efi_recover_from_page_fault() doesn't recover -- it does a special EFI
mini-oops. Rename it to make it clear that it crashes.
While renaming it, I noticed a blatant bug: a page fault oops in a
different thread happening concurrently with an EFI runtime service call
would be misinterpreted as an EFI page fault. Fix that.
This isn't quite exact. The situation could be improved by using a
special CS for calls into EFI.
[ bp: Massage commit message and simplify in interrupt check. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/f43b1e80830dc78ed60ed8b0826f4f189254570c.1612924255.git.luto@kernel.org
A SMAP-violating kernel access is not a recoverable condition. Imagine
kernel code that, outside of a uaccess region, dereferences a pointer to
the user range by accident. If SMAP is on, this will reliably generate
as an intentional user access. This makes it easy for bugs to be
overlooked if code is inadequately tested both with and without SMAP.
This was discovered because BPF can generate invalid accesses to user
memory, but those warnings only got printed if SMAP was off. Make it so
that this type of error will be discovered with SMAP on as well.
[ bp: Massage commit message. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/66a02343624b1ff46f02a838c497fc05c1a871b3.1612924255.git.luto@kernel.org
Right now, the case of the kernel trying to execute from user memory
is treated more or less just like the kernel getting a page fault on a
user access. In the failure path, it checks for erratum #93, tries to
otherwise fix up the error, and then oopses.
If it manages to jump to the user address space, with or without SMEP,
it should not try to resolve the page fault. This is an error, pure and
simple. Rearrange the code so that this case is caught early, check for
erratum #93, and bail out.
[ bp: Massage commit message. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/ab8719c7afb8bd501c4eee0e36493150fbbe5f6a.1612924255.git.luto@kernel.org
In general, page fault errors for WRUSS should be just like get_user(),
etc. Fix three bugs in this area:
There is a comment that says that, if the kernel can't handle a page fault
on a user address due to OOM, the OOM-kill-and-retry logic would be
skipped. The code checked kernel *privilege*, not kernel mode, so it
missed WRUSS. This means that the kernel would malfunction if it got OOM
on a WRUSS fault -- this would be a kernel-mode, user-privilege fault, and
the OOM killer would be invoked and the handler would retry the faulting
instruction.
A failed user access from kernel while a fatal signal is pending should
fail even if the instruction in question was WRUSS.
do_sigbus() should not send SIGBUS for WRUSS -- it should handle it like
any other kernel mode failure.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/a7b7bcea730bd4069e6b7e629236bb2cf526c2fb.1612924255.git.luto@kernel.org
mm_fault_error() is logically just the end of do_user_addr_fault().
Combine the functions. This makes the code easier to read.
Most of the churn here is from renaming hw_error_code to error_code in
do_user_addr_fault().
This makes no difference at all to the generated code (objdump -dr) as
compared to changing noinline to __always_inline in the definition of
mm_fault_error().
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/dedc4d9c9b047e51ce38b991bd23971a28af4e7b.1612924255.git.luto@kernel.org
The recent rework of probe_kernel_address() and its conversion to
get_kernel_nofault() inadvertently broke is_prefetch(). Before this
change, probe_kernel_address() was used as a sloppy "read user or
kernel memory" helper, but it doesn't do that any more. The new
get_kernel_nofault() reads *kernel* memory only, which completely broke
is_prefetch() for user access.
Adjust the code to the correct accessor based on access mode. The
manual address bounds check is no longer necessary, since the accessor
helpers (get_user() / get_kernel_nofault()) do the right thing all by
themselves. As a bonus, by using the correct accessor, the open-coded
address bounds check is not needed anymore.
[ bp: Massage commit message. ]
Fixes: eab0c6089b ("maccess: unify the probe kernel arch hooks")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/b91f7f92f3367d2d3a88eec3b09c6aab1b2dc8ef.1612924255.git.luto@kernel.org
Comment says "by preventing anything executable" which is not true. Even
PROT_NONE mapping can't be installed at (1<<47 - 4096).
mmap(0x7ffffffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM
[ bp: Fixup to the moved location in page_64_types.h. ]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200305181719.GA5490@avx2
task_user_regset_view() has nonsensical semantics, but those semantics
appear to be relied on by existing users of PTRACE_GETREGSET and
PTRACE_SETREGSET. (See added comments below for details.)
It shouldn't be used for PTRACE_GETREGS or PTRACE_SETREGS, though. A
native 64-bit ptrace() call and an x32 ptrace() call using GETREGS
or SETREGS wants the 64-bit regset views, and a 32-bit ptrace() call
(native or compat) should use the 32-bit regset.
task_user_regset_view() almost does this except that it will
malfunction if a ptracer is itself ptraced and the outer ptracer
modifies CS on entry to a ptrace() syscall. Hopefully that has never
happened. (The compat ptrace() code already hardcoded the 32-bit
regset, so this change has no effect on that path.)
Improve the situation and deobfuscate the code by hardcoding the
64-bit view in the x32 ptrace() and selecting the view based on the
kernel config in the native ptrace().
I tried to figure out the history behind this API. I naïvely assumed
that PTRAGE_GETREGSET and PTRACE_SETREGSET were ancient APIs that
predated compat, but no. They were introduced by
2225a122ae ("ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET")
in 2010, and they are simply a poor design. ELF core dumps have the
ELF e_machine field and a bunch of register sets in ELF notes, and the
pair (e_machine, NT_XXX) indicates the format of the regset blob. But
the new PTRACE_GET/SETREGSET API coopted the NT_XXX numbering without
any way to specify which e_machine was in effect. This is especially
bad on x86, where a process can freely switch between 32-bit and
64-bit mode, and, in fact, the PTRAGE_SETREGSET call itself can cause
this switch to happen. Oops.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/9daa791d0c7eaebd59c5bc2b2af1b0e7bebe707d.1612375698.git.luto@kernel.org
The implementation was rather buggy. It unconditionally marked PTEs
read-only, even for VM_SHARED mappings. I'm not sure whether this is
actually a problem, but it certainly seems unwise. More importantly, it
released the mmap lock before flushing the TLB, which could allow a racing
CoW operation to falsely believe that the underlying memory was not
writable.
I can't find any users at all of this mechanism, so just remove it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Stas Sergeev <stsp2@yandex.ru>
Link: https://lkml.kernel.org/r/f3086de0babcab36f69949b5780bde851f719bc8.1611078018.git.luto@kernel.org
pgt_buf is used to allocate page tables on initial direct page mapping
which bootstraps the kernel into being able to allocate these before the
direct mapping makes further pages available.
INIT_PGD_PAGE_COUNT is set to 6 pages (doubled for KASLR) - 3 (PUD, PMD,
PTE) for the 1 MiB ISA mapping and 3 more for the first direct mapping
assignment in each case providing 2 MiB of address space.
This has not been updated for 5-level page tables which has an
additional P4D page table level above PUD.
In most instances, this will not have a material impact as the first
4 page levels allocated for the ISA mapping will provide sufficient
address space to encompass all further address mappings.
If the first direct mapping is within 512 GiB of the ISA mapping, only
a PMD and PTE needs to be added in the instance the kernel is using 4
KiB page tables (e.g. CONFIG_DEBUG_PAGEALLOC is enabled) and only a PMD
if the kernel can use 2 MiB pages (the first allocation is limited to
PMD_SIZE so a GiB page cannot be used there).
However, if the machine has more than 512 GiB of RAM and the kernel is
allocating 4 KiB page size, 3 further page tables are required.
If the machine has more than 256 TiB of RAM at 4 KiB or 2 MiB page size,
further 3 or 4 page tables are required respectively.
Update INIT_PGD_PAGE_COUNT to reflect this.
[ bp: Sanitize text into passive voice without ambiguous personal pronouns. ]
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/20201215205641.34096-1-lstoakes@gmail.com
Pull s390 cleanups from Vasily Gorbik:
"Update defconfigs and sort config select list"
* tag 's390-5.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/Kconfig: sort config S390 select list once again
s390: update defconfigs
Pull power management fixes from Rafael Wysocki:
"These fix a crash in intel_pstate during resume from suspend-to-RAM
that may occur after recent changes and two resource leaks in error
paths in the operating performance points (OPP) framework, add a new
C-states table to intel_idle and update the cpuidle MAINTAINERS entry
to cover the governors too.
Specifics:
- Fix recently introduced crash in the intel_pstate driver that
occurs if scale-invariance is disabled during resume from
suspend-to-RAM due to inconsistent changes of APERF or MPERF MSR
values made by the platform firmware (Rafael Wysocki).
- Fix a memory leak and add a missing clk_put() in error paths in the
OPP framework (Quanyang Wang, Viresh Kumar).
- Add new C-states table for SnowRidge processors to the intel_idle
driver (Artem Bityutskiy).
- Update the MAINTAINERS entry for cpuidle to make it clear that the
governors are covered by it too (Lukas Bulwahn)"
* tag 'pm-5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
intel_idle: add SnowRidge C-state table
cpufreq: intel_pstate: Fix fast-switch fallback path
opp: Call the missing clk_put() on error
opp: fix memory leak in _allocate_opp_table
MAINTAINERS: include governors into CPU IDLE TIME MANAGEMENT FRAMEWORK
Pull SCSI fixes from James Bottomley:
"This is a load of driver fixes (12 ufs, 1 mpt3sas, 1 cxgbi).
The big core two fixes are for power management ("block: Do not accept
any requests while suspended" and "block: Fix a race in the runtime
power management code") which finally sorts out the resume problems
we've occasionally been having.
To make the resume fix, there are seven necessary precursors which
effectively renames REQ_PREEMPT to REQ_PM, so every "special" request
in block is automatically a power management exempt one.
All of the non-PM preempt cases are removed except for the one in the
SCSI Parallel Interface (spi) domain validation which is a genuine
case where we have to run requests at high priority to validate the
bus so this becomes an autopm get/put protected request"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (22 commits)
scsi: cxgb4i: Fix TLS dependency
scsi: ufs: Un-inline ufshcd_vops_device_reset function
scsi: ufs: Re-enable WriteBooster after device reset
scsi: ufs-mediatek: Use correct path to fix compile error
scsi: mpt3sas: Signedness bug in _base_get_diag_triggers()
scsi: block: Do not accept any requests while suspended
scsi: block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT
scsi: core: Only process PM requests if rpm_status != RPM_ACTIVE
scsi: scsi_transport_spi: Set RQF_PM for domain validation commands
scsi: ide: Mark power management requests with RQF_PM instead of RQF_PREEMPT
scsi: ide: Do not set the RQF_PREEMPT flag for sense requests
scsi: block: Introduce BLK_MQ_REQ_PM
scsi: block: Fix a race in the runtime power management code
scsi: ufs-pci: Enable UFSHCD_CAP_RPM_AUTOSUSPEND for Intel controllers
scsi: ufs-pci: Fix recovery from hibernate exit errors for Intel controllers
scsi: ufs-pci: Ensure UFS device is in PowerDown mode for suspend-to-disk ->poweroff()
scsi: ufs-pci: Fix restore from S4 for Intel controllers
scsi: ufs-mediatek: Keep VCC always-on for specific devices
scsi: ufs: Allow regulators being always-on
scsi: ufs: Clear UAC for RPMB after ufshcd resets
...
Pull block fixes from Jens Axboe:
"Two minor block fixes from this last week that should go into 5.11:
- Add missing NOWAIT debugfs definition (Andres)
- Fix kerneldoc warning introduced this merge window (Randy)"
* tag 'block-5.11-2021-01-01' of git://git.kernel.dk/linux-block:
block: add debugfs stanza for QUEUE_FLAG_NOWAIT
fs: block_dev.c: fix kernel-doc warnings from struct block_device changes
Pull io_uring fixes from Jens Axboe:
"A few fixes that should go into 5.11, all marked for stable as well:
- Fix issue around identity COW'ing and users that share a ring
across processes
- Fix a hang associated with unregistering fixed files (Pavel)
- Move the 'process is exiting' cancelation a bit earlier, so
task_works aren't affected by it (Pavel)"
* tag 'io_uring-5.11-2021-01-01' of git://git.kernel.dk/linux-block:
kernel/io_uring: cancel io_uring before task works
io_uring: fix io_sqe_files_unregister() hangs
io_uring: add a helper for setting a ref node
io_uring: don't assume mm is constant across submits
Commit 436e980e2e ("kbuild: don't hardcode depmod path") stopped
hard-coding the path of depmod, but in the process caused trouble for
distributions that had that /sbin location, but didn't have it in the
PATH (generally because /sbin is limited to the super-user path).
Work around it for now by just adding /sbin to the end of PATH in the
depmod.sh script.
Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For cancelling io_uring requests it needs either to be able to run
currently enqueued task_works or having it shut down by that moment.
Otherwise io_uring_cancel_files() may be waiting for requests that won't
ever complete.
Go with the first way and do cancellations before setting PF_EXITING and
so before putting the task_work infrastructure into a transition state
where task_work_run() would better not be called.
Cc: stable@vger.kernel.org # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_sqe_files_unregister() uninterruptibly waits for enqueued ref nodes,
however requests keeping them may never complete, e.g. because of some
userspace dependency. Make sure it's interruptible otherwise it would
hang forever.
Cc: stable@vger.kernel.org # 5.6+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull ceph fixes from Ilya Dryomov:
"A fix for an edge case in MClientRequest encoding and a couple of
trivial fixups for the new msgr2 support"
* tag 'ceph-for-5.11-rc2' of git://github.com/ceph/ceph-client:
libceph: add __maybe_unused to DEFINE_MSGR2_FEATURE
libceph: align session_key and con_secret to 16 bytes
libceph: fix auth_signature buffer allocation in secure mode
ceph: reencode gid_list when reconnecting
Add C-state table for the SnowRidge SoC which is found on Intel Jacobsville
platforms.
The following has been changed.
1. C1E latency changed from 10us to 15us. It was measured using the
open source "wult" tool (the "nic" method, 15us is the 99.99th
percentile).
2. C1E power break even changed from 20us to 25us, which may result
in less C1E residency in some workloads.
3. C6 latency changed from 50us to 130us. Measured the same way as C1E.
The C6 C-state is supported only by some SnowRidge revisions, so add a C-state
table commentary about this.
On SnowRidge, C6 support is enumerated via the usual mechanism: "mwait" leaf of
the "cpuid" instruction. The 'intel_idle' driver does check this leaf, so even
though C6 is present in the table, the driver will only use it if the CPU does
support it.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When sugov_update_single_perf() falls back to the "frequency"
path due to the missing scale-invariance, it will call
cpufreq_driver_fast_switch() via sugov_fast_switch()
and the driver's ->fast_switch() callback will be invoked,
so it must not be NULL.
However, after commit a365ab6b9d ("cpufreq: intel_pstate: Implement
the ->adjust_perf() callback") intel_pstate sets ->fast_switch() to
NULL when it is going to use intel_cpufreq_adjust_perf(), which is a
mistake, because on x86 the scale-invariance may be turned off
dynamically, so modify it to retain the original ->adjust_perf()
callback pointer.
Fixes: a365ab6b9d ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback")
Reported-by: Kenneth R. Crudup <kenny@panix.com>
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull operating performance points (OPP) framework fixes for 5.11-rc2
from Viresh Kumar:
"This contains two patches to fix freeing of resources in error paths."
* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
opp: Call the missing clk_put() on error
opp: fix memory leak in _allocate_opp_table
Fix new kernel-doc warnings in fs/block_dev.c:
../fs/block_dev.c:1066: warning: Excess function parameter 'whole' description in 'bd_abort_claiming'
../fs/block_dev.c:1837: warning: Function parameter or member 'dev' not described in 'lookup_bdev'
Fixes: 4e7b5671c6 ("block: remove i_bdev")
Fixes: 37c3fc9abb ("block: simplify the block device claiming interface")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge misc fixes from Andrew Morton:
"16 patches
Subsystems affected by this patch series: mm (selftests, hugetlb,
pagecache, mremap, kasan, and slub), kbuild, checkpatch, misc, and
lib"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: slub: call account_slab_page() after slab page initialization
zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c
lib/zlib: fix inflating zlib streams on s390
lib/genalloc: fix the overflow when size is too big
kdev_t: always inline major/minor helper functions
sizes.h: add SZ_8G/SZ_16G/SZ_32G macros
local64.h: make <asm/local64.h> mandatory
kasan: fix null pointer dereference in kasan_record_aux_stack
mm: generalise COW SMC TLB flushing race comment
mm/mremap.c: fix extent calculation
mm: memmap defer init doesn't work as expected
mm: add prototype for __add_to_page_cache_locked()
checkpatch: prefer strscpy to strlcpy
Revert "kbuild: avoid static_assert for genksyms"
mm/hugetlb: fix deadlock in hugetlb_cow error path
selftests/vm: fix building protection keys test
It's convenient to have page->objects initialized before calling into
account_slab_page(). In particular, this information can be used to
pre-alloc the obj_cgroup vector.
Let's call account_slab_page() a bit later, after the initialization of
page->objects.
This commit doesn't bring any functional change, but is required for
further optimizations.
[akpm@linux-foundation.org: undo changes needed by forthcoming mm-memcg-slab-pre-allocate-obj_cgroups-for-slab-caches-with-slab_account.patch]
Link: https://lkml.kernel.org/r/20201110195753.530157-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Decompressing zlib streams on s390 fails with "incorrect data check"
error.
Userspace zlib checks inflate_state.flags in order to byteswap checksums
only for zlib streams, and s390 hardware inflate code, which was ported
from there, tries to match this behavior. At the same time, kernel zlib
does not use inflate_state.flags, so it contains essentially random
values. For many use cases either zlib stream is zeroed out or checksum
is not used, so this problem is masked, but at least SquashFS is still
affected.
Fix by always passing a checksum to and from the hardware as is, which
matches zlib_inflate()'s expectations.
Link: https://lkml.kernel.org/r/20201215155551.894884-1-iii@linux.ibm.com
Fixes: 1261961000 ("lib/zlib: add s390 hardware support for kernel zlib_inflate")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: <stable@vger.kernel.org> [5.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some graphic card has very big memory on chip, such as 32G bytes.
In the following case, it will cause overflow:
pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
ret = gen_pool_add(pool, 0x1000000, SZ_32G, NUMA_NO_NODE);
va = gen_pool_alloc(pool, SZ_4G);
The overflow occurs in gen_pool_alloc_algo_owner():
....
size = nbits << order;
....
The @nbits is "int" type, so it will overflow.
Then the gen_pool_avail() will return the wrong value.
This patch converts some "int" to "unsigned long", and
changes the compare code in while.
Link: https://lkml.kernel.org/r/20201229060657.3389-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Reported-by: Shi Jiasheng <jiasheng.shi@iluvatar.ai>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
