Add support for ARM Common Platform Error Record (CPER).
UEFI 2.6 specification adds support for ARM specific
processor error information to be reported as part of the
CPER records. This provides more detail on for processor error logs.
Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ACPI 6.1 spec added a timestamp to the generic error data
entry structure. Print the timestamp out when printing out the
error information.
Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ACPI 6.1 spec adds a new revision of the generic error data
entry structure. Add support to handle the new structure as well
as properly verify and iterate through the generic data entries.
Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Maniaxx reported a kernel boot crash in the EFI code, which I emulated
by using same invalid phys addr in code:
BUG: unable to handle kernel paging request at ffffffffff280001
IP: efi_bgrt_init+0xfb/0x153
...
Call Trace:
? bgrt_init+0xbc/0xbc
acpi_parse_bgrt+0xe/0x12
acpi_table_parse+0x89/0xb8
acpi_boot_init+0x445/0x4e2
? acpi_parse_x2apic+0x79/0x79
? dmi_ignore_irq0_timer_override+0x33/0x33
setup_arch+0xb63/0xc82
? early_idt_handler_array+0x120/0x120
start_kernel+0xb7/0x443
? early_idt_handler_array+0x120/0x120
x86_64_start_reservations+0x29/0x2b
x86_64_start_kernel+0x154/0x177
secondary_startup_64+0x9f/0x9f
There is also a similar bug filed in bugzilla.kernel.org:
https://bugzilla.kernel.org/show_bug.cgi?id=195633
The crash is caused by this commit:
7b0a911478 efi/x86: Move the EFI BGRT init code to early init code
The root cause is the firmware on those machines provides invalid BGRT
image addresses.
In a kernel before above commit BGRT initializes late and uses ioremap()
to map the image address. Ioremap validates the address, if it is not a
valid physical address ioremap() just fails and returns. However in current
kernel EFI BGRT initializes early and uses early_memremap() which does not
validate the image address, and kernel panic happens.
According to ACPI spec the BGRT image address should fall into
EFI_BOOT_SERVICES_DATA, see the section 5.2.22.4 of below document:
http://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdf
Fix this issue by validating the image address in efi_bgrt_init(). If the
image address does not fall into any EFI_BOOT_SERVICES_DATA areas we just
bail out with a warning message.
Reported-by: Maniaxx <tripleshiftone@gmail.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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: 7b0a911478 ("efi/x86: Move the EFI BGRT init code to early init code")
Link: http://lkml.kernel.org/r/20170609084558.26766-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Wire up the existing arm64 support for SMBIOS tables (aka DMI) for ARM as
well, by moving the arm64 init code to drivers/firmware/efi/arm-runtime.c
(which is shared between ARM and arm64), and adding a asm/dmi.h header to
ARM that defines the mapping routines for the firmware tables.
This allows userspace to access these tables to discover system information
exposed by the firmware. It also sets the hardware name used in crash
dumps, e.g.:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ed3c0000
[00000000] *pgd=bf1f3835
Internal error: Oops: 817 [#1] SMP THUMB2
Modules linked in:
CPU: 0 PID: 759 Comm: bash Not tainted 4.10.0-09601-g0e8f38792120-dirty #112
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
^^^
NOTE: This does *NOT* enable or encourage the use of DMI quirks, i.e., the
the practice of identifying the platform via DMI to decide whether
certain workarounds for buggy hardware and/or firmware need to be
enabled. This would require the DMI subsystem to be enabled much
earlier than we do on ARM, which is non-trivial.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
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
Link: http://lkml.kernel.org/r/20170602135207.21708-14-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current time will be initially available in the record->time field
for all pstore_read() and pstore_write() calls. Backends can either
update the field during read(), or use the field during write() instead
of fetching time themselves.
Signed-off-by: Kees Cook <keescook@chromium.org>
Right now, every pass through the EFI variables during erase would build
a copy of the old format variable name. Instead, try each name one time
through the EFI variables list. Additionally bump up the buffer size to
avoid truncation in pathological cases, and wipe the write name buffer.
Signed-off-by: Kees Cook <keescook@chromium.org>
Sabrina Dubroca reported an early panic:
BUG: unable to handle kernel paging request at ffffffffff240001
IP: efi_bgrt_init+0xdc/0x134
[...]
---[ end Kernel panic - not syncing: Attempted to kill the idle task!
... which was introduced by:
7b0a911478 ("efi/x86: Move the EFI BGRT init code to early init code")
The cause is that on this machine the firmware provides the EFI ACPI BGRT
table even on legacy non-EFI bootups - which table should be EFI only.
The garbage BGRT data causes the efi_bgrt_init() panic.
Add a check to skip efi_bgrt_init() in case non-EFI bootup to work around
this firmware bug.
Tested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: <stable@vger.kernel.org> # v4.11+
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
Fixes: 7b0a911478 ("efi/x86: Move the EFI BGRT init code to early init code")
Link: http://lkml.kernel.org/r/20170526113652.21339-6-matt@codeblueprint.co.uk
[ Rewrote the changelog to be more readable. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull pstore fix from Kees Cook:
"Marta noticed another misbehavior in EFI pstore, which this fixes.
Hopefully this is the last of the v4.12 fixes for pstore!"
* tag 'pstore-v4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
efi-pstore: Fix write/erase id tracking
Prior to the pstore interface refactoring, the "id" generated during
a backend pstore_write() was only retained by the internal pstore
inode tracking list. Additionally the "part" was ignored, so EFI
would encode this in the id. This corrects the misunderstandings
and correctly sets "id" during pstore_write(), and uses "part"
directly during pstore_erase().
Reported-by: Marta Lofstedt <marta.lofstedt@intel.com>
Fixes: 76cc9580e3 ("pstore: Replace arguments for write() API")
Fixes: a61072aae6 ("pstore: Replace arguments for erase() API")
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Marta Lofstedt <marta.lofstedt@intel.com>
Pull pstore fix from Kees Cook:
"Fix bad EFI vars iterator usage"
* tag 'pstore-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
efi-pstore: Fix read iter after pstore API refactor
During the internal pstore API refactoring, the EFI vars read entry was
accidentally made to update a stack variable instead of the pstore
private data pointer. This corrects the problem (and removes the now
needless argument).
Fixes: 125cc42baf ("pstore: Replace arguments for read() API")
Signed-off-by: Kees Cook <keescook@chromium.org>
Pull arm64 updates from Catalin Marinas:
- kdump support, including two necessary memblock additions:
memblock_clear_nomap() and memblock_cap_memory_range()
- ARMv8.3 HWCAP bits for JavaScript conversion instructions, complex
numbers and weaker release consistency
- arm64 ACPI platform MSI support
- arm perf updates: ACPI PMU support, L3 cache PMU in some Qualcomm
SoCs, Cortex-A53 L2 cache events and DTLB refills, MAINTAINERS update
for DT perf bindings
- architected timer errata framework (the arch/arm64 changes only)
- support for DMA_ATTR_FORCE_CONTIGUOUS in the arm64 iommu DMA API
- arm64 KVM refactoring to use common system register definitions
- remove support for ASID-tagged VIVT I-cache (no ARMv8 implementation
using it and deprecated in the architecture) together with some
I-cache handling clean-up
- PE/COFF EFI header clean-up/hardening
- define BUG() instruction without CONFIG_BUG
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS
arm64: Print DT machine model in setup_machine_fdt()
arm64: pmu: Wire-up Cortex A53 L2 cache events and DTLB refills
arm64: module: split core and init PLT sections
arm64: pmuv3: handle pmuv3+
arm64: Add CNTFRQ_EL0 trap handler
arm64: Silence spurious kbuild warning on menuconfig
arm64: pmuv3: use arm_pmu ACPI framework
arm64: pmuv3: handle !PMUv3 when probing
drivers/perf: arm_pmu: add ACPI framework
arm64: add function to get a cpu's MADT GICC table
drivers/perf: arm_pmu: split out platform device probe logic
drivers/perf: arm_pmu: move irq request/free into probe
drivers/perf: arm_pmu: split cpu-local irq request/free
drivers/perf: arm_pmu: rename irq request/free functions
drivers/perf: arm_pmu: handle no platform_device
drivers/perf: arm_pmu: simplify cpu_pmu_request_irqs()
drivers/perf: arm_pmu: factor out pmu registration
drivers/perf: arm_pmu: fold init into alloc
drivers/perf: arm_pmu: define armpmu_init_fn
...
Pull pstore updates from Kees Cook:
"This has a large internal refactoring along with several smaller
fixes.
- constify compression structures; Bhumika Goyal
- restore powerpc dumping; Ankit Kumar
- fix more bugs in the rarely exercises module unloading logic
- reorganize filesystem locking to fix problems noticed by lockdep
- refactor internal pstore APIs to make development and review
easier:
- improve error reporting
- add kernel-doc structure and function comments
- avoid insane argument passing by using a common record
structure"
* tag 'pstore-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits)
pstore: Solve lockdep warning by moving inode locks
pstore: Fix flags to enable dumps on powerpc
pstore: Remove unused vmalloc.h in pmsg
pstore: simplify write_user_compat()
pstore: Remove write_buf() callback
pstore: Replace arguments for write_buf_user() API
pstore: Replace arguments for write_buf() API
pstore: Replace arguments for erase() API
pstore: Do not duplicate record metadata
pstore: Allocate records on heap instead of stack
pstore: Pass record contents instead of copying
pstore: Always allocate buffer for decompression
pstore: Replace arguments for write() API
pstore: Replace arguments for read() API
pstore: Switch pstore_mkfile to pass record
pstore: Move record decompression to function
pstore: Extract common arguments into structure
pstore: Add kernel-doc for struct pstore_info
pstore: Improve register_pstore() error reporting
pstore: Avoid race in module unloading
...
As reported by James, Catalin and Mark, commit:
e69176d68d ("ef/libstub/arm/arm64: Randomize the base of the UEFI rt services region")
... results in a crash in the firmware, regardless of whether KASLR
is in effect or not and whether the firmware implements EFI_RNG_PROTOCOL
or not.
Mark has identified the root cause to be the inappropriate use of
TASK_SIZE in the stub, which arm64 defines as:
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
and testing thread flags at this point results in the dereference of
pointers in uninitialized structures.
So instead, introduce a preprocessor symbol EFI_RT_VIRTUAL_LIMIT and
define it to TASK_SIZE_64 on arm64 and TASK_SIZE on ARM, both of which
are compile time constants. Also, change the 'headroom' variable to
static const to force an error if this might change in the future.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170417093201.10181-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In cases where a device tree is not provided (ie ACPI based system), an
empty fdt is generated by efistub. #address-cells and #size-cells are not
set in the empty fdt, so they default to 1 (4 byte wide). This can be an
issue on 64-bit systems where values representing addresses, etc may be
8 bytes wide as the default value does not align with the general
requirements for an empty DTB, and is fragile when passed to other agents
as extra care is required to read the entire width of a value.
This issue is observed on Qualcomm Technologies QDF24XX platforms when
kexec-tools inserts 64-bit addresses into the "linux,elfcorehdr" and
"linux,usable-memory-range" properties of the fdt. When the values are
later consumed, they are truncated to 32-bit.
Setting #address-cells and #size-cells to 2 at creation of the empty fdt
resolves the observed issue, and makes the fdt less fragile.
Signed-off-by: Sameer Goel <sgoel@codeaurora.org>
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The FDT is mapped via a fixmap entry that is at least 2 MB in size and
2 MB aligned on 4 KB page size kernels.
On UEFI systems, the FDT allocation may share this 2 MB mapping with a
reserved region (or another memory region that we should never map),
unless we account for this in the size of the allocation (the alignment
is already 2 MB)
So instead of taking guesses at the needed space, simply allocate 2 MB
immediately. The allocation will be recorded as EFI_LOADER_DATA, and the
kernel only memblock_reserve()'s the actual size of the FDT, so the
unused space will be released back to the kernel.
Reviewed-By: Jeffrey Hugo <jhugo@codeaurora.org>
Tested-by: Richard Ruigrok <rruigrok@codeaurora.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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
Link: http://lkml.kernel.org/r/20170404160245.27812-6-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On arm64, we have made some changes over the past year to the way the
kernel itself is allocated and to how it deals with the initrd and FDT.
This patch brings the allocation logic in the EFI stub in line with that,
which is necessary because the introduction of KASLR has created the
possibility for the initrd to be allocated in a place where the kernel
may not be able to map it. (This is mostly a theoretical scenario, since
it only affects systems where the physical memory footprint exceeds the
size of the linear mapping.)
Since we know the kernel itself will be covered by the linear mapping,
choose a suitably sized window (i.e., based on the size of the linear
region) covering the kernel when allocating memory for the initrd.
The FDT may be anywhere in memory on arm64 now that we map it via the
fixmap, so we can lift the address restriction there completely.
Tested-by: Richard Ruigrok <rruigrok@codeaurora.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
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
Link: http://lkml.kernel.org/r/20170404160245.27812-4-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The UEFI Specification permits Graphics Output Protocol (GOP) instances
without direct framebuffer access. This is indicated in the Mode structure
with a PixelFormat enumeration value of PIXEL_BLT_ONLY. Given that the
kernel does not know how to drive a Blt() only framebuffer (which is only
permitted before ExitBootServices() anyway), we should disregard such
framebuffers when looking for a GOP instance that is suitable for use as
the boot console.
So modify the EFI GOP initialization to not use a PIXEL_BLT_ONLY instance,
preventing attempts later in boot to use an invalid screen_info.lfb_base
address.
Signed-off-by: Eugene Cohen <eugene@hp.com>
[ Moved the Blt() only check into the loop and clarified that Blt() only GOPs are unusable by the kernel. ]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org> # v4.7+
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: leif.lindholm@linaro.org
Cc: linux-efi@vger.kernel.org
Cc: lorenzo.pieralisi@arm.com
Fixes: 9822504c1f ("efifb: Enable the efi-framebuffer platform driver ...")
Link: http://lkml.kernel.org/r/20170404152744.26687-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The Intel Compute Stick STCK1A8LFC and Weibu F3C platforms both
log 2 error messages during boot:
efi: requested map not found.
esrt: ESRT header is not in the memory map.
Searching the web, this seems to affect many other platforms too.
Since these messages are logged as errors, they appear on-screen during
the boot process even when using the "quiet" boot parameter used by
distros.
Demote the ESRT error to a warning so that it does not appear on-screen,
and delete the error logging from efi_mem_desc_lookup; both callsites
of that function log more specific messages upon failure.
Out of curiosity I looked closer at the Weibu F3C. There is no entry in
the UEFI-provided memory map which corresponds to the ESRT pointer, but
hacking the code to map it anyway, the ESRT does appear to be valid with
2 entries.
Signed-off-by: Daniel Drake <drake@endlessm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
This removes the argument list for the erase() callback and replaces it
with a pointer to the backend record details to be removed.
Signed-off-by: Kees Cook <keescook@chromium.org>
Similar to the pstore_info read() callback, there were too many arguments.
This switches to the new struct pstore_record pointer instead. This adds
"reason" and "part" to the record structure as well.
Signed-off-by: Kees Cook <keescook@chromium.org>
The argument list for the pstore_read() interface is unwieldy. This changes
passes the new struct pstore_record instead. The erst backend was already
doing something similar internally.
Signed-off-by: Kees Cook <keescook@chromium.org>
On ARM and arm64, we use a dedicated mm_struct to map the UEFI
Runtime Services regions, which allows us to map those regions
on demand, and in a way that is guaranteed to be compatible
with incoming kernels across kexec.
As it turns out, we don't fully initialize the mm_struct in the
same way as process mm_structs are initialized on fork(), which
results in the following crash on ARM if CONFIG_CPUMASK_OFFSTACK=y
is enabled:
...
EFI Variables Facility v0.08 2004-May-17
Unable to handle kernel NULL pointer dereference at virtual address 00000000
[...]
Process swapper/0 (pid: 1)
...
__memzero()
check_and_switch_context()
virt_efi_get_next_variable()
efivar_init()
efivars_sysfs_init()
do_one_initcall()
...
This is due to a missing call to mm_init_cpumask(), so add it.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org> # v4.5+
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
Link: http://lkml.kernel.org/r/1488395154-29786-1-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The ARM decompressor is finicky when it comes to uninitialized variables
with local linkage, the reason being that it may relocate .text and .bss
independently when executing from ROM. This is only possible if all
references into .bss from .text are absolute, and this happens to be the
case for references emitted under -fpic to symbols with external linkage,
and so all .bss references must involve symbols with external linkage.
When building the ARM stub using clang, the initialized local variable
__chunk_size is optimized into a zero-initialized flag that indicates
whether chunking is in effect or not. This flag is therefore emitted into
.bss, which triggers the ARM decompressor's diagnostics, resulting in a
failed build.
Under UEFI, we never execute the decompressor from ROM, so the diagnostic
makes little sense here. But we can easily work around the issue by making
__chunk_size global instead.
However, given that the file I/O chunking that is controlled by the
__chunk_size variable is intended to work around known bugs on various
x86 implementations of UEFI, we can simply make the chunking an x86
specific feature. This is an improvement by itself, and also removes the
need to parse the efi= options in the stub entirely.
Tested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt 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: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1486380166-31868-8-git-send-email-ard.biesheuvel@linaro.org
[ Small readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.
Commit:
abfb7b686a ("efi/libstub/arm*: Pass latest memory map to the kernel")
fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().
Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.
So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)
Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.
Fixes: abfb7b686a ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Riku Voipio <riku.voipio@linaro.org>
Cc: <stable@vger.kernel.org>
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The build commands for the ARM and arm64 EFI stubs strip the .debug
sections and other sections that may legally contain absolute relocations,
in order to inspect the remaining sections for the presence of such
relocations.
This leaves us without debugging symbols in the stub for no good reason,
considering that these sections are omitted from the kernel binary anyway,
and that these relocations are thus only consumed by users of the ELF
binary, such as debuggers.
So move to 'strip' for performing the relocation check, and if it succeeds,
invoke objcopy as before, but leaving the .debug sections in place. Note
that these sections may refer to ksymtab/kcrctab contents, so leave those
in place as well.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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
Link: http://lkml.kernel.org/r/1485868902-20401-11-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
