requires EFI in order
to powerdown and reboot and no other reliable method exists.
This quirk is generally applicable to all hardware that has the ACPI
Hardware Reduced bit set, since usually ACPI would be the preferred
method.
Cc: Len Brown <len.brown@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Not only can EfiResetSystem() be used to reboot, it can also be used to
power down machines.
By and large, this functionality doesn't work very well across the range
of EFI machines in the wild, so it should definitely only be used as a
last resort. In an ideal world, this wouldn't be needed at all.
Unfortunately, we're starting to see machines where EFI is the *only*
reliable way to power down, and nothing else, not PCI, not ACPI, works.
efi_poweroff_required() should be implemented on a per-architecture
basis, since exactly when we should be using EFI runtime services is a
platform-specific decision. There's no analogue for reboot because each
architecture handles reboot very differently - the x86 code in
particular is pretty complex.
Patches to enable this for specific classes of hardware will be
submitted separately.
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Implement efi_reboot(), which is really just a wrapper around the
EfiResetSystem() EFI runtime service, but it does at least allow us to
funnel all callers through a single location.
It also simplifies the callsites since users no longer need to check to
see whether EFI_RUNTIME_SERVICES are enabled.
Cc: Tony Luck <tony.luck@intel.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
In order to move from the #include "../../../xxxxx.c" anti-pattern used
by both the x86 and arm64 versions of the stub to a static library
linked into either the kernel proper (arm64) or a separate boot
executable (x86), there is some prepatory work required.
This patch does the following:
- move forward declarations of functions shared between the arch
specific and the generic parts of the stub to include/linux/efi.h
- move forward declarations of functions shared between various .c files
of the generic stub code to a new local header file called "efistub.h"
- add #includes to all .c files which were formerly relying on the
#includor to include the correct header files
- remove all static modifiers from functions which will need to be
externally visible once we move to a static library
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
In order for other archs (such as arm64) to be able to reuse the virtual
mode function call wrappers, move them to drivers/firmware/efi/runtime-wrappers.c.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Both ARM and ARM64 stubs will update the device tree that they pass to
the kernel. In both cases they primarily need to add the same UEFI
related information, so the function can be shared. Create a new FDT
related file for this to avoid use of architecture #ifdefs in
efi-stub-helper.c.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
[ Fixed memory node deletion code. ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
ARM and ARM64 architectures use the device tree to pass UEFI parameters
from stub to kernel. These parameters are things known to the stub but
not discoverable by the kernel after the stub calls ExitBootSerives().
There is a helper function in:
drivers/firmware/efi/fdt.c
which the stub uses to add the UEFI parameters to the device tree.
This patch adds a complimentary helper function which UEFI runtime
support may use to retrieve the parameters from the device tree.
If an architecture wants to use this helper, it should select
CONFIG_EFI_PARAMS_FROM_FDT.
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
In preparation for compat support, we can't assume that user variable
object is represented by a 'struct efi_variable'. Convert the validation
functions to take the variable name as an argument, which is the only
piece of the struct that was ever used anyway.
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There are a lot of places in the kernel which iterate through an
EFI memory map. Most of these places use essentially the same
for-loop code. This patch adds a for_each_efi_memory_desc()
helper to clean up all of the existing duplicate code and avoid
more in the future.
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
The traditional approach of using machine-specific types such as
'unsigned long' does not allow the kernel to interact with firmware
running in a different CPU mode, e.g. 64-bit kernel with 32-bit EFI.
Add distinct EFI structure definitions for both 32-bit and 64-bit so
that we can use them in the 32-bit and 64-bit code paths.
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There's no good reason to keep efi_enabled() under CONFIG_X86 anymore,
since nothing about the implementation is specific to x86.
Set EFI feature flags in the ia64 boot path instead of claiming to
support all features. The old behaviour was actually buggy since
efi.memmap never points to a valid memory map, so we shouldn't be
claiming to support EFI_MEMMAP.
Fortunately, this bug was never triggered because EFI_MEMMAP isn't used
outside of arch/x86 currently, but that may not always be the case.
Reviewed-and-tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
As we grow support for more EFI architectures they're going to want the
ability to query which EFI features are available on the running system.
Instead of storing this information in an architecture-specific place,
stick it in the global 'struct efi', which is already the central
location for EFI state.
While we're at it, let's change the return value of efi_enabled() to be
bool and replace all references to 'facility' with 'feature', which is
the usual word used to describe the attributes of the running system.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
kexec kernel will need exactly same mapping for EFI runtime memory
ranges. Thus here export the runtime ranges mapping to sysfs,
kexec-tools will assemble them and pass to 2nd kernel via setup_data.
Introducing a new directory /sys/firmware/efi/runtime-map just like
/sys/firmware/memmap. Containing below attribute in each file of that
directory:
attribute num_pages phys_addr type virt_addr
Signed-off-by: Dave Young <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Export fw_vendor, runtime and config table physical addresses to
/sys/firmware/efi/{fw_vendor,runtime,config_table} because kexec kernels
need them.
From EFI spec these 3 variables will be updated to virtual address after
entering virtual mode. But kernel startup code will need the physical
address.
Signed-off-by: Dave Young <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Currently, when mounting pstore file system, a read callback of
efi_pstore driver runs mutiple times as below.
- In the first read callback, scan efivar_sysfs_list from head and pass
a kmsg buffer of a entry to an upper pstore layer.
- In the second read callback, rescan efivar_sysfs_list from the entry
and pass another kmsg buffer to it.
- Repeat the scan and pass until the end of efivar_sysfs_list.
In this process, an entry is read across the multiple read function
calls. To avoid race between the read and erasion, the whole process
above is protected by a spinlock, holding in open() and releasing in
close().
At the same time, kmemdup() is called to pass the buffer to pstore
filesystem during it. And then, it causes a following lockdep warning.
To make the dynamic memory allocation runnable without taking spinlock,
holding off a deletion of sysfs entry if it happens while scanning it
via efi_pstore, and deleting it after the scan is completed.
To implement it, this patch introduces two flags, scanning and deleting,
to efivar_entry.
On the code basis, it seems that all the scanning and deleting logic is
not needed because __efivars->lock are not dropped when reading from the
EFI variable store.
But, the scanning and deleting logic is still needed because an
efi-pstore and a pstore filesystem works as follows.
In case an entry(A) is found, the pointer is saved to psi->data. And
efi_pstore_read() passes the entry(A) to a pstore filesystem by
releasing __efivars->lock.
And then, the pstore filesystem calls efi_pstore_read() again and the
same entry(A), which is saved to psi->data, is used for resuming to scan
a sysfs-list.
So, to protect the entry(A), the logic is needed.
[ 1.143710] ------------[ cut here ]------------
[ 1.144058] WARNING: CPU: 1 PID: 1 at kernel/lockdep.c:2740 lockdep_trace_alloc+0x104/0x110()
[ 1.144058] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
[ 1.144058] Modules linked in:
[ 1.144058] CPU: 1 PID: 1 Comm: systemd Not tainted 3.11.0-rc5 #2
[ 1.144058] 0000000000000009 ffff8800797e9ae0 ffffffff816614a5 ffff8800797e9b28
[ 1.144058] ffff8800797e9b18 ffffffff8105510d 0000000000000080 0000000000000046
[ 1.144058] 00000000000000d0 00000000000003af ffffffff81ccd0c0 ffff8800797e9b78
[ 1.144058] Call Trace:
[ 1.144058] [<ffffffff816614a5>] dump_stack+0x54/0x74
[ 1.144058] [<ffffffff8105510d>] warn_slowpath_common+0x7d/0xa0
[ 1.144058] [<ffffffff8105517c>] warn_slowpath_fmt+0x4c/0x50
[ 1.144058] [<ffffffff8131290f>] ? vsscanf+0x57f/0x7b0
[ 1.144058] [<ffffffff810bbd74>] lockdep_trace_alloc+0x104/0x110
[ 1.144058] [<ffffffff81192da0>] __kmalloc_track_caller+0x50/0x280
[ 1.144058] [<ffffffff815147bb>] ? efi_pstore_read_func.part.1+0x12b/0x170
[ 1.144058] [<ffffffff8115b260>] kmemdup+0x20/0x50
[ 1.144058] [<ffffffff815147bb>] efi_pstore_read_func.part.1+0x12b/0x170
[ 1.144058] [<ffffffff81514800>] ? efi_pstore_read_func.part.1+0x170/0x170
[ 1.144058] [<ffffffff815148b4>] efi_pstore_read_func+0xb4/0xe0
[ 1.144058] [<ffffffff81512b7b>] __efivar_entry_iter+0xfb/0x120
[ 1.144058] [<ffffffff8151428f>] efi_pstore_read+0x3f/0x50
[ 1.144058] [<ffffffff8128d7ba>] pstore_get_records+0x9a/0x150
[ 1.158207] [<ffffffff812af25c>] ? selinux_d_instantiate+0x1c/0x20
[ 1.158207] [<ffffffff8128ce30>] ? parse_options+0x80/0x80
[ 1.158207] [<ffffffff8128ced5>] pstore_fill_super+0xa5/0xc0
[ 1.158207] [<ffffffff811ae7d2>] mount_single+0xa2/0xd0
[ 1.158207] [<ffffffff8128ccf8>] pstore_mount+0x18/0x20
[ 1.158207] [<ffffffff811ae8b9>] mount_fs+0x39/0x1b0
[ 1.158207] [<ffffffff81160550>] ? __alloc_percpu+0x10/0x20
[ 1.158207] [<ffffffff811c9493>] vfs_kern_mount+0x63/0xf0
[ 1.158207] [<ffffffff811cbb0e>] do_mount+0x23e/0xa20
[ 1.158207] [<ffffffff8115b51b>] ? strndup_user+0x4b/0xf0
[ 1.158207] [<ffffffff811cc373>] SyS_mount+0x83/0xc0
[ 1.158207] [<ffffffff81673cc2>] system_call_fastpath+0x16/0x1b
[ 1.158207] ---[ end trace 61981bc62de9f6f4 ]---
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Tested-by: Madper Xie <cxie@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We map the EFI regions needed for runtime services non-contiguously,
with preserved alignment on virtual addresses starting from -4G down
for a total max space of 64G. This way, we provide for stable runtime
services addresses across kernels so that a kexec'd kernel can still use
them.
Thus, they're mapped in a separate pagetable so that we don't pollute
the kernel namespace.
Add an efi= kernel command line parameter for passing miscellaneous
options and chicken bits from the command line.
While at it, add a chicken bit called "efi=old_map" which can be used as
a fallback to the old runtime services mapping method in case there's
some b0rkage with a particular EFI implementation (haha, it is hard to
hold up the sarcasm here...).
Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
The x86/AMD64 EFI stubs must use a call wrapper to convert between
the Linux and EFI ABIs, so void pointers are sufficient. For ARM,
the ABIs are compatible, so we can directly invoke the function
pointers. The functions that are used by the ARM stub are updated
to match the EFI definitions.
Also add some EFI types used by EFI functions.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
efi_lookup_mapped_addr() is a handy utility for other platforms than
x86. Move it from arch/x86 to drivers/firmware. Add memmap pointer
to global efi structure, and initialise it on x86.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Common to (U)EFI support on all platforms is the global "efi" data
structure, and the code that parses the System Table to locate
addresses to populate that structure with.
This patch adds both of these to the global EFI driver code and
removes the local definition of the global "efi" data structure from
the x86 and ia64 code.
Squashed into one big patch to avoid breaking bisection.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Pull timer core updates from Thomas Gleixner:
"The timer changes contain:
- posix timer code consolidation and fixes for odd corner cases
- sched_clock implementation moved from ARM to core code to avoid
duplication by other architectures
- alarm timer updates
- clocksource and clockevents unregistration facilities
- clocksource/events support for new hardware
- precise nanoseconds RTC readout (Xen feature)
- generic support for Xen suspend/resume oddities
- the usual lot of fixes and cleanups all over the place
The parts which touch other areas (ARM/XEN) have been coordinated with
the relevant maintainers. Though this results in an handful of
trivial to solve merge conflicts, which we preferred over nasty cross
tree merge dependencies.
The patches which have been committed in the last few days are bug
fixes plus the posix timer lot. The latter was in akpms queue and
next for quite some time; they just got forgotten and Frederic
collected them last minute."
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
hrtimer: Remove unused variable
hrtimers: Move SMP function call to thread context
clocksource: Reselect clocksource when watchdog validated high-res capability
posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting
posix_timers: fix racy timer delta caching on task exit
posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule()
selftests: add basic posix timers selftests
posix_cpu_timers: consolidate expired timers check
posix_cpu_timers: consolidate timer list cleanups
posix_cpu_timer: consolidate expiry time type
tick: Sanitize broadcast control logic
tick: Prevent uncontrolled switch to oneshot mode
tick: Make oneshot broadcast robust vs. CPU offlining
x86: xen: Sync the CMOS RTC as well as the Xen wallclock
x86: xen: Sync the wallclock when the system time is set
timekeeping: Indicate that clock was set in the pvclock gtod notifier
timekeeping: Pass flags instead of multiple bools to timekeeping_update()
xen: Remove clock_was_set() call in the resume path
hrtimers: Support resuming with two or more CPUs online (but stopped)
timer: Fix jiffies wrap behavior of round_jiffies_common()
...
... to void * like the boot services and lose all the void * casts. No
functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.
read_persistent_wallclock() and update_persistent_wallclock() allow
for nanosecond precision but their implementation on x86 with
x86_platform.get/set_wallclock() only allows for one second precision.
This means guests may see a wallclock time that is off by up to 1
second.
Make set_wallclock() and get_wallclock() take a struct timespec
parameter (which allows for nanosecond precision) so KVM and Xen
guests may start with a more accurate wallclock time and a Xen dom0
can maintain a more accurate wallclock for guests.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Seiji reported getting empty dmesg-* files, because the data was never
actually read in efi_pstore_read_func(), and so the memcpy() was copying
garbage data.
This patch necessitated adding __efivar_entry_get() which is callable
between efivar_entry_iter_{begin,end}(). We can also delete
__efivar_entry_size() because efi_pstore_read_func() was the only
caller.
Reported-by: Seiji Aguchi <seiji.aguchi@hds.com>
Tested-by: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This registers /sys/firmware/efi/{,systab,efivars/} whenever EFI is enabled
and the system is booted with EFI.
This allows
*) userspace to check for the existence of /sys/firmware/efi as a way
to determine whether or it is running on an EFI system.
*) 'mount -t efivarfs none /sys/firmware/efi/efivars' without manually
loading any modules.
[ Also, move the efivar API into vars.c and unconditionally compile it.
This allows us to move efivars.c, which now only contains the sysfs
variable code, into the firmware/efi directory. Note that the efivars.c
filename is kept to maintain backwards compatability with the old
efivars.ko module. With this patch it is now possible for efivarfs
to be built without CONFIG_EFI_VARS - Matt ]
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mike Waychison <mikew@google.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Chun-Yi Lee <jlee@suse.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Tobias Powalowski <tpowa@archlinux.org>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
efivars.c has grown far too large and needs to be divided up. Create a
new directory and move the persistence storage code to efi-pstore.c now
that it uses the new efivar API. This helps us to greatly reduce the
size of efivars.c and paves the way for moving other code out of
efivars.c.
Note that because CONFIG_EFI_VARS can be built as a module efi-pstore
must also include support for building as a module.
Reviewed-by: Tom Gundersen <teg@jklm.no>
Tested-by: Tom Gundersen <teg@jklm.no>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There isn't really a formal interface for dealing with EFI variables
or struct efivar_entry. Historically, this has led to various bits of
code directly accessing the generic EFI variable ops, which inherently
ties it to specific EFI variable operations instead of indirectly
using whatever ops were registered with register_efivars(). This lead
to the efivarfs code only working with the generic EFI variable ops
and not CONFIG_GOOGLE_SMI.
Encapsulate everything that needs to access '__efivars' inside an
efivar_entry_* API and use the new API in the pstore, sysfs and
efivarfs code.
Much of the efivars code had to be rewritten to use this new API. For
instance, it is now up to the users of the API to build the initial
list of EFI variables in their efivar_init() callback function. The
variable list needs to be passed to efivar_init() which allows us to
keep work arounds for things like implementation bugs in
GetNextVariable() in a central location.
Allowing users of the API to use a callback function to build the list
greatly benefits the efivarfs code which needs to allocate inodes and
dentries for every variable. It previously did this in a racy way
because the code ran without holding the variable spinlock. Both the
sysfs and efivarfs code maintain their own lists which means the two
interfaces can be running simultaneously without interference, though
it should be noted that because no synchronisation is performed it is
very easy to create inconsistencies. efibootmgr doesn't currently use
efivarfs and users are likely to also require the old sysfs interface,
so it makes sense to allow both to be built.
Reviewed-by: Tom Gundersen <teg@jklm.no>
Tested-by: Tom Gundersen <teg@jklm.no>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There are currently two implementations of the utf16 string functions.
Somewhat confusingly, they've got different names.
Centralise the functions in efi.h.
Reviewed-by: Tom Gundersen <teg@jklm.no>
Tested-by: Tom Gundersen <teg@jklm.no>
Reviewed-by: Mike Waychison <mikew@google.com>
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>
a system in the crash path. Plus a new mountpoint
(/sys/fs/pstore ... makes more sense then /dev/pstore).
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Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull pstore patches from Tony Luck:
"A few fixes to reduce places where pstore might hang a system in the
crash path. Plus a new mountpoint (/sys/fs/pstore ... makes more
sense then /dev/pstore)."
Fix up trivial conflict in drivers/firmware/efivars.c
* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
pstore: Create a convenient mount point for pstore
efi_pstore: Introducing workqueue updating sysfs
efivars: Disable external interrupt while holding efivars->lock
efi_pstore: Avoid deadlock in non-blocking paths
pstore: Avoid deadlock in panic and emergency-restart path
[Problem]
efi_pstore creates sysfs entries, which enable users to access to NVRAM,
in a write callback. If a kernel panic happens in an interrupt context,
it may fail because it could sleep due to dynamic memory allocations during
creating sysfs entries.
[Patch Description]
This patch removes sysfs operations from a write callback by introducing
a workqueue updating sysfs entries which is scheduled after the write
callback is called.
Also, the workqueue is kicked in a just oops case.
A system will go down in other cases such as panic, clean shutdown and emergency
restart. And we don't need to create sysfs entries because there is no chance for
users to access to them.
efi_pstore will be robust against a kernel panic in an interrupt context with this patch.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.
The immediate motivation for this patch is the bug report at,
https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,
https://bugzilla.kernel.org/show_bug.cgi?id=47121
details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,
if (!efi_enabled)
hasn't been a sufficient condition for quite some time.
Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.
For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).
This patch is a prereq for the samsung-laptop fix patch.
Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This reverts commit bd52276fa1 ("x86-64/efi: Use EFI to deal with
platform wall clock (again)"), and the two supporting commits:
da5a108d05b4: "x86/kernel: remove tboot 1:1 page table creation code"
185034e72d59: "x86, efi: 1:1 pagetable mapping for virtual EFI calls")
as they all depend semantically on commit 53b87cf088 ("x86, mm:
Include the entire kernel memory map in trampoline_pgd") that got
reverted earlier due to the problems it caused.
This was pointed out by Yinghai Lu, and verified by me on my Macbook Air
that uses EFI.
Pointed-out-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 EFI update from Peter Anvin:
"EFI tree, from Matt Fleming. Most of the patches are the new efivarfs
filesystem by Matt Garrett & co. The balance are support for EFI
wallclock in the absence of a hardware-specific driver, and various
fixes and cleanups."
* 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
efivarfs: Make efivarfs_fill_super() static
x86, efi: Check table header length in efi_bgrt_init()
efivarfs: Use query_variable_info() to limit kmalloc()
efivarfs: Fix return value of efivarfs_file_write()
efivarfs: Return a consistent error when efivarfs_get_inode() fails
efivarfs: Make 'datasize' unsigned long
efivarfs: Add unique magic number
efivarfs: Replace magic number with sizeof(attributes)
efivarfs: Return an error if we fail to read a variable
efi: Clarify GUID length calculations
efivarfs: Implement exclusive access for {get,set}_variable
efivarfs: efivarfs_fill_super() ensure we clean up correctly on error
efivarfs: efivarfs_fill_super() ensure we free our temporary name
efivarfs: efivarfs_fill_super() fix inode reference counts
efivarfs: efivarfs_create() ensure we drop our reference on inode on error
efivarfs: efivarfs_file_read ensure we free data in error paths
x86-64/efi: Use EFI to deal with platform wall clock (again)
x86/kernel: remove tboot 1:1 page table creation code
x86, efi: 1:1 pagetable mapping for virtual EFI calls
x86, mm: Include the entire kernel memory map in trampoline_pgd
...
Host bridge hotplug:
- Untangle _PRT from struct pci_bus (Bjorn Helgaas)
- Request _OSC control before scanning root bus (Taku Izumi)
- Assign resources when adding host bridge (Yinghai Lu)
- Remove root bus when removing host bridge (Yinghai Lu)
- Remove _PRT during hot remove (Yinghai Lu)
SRIOV
- Add sysfs knobs to control numVFs (Don Dutile)
Power management
- Notify devices when power resource turned on (Huang Ying)
Bug fixes
- Work around broken _SEG on HP xw9300 (Bjorn Helgaas)
- Keep runtime PM enabled for unbound PCI devices (Huang Ying)
- Fix Optimus dual-GPU runtime D3 suspend issue (Dave Airlie)
- Fix xen frontend shutdown issue (David Vrabel)
- Work around PLX PCI 9050 BAR alignment erratum (Ian Abbott)
Miscellaneous
- Add GPL license for drivers/pci/ioapic (Andrew Cooks)
- Add standard PCI-X, PCIe ASPM register #defines (Bjorn Helgaas)
- NumaChip remote PCI support (Daniel Blueman)
- Fix PCIe Link Capabilities Supported Link Speed definition (Jingoo Han)
- Convert dev_printk() to dev_info(), etc (Joe Perches)
- Add support for non PCI BAR ROM data (Matthew Garrett)
- Add x86 support for host bridge translation offset (Mike Yoknis)
- Report success only when every driver supports AER (Vijay Pandarathil)
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Merge tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI update from Bjorn Helgaas:
"Host bridge hotplug:
- Untangle _PRT from struct pci_bus (Bjorn Helgaas)
- Request _OSC control before scanning root bus (Taku Izumi)
- Assign resources when adding host bridge (Yinghai Lu)
- Remove root bus when removing host bridge (Yinghai Lu)
- Remove _PRT during hot remove (Yinghai Lu)
SRIOV
- Add sysfs knobs to control numVFs (Don Dutile)
Power management
- Notify devices when power resource turned on (Huang Ying)
Bug fixes
- Work around broken _SEG on HP xw9300 (Bjorn Helgaas)
- Keep runtime PM enabled for unbound PCI devices (Huang Ying)
- Fix Optimus dual-GPU runtime D3 suspend issue (Dave Airlie)
- Fix xen frontend shutdown issue (David Vrabel)
- Work around PLX PCI 9050 BAR alignment erratum (Ian Abbott)
Miscellaneous
- Add GPL license for drivers/pci/ioapic (Andrew Cooks)
- Add standard PCI-X, PCIe ASPM register #defines (Bjorn Helgaas)
- NumaChip remote PCI support (Daniel Blueman)
- Fix PCIe Link Capabilities Supported Link Speed definition (Jingoo
Han)
- Convert dev_printk() to dev_info(), etc (Joe Perches)
- Add support for non PCI BAR ROM data (Matthew Garrett)
- Add x86 support for host bridge translation offset (Mike Yoknis)
- Report success only when every driver supports AER (Vijay
Pandarathil)"
Fix up trivial conflicts.
* tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (48 commits)
PCI: Use phys_addr_t for physical ROM address
x86/PCI: Add NumaChip remote PCI support
ath9k: Use standard #defines for PCIe Capability ASPM fields
iwlwifi: Use standard #defines for PCIe Capability ASPM fields
iwlwifi: collapse wrapper for pcie_capability_read_word()
iwlegacy: Use standard #defines for PCIe Capability ASPM fields
iwlegacy: collapse wrapper for pcie_capability_read_word()
cxgb3: Use standard #defines for PCIe Capability ASPM fields
PCI: Add standard PCIe Capability Link ASPM field names
PCI/portdrv: Use PCI Express Capability accessors
PCI: Use standard PCIe Capability Link register field names
x86: Use PCI setup data
PCI: Add support for non-BAR ROMs
PCI: Add pcibios_add_device
EFI: Stash ROMs if they're not in the PCI BAR
PCI: Add and use standard PCI-X Capability register names
PCI/PM: Keep runtime PM enabled for unbound PCI devices
xen-pcifront: Handle backend CLOSED without CLOSING
PCI: SRIOV control and status via sysfs (documentation)
PCI/AER: Report success only when every device has AER-aware driver
...
EFI provides support for providing PCI ROMs via means other than the ROM
BAR. This support vanishes after we've exited boot services, so add support
for stashing copies of the ROMs in setup_data if they're not otherwise
available.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
[Issue]
As discussed in a thread below, Running out of space in EFI isn't a well-tested scenario.
And we wouldn't expect all firmware to handle it gracefully.
http://marc.info/?l=linux-kernel&m=134305325801789&w=2
On the other hand, current efi_pstore doesn't check a remaining space of storage at writing time.
Therefore, efi_pstore may not work if it tries to write a large amount of data.
[Patch Description]
To avoid handling the situation above, this patch checks if there is a space enough to log with
QueryVariableInfo() before writing data.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
We don't want someone who can write EFI variables to be able to
allocate arbitrarily large amounts of memory, so cap it to something
sensible like the amount of free space for EFI variables.
Acked-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Other than ix86, x86-64 on EFI so far didn't set the
{g,s}et_wallclock accessors to the EFI routines, thus
incorrectly using raw RTC accesses instead.
Simply removing the #ifdef around the respective code isn't
enough, however: While so far early get-time calls were done in
physical mode, this doesn't work properly for x86-64, as virtual
addresses would still need to be set up for all runtime regions
(which wasn't the case on the system I have access to), so
instead the patch moves the call to efi_enter_virtual_mode()
ahead (which in turn allows to drop all code related to calling
efi-get-time in physical mode).
Additionally the earlier calling of efi_set_executable()
requires the CPA code to cope, i.e. during early boot it must be
avoided to call cpa_flush_array(), as the first thing this
function does is a BUG_ON(irqs_disabled()).
Also make the two EFI functions in question here static -
they're not being referenced elsewhere.
History:
This commit was originally merged as bacef661ac ("x86-64/efi:
Use EFI to deal with platform wall clock") but it resulted in some
ASUS machines no longer booting due to a firmware bug, and so was
reverted in f026cfa82f. A pre-emptive fix for the buggy ASUS
firmware was merged in 03a1c254975e ("x86, efi: 1:1 pagetable
mapping for virtual EFI calls") so now this patch can be
reapplied.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com> [added commit history]
Matt Fleming