linux-stable.git/drivers/firmware/efi, branch v4.7

efi/arm: Fix the format of EFI debug messages

2016-06-03T07:57:36+00:00

When both EFI and memblock debugging is enabled on the kernel command line:

  'efi=debug memblock=debug'

.. the debug messages for early_con look the following way:

 [    0.000000] efi:   0x0000e1050000-0x0000e105ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e1300000-0x0000e1300fff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e8200000-0x0000e827ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x008000000000-0x008001e7ffff [Runtime Data       |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC]
 [    0.000000] memblock_add: [0x00008000000000-0x00008001e7ffff] flags 0x0 early_init_dt_add_memory_arch+0x54/0x5c
 [    0.000000] *
 ...

Note the misplaced '*' line, which happened because the memblock debug message
was printed while the EFI debug message was still being constructed..

This patch fixes the output to be the expected:

 [    0.000000] efi:   0x0000e1050000-0x0000e105ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e1300000-0x0000e1300fff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x0000e8200000-0x0000e827ffff [Memory Mapped I/O  |RUN|  |  |  |  |  |  |   |  |  |  |UC]
 [    0.000000] efi:   0x008000000000-0x008001e7ffff [Runtime Data       |RUN|  |  |  |  |  |  |   |WB|WT|WC|UC]*
 [    0.000000] memblock_add: [0x00008000000000-0x00008001e7ffff] flags 0x0 early_init_dt_add_memory_arch+0x54/0x5c
 ...

Note how the '*' is now in the proper EFI debug message line.

Signed-off-by: Dennis Chen 
Signed-off-by: Matt Fleming 
Acked-by: Mark Rutland 
Cc: Ard Biesheuvel 
Cc: Catalin Marinas 
Cc: Dan Williams 
Cc: Linus Torvalds 
Cc: Mark Salter 
Cc: Peter Zijlstra 
Cc: Steve Capper 
Cc: Steve McIntyre 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1464690224-4503-3-git-send-email-matt@codeblueprint.co.uk
[ Made the changelog more readable. ]
Signed-off-by: Ingo Molnar

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2016-05-17T00:17:24+00:00

Pull arm64 updates from Will Deacon:

 - virt_to_page/page_address optimisations

 - support for NUMA systems described using device-tree

 - support for hibernate/suspend-to-disk

 - proper support for maxcpus= command line parameter

 - detection and graceful handling of AArch64-only CPUs

 - miscellaneous cleanups and non-critical fixes

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
  arm64: do not enforce strict 16 byte alignment to stack pointer
  arm64: kernel: Fix incorrect brk randomization
  arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
  arm64: secondary_start_kernel: Remove unnecessary barrier
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
  arm64: Replace hard-coded values in the pmd/pud_bad() macros
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL
  arm64: always use STRICT_MM_TYPECHECKS
  arm64: kvm: Fix kvm teardown for systems using the extended idmap
  arm64: kaslr: increase randomization granularity
  arm64: kconfig: drop CONFIG_RTC_LIB dependency
  arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION
  arm64: hibernate: Refuse to hibernate if the boot cpu is offline
  arm64: kernel: Add support for hibernate/suspend-to-disk
  PM / Hibernate: Call flush_icache_range() on pages restored in-place
  arm64: Add new asm macro copy_page
  arm64: Promote KERNEL_START/KERNEL_END definitions to a header file
  arm64: kernel: Include _AC definition in page.h
  ...

efi: Merge boolean flag arguments

2016-05-07T05:06:13+00:00

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: Julia Lawall 
Signed-off-by: Matt Fleming 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Jeremy Kerr 
Cc: Linus Torvalds 
Cc: Matthew Garrett 
Cc: Peter Zijlstra 
Cc: Saurabh Sengar 
Cc: Thomas Gleixner 
Cc: Vaishali Thakkar 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-5-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

efi/capsule: Move 'capsule' to the stack in efi_capsule_supported()

2016-05-07T05:06:13+00:00

Dan Carpenter reports that passing the address of the pointer to the
kmalloc()'d memory for 'capsule' is dangerous:

 "drivers/firmware/efi/capsule.c:109 efi_capsule_supported()
  warn: did you mean to pass the address of 'capsule'

   108
   109          status = efi.query_capsule_caps(&capsule, 1, &max_size, reset);
                                                ^^^^^^^^
  If we modify capsule inside this function call then at the end of the
  function we aren't freeing the original pointer that we allocated."

Ard Biesheuvel noted that we don't even need to call kmalloc() since the
object we allocate isn't very big and doesn't need to persist after the
function returns.

Place 'capsule' on the stack instead.

Suggested-by: Ard Biesheuvel 
Reported-by: Dan Carpenter 
Signed-off-by: Matt Fleming 
Acked-by: Ard Biesheuvel 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Bryan O'Donoghue 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Kweh Hock Leong 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: joeyli 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-4-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

efibc: Fix excessive stack footprint warning

2016-05-07T05:06:13+00:00

GCC complains about a newly added file for the EFI Bootloader Control:

  drivers/firmware/efi/efibc.c: In function 'efibc_set_variable':
  drivers/firmware/efi/efibc.c:53:1: error: the frame size of 2272 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

The problem is the declaration of a local variable of type struct
efivar_entry, which is by itself larger than the warning limit of 1024
bytes.

Use dynamic memory allocation instead of stack memory for the entry
object.

This patch also fixes a potential buffer overflow.

Reported-by: Ingo Molnar 
Reported-by: Arnd Bergmann 
Signed-off-by: Jeremy Compostella 
[ Updated changelog to include GCC error ]
Signed-off-by: Matt Fleming 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-3-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

efi/capsule: Make efi_capsule_pending() lockless

2016-05-07T05:06:13+00:00

Taking a mutex in the reboot path is bogus because we cannot sleep
with interrupts disabled, such as when rebooting due to panic(),

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:97
  in_atomic(): 0, irqs_disabled(): 1, pid: 7, name: rcu_sched
  Call Trace:
    dump_stack+0x63/0x89
    ___might_sleep+0xd8/0x120
    __might_sleep+0x49/0x80
    mutex_lock+0x20/0x50
    efi_capsule_pending+0x1d/0x60
    native_machine_emergency_restart+0x59/0x280
    machine_emergency_restart+0x19/0x20
    emergency_restart+0x18/0x20
    panic+0x1ba/0x217

In this case all other CPUs will have been stopped by the time we
execute the platform reboot code, so 'capsule_pending' cannot change
under our feet. We wouldn't care even if it could since we cannot wait
for it complete.

Also, instead of relying on the external 'system_state' variable just
use a reboot notifier, so we can set 'stop_capsules' while holding
'capsule_mutex', thereby avoiding a race where system_state is updated
while we're in the middle of efi_capsule_update_locked() (since CPUs
won't have been stopped at that point).

Signed-off-by: Matt Fleming 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Bryan O'Donoghue 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Kweh Hock Leong 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: joeyli 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462570771-13324-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

arm64: kaslr: increase randomization granularity

2016-04-28T18:44:15+00:00

Currently, our KASLR implementation randomizes the placement of the core
kernel at 2 MB granularity. This is based on the arm64 kernel boot
protocol, which mandates that the kernel is loaded TEXT_OFFSET bytes above
a 2 MB aligned base address. This requirement is a result of the fact that
the block size used by the early mapping code may be 2 MB at the most (for
a 4 KB granule kernel)

But we can do better than that: since a KASLR kernel needs to be relocated
in any case, we can tolerate a physical misalignment as long as the virtual
misalignment relative to this 2 MB block size is equal in size, and code to
deal with this is already in place.

Since we align the kernel segments to 64 KB, let's randomize the physical
offset at 64 KB granularity as well (unless CONFIG_DEBUG_ALIGN_RODATA is
enabled). This way, the page table and TLB footprint is not affected.

The higher granularity allows for 5 bits of additional entropy to be used.

Reviewed-by: Matt Fleming 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Will Deacon

efi/runtime-wrappers: Remove ARCH_EFI_IRQ_FLAGS_MASK #ifdef

2016-04-28T09:34:13+00:00

Now that arm, arm64, and x86 all provide ARCH_EFI_IRQ_FLAGS_MASK, we can
get rid of the trivial and now unused implementation of
efi_call_virt_check_flags().

Signed-off-by: Mark Rutland 
Signed-off-by: Matt Fleming 
Cc: Ard Biesheuvel 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Leif Lindholm 
Cc: Peter Zijlstra 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-41-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

efi/runtime-wrappers: Detect firmware IRQ flag corruption

2016-04-28T09:34:11+00:00

The UEFI spec allows runtime services to be called with interrupts
masked or unmasked, and if a runtime service function needs to mask
interrupts, it must restore the mask to its original state before
returning (i.e. from the PoV of the OS, this does not change across a
call). Firmware should never unmask exceptions, as these may then be
taken by the OS unexpectedly.

Unfortunately, some firmware has been seen to unmask IRQs (and
potentially other maskable exceptions) across runtime services calls,
leaving IRQ flags corrupted after returning from a runtime services
function call. This may be detected by the IRQ tracing code, but often
goes unnoticed, leaving a potentially disastrous bug hidden.

This patch detects when the IRQ flags are corrupted by an EFI runtime
services call, logging the call and specific corruption to the console.
While restoring the expected value of the flags is insufficient to avoid
problems, we do so to avoid redundant warnings from elsewhere (e.g. IRQ
tracing).

The set of bits in flags which we want to check is architecture-specific
(e.g. we want to check FIQ on arm64, but not the zero flag on x86), so
each arch must provide ARCH_EFI_IRQ_FLAGS_MASK to describe those. In the
absence of this mask, the check is a no-op, and we redundantly save the
flags twice, but that will be short-lived as subsequent patches
will implement this and remove the scaffolding.

Signed-off-by: Mark Rutland 
Signed-off-by: Matt Fleming 
Cc: Ard Biesheuvel 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Leif Lindholm 
Cc: Peter Zijlstra 
Cc: Robin Murphy 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-37-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

efi/runtime-wrappers: Remove redundant #ifdefs

2016-04-28T09:34:10+00:00

Now that all users of the EFI runtime wrappers (arm,arm64,x86) have been
migrated to the new setup/teardown macros, we don't need to support
overridden {__,}efi_call_virt() implementations.

This patch removes the unnecessary #ifdefs.

Signed-off-by: Mark Rutland 
Signed-off-by: Matt Fleming 
Cc: Ard Biesheuvel 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Leif Lindholm 
Cc: Peter Zijlstra 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-36-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar