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  1. 05 6月, 2017 2 次提交
  3. 05 4月, 2017 2 次提交
  5. 07 2月, 2017 2 次提交
  7. 01 2月, 2017 3 次提交
  9. 14 1月, 2017 1 次提交
    • P
      efi/x86: Prune invalid memory map entries and fix boot regression · 0100a3e6
      由 Peter Jones 提交于 
      Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.

These machines fail to boot after the following commit,

  commit 8e80632f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()")

Fix this by removing such bogus entries from the memory map.

Furthermore, currently the log output for this case (with efi=debug)
looks like:

 [    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |  |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)

This is clearly wrong, and also not as informative as it could be.  This
patch changes it so that if we find obviously invalid memory map
entries, we print an error and skip those entries.  It also detects the
display of the address range calculation overflow, so the new output is:

 [    0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries:
 [    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0x0000000000000000] (invalid)

It also detects memory map sizes that would overflow the physical
address, for example phys_addr=0xfffffffffffff000 and
num_pages=0x0200000000000001, and prints:

 [    0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries:
 [    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[phys_addr=0xfffffffffffff000-0x20ffffffffffffffff] (invalid)

It then removes these entries from the memory map.
Signed-off-by: NPeter Jones <pjones@redhat.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
[ardb: refactor for clarity with no functional changes, avoid PAGE_SHIFT]
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
[Matt: Include bugzilla info in commit log]
Cc: <stable@vger.kernel.org> # v4.9+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=191121Signed-off-by: NIngo Molnar <mingo@kernel.org>
      0100a3e6
  11. 07 1月, 2017 1 次提交
    • N
      x86/efi: Don't allocate memmap through memblock after mm_init() · 20b1e22d
      由 Nicolai Stange 提交于 
      With the following commit:

  4bc9f92e ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data")

...  efi_bgrt_init() calls into the memblock allocator through
efi_mem_reserve() => efi_arch_mem_reserve() *after* mm_init() has been called.

Indeed, KASAN reports a bad read access later on in efi_free_boot_services():

  BUG: KASAN: use-after-free in efi_free_boot_services+0xae/0x24c
            at addr ffff88022de12740
  Read of size 4 by task swapper/0/0
  page:ffffea0008b78480 count:0 mapcount:-127
  mapping:          (null) index:0x1 flags: 0x5fff8000000000()
  [...]
  Call Trace:
   dump_stack+0x68/0x9f
   kasan_report_error+0x4c8/0x500
   kasan_report+0x58/0x60
   __asan_load4+0x61/0x80
   efi_free_boot_services+0xae/0x24c
   start_kernel+0x527/0x562
   x86_64_start_reservations+0x24/0x26
   x86_64_start_kernel+0x157/0x17a
   start_cpu+0x5/0x14

The instruction at the given address is the first read from the memmap's
memory, i.e. the read of md->type in efi_free_boot_services().

Note that the writes earlier in efi_arch_mem_reserve() don't splat because
they're done through early_memremap()ed addresses.

So, after memblock is gone, allocations should be done through the "normal"
page allocator. Introduce a helper, efi_memmap_alloc() for this. Use
it from efi_arch_mem_reserve(), efi_free_boot_services() and, for the sake
of consistency, from efi_fake_memmap() as well.

Note that for the latter, the memmap allocations cease to be page aligned.
This isn't needed though.
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org> # v4.9
Cc: Dave Young <dyoung@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 4bc9f92e ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data")
Link: http://lkml.kernel.org/r/20170105125130.2815-1-nicstange@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      20b1e22d
  13. 13 11月, 2016 4 次提交
    • L
      x86/efi: Retrieve and assign Apple device properties · 58c5475a
      由 Lukas Wunner 提交于 
      Apple's EFI drivers supply device properties which are needed to support
Macs optimally. They contain vital information which cannot be obtained
any other way (e.g. Thunderbolt Device ROM). They're also used to convey
the current device state so that OS drivers can pick up where EFI
drivers left (e.g. GPU mode setting).

There's an EFI driver dubbed "AAPL,PathProperties" which implements a
per-device key/value store. Other EFI drivers populate it using a custom
protocol. The macOS bootloader /System/Library/CoreServices/boot.efi
retrieves the properties with the same protocol. The kernel extension
AppleACPIPlatform.kext subsequently merges them into the I/O Kit
registry (see ioreg(8)) where they can be queried by other kernel
extensions and user space.

This commit extends the efistub to retrieve the device properties before
ExitBootServices is called. It assigns them to devices in an fs_initcall
so that they can be queried with the API in <linux/property.h>.

Note that the device properties will only be available if the kernel is
booted with the efistub. Distros should adjust their installers to
always use the efistub on Macs. grub with the "linux" directive will not
work unless the functionality of this commit is duplicated in grub.
(The "linuxefi" directive should work but is not included upstream as of
this writing.)

The custom protocol has GUID 91BD12FE-F6C3-44FB-A5B7-5122AB303AE0 and
looks like this:

typedef struct {
	unsigned long version; /* 0x10000 */
	efi_status_t (*get) (
		IN	struct apple_properties_protocol *this,
		IN	struct efi_dev_path *device,
		IN	efi_char16_t *property_name,
		OUT	void *buffer,
		IN OUT	u32 *buffer_len);
		/* EFI_SUCCESS, EFI_NOT_FOUND, EFI_BUFFER_TOO_SMALL */
	efi_status_t (*set) (
		IN	struct apple_properties_protocol *this,
		IN	struct efi_dev_path *device,
		IN	efi_char16_t *property_name,
		IN	void *property_value,
		IN	u32 property_value_len);
		/* allocates copies of property name and value */
		/* EFI_SUCCESS, EFI_OUT_OF_RESOURCES */
	efi_status_t (*del) (
		IN	struct apple_properties_protocol *this,
		IN	struct efi_dev_path *device,
		IN	efi_char16_t *property_name);
		/* EFI_SUCCESS, EFI_NOT_FOUND */
	efi_status_t (*get_all) (
		IN	struct apple_properties_protocol *this,
		OUT	void *buffer,
		IN OUT	u32 *buffer_len);
		/* EFI_SUCCESS, EFI_BUFFER_TOO_SMALL */
} apple_properties_protocol;

Thanks to Pedro Vilaça for this blog post which was helpful in reverse
engineering Apple's EFI drivers and bootloader:
https://reverse.put.as/2016/06/25/apple-efi-firmware-passwords-and-the-scbo-myth/

If someone at Apple is reading this, please note there's a memory leak
in your implementation of the del() function as the property struct is
freed but the name and value allocations are not.

Neither the macOS bootloader nor Apple's EFI drivers check the protocol
version, but we do to avoid breakage if it's ever changed. It's been the
same since at least OS X 10.6 (2009).

The get_all() function conveniently fills a buffer with all properties
in marshalled form which can be passed to the kernel as a setup_data
payload. The number of device properties is dynamic and can change
between a first invocation of get_all() (to determine the buffer size)
and a second invocation (to retrieve the actual buffer), hence the
peculiar loop which does not finish until the buffer size settles.
The macOS bootloader does the same.

The setup_data payload is later on unmarshalled in an fs_initcall. The
idea is that most buses instantiate devices in "subsys" initcall level
and drivers are usually bound to these devices in "device" initcall
level, so we assign the properties in-between, i.e. in "fs" initcall
level.

This assumes that devices to which properties pertain are instantiated
from a "subsys" initcall or earlier. That should always be the case
since on macOS, AppleACPIPlatformExpert::matchEFIDevicePath() only
supports ACPI and PCI nodes and we've fully scanned those buses during
"subsys" initcall level.

The second assumption is that properties are only needed from a "device"
initcall or later. Seems reasonable to me, but should this ever not work
out, an alternative approach would be to store the property sets e.g. in
a btree early during boot. Then whenever device_add() is called, an EFI
Device Path would have to be constructed for the newly added device,
and looked up in the btree. That way, the property set could be assigned
to the device immediately on instantiation. And this would also work for
devices instantiated in a deferred fashion. It seems like this approach
would be more complicated and require more code. That doesn't seem
justified without a specific use case.

For comparison, the strategy on macOS is to assign properties to objects
in the ACPI namespace (AppleACPIPlatformExpert::mergeEFIProperties()).
That approach is definitely wrong as it fails for devices not present in
the namespace: The NHI EFI driver supplies properties for attached
Thunderbolt devices, yet on Macs with Thunderbolt 1 only one device
level behind the host controller is described in the namespace.
Consequently macOS cannot assign properties for chained devices. With
Thunderbolt 2 they started to describe three device levels behind host
controllers in the namespace but this grossly inflates the SSDT and
still fails if the user daisy-chained more than three devices.

We copy the property names and values from the setup_data payload to
swappable virtual memory and afterwards make the payload available to
the page allocator. This is just for the sake of good housekeeping, it
wouldn't occupy a meaningful amount of physical memory (4444 bytes on my
machine). Only the payload is freed, not the setup_data header since
otherwise we'd break the list linkage and we cannot safely update the
predecessor's ->next link because there's no locking for the list.

The payload is currently not passed on to kexec'ed kernels, same for PCI
ROMs retrieved by setup_efi_pci(). This can be added later if there is
demand by amending setup_efi_state(). The payload can then no longer be
made available to the page allocator of course.

Tested-by: Lukas Wunner <lukas@wunner.de> [MacBookPro9,1]
Tested-by: Pierre Moreau <pierre.morrow@free.fr> [MacBookPro11,3]
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pedro Vilaça <reverser@put.as>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: grub-devel@gnu.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161112213237.8804-9-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      58c5475a
    • L
      efi: Add device path parser · 46cd4b75
      由 Lukas Wunner 提交于 
      We're about to extended the efistub to retrieve device properties from
EFI on Apple Macs. The properties use EFI Device Paths to indicate the
device they belong to. This commit adds a parser which, given an EFI
Device Path, locates the corresponding struct device and returns a
reference to it.

Initially only ACPI and PCI Device Path nodes are supported, these are
the only types needed for Apple device properties (the corresponding
macOS function AppleACPIPlatformExpert::matchEFIDevicePath() does not
support any others). Further node types can be added with little to
moderate effort.

Apple device properties is currently the only use case of this parser,
but Peter Jones intends to use it to match up devices with the
ConInDev/ConOutDev/ErrOutDev variables and add sysfs attributes to these
devices to say the hardware supports using them as console. Thus,
make this parser a separate component which can be selected with config
option EFI_DEV_PATH_PARSER. It can in principle be compiled as a module
if acpi_get_first_physical_node() and acpi_bus_type are exported (and
efi_get_device_by_path() itself is exported).

The dependency on CONFIG_ACPI is needed for acpi_match_device_ids().
It can be removed if an empty inline stub is added for that function.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161112213237.8804-7-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      46cd4b75
    • A
      efi/arm*/libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table · 568bc4e8
      由 Ard Biesheuvel 提交于 
      Invoke the EFI_RNG_PROTOCOL protocol in the context of the stub and
install the Linux-specific RNG seed UEFI config table. This will be
picked up by the EFI routines in the core kernel to seed the kernel
entropy pool.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: NKees Cook <keescook@chromium.org>
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/20161112213237.8804-6-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      568bc4e8
    • A
      efi: Add support for seeding the RNG from a UEFI config table · 63625988
      由 Ard Biesheuvel 提交于 
      Specify a Linux specific UEFI configuration table that carries some
random bits, and use the contents during early boot to seed the kernel's
random number generator. This allows much strong random numbers to be
generated early on.

The entropy is fed to the kernel using add_device_randomness(), which is
documented as being appropriate for being called very early.

Since UEFI configuration tables may also be consumed by kexec'd kernels,
register a reboot notifier that updates the seed in the table.

Note that the config table could be generated by the EFI stub or by any
other UEFI driver or application (e.g., GRUB), but the random seed table
GUID and the associated functionality should be considered an internal
kernel interface (unless it is promoted to ABI later on)
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: NKees Cook <keescook@chromium.org>
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/20161112213237.8804-4-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      63625988
  15. 09 9月, 2016 9 次提交
    • A
      efi: Replace runtime services spinlock with semaphore · dce48e35
      由 Ard Biesheuvel 提交于 
      The purpose of the efi_runtime_lock is to prevent concurrent calls into
the firmware. There is no need to use spinlocks here, as long as we ensure
that runtime service invocations from an atomic context (i.e., EFI pstore)
cannot block.

So use a semaphore instead, and use down_trylock() in the nonblocking case.
We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      dce48e35
    • S
      efi: Don't use spinlocks for efi vars · 21b3ddd3
      由 Sylvain Chouleur 提交于 
      All efivars operations are protected by a spinlock which prevents
interruptions and preemption. This is too restricted, we just need a
lock preventing concurrency.
The idea is to use a semaphore of count 1 and to have two ways of
locking, depending on the context:
- In interrupt context, we call down_trylock(), if it fails we return
  an error
- In normal context, we call down_interruptible()

We don't use a mutex here because the mutex_trylock() function must not
be called from interrupt context, whereas the down_trylock() can.
Signed-off-by: NSylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      21b3ddd3
    • S
      efi: Use a file local lock for efivars · 217b27d4
      由 Sylvain Chouleur 提交于 
      This patch replaces the spinlock in the efivars struct with a single lock
for the whole vars.c file.  The goal of this lock is to protect concurrent
calls to efi variable services, registering and unregistering. This allows
us to register new efivars operations without having in-progress call.
Signed-off-by: NSylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      217b27d4
    • M
      efi/runtime-map: Use efi.memmap directly instead of a copy · 31ce8cc6
      由 Matt Fleming 提交于 
      Now that efi.memmap is available all of the time there's no need to
allocate and build a separate copy of the EFI memory map.

Furthermore, efi.memmap contains boot services regions but only those
regions that have been reserved via efi_mem_reserve(). Using
efi.memmap allows us to pass boot services across kexec reboot so that
the ESRT and BGRT drivers will now work.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      31ce8cc6
    • M
      efi: Allow drivers to reserve boot services forever · 816e7612
      由 Matt Fleming 提交于 
      Today, it is not possible for drivers to reserve EFI boot services for
access after efi_free_boot_services() has been called on x86. For
ARM/arm64 it can be done simply by calling memblock_reserve().

Having this ability for all three architectures is desirable for a
couple of reasons,

  1) It saves drivers copying data out of those regions
  2) kexec reboot can now make use of things like ESRT

Instead of using the standard memblock_reserve() which is insufficient
to reserve the region on x86 (see efi_reserve_boot_services()), a new
API is introduced in this patch; efi_mem_reserve().

efi.memmap now always represents which EFI memory regions are
available. On x86 the EFI boot services regions that have not been
reserved via efi_mem_reserve() will be removed from efi.memmap during
efi_free_boot_services().

This has implications for kexec, since it is not possible for a newly
kexec'd kernel to access the same boot services regions that the
initial boot kernel had access to unless they are reserved by every
kexec kernel in the chain.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      816e7612
    • M
      efi: Add efi_memmap_install() for installing new EFI memory maps · c45f4da3
      由 Matt Fleming 提交于 
      While efi_memmap_init_{early,late}() exist for architecture code to
install memory maps from firmware data and for the virtual memory
regions respectively, drivers don't care which stage of the boot we're
at and just want to swap the existing memmap for a modified one.

efi_memmap_install() abstracts the details of how the new memory map
should be mapped and the existing one unmapped.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      c45f4da3
    • M
      efi: Split out EFI memory map functions into new file · 60863c0d
      由 Matt Fleming 提交于 
      Also move the functions from the EFI fake mem driver since future
patches will require access to the memmap insertion code even if
CONFIG_EFI_FAKE_MEM isn't enabled.

This will be useful when we need to build custom EFI memory maps to
allow drivers to mark regions as reserved.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      60863c0d
    • M
      efi: Add efi_memmap_init_late() for permanent EFI memmap · dca0f971
      由 Matt Fleming 提交于 
      Drivers need a way to access the EFI memory map at runtime. ARM and
arm64 currently provide this by remapping the EFI memory map into the
vmalloc space before setting up the EFI virtual mappings.

x86 does not provide this functionality which has resulted in the code
in efi_mem_desc_lookup() where it will manually map individual EFI
memmap entries if the memmap has already been torn down on x86,

  /*
   * If a driver calls this after efi_free_boot_services,
   * ->map will be NULL, and the target may also not be mapped.
   * So just always get our own virtual map on the CPU.
   *
   */
  md = early_memremap(p, sizeof (*md));

There isn't a good reason for not providing a permanent EFI memory map
for runtime queries, especially since the EFI regions are not mapped
into the standard kernel page tables.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      dca0f971
    • M
      efi: Refactor efi_memmap_init_early() into arch-neutral code · 9479c7ce
      由 Matt Fleming 提交于 
      Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.

The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.

In the process, this patch also fixes a few undesirable implementation
differences:

 - ARM and arm64 were failing to clear the EFI_MEMMAP bit when
   unmapping the early EFI memory map. EFI_MEMMAP indicates whether
   the EFI memory map is mapped (not the regions contained within) and
   can be traversed.  It's more correct to set the bit as soon as we
   memremap() the passed in EFI memmap.

 - Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
   regular naming scheme.

This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).

There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      9479c7ce
  17. 05 9月, 2016 3 次提交
    • J
      efi/libstub: Introduce ExitBootServices helper · fc07716b
      由 Jeffrey Hugo 提交于 
      The spec allows ExitBootServices to fail with EFI_INVALID_PARAMETER if a
race condition has occurred where the EFI has updated the memory map after
the stub grabbed a reference to the map.  The spec defines a retry
proceedure with specific requirements to handle this scenario.

This scenario was previously observed on x86 - commit d3768d88 ("x86,
efi: retry ExitBootServices() on failure") but the current fix is not spec
compliant and the scenario is now observed on the Qualcomm Technologies
QDF2432 via the FDT stub which does not handle the error and thus causes
boot failures.  The user will notice the boot failure as the kernel is not
executed and the system may drop back to a UEFI shell, but will be
unresponsive to input and the system will require a power cycle to recover.

Add a helper to the stub library that correctly adheres to the spec in the
case of EFI_INVALID_PARAMETER from ExitBootServices and can be universally
used across all stub implementations.
Signed-off-by: NJeffrey Hugo <jhugo@codeaurora.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      fc07716b
    • J
      efi/libstub: Allocate headspace in efi_get_memory_map() · dadb57ab
      由 Jeffrey Hugo 提交于 
      efi_get_memory_map() allocates a buffer to store the memory map that it
retrieves.  This buffer may need to be reused by the client after
ExitBootServices() is called, at which point allocations are not longer
permitted.  To support this usecase, provide the allocated buffer size back
to the client, and allocate some additional headroom to account for any
reasonable growth in the map that is likely to happen between the call to
efi_get_memory_map() and the client reusing the buffer.
Signed-off-by: NJeffrey Hugo <jhugo@codeaurora.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      dadb57ab
    • J
      efi: Make for_each_efi_memory_desc_in_map() cope with running on Xen · d4c4fed0
      由 Jan Beulich 提交于 
      While commit 55f1ea15 ("efi: Fix for_each_efi_memory_desc_in_map()
for empty memmaps") made an attempt to deal with empty memory maps, it
didn't address the case where the map field never gets set, as is
apparently the case when running under Xen.

Reported-by: <lists@ssl-mail.com>
Tested-by: <lists@ssl-mail.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: NJan Beulich <jbeulich@suse.com>
[ Guard the loop with a NULL check instead of pointer underflow ]
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      d4c4fed0
  19. 08 7月, 2016 1 次提交
  21. 27 6月, 2016 3 次提交
  23. 18 6月, 2016 1 次提交
    • A
      ia64: efi: use timespec64 for persistent clock · 70f4f935
      由 Arnd Bergmann 提交于 
      We have a generic read_persistent_clock64 interface now, and can
change the ia64 implementation to provide that instead of
read_persistent_clock.

The main point of this is to avoid the use of struct timespec
in the global efi.h, which would cause build errors as soon
as we want to build a kernel without 'struct timespec' defined
on 32-bit architectures.

Aside from this, we get a little closer to removing the
__weak read_persistent_clock() definition, which relies on
converting all architectures to provide read_persistent_clock64
instead.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NTony Luck <tony.luck@intel.com>
      70f4f935
  25. 03 6月, 2016 1 次提交
    • V
      efi: Fix for_each_efi_memory_desc_in_map() for empty memmaps · 55f1ea15
      由 Vitaly Kuznetsov 提交于 
      Commit:

  78ce248f ("efi: Iterate over efi.memmap in for_each_efi_memory_desc()")

introduced a regression for systems booted with the 'noefi' kernel option.

In particular, I observed an early kernel hang in efi_find_mirror()'s
for_each_efi_memory_desc() call. As we don't have efi memmap on this
system we enter this iterator with the following parameters:

  efi.memmap.map = 0, efi.memmap.map_end = 0, efi.memmap.desc_size = 28

... then for_each_efi_memory_desc_in_map() does the following comparison:

  (md) <= (efi_memory_desc_t *)((m)->map_end - (m)->desc_size);

... where md = 0, (m)->map_end = 0 and (m)->desc_size = 28 but when we subtract
something from a NULL pointer wrap around happens and we end up returning
invalid pointer and crash.

Fix it by using the correct pointer arithmetics.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 78ce248f ("efi: Iterate over efi.memmap in for_each_efi_memory_desc()")
Link: http://lkml.kernel.org/r/1464690224-4503-2-git-send-email-matt@codeblueprint.co.uk
[ Made the changelog more readable. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      55f1ea15
  27. 21 5月, 2016 1 次提交
  29. 07 5月, 2016 1 次提交
    • J
      efi: Merge boolean flag arguments · 1cfd6316
      由 Julia Lawall 提交于 
      The parameters atomic and duplicates of efivar_init always have opposite
values.  Drop the parameter atomic, replace the uses of !atomic with
duplicates, and update the call sites accordingly.

The code using duplicates is slightly reorganized with an 'else', to avoid
duplicating the lock code.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NMatt 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: Jeremy Kerr <jk@ozlabs.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Saurabh Sengar <saurabh.truth@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-5-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1cfd6316
  31. 28 4月, 2016 5 次提交