commit 196dff2712ca5a2e651977bb2fe6b05474111a83 upstream.
Instead of blindly creating the EFI random seed configuration table if
the RNG protocol is implemented and works, check whether such a EFI
configuration table was provided by an earlier boot stage and if so,
concatenate the existing and the new seeds, leaving it up to the core
code to mix it in and credit it the way it sees fit.
This can be used for, e.g., systemd-boot, to pass an additional seed to
Linux in a way that can be consumed by the kernel very early. In that
case, the following definitions should be used to pass the seed to the
EFI stub:
struct linux_efi_random_seed {
u32 size; // of the 'seed' array in bytes
u8 seed[];
};
The memory for the struct must be allocated as EFI_ACPI_RECLAIM_MEMORY
pool memory, and the address of the struct in memory should be installed
as a EFI configuration table using the following GUID:
LINUX_EFI_RANDOM_SEED_TABLE_GUID 1ce1e5bc-7ceb-42f2-81e5-8aadf180f57b
Note that doing so is safe even on kernels that were built without this
patch applied, but the seed will simply be overwritten with a seed
derived from the EFI RNG protocol, if available. The recommended seed
size is 32 bytes, and seeds larger than 512 bytes are considered
corrupted and ignored entirely.
In order to preserve forward secrecy, seeds from previous bootloaders
are memzero'd out, and in order to preserve memory, those older seeds
are also freed from memory. Freeing from memory without first memzeroing
is not safe to do, as it's possible that nothing else will ever
overwrite those pages used by EFI.
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
[ardb: incorporate Jason's followup changes to extend the maximum seed
size on the consumer end, memzero() it and drop a needless printk]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7d866e38c7e9ece8a096d0d098fa9d92b9d4f97e upstream.
EFI runtime services data is guaranteed to be preserved by the OS,
making it a suitable candidate for the EFI random seed table, which may
be passed to kexec kernels as well (after refreshing the seed), and so
we need to ensure that the memory is preserved without support from the
OS itself.
However, runtime services data is intended for allocations that are
relevant to the implementations of the runtime services themselves, and
so they are unmapped from the kernel linear map, and mapped into the EFI
page tables that are active while runtime service invocations are in
progress. None of this is needed for the RNG seed.
So let's switch to EFI 'ACPI reclaim' memory: in spite of the name,
there is nothing exclusively ACPI about it, it is simply a type of
allocation that carries firmware provided data which may or may not be
relevant to the OS, and it is left up to the OS to decide whether to
reclaim it after having consumed its contents.
Given that in Linux, we never reclaim these allocations, it is a good
choice for the EFI RNG seed, as the allocation is guaranteed to survive
kexec reboots.
One additional reason for changing this now is to align it with the
upcoming recommendation for EFI bootloader provided RNG seeds, which
must not use EFI runtime services code/data allocations.
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d80ca810f096ff66f451e7a3ed2f0cd9ef1ff519 upstream.
Currently, the non-x86 stub code calls get_memory_map() redundantly,
given that the data it returns is never used anywhere. So drop the call.
Cc: <stable@vger.kernel.org> # v4.14+
Fixes: 24d7c494ce ("efi/arm-stub: Round up FDT allocation to mapping size")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f56a74cc0a6d9b9f8ba89cea29cd7c4774cb2b1 upstream.
We currently check the MokSBState variable to decide whether we should
treat UEFI secure boot as being disabled, even if the firmware thinks
otherwise. This is used by shim to indicate that it is not checking
signatures on boot images. In the kernel, we use this to relax lockdown
policies.
However, in cases where shim is not even being used, we don't want this
variable to interfere with lockdown, given that the variable may be
non-volatile and therefore persist across a reboot. This means setting
it once will persistently disable lockdown checks on a given system.
So switch to the mirrored version of this variable, called MokSBStateRT,
which is supposed to be volatile, and this is something we can check.
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 63bf28ceb3ebbe76048c3fb2987996ca1ae64f83 upstream.
When booting the x86 kernel via EFI using the LoadImage/StartImage boot
services [as opposed to the deprecated EFI handover protocol], the setup
header is taken from the image directly, and given that EFI's LoadImage
has no Linux/x86 specific knowledge regarding struct bootparams or
struct setup_header, any absolute addresses in the setup header must
originate from the file and not from a prior loading stage.
Since we cannot generally predict where LoadImage() decides to load an
image (*), such absolute addresses must be treated as suspect: even if a
prior boot stage intended to make them point somewhere inside the
[signed] image, there is no way to validate that, and if they point at
an arbitrary location in memory, the setup_data nodes will not be
covered by any signatures or TPM measurements either, and could be made
to contain an arbitrary sequence of SETUP_xxx nodes, which could
interfere quite badly with the early x86 boot sequence.
(*) Note that, while LoadImage() does take a buffer/size tuple in
addition to a device path, which can be used to provide the image
contents directly, it will re-allocate such images, as the memory
footprint of an image is generally larger than the PE/COFF file
representation.
Cc: <stable@vger.kernel.org> # v5.10+
Link: https://lore.kernel.org/all/20220904165321.1140894-1-Jason@zx2c4.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1a3887924a7e6edd331be76da7bf4c1e8eab4b1e upstream.
The EFI stub is a wrapper around the core kernel that makes it look like
a EFI compatible PE/COFF application to the EFI firmware. EFI
applications run on top of the EFI runtime, which is heavily based on
so-called protocols, which are struct types consisting [mostly] of
function pointer members that are instantiated and recorded in a
protocol database.
These structs look like the ideal randomization candidates to the
randstruct plugin (as they only carry function pointers), but of course,
these protocols are contracts between the firmware that exposes them,
and the EFI applications (including our stubbed kernel) that invoke
them. This means that struct randomization for EFI protocols is not a
great idea, and given that the stub shares very little data with the
core kernel that is represented as a randomizable struct, we're better
off just disabling it completely here.
Cc: <stable@vger.kernel.org> # v4.14+
Reported-by: Daniel Marth <daniel.marth@inso.tuwien.ac.at>
Tested-by: Daniel Marth <daniel.marth@inso.tuwien.ac.at>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dcf0c838854c86e1f41fb1934aea906845d69782 upstream.
The get_boot_hartid_from_fdt() function currently returns U32_MAX
for failure case which is not correct because U32_MAX is a valid
hartid value. This patch fixes the issue by returning error code.
Cc: <stable@vger.kernel.org>
Fixes: d7071743db ("RISC-V: Add EFI stub support.")
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e9b7c3a4263bdcfd31bc3d03d48ce0ded7a94635 ]
The kernel is aligned at SEGMENT_SIZE and this is the size populated in the PE
headers:
arch/arm64/kernel/efi-header.S: .long SEGMENT_ALIGN // SectionAlignment
EFI_KIMG_ALIGN is defined as: (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN :
THREAD_ALIGN)
So it depends on THREAD_ALIGN. On newer builds this message started to appear
even though the loader is taking into account the PE header (which is stating
SEGMENT_ALIGN).
Fixes: c32ac11da3f8 ("efi/libstub: arm64: Double check image alignment at entry")
Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c32ac11da3f83bb42b986702a9b92f0a14ed4182 upstream.
On arm64, the stub only moves the kernel image around in memory if
needed, which is typically only for KASLR, given that relocatable
kernels (which is the default) can run from any 64k aligned address,
which is also the minimum alignment communicated to EFI via the PE/COFF
header.
Unfortunately, some loaders appear to ignore this header, and load the
kernel at some arbitrary offset in memory. We can deal with this, but
let's check for this condition anyway, so non-compliant code can be
spotted and fixed.
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3a262423755b83a5f85009ace415d6e7f572dfe8 ]
Commit 82046702e2 ("efi/libstub/arm64: Replace 'preferred' offset with
alignment check") simplified the way the stub moves the kernel image
around in memory before booting it, given that a relocatable image does
not need to be copied to a 2M aligned offset if it was loaded on a 64k
boundary by EFI.
Commit d32de9130f ("efi/arm64: libstub: Deal gracefully with
EFI_RNG_PROTOCOL failure") inadvertently defeated this logic by
overriding the value of efi_nokaslr if EFI_RNG_PROTOCOL is not
available, which was mistaken by the loader logic as an explicit request
on the part of the user to disable KASLR and any associated relocation
of an Image not loaded on a 2M boundary.
So let's reinstate this functionality, by capturing the value of
efi_nokaslr at function entry to choose the minimum alignment.
Fixes: d32de9130f ("efi/arm64: libstub: Deal gracefully with EFI_RNG_PROTOCOL failure")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b94046efb4706b3429c9c8e7377bd8d1621d588 ]
Distro versions of GRUB replace the usual LoadImage/StartImage calls
used to load the kernel image with some local code that fails to honor
the allocation requirements described in the PE/COFF header, as it
does not account for the image's BSS section at all: it fails to
allocate space for it, and fails to zero initialize it.
Since the EFI stub itself is allocated in the .init segment, which is
in the middle of the image, its BSS section is not impacted by this,
and the main consequence of this omission is that the BSS section may
overlap with memory regions that are already used by the firmware.
So let's warn about this condition, and force image reallocation to
occur in this case, which works around the problem.
Fixes: 82046702e2 ("efi/libstub/arm64: Replace 'preferred' offset with alignment check")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4152433c397697acc4b02c4a10d17d5859c2730d ]
The EFI stub random allocator used for kaslr on arm64 has a subtle
bug. In function get_entry_num_slots() which counts the number of
possible allocation "slots" for the image in a given chunk of free
EFI memory, "last_slot" can become negative if the chunk is smaller
than the requested allocation size.
The test "if (first_slot > last_slot)" doesn't catch it because
both first_slot and last_slot are unsigned.
I chose not to make them signed to avoid problems if this is ever
used on architectures where there are meaningful addresses with the
top bit set. Instead, fix it with an additional test against the
allocation size.
This can cause a boot failure in addition to a loss of randomisation
due to another bug in the arm64 stub fixed separately.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes: 2ddbfc81ea ("efi: stub: add implementation of efi_random_alloc()")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c4039b29fe9637e1135912813f830994af4c867f ]
If the buffer has slashes up to the end then this will read past the end
of the array. I don't anticipate that this is an issue for many people
in real life, but it's the right thing to do and it makes static
checkers happy.
Fixes: 7a88a6227d ("efi/libstub: Fix path separator regression")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 58d746c119dfa28e72fc35aacaf3d2a3ac625cd0 ]
When cross compiling x86 on an ARM machine with clang, there are several
errors along the lines of:
arch/x86/include/asm/page_64.h:52:7: error: invalid output constraint '=D' in asm
This happens because the x86 flags in the EFI stub are not derived from
KBUILD_CFLAGS like the other architectures are and the clang flags that
set the target architecture ('--target=') and the path to the GNU cross
tools ('--prefix=') are not present, meaning that the host architecture
is targeted.
These flags are available as $(CLANG_FLAGS) from the main Makefile so
add them to the cflags for x86 so that cross compiling works as expected.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lkml.kernel.org/r/20210326000435.4785-4-nathan@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9e9888a0fe97b9501a40f717225d2bef7100a2c1 upstream.
The EFI_RT_PROPERTIES_TABLE contains a mask of runtime services that are
available after ExitBootServices(). This mostly does not concern the EFI
stub at all, given that it runs before that. However, there is one call
that is made at runtime, which is the call to SetVirtualAddressMap()
(which is not even callable at boot time to begin with)
So add the missing handling of the RT_PROP table to ensure that we only
call SetVirtualAddressMap() if it is not being advertised as unsupported
by the firmware.
Cc: <stable@vger.kernel.org> # v5.10+
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull RISC-V updates from Palmer Dabbelt:
"A handful of cleanups and new features:
- A handful of cleanups for our page fault handling
- Improvements to how we fill out cacheinfo
- Support for EFI-based systems"
* tag 'riscv-for-linus-5.10-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (22 commits)
RISC-V: Add page table dump support for uefi
RISC-V: Add EFI runtime services
RISC-V: Add EFI stub support.
RISC-V: Add PE/COFF header for EFI stub
RISC-V: Implement late mapping page table allocation functions
RISC-V: Add early ioremap support
RISC-V: Move DT mapping outof fixmap
RISC-V: Fix duplicate included thread_info.h
riscv/mm/fault: Set FAULT_FLAG_INSTRUCTION flag in do_page_fault()
riscv/mm/fault: Fix inline placement in vmalloc_fault() declaration
riscv: Add cache information in AUX vector
riscv: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO
riscv: Set more data to cacheinfo
riscv/mm/fault: Move access error check to function
riscv/mm/fault: Move FAULT_FLAG_WRITE handling in do_page_fault()
riscv/mm/fault: Simplify mm_fault_error()
riscv/mm/fault: Move fault error handling to mm_fault_error()
riscv/mm/fault: Simplify fault error handling
riscv/mm/fault: Move vmalloc fault handling to vmalloc_fault()
riscv/mm/fault: Move bad area handling to bad_area()
...
Pull orphan section checking from Ingo Molnar:
"Orphan link sections were a long-standing source of obscure bugs,
because the heuristics that various linkers & compilers use to handle
them (include these bits into the output image vs discarding them
silently) are both highly idiosyncratic and also version dependent.
Instead of this historically problematic mess, this tree by Kees Cook
(et al) adds build time asserts and build time warnings if there's any
orphan section in the kernel or if a section is not sized as expected.
And because we relied on so many silent assumptions in this area, fix
a metric ton of dependencies and some outright bugs related to this,
before we can finally enable the checks on the x86, ARM and ARM64
platforms"
* tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/boot/compressed: Warn on orphan section placement
x86/build: Warn on orphan section placement
arm/boot: Warn on orphan section placement
arm/build: Warn on orphan section placement
arm64/build: Warn on orphan section placement
x86/boot/compressed: Add missing debugging sections to output
x86/boot/compressed: Remove, discard, or assert for unwanted sections
x86/boot/compressed: Reorganize zero-size section asserts
x86/build: Add asserts for unwanted sections
x86/build: Enforce an empty .got.plt section
x86/asm: Avoid generating unused kprobe sections
arm/boot: Handle all sections explicitly
arm/build: Assert for unwanted sections
arm/build: Add missing sections
arm/build: Explicitly keep .ARM.attributes sections
arm/build: Refactor linker script headers
arm64/build: Assert for unwanted sections
arm64/build: Add missing DWARF sections
arm64/build: Use common DISCARDS in linker script
arm64/build: Remove .eh_frame* sections due to unwind tables
...
Pull EFI changes from Ingo Molnar:
- Preliminary RISC-V enablement - the bulk of it will arrive via the
RISCV tree.
- Relax decompressed image placement rules for 32-bit ARM
- Add support for passing MOK certificate table contents via a config
table rather than a EFI variable.
- Add support for 18 bit DIMM row IDs in the CPER records.
- Work around broken Dell firmware that passes the entire Boot####
variable contents as the command line
- Add definition of the EFI_MEMORY_CPU_CRYPTO memory attribute so we
can identify it in the memory map listings.
- Don't abort the boot on arm64 if the EFI RNG protocol is available
but returns with an error
- Replace slashes with exclamation marks in efivarfs file names
- Split efi-pstore from the deprecated efivars sysfs code, so we can
disable the latter on !x86.
- Misc fixes, cleanups and updates.
* tag 'efi-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
efi: mokvar: add missing include of asm/early_ioremap.h
efi: efivars: limit availability to X86 builds
efi: remove some false dependencies on CONFIG_EFI_VARS
efi: gsmi: fix false dependency on CONFIG_EFI_VARS
efi: efivars: un-export efivars_sysfs_init()
efi: pstore: move workqueue handling out of efivars
efi: pstore: disentangle from deprecated efivars module
efi: mokvar-table: fix some issues in new code
efi/arm64: libstub: Deal gracefully with EFI_RNG_PROTOCOL failure
efivarfs: Replace invalid slashes with exclamation marks in dentries.
efi: Delete deprecated parameter comments
efi/libstub: Fix missing-prototypes in string.c
efi: Add definition of EFI_MEMORY_CPU_CRYPTO and ability to report it
cper,edac,efi: Memory Error Record: bank group/address and chip id
edac,ghes,cper: Add Row Extension to Memory Error Record
efi/x86: Add a quirk to support command line arguments on Dell EFI firmware
efi/libstub: Add efi_warn and *_once logging helpers
integrity: Load certs from the EFI MOK config table
integrity: Move import of MokListRT certs to a separate routine
efi: Support for MOK variable config table
...
Add a RISC-V architecture specific stub code that actually copies the
actual kernel image to a valid address and jump to it after boot services
are terminated. Enable UEFI related kernel configs as well for RISC-V.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com
[ardb: - move hartid fetch into check_platform_features()
- use image_size not reserve_size
- select ISA_C
- do not use dram_base]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Stable branch for v5.10 shared between the EFI and RISC-V trees
The RISC-V EFI boot and runtime support will be merged for v5.10 via
the RISC-V tree. However, it incorporates some changes that conflict
with other EFI changes that are in flight, so this tag serves as a
shared base that allows those conflicts to be resolved beforehand.
* tag 'efi-riscv-shared-for-v5.10' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi/libstub: arm32: Use low allocation for the uncompressed kernel
efi/libstub: Export efi_low_alloc_above() to other units
efi/libstub: arm32: Base FDT and initrd placement on image address
efi: Rename arm-init to efi-init common for all arch
include: pe.h: Add RISC-V related PE definition
Currently, on arm64, we abort on any failure from efi_get_random_bytes()
other than EFI_NOT_FOUND when it comes to setting the physical seed for
KASLR, but ignore such failures when obtaining the seed for virtual
KASLR or for early seeding of the kernel's entropy pool via the config
table. This is inconsistent, and may lead to unexpected boot failures.
So let's permit any failure for the physical seed, and simply report
the error code if it does not equal EFI_NOT_FOUND.
Cc: <stable@vger.kernel.org> # v5.8+
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Before commit
d0f9ca9be1 ("ARM: decompressor: run decompressor in place if loaded via UEFI")
we were rather limited in the choice of base address for the uncompressed
kernel, as we were relying on the logic in the decompressor that blindly
rounds down the decompressor execution address to the next multiple of 128
MiB, and decompresses the kernel there. For this reason, we have a lot of
complicated memory region handling code, to ensure that this memory window
is available, even though it could be occupied by reserved regions or
other allocations that may or may not collide with the uncompressed image.
Today, we simply pass the target address for the decompressed image to the
decompressor directly, and so we can choose a suitable window just by
finding a 16 MiB aligned region, while taking TEXT_OFFSET and the region
for the swapper page tables into account.
So let's get rid of the complicated logic, and instead, use the existing
bottom up allocation routine to allocate a suitable window as low as
possible, and carve out a memory region that has the right properties.
Note that this removes any dependencies on the 'dram_base' argument to
handle_kernel_image(), and so this is removed as well. Given that this
was the only remaining use of dram_base, the code that produces it is
removed entirely as well.
Reviewed-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Tested-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Permit arm32-stub.c to access efi_low_alloc_above() in a subsequent
patch by giving it external linkage and declaring it in efistub.h.
Reviewed-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Tested-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The way we use the base of DRAM in the EFI stub is problematic as it
is ill defined what the base of DRAM actually means. There are some
restrictions on the placement of FDT and initrd which are defined in
terms of dram_base, but given that the placement of the kernel in
memory is what defines these boundaries (as on ARM, this is where the
linear region starts), it is better to use the image address in these
cases, and disregard dram_base altogether.
Reviewed-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Tested-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
TEXT_OFFSET serves no purpose, and for this reason, it was redefined
as 0x0 in the v5.8 timeframe. Since this does not appear to have caused
any issues that require us to revisit that decision, let's get rid of the
macro entirely, along with any references to it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Eliminate all GOT entries in the decompressor binary, by forcing hidden
visibility for all symbol references, which informs the compiler that
such references will be resolved at link time without the need for
allocating GOT entries.
To ensure that no GOT entries will creep back in, add an assertion to
the decompressor linker script that will fire if the .got section has
a non-zero size.
[Arvind: move hidden.h to include/linux instead of making a copy]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200731230820.1742553-3-keescook@chromium.org
Pull Kbuild updates from Masahiro Yamada:
- run the checker (e.g. sparse) after the compiler
- remove unneeded cc-option tests for old compiler flags
- fix tar-pkg to install dtbs
- introduce ccflags-remove-y and asflags-remove-y syntax
- allow to trace functions in sub-directories of lib/
- introduce hostprogs-always-y and userprogs-always-y syntax
- various Makefile cleanups
* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
kbuild: introduce hostprogs-always-y and userprogs-always-y
kbuild: sort hostprogs before passing it to ifneq
kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
kbuild: Replace HTTP links with HTTPS ones
kbuild: trace functions in subdirectories of lib/
kbuild: introduce ccflags-remove-y and asflags-remove-y
kbuild: do not export LDFLAGS_vmlinux
kbuild: always create directories of targets
powerpc/boot: add DTB to 'targets'
kbuild: buildtar: add dtbs support
kbuild: remove cc-option test of -ffreestanding
kbuild: remove cc-option test of -fno-stack-protector
Revert "kbuild: Create directory for target DTB"
kbuild: run the checker after the compiler
Pull EFI fixes from Ingo Molnar:
"Various EFI fixes:
- Fix the layering violation in the use of the EFI runtime services
availability mask in users of the 'efivars' abstraction
- Revert build fix for GCC v4.8 which is no longer supported
- Clean up some x86 EFI stub details, some of which are borderline
bugs that copy around garbage into padding fields - let's fix these
out of caution.
- Fix build issues while working on RISC-V support
- Avoid --whole-archive when linking the stub on arm64"
* tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Revert "efi/x86: Fix build with gcc 4"
efi/efivars: Expose RT service availability via efivars abstraction
efi/libstub: Move the function prototypes to header file
efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds
efi/libstub/arm64: link stub lib.a conditionally
efi/x86: Only copy upto the end of setup_header
efi/x86: Remove unused variables
Pull arm64 fixes from Will Deacon:
"A batch of arm64 fixes.
Although the diffstat is a bit larger than we'd usually have at this
stage, a decent amount of it is the addition of comments describing
our syscall tracing behaviour, and also a sweep across all the modular
arm64 PMU drivers to make them rebust against unloading and unbinding.
There are a couple of minor things kicking around at the moment (CPU
errata and module PLTs for very large modules), but I'm not expecting
any significant changes now for us in 5.8.
- Fix kernel text addresses for relocatable images booting using EFI
and with KASLR disabled so that they match the vmlinux ELF binary.
- Fix unloading and unbinding of PMU driver modules.
- Fix generic mmiowb() when writeX() is called from preemptible
context (reported by the riscv folks).
- Fix ptrace hardware single-step interactions with signal handlers,
system calls and reverse debugging.
- Fix reporting of 64-bit x0 register for 32-bit tasks via
'perf_regs'.
- Add comments describing syscall entry/exit tracing ABI"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
drivers/perf: Prevent forced unbinding of PMU drivers
asm-generic/mmiowb: Allow mmiowb_set_pending() when preemptible()
arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEP
arm64: ptrace: Use NO_SYSCALL instead of -1 in syscall_trace_enter()
arm64: syscall: Expand the comment about ptrace and syscall(-1)
arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI
arm64: compat: Ensure upper 32 bits of x0 are zero on syscall return
arm64: ptrace: Override SPSR.SS when single-stepping is enabled
arm64: ptrace: Consistently use pseudo-singlestep exceptions
drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling
efi/libstub/arm64: Retain 2MB kernel Image alignment if !KASLR
Since commit 82046702e2 ("efi/libstub/arm64: Replace 'preferred' offset
with alignment check"), loading a relocatable arm64 kernel at a physical
address which is not 2MB aligned and subsequently booting with EFI will
leave the Image in-place, relying on the kernel to relocate itself early
during boot. In conjunction with commit dd4bc60765 ("arm64: warn on
incorrect placement of the kernel by the bootloader"), which enables
CONFIG_RELOCATABLE by default, this effectively means that entering an
arm64 kernel loaded at an alignment smaller than 2MB with EFI (e.g. using
QEMU) will result in silent relocation at runtime.
Unfortunately, this has a subtle but confusing affect for developers
trying to inspect the PC value during a crash and comparing it to the
symbol addresses in vmlinux using tools such as 'nm' or 'addr2line';
all text addresses will be displaced by a sub-2MB offset, resulting in
the wrong symbol being identified in many cases. Passing "nokaslr" on
the command line or disabling "CONFIG_RANDOMIZE_BASE" does not help,
since the EFI stub only copies the kernel Image to a 2MB boundary if it
is not relocatable.
Adjust the EFI stub for arm64 so that the minimum Image alignment is 2MB
unless KASLR is in use.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
This reverts commit 5435f73d5c, which is no longer needed now
that the minimum GCC version has been bumped to v4.9
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The prototype of the functions handle_kernel_image & efi_enter_kernel
are defined in efi-stub.c which may result in a compiler warnings if
-Wmissing-prototypes is set in gcc compiler.
Move the prototype to efistub.h to make the compiler happy.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200706172609.25965-2-atish.patra@wdc.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Some Makefiles already pass -ffreestanding unconditionally.
For example, arch/arm64/lib/Makefile, arch/x86/purgatory/Makefile.
No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -ffreestanding.
I confirmed GCC 4.8 and Clang manuals document this option.
Get rid of cc-option from -ffreestanding.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.
No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.
GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)
Get rid of cc-option from -fno-stack-protector.
Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.
Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
When copying the setup_header into the boot_params buffer, only the data
that is actually part of the setup_header should be copied.
efi_pe_entry() currently copies the entire second sector, which
initializes some of the fields in boot_params beyond the setup_header
with garbage (i.e. part of the real-mode boot code gets copied into
those fields).
This does not cause any issues currently because the fields that are
overwritten are padding, BIOS EDD information that won't get used, and
the E820 table which will get properly filled in later.
Fix this to only copy data that is actually part of the setup_header
structure.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Commit
987053a300 ("efi/x86: Move command-line initrd loading to efi_main")
made the ramdisk_addr/ramdisk_size variables in efi_pe_entry unused, but
neglected to delete them.
Delete these unused variables.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
On 32-bit ARM, we may boot at HYP mode, or with the MMU and caches off
(or both), even though the EFI spec does not actually support this.
While booting at HYP mode is something we might tolerate, fiddling
with the caches is a more serious issue, as disabling the caches is
tricky to do safely from C code, and running without the Dcache makes
it impossible to support unaligned memory accesses, which is another
explicit requirement imposed by the EFI spec.
So take note of the CPU mode and MMU state in the EFI stub diagnostic
output so that we can easily diagnose any issues that may arise from
this. E.g.,
EFI stub: Entering in SVC mode with MMU enabled
Also, capture the CPSR and SCTLR system register values at EFI stub
entry, and after ExitBootServices() returns, and check whether the
MMU and Dcache were disabled at any point. If this is the case, a
diagnostic message like the following will be emitted:
efi: [Firmware Bug]: EFI stub was entered with MMU and Dcache disabled, please fix your firmware!
efi: CPSR at EFI stub entry : 0x600001d3
efi: SCTLR at EFI stub entry : 0x00c51838
efi: CPSR after ExitBootServices() : 0x600001d3
efi: SCTLR after ExitBootServices(): 0x00c50838
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
