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  1. 17 5月, 2019 1 次提交
  3. 22 7月, 2018 1 次提交
  5. 16 7月, 2018 2 次提交
    • S
      efi: Remove the declaration of efi_late_init() as the function is unused · f5dcc214
      由 Sai Praneeth 提交于 
      The following commit:

  7b0a9114 ("efi/x86: Move the EFI BGRT init code to early init code")

... removed the implementation and all the references to
efi_late_init() but the function is still declared at
include/linux/efi.h.

Hence, remove the unnecessary declaration.
Signed-off-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.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/20180711094040.12506-6-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f5dcc214
    • S
      efi: Use a work queue to invoke EFI Runtime Services · 3eb420e7
      由 Sai Praneeth 提交于 
      Presently, when a user process requests the kernel to execute any
UEFI runtime service, the kernel temporarily switches to a separate
set of page tables that describe the virtual mapping of the UEFI
runtime services regions in memory. Since UEFI runtime services are
typically invoked with interrupts enabled, any code that may be called
during this time, will have an incorrect view of the process's address
space. Although it is unusual for code running in interrupt context to
make assumptions about the process context it runs in, there are cases
(such as the perf subsystem taking samples) where this causes problems.

So let's set up a work queue for calling UEFI runtime services, so that
the actual calls are made when the work queue items are dispatched by a
work queue worker running in a separate kernel thread. Such threads are
not expected to have userland mappings in the first place, and so the
additional mappings created for the UEFI runtime services can never
clash with any.

The ResetSystem() runtime service is not covered by the work queue
handling, since it is not expected to return, and may be called at a
time when the kernel is torn down to the point where we cannot expect
work queues to still be operational.

The non-blocking variants of SetVariable() and QueryVariableInfo()
are also excluded: these are intended to be used from atomic context,
which obviously rules out waiting for a completion to be signalled by
another thread. Note that these variants are currently only used for
UEFI runtime services calls that occur very early in the boot, and
for ones that occur in critical conditions, e.g., to flush kernel logs
to UEFI variables via efi-pstore.
Suggested-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
[ardb: exclude ResetSystem() from the workqueue treatment
       merge from 2 separate patches and rewrite commit log]
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.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/20180711094040.12506-4-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3eb420e7
  7. 14 5月, 2018 2 次提交
  9. 12 3月, 2018 1 次提交
  11. 08 1月, 2018 1 次提交
  13. 03 1月, 2018 1 次提交
    • A
      efi/capsule-loader: Reinstate virtual capsule mapping · f24c4d47
      由 Ard Biesheuvel 提交于 
      Commit:

  82c3768b ("efi/capsule-loader: Use a cached copy of the capsule header")

... refactored the capsule loading code that maps the capsule header,
to avoid having to map it several times.

However, as it turns out, the vmap() call we ended up removing did not
just map the header, but the entire capsule image, and dropping this
virtual mapping breaks capsules that are processed by the firmware
immediately (i.e., without a reboot).

Unfortunately, that change was part of a larger refactor that allowed
a quirk to be implemented for Quark, which has a non-standard memory
layout for capsules, and we have slightly painted ourselves into a
corner by allowing quirk code to mangle the capsule header and memory
layout.

So we need to fix this without breaking Quark. Fortunately, Quark does
not appear to care about the virtual mapping, and so we can simply
do a partial revert of commit:

  2a457fb3 ("efi/capsule-loader: Use page addresses rather than struct page pointers")

... and create a vmap() mapping of the entire capsule (including header)
based on the reinstated struct page array, unless running on Quark, in
which case we pass the capsule header copy as before.
Reported-by: NGe Song <ge.song@hxt-semitech.com>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Tested-by: NGe Song <ge.song@hxt-semitech.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 82c3768b ("efi/capsule-loader: Use a cached copy of the capsule header")
Link: http://lkml.kernel.org/r/20180102172110.17018-3-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f24c4d47
  15. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      由 Greg Kroah-Hartman 提交于 
      Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  17. 30 8月, 2017 1 次提交
  19. 26 8月, 2017 2 次提交
  21. 17 8月, 2017 1 次提交
    • B
      efi: Introduce efi_early_memdesc_ptr to get pointer to memmap descriptor · 02e43c2d
      由 Baoquan He 提交于 
      The existing map iteration helper for_each_efi_memory_desc_in_map can
only be used after the kernel initializes the EFI subsystem to set up
struct efi_memory_map.

Before that we also need iterate map descriptors which are stored in several
intermediate structures, like struct efi_boot_memmap for arch independent
usage and struct efi_info for x86 arch only.

Introduce efi_early_memdesc_ptr() to get pointer to a map descriptor, and
replace several places where that primitive is open coded.
Signed-off-by: NBaoquan He <bhe@redhat.com>
[ Various improvements to the text. ]
Acked-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: ard.biesheuvel@linaro.org
Cc: fanc.fnst@cn.fujitsu.com
Cc: izumi.taku@jp.fujitsu.com
Cc: keescook@chromium.org
Cc: linux-efi@vger.kernel.org
Cc: n-horiguchi@ah.jp.nec.com
Cc: thgarnie@google.com
Link: http://lkml.kernel.org/r/20170816134651.GF21273@x1Signed-off-by: NIngo Molnar <mingo@kernel.org>
      02e43c2d
  23. 18 7月, 2017 2 次提交
  25. 05 6月, 2017 2 次提交
  27. 05 4月, 2017 2 次提交
  29. 07 2月, 2017 2 次提交
  31. 01 2月, 2017 3 次提交
  33. 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
  35. 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
  37. 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
  39. 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