commit 8126b1c731 upstream.
pstore_dump() is *always* invoked in atomic context (nowadays in an RCU
read-side critical section, before that under a spinlock).
It doesn't make sense to try to use semaphores here.
This is mostly a revert of commit ea84b580b9 ("pstore: Convert buf_lock
to semaphore"), except that two parts aren't restored back exactly as they
were:
- keep the lock initialization in pstore_register
- in efi_pstore_write(), always set the "block" flag to false
- omit "is_locked", that was unnecessary since
commit 959217c84c ("pstore: Actually give up during locking failure")
- fix the bailout message
The actual problem that the buggy commit was trying to address may have
been that the use of preemptible() in efi_pstore_write() was wrong - it
only looks at preempt_count() and the state of IRQs, but __rcu_read_lock()
doesn't touch either of those under CONFIG_PREEMPT_RCU.
(Sidenote: CONFIG_PREEMPT_RCU means that the scheduler can preempt tasks in
RCU read-side critical sections, but you're not allowed to actively
block/reschedule.)
Lockdep probably never caught the problem because it's very rare that you
actually hit the contended case, so lockdep always just sees the
down_trylock(), not the down_interruptible(), and so it can't tell that
there's a problem.
Fixes: ea84b580b9 ("pstore: Convert buf_lock to semaphore")
Cc: stable@vger.kernel.org
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220314185953.2068993-1-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9feaf8b387 ]
When "dump_apple_properties" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
argument strings:
Unknown kernel command line parameters "dump_apple_properties
BOOT_IMAGE=/boot/bzImage-517rc6 efivar_ssdt=newcpu_ssdt", will be
passed to user space.
Run /sbin/init as init process
with arguments:
/sbin/init
dump_apple_properties
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc6
efivar_ssdt=newcpu_ssdt
Similarly when "efivar_ssdt=somestring" is used, it is added to the
Unknown parameter message and to init's environment strings, polluting
them (see examples above).
Change the return value of the __setup functions to 1 to indicate
that the __setup options have been handled.
Fixes: 58c5475aba ("x86/efi: Retrieve and assign Apple device properties")
Fixes: 475fb4e8b2 ("efi / ACPI: load SSTDs from EFI variables")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Link: https://lore.kernel.org/r/20220301041851.12459-1-rdunlap@infradead.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 258dd90202 upstream.
When the "block" flag is false, the old code would sometimes still call
check_var_size(), which wrongly tells ->query_variable_store() that it can
block.
As far as I can tell, this can't really materialize as a bug at the moment,
because ->query_variable_store only does something on X86 with generic EFI,
and in that configuration we always take the efivar_entry_set_nonblocking()
path.
Fixes: ca0e30dcaa ("efi: Add nonblocking option to efi_query_variable_store()")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220218180559.1432559-1-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e9b7c3a426 ]
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: c32ac11da3 ("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 f5390cd0b4 upstream.
Aditya reports [0] that his recent MacbookPro crashes in the firmware
when using the variable services at runtime. The culprit appears to be a
call to QueryVariableInfo(), which we did not use to call on Apple x86
machines in the past as they only upgraded from EFI v1.10 to EFI v2.40
firmware fairly recently, and QueryVariableInfo() (along with
UpdateCapsule() et al) was added in EFI v2.00.
The only runtime service introduced in EFI v2.00 that we actually use in
Linux is QueryVariableInfo(), as the capsule based ones are optional,
generally not used at runtime (all the LVFS/fwupd firmware update
infrastructure uses helper EFI programs that invoke capsule update at
boot time, not runtime), and not implemented by Apple machines in the
first place. QueryVariableInfo() is used to 'safely' set variables,
i.e., only when there is enough space. This prevents machines with buggy
firmwares from corrupting their NVRAMs when they run out of space.
Given that Apple machines have been using EFI v1.10 services only for
the longest time (the EFI v2.0 spec was released in 2006, and Linux
support for the newly introduced runtime services was added in 2011, but
the MacbookPro12,1 released in 2015 still claims to be EFI v1.10 only),
let's avoid the EFI v2.0 ones on all Apple x86 machines.
[0] https://lore.kernel.org/all/6D757C75-65B1-468B-842D-10410081A8E4@live.com/
Cc: <stable@vger.kernel.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Reported-by: Aditya Garg <gargaditya08@live.com>
Tested-by: Orlando Chamberlain <redecorating@protonmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Aditya Garg <gargaditya08@live.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215277
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 38fa3206bf upstream.
While reboot the system by sysrq, the following bug will be occur.
BUG: sleeping function called from invalid context at kernel/locking/semaphore.c:90
in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 10052, name: rc.shutdown
CPU: 3 PID: 10052 Comm: rc.shutdown Tainted: G W O 5.10.0 #1
Call trace:
dump_backtrace+0x0/0x1c8
show_stack+0x18/0x28
dump_stack+0xd0/0x110
___might_sleep+0x14c/0x160
__might_sleep+0x74/0x88
down_interruptible+0x40/0x118
virt_efi_reset_system+0x3c/0xd0
efi_reboot+0xd4/0x11c
machine_restart+0x60/0x9c
emergency_restart+0x1c/0x2c
sysrq_handle_reboot+0x1c/0x2c
__handle_sysrq+0xd0/0x194
write_sysrq_trigger+0xbc/0xe4
proc_reg_write+0xd4/0xf0
vfs_write+0xa8/0x148
ksys_write+0x6c/0xd8
__arm64_sys_write+0x18/0x28
el0_svc_common.constprop.3+0xe4/0x16c
do_el0_svc+0x1c/0x2c
el0_svc+0x20/0x30
el0_sync_handler+0x80/0x17c
el0_sync+0x158/0x180
The reason for this problem is that irq has been disabled in
machine_restart() and then it calls down_interruptible() in
virt_efi_reset_system(), which would occur sleep in irq context,
it is dangerous! Commit 99409b935c9a("locking/semaphore: Add
might_sleep() to down_*() family") add might_sleep() in
down_interruptible(), so the bug info is here. down_trylock()
can solve this problem, cause there is no might_sleep.
--------
Cc: <stable@vger.kernel.org>
Signed-off-by: Zhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b3a72ca803 upstream.
Joe reports that using a statically allocated buffer for converting CPER
error records into human readable text is probably a bad idea. Even
though we are not aware of any actual issues, a stack buffer is clearly
a better choice here anyway, so let's move the buffer into the stack
frames of the two functions that refer to it.
Cc: <stable@vger.kernel.org>
Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c32ac11da3 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 3a26242375 ]
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 5b94046efb ]
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 4152433c39 ]
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 47e1e233e9 ]
One of the SUSE QA tests triggered:
localhost kernel: efi: Failed to lookup EFI memory descriptor for 0x000000003dcf8000
which comes from x86's version of efi_arch_mem_reserve() trying to
reserve a memory region. Usually, that function expects
EFI_BOOT_SERVICES_DATA memory descriptors but the above case is for the
MOKvar table which is allocated in the EFI shim as runtime services.
That lead to a fix changing the allocation of that table to boot services.
However, that fix broke booting SEV guests with that shim leading to
this kernel fix
8d651ee9c7 ("x86/ioremap: Map EFI-reserved memory as encrypted for SEV")
which extended the ioremap hint to map reserved EFI boot services as
decrypted too.
However, all that wasn't needed, IMO, because that error message in
efi_arch_mem_reserve() was innocuous in this case - if the MOKvar table
is not in boot services, then it doesn't need to be reserved in the
first place because it is, well, in runtime services which *should* be
reserved anyway.
So do that reservation for the MOKvar table only if it is allocated
in boot services data. I couldn't find any requirement about where
that table should be allocated in, unlike the ESRT which allocation is
mandated to be done in boot services data by the UEFI spec.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2bab693a60 upstream.
kexec_load_file() relies on the memblock infrastructure to avoid
stamping over regions of memory that are essential to the survival
of the system.
However, nobody seems to agree how to flag these regions as reserved,
and (for example) EFI only publishes its reservations in /proc/iomem
for the benefit of the traditional, userspace based kexec tool.
On arm64 platforms with GICv3, this can result in the payload being
placed at the location of the LPI tables. Shock, horror!
Let's augment the EFI reservation code with a memblock_reserve() call,
protecting our dear tables from the secondary kernel invasion.
Reported-by: Moritz Fischer <mdf@kernel.org>
Tested-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 674a9f1f68 ]
Missing TPM final event log table is not a firmware bug.
Clearly if providing event log in the old format makes the final event
log invalid it should not be provided at least in that case.
Fixes: b4f1874c62 ("tpm: check event log version before reading final events")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 942859d969 ]
snprintf() should be given the full buffer size, not one less. And it
guarantees nul-termination, so doing it manually afterwards is
pointless.
It's even potentially harmful (though probably not in practice because
CPER_REC_LEN is 256), due to the "return how much would have been
written had the buffer been big enough" semantics. I.e., if the bank
and/or device strings are long enough that the "DIMM location ..."
output gets truncated, writing to msg[n] is a buffer overflow.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Fixes: 3760cd2040 ("CPER: Adjust code flow of some functions")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c4039b29fe ]
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 45add3cc99 ]
UEFI spec 2.9, p.108, table 4-1 lists the scenario that both attributes
are cleared with the description "No memory access protection is
possible for Entry". So we can have valid entries where both attributes
are cleared, so remove the check.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Fixes: 10f0d2f577 ("efi: Implement generic support for the Memory Attributes table")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 668a84c1bf ]
setup_arch() would invoke efi_init()->efi_get_fdt_params(). If no
valid fdt found then initial_boot_params will be null. So we
should stop further fdt processing here. I encountered this
issue on risc-v.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: b91540d52a ("RISC-V: Add EFI runtime services")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 58d746c119 ]
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 9ceee7d084 upstream.
In the for loop in efi_mem_reserve_persistent(), prsv = rsv->next
use the unmapped rsv. Use the unmapped pages will cause segment
fault.
Fixes: 18df7577ad ("efi/memreserve: deal with memreserve entries in unmapped memory")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 483028edac upstream.
As per UEFI spec 2.8B section 8.2, EFI_UNSUPPORTED may be returned by
EFI variable runtime services if no variable storage is supported by
firmware. In this case, there is no point for kernel to continue
efivars initialization. That said, efivar_init() should fail by
returning an error code, so that efivarfs will not be mounted on
/sys/firmware/efi/efivars at all. Otherwise, user space like efibootmgr
will be confused by the EFIVARFS_MAGIC seen there, while EFI variable
calls cannot be made successfully.
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9e9888a0fe 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>
commit 355845b738 upstream.
Since commit 4466bf8282 ("efi/apple-properties: use
PROPERTY_ENTRY_U8_ARRAY_LEN"), my MacBook Pro issues a -ENODATA error
when trying to assign EFI properties to the discrete GPU:
pci 0000:01:00.0: assigning 56 device properties
pci 0000:01:00.0: error -61 assigning properties
That's because some of the properties have no value. They're booleans
whose presence can be checked by drivers, e.g. "use-backlight-blanking".
Commit 6e98503dba ("efi/apple-properties: Remove redundant attribute
initialization from unmarshal_key_value_pairs()") employed a trick to
store such booleans as u8 arrays (which is the data type used for all
other EFI properties on Macs): It cleared the property_entry's
"is_array" flag, thereby denoting that the value is stored inline in the
property_entry.
Commit 4466bf8282 erroneously removed that trick. It was probably a
little fragile to begin with.
Reinstate support for boolean properties by explicitly invoking the
PROPERTY_ENTRY_BOOL() initializer for properties with zero-length value.
Fixes: 4466bf8282 ("efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN")
Cc: <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/be958bda75331a011d53c696d1deec8dccd06fd2.1609388549.git.lukas@wunner.de
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 57efa1fe59 ]
Since commit 70e806e4e6 ("mm: Do early cow for pinned pages during
fork() for ptes") pages under a FOLL_PIN will not be write protected
during COW for fork. This means that pages returned from
pin_user_pages(FOLL_WRITE) should not become write protected while the pin
is active.
However, there is a small race where get_user_pages_fast(FOLL_PIN) can
establish a FOLL_PIN at the same time copy_present_page() is write
protecting it:
CPU 0 CPU 1
get_user_pages_fast()
internal_get_user_pages_fast()
copy_page_range()
pte_alloc_map_lock()
copy_present_page()
atomic_read(has_pinned) == 0
page_maybe_dma_pinned() == false
atomic_set(has_pinned, 1);
gup_pgd_range()
gup_pte_range()
pte_t pte = gup_get_pte(ptep)
pte_access_permitted(pte)
try_grab_compound_head()
pte = pte_wrprotect(pte)
set_pte_at();
pte_unmap_unlock()
// GUP now returns with a write protected page
The first attempt to resolve this by using the write protect caused
problems (and was missing a barrrier), see commit f3c64eda3e ("mm: avoid
early COW write protect games during fork()")
Instead wrap copy_p4d_range() with the write side of a seqcount and check
the read side around gup_pgd_range(). If there is a collision then
get_user_pages_fast() fails and falls back to slow GUP.
Slow GUP is safe against this race because copy_page_range() is only
called while holding the exclusive side of the mmap_lock on the src
mm_struct.
[akpm@linux-foundation.org: coding style fixes]
Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com
Link: https://lkml.kernel.org/r/2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Fixes: f3c64eda3e ("mm: avoid early COW write protect games during fork()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: "Ahmed S. Darwish" <a.darwish@linutronix.de> [seqcount_t parts]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
CONFIG_EFI_EARLYCON defaults to yes, and thus is enabled on systems that
do not support EFI, or do not have EFI support enabled, but do satisfy
the symbol's other dependencies.
While drivers/firmware/efi/ won't be entered during the build phase if
CONFIG_EFI=n, and drivers/firmware/efi/earlycon.c itself thus won't be
built, enabling EFI_EARLYCON does force-enable CONFIG_FONT_SUPPORT and
CONFIG_ARCH_USE_MEMREMAP_PROT, and CONFIG_FONT_8x16, which is
undesirable.
Fix this by making CONFIG_EFI_EARLYCON depend on CONFIG_EFI.
This reduces kernel size on headless systems by more than 4 KiB.
Fixes: 69c1f396f2 ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20201124191646.3559757-1-geert@linux-m68k.org
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.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
...
Pull arm64 updates from Will Deacon:
"There's quite a lot of code here, but much of it is due to the
addition of a new PMU driver as well as some arm64-specific selftests
which is an area where we've traditionally been lagging a bit.
In terms of exciting features, this includes support for the Memory
Tagging Extension which narrowly missed 5.9, hopefully allowing
userspace to run with use-after-free detection in production on CPUs
that support it. Work is ongoing to integrate the feature with KASAN
for 5.11.
Another change that I'm excited about (assuming they get the hardware
right) is preparing the ASID allocator for sharing the CPU page-table
with the SMMU. Those changes will also come in via Joerg with the
IOMMU pull.
We do stray outside of our usual directories in a few places, mostly
due to core changes required by MTE. Although much of this has been
Acked, there were a couple of places where we unfortunately didn't get
any review feedback.
Other than that, we ran into a handful of minor conflicts in -next,
but nothing that should post any issues.
Summary:
- Userspace support for the Memory Tagging Extension introduced by
Armv8.5. Kernel support (via KASAN) is likely to follow in 5.11.
- Selftests for MTE, Pointer Authentication and FPSIMD/SVE context
switching.
- Fix and subsequent rewrite of our Spectre mitigations, including
the addition of support for PR_SPEC_DISABLE_NOEXEC.
- Support for the Armv8.3 Pointer Authentication enhancements.
- Support for ASID pinning, which is required when sharing
page-tables with the SMMU.
- MM updates, including treating flush_tlb_fix_spurious_fault() as a
no-op.
- Perf/PMU driver updates, including addition of the ARM CMN PMU
driver and also support to handle CPU PMU IRQs as NMIs.
- Allow prefetchable PCI BARs to be exposed to userspace using normal
non-cacheable mappings.
- Implementation of ARCH_STACKWALK for unwinding.
- Improve reporting of unexpected kernel traps due to BPF JIT
failure.
- Improve robustness of user-visible HWCAP strings and their
corresponding numerical constants.
- Removal of TEXT_OFFSET.
- Removal of some unused functions, parameters and prototypes.
- Removal of MPIDR-based topology detection in favour of firmware
description.
- Cleanups to handling of SVE and FPSIMD register state in
preparation for potential future optimisation of handling across
syscalls.
- Cleanups to the SDEI driver in preparation for support in KVM.
- Miscellaneous cleanups and refactoring work"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (148 commits)
Revert "arm64: initialize per-cpu offsets earlier"
arm64: random: Remove no longer needed prototypes
arm64: initialize per-cpu offsets earlier
kselftest/arm64: Check mte tagged user address in kernel
kselftest/arm64: Verify KSM page merge for MTE pages
kselftest/arm64: Verify all different mmap MTE options
kselftest/arm64: Check forked child mte memory accessibility
kselftest/arm64: Verify mte tag inclusion via prctl
kselftest/arm64: Add utilities and a test to validate mte memory
perf: arm-cmn: Fix conversion specifiers for node type
perf: arm-cmn: Fix unsigned comparison to less than zero
arm64: dbm: Invalidate local TLB when setting TCR_EL1.HD
arm64: mm: Make flush_tlb_fix_spurious_fault() a no-op
arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() option
arm64: Pull in task_stack_page() to Spectre-v4 mitigation code
KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled
arm64: Get rid of arm64_ssbd_state
KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state()
KVM: arm64: Get rid of kvm_arm_have_ssbd()
KVM: arm64: Simplify handling of ARCH_WORKAROUND_2
...
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
Nathan reports that building the new mokvar table code for 32-bit
ARM fails with errors such as
error: implicit declaration of function 'early_memunmap'
error: implicit declaration of function 'early_memremap'
This is caused by the lack of an explicit #include of the appropriate
header, and ARM apparently does not inherit that inclusion via another
header file. So add the #include.
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
CONFIG_EFI_VARS controls the code that exposes EFI variables via
sysfs entries, which was deprecated before support for non-Intel
architectures was added to EFI. So let's limit its availability
to Intel architectures for the time being, and hopefully remove
it entirely in the not too distant future.
While at it, let's remove the module alias so that the module is
no longer loaded automatically.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Remove some false dependencies on CONFIG_EFI_VARS, which only controls
the creation of the sysfs entries, whereas the underlying functionality
that these modules rely on is enabled unconditionally when CONFIG_EFI
is set.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efivars_sysfs_init() is only used locally in the source file that
defines it, so make it static and unexport it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The worker thread that gets kicked off to sync the state of the
EFI variable list is only used by the EFI pstore implementation,
and is defined in its source file. So let's move its scheduling
there as well. Since our efivar_init() scan will bail on duplicate
entries, there is no need to disable the workqueue like we did
before, so we can run it unconditionally.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The EFI pstore implementation relies on the 'efivars' abstraction,
which encapsulates the EFI variable store in a way that can be
overridden by other backing stores, like the Google SMI one.
On top of that, the EFI pstore implementation also relies on the
efivars.ko module, which is a separate layer built on top of the
'efivars' abstraction that exposes the [deprecated] sysfs entries
for each variable that exists in the backing store.
Since the efivars.ko module is deprecated, and all users appear to
have moved to the efivarfs file system instead, let's prepare for
its removal, by removing EFI pstore's dependency on it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Fix a couple of issues in the new mokvar-table handling code, as
pointed out by Arvind and Boris:
- don't bother checking the end of the physical region against the start
address of the mokvar table,
- ensure that we enter the loop with err = -EINVAL,
- replace size_t with unsigned long to appease pedantic type equality
checks.
Reviewed-by: Arvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: Lenny Szubowicz <lszubowi@redhat.com>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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>
Incorporate the definition of EFI_MEMORY_CPU_CRYPTO from the UEFI
specification v2.8, and wire it into our memory map dumping routine
as well.
To make a bit of space in the output buffer, which is provided by
the various callers, shorten the descriptive names of the memory
types.
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull EFI fix from Borislav Petkov:
"Ensure that the EFI bootloader control module only probes successfully
on systems that support the EFI SetVariable runtime service"
[ Tag and commit from Ard Biesheuvel, forwarded by Borislav ]
* tag 'efi-urgent-for-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: efibc: check for efivars write capability
Memory errors could be printed with incorrect row values since the DIMM
size has outgrown the 16 bit row field in the CPER structure. UEFI
Specification Version 2.8 has increased the size of row by allowing it to
use the first 2 bits from a previously reserved space within the structure.
When needed, add the extension bits to the row value printed.
Based on UEFI 2.8 Table 299. Memory Error Record
Signed-off-by: Alex Kluver <alex.kluver@hpe.com>
Tested-by: Russ Anderson <russ.anderson@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Kyle Meyer <kyle.meyer@hpe.com>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20200819143544.155096-2-alex.kluver@hpe.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Jann Horn
Randy Dunlap
Sunil V L
Mihai Carabas
Ard Biesheuvel
Zhang Jianhua
Benjamin Herrenschmidt
Borislav Petkov
Marc Zyngier
Michal Suchanek
Rasmus Villemoes
Dan Carpenter
Heiner Kallweit
Changbin Du
Nathan Chancellor
Lv Yunlong
Shawn Guo
Lukas Wunner
Jason Gunthorpe
Geert Uytterhoeven
Amadeusz Sławiński
Linus Torvalds
Dan Williams
Ingo Molnar
Atish Patra
Palmer Dabbelt
Tian Tao
Alex Kluver