[ Upstream commit 5f97f18fea ]
The driver tracks per-channel data via struct pwm_device::chip_data and
struct meson_pwm::channels[]. The latter holds the actual data, the former
is only a pointer to the latter. So simplify by using struct
meson_pwm::channels[] consistently.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Stable-dep-of: 87a2cbf02d ("pwm: meson: fix handling of period/duty if greater than UINT_MAX")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 437fb760d0 ]
The variable fin_freq is being initialized with a value that is never
read and it is being updated later with a new value. The initialization
is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Stable-dep-of: 87a2cbf02d ("pwm: meson: fix handling of period/duty if greater than UINT_MAX")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 26efd79c46 ]
As comments in ftrace_process_locs(), there may be NULL pointers in
mcount_loc section:
> Some architecture linkers will pad between
> the different mcount_loc sections of different
> object files to satisfy alignments.
> Skip any NULL pointers.
After commit 20e5227e9f ("ftrace: allow NULL pointers in mcount_loc"),
NULL pointers will be accounted when allocating ftrace pages but skipped
before adding into ftrace pages, this may result in some pages not being
used. Then after commit 706c81f87f ("ftrace: Remove extra helper
functions"), warning may occur at:
WARN_ON(pg->next);
To fix it, only warn for case that no pointers skipped but pages not used
up, then free those unused pages after releasing ftrace_lock.
Link: https://lore.kernel.org/linux-trace-kernel/20230712060452.3175675-1-zhengyejian1@huawei.com
Cc: stable@vger.kernel.org
Fixes: 706c81f87f ("ftrace: Remove extra helper functions")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 59300b36f8 ]
It is possible that on error pg->size can be zero when getting its order,
which would return a -1 value. It is dangerous to pass in an order of -1
to free_pages(). Check if order is greater than or equal to zero before
calling free_pages().
Link: https://lore.kernel.org/lkml/20210330093916.432697c7@gandalf.local.home/
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Stable-dep-of: 26efd79c46 ("ftrace: Fix possible warning on checking all pages used in ftrace_process_locs()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit da537f0aef ]
Looking for ways to shrink the size of the dyn_ftrace structure, knowing the
information about how many pages and the number of groups of those pages, is
useful in working out the best ways to save on memory.
This adds one info print on how many groups of pages were used to allocate
the ftrace dyn_ftrace structures, and also shows the number of pages and
groups in the dyn_ftrace_total_info (which is used for debugging).
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Stable-dep-of: 26efd79c46 ("ftrace: Fix possible warning on checking all pages used in ftrace_process_locs()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 59e45c758c ]
If a posix lock request is waiting for a result from user space
(dlm_controld), do not let it be interrupted unless the process
is killed. This reverts commit a6b1533e9a ("dlm: make posix locks
interruptible"). The problem with the interruptible change is
that all locks were cleared on any signal interrupt. If a signal
was received that did not terminate the process, the process
could continue running after all its dlm posix locks had been
cleared. A future patch will add cancelation to allow proper
interruption.
Cc: stable@vger.kernel.org
Fixes: a6b1533e9a ("dlm: make posix locks interruptible")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a800ba77fd ]
This patch moves the return of FILE_LOCK_DEFERRED a little bit earlier
than checking afterwards again if the request was an asynchronous request.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Stable-dep-of: 59e45c758c ("fs: dlm: interrupt posix locks only when process is killed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bcbb4ba6c9 ]
Lately the different casting between plock_op and plock_xop and list
holders which was involved showed some issues which were hard to see.
This patch removes the "plock_xop" structure and introduces a
"struct plock_async_data". This structure will be set in "struct plock_op"
in case of asynchronous lock handling as the original "plock_xop" was
made for. There is no need anymore to cast pointers around for
additional fields in case of asynchronous lock handling. As disadvantage
another allocation was introduces but only needed in the asynchronous
case which is currently only used in combination with nfs lockd.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Stable-dep-of: 59e45c758c ("fs: dlm: interrupt posix locks only when process is killed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e7e3975636 ]
PCIe r6.0.1, sec 7.5.3.7, recommends setting the link control parameters,
then waiting for the Link Training bit to be clear before setting the
Retrain Link bit.
This avoids a race where the LTSSM may not use the updated parameters if it
is already in the midst of link training because of other normal link
activity.
Wait for the Link Training bit to be clear before toggling the Retrain Link
bit to ensure that the LTSSM uses the updated link control parameters.
[bhelgaas: commit log, return 0 (success)/-ETIMEDOUT instead of bool for
both pcie_wait_for_retrain() and the existing pcie_retrain_link()]
Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 26fb529024 ]
Following process makes ext4 load stale buffer heads from last failed
mounting in a new mounting operation:
mount_bdev
ext4_fill_super
| ext4_load_and_init_journal
| ext4_load_journal
| jbd2_journal_load
| load_superblock
| journal_get_superblock
| set_buffer_verified(bh) // buffer head is verified
| jbd2_journal_recover // failed caused by EIO
| goto failed_mount3a // skip 'sb->s_root' initialization
deactivate_locked_super
kill_block_super
generic_shutdown_super
if (sb->s_root)
// false, skip ext4_put_super->invalidate_bdev->
// invalidate_mapping_pages->mapping_evict_folio->
// filemap_release_folio->try_to_free_buffers, which
// cannot drop buffer head.
blkdev_put
blkdev_put_whole
if (atomic_dec_and_test(&bdev->bd_openers))
// false, systemd-udev happens to open the device. Then
// blkdev_flush_mapping->kill_bdev->truncate_inode_pages->
// truncate_inode_folio->truncate_cleanup_folio->
// folio_invalidate->block_invalidate_folio->
// filemap_release_folio->try_to_free_buffers will be skipped,
// dropping buffer head is missed again.
Second mount:
ext4_fill_super
ext4_load_and_init_journal
ext4_load_journal
ext4_get_journal
jbd2_journal_init_inode
journal_init_common
bh = getblk_unmovable
bh = __find_get_block // Found stale bh in last failed mounting
journal->j_sb_buffer = bh
jbd2_journal_load
load_superblock
journal_get_superblock
if (buffer_verified(bh))
// true, skip journal->j_format_version = 2, value is 0
jbd2_journal_recover
do_one_pass
next_log_block += count_tags(journal, bh)
// According to journal_tag_bytes(), 'tag_bytes' calculating is
// affected by jbd2_has_feature_csum3(), jbd2_has_feature_csum3()
// returns false because 'j->j_format_version >= 2' is not true,
// then we get wrong next_log_block. The do_one_pass may exit
// early whenoccuring non JBD2_MAGIC_NUMBER in 'next_log_block'.
The filesystem is corrupted here, journal is partially replayed, and
new journal sequence number actually is already used by last mounting.
The invalidate_bdev() can drop all buffer heads even racing with bare
reading block device(eg. systemd-udev), so we can fix it by invalidating
bdev in error handling path in __ext4_fill_super().
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217171
Fixes: 25ed6e8a54 ("jbd2: enable journal clients to enable v2 checksumming")
Cc: stable@vger.kernel.org # v3.5
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230315013128.3911115-2-chengzhihao1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ede600e497 ]
At split_node(), if we fail to log the tree mod log copy operation, we
return without unlocking the split extent buffer we just allocated and
without decrementing the reference we own on it. Fix this by unlocking
it and decrementing the ref count before returning.
Fixes: 5de865eebb ("Btrfs: fix tree mod logging")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8a4a0b2a3e ]
If we disable quotas while we have a relocation of a metadata block group
that has extents belonging to the quota root, we can cause the relocation
to fail with -ENOENT. This is because relocation builds backref nodes for
extents of the quota root and later needs to walk the backrefs and access
the quota root - however if in between a task disables quotas, it results
in deleting the quota root from the root tree (with btrfs_del_root(),
called from btrfs_quota_disable().
This can be sporadically triggered by test case btrfs/255 from fstests:
$ ./check btrfs/255
FSTYP -- btrfs
PLATFORM -- Linux/x86_64 debian0 6.4.0-rc6-btrfs-next-134+ #1 SMP PREEMPT_DYNAMIC Thu Jun 15 11:59:28 WEST 2023
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
btrfs/255 6s ... _check_dmesg: something found in dmesg (see /home/fdmanana/git/hub/xfstests/results//btrfs/255.dmesg)
- output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/255.out.bad)
# --- tests/btrfs/255.out 2023-03-02 21:47:53.876609426 +0000
# +++ /home/fdmanana/git/hub/xfstests/results//btrfs/255.out.bad 2023-06-16 10:20:39.267563212 +0100
# @@ -1,2 +1,4 @@
# QA output created by 255
# +ERROR: error during balancing '/home/fdmanana/btrfs-tests/scratch_1': No such file or directory
# +There may be more info in syslog - try dmesg | tail
# Silence is golden
# ...
(Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/255.out /home/fdmanana/git/hub/xfstests/results//btrfs/255.out.bad' to see the entire diff)
Ran: btrfs/255
Failures: btrfs/255
Failed 1 of 1 tests
To fix this make the quota disable operation take the cleaner mutex, as
relocation of a block group also takes this mutex. This is also what we
do when deleting a subvolume/snapshot, we take the cleaner mutex in the
cleaner kthread (at cleaner_kthread()) and then we call btrfs_del_root()
at btrfs_drop_snapshot() while under the protection of the cleaner mutex.
Fixes: bed92eae26 ("Btrfs: qgroup implementation and prototypes")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5958253cf6 ]
Before this patch, qgroup completely relies on per-inode extent io tree
to detect reserved data space leak.
However previous bug has already shown how release page before
btrfs_finish_ordered_io() could lead to leak, and since it's
QGROUP_RESERVED bit cleared without triggering qgroup rsv, it can't be
detected by per-inode extent io tree.
So this patch adds another (and hopefully the final) safety net to catch
qgroup data reserved space leak. At least the new safety net catches
all the leaks during development, so it should be pretty useful in the
real world.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 8a4a0b2a3e ("btrfs: fix race between quota disable and relocation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 17e4aed830 ]
The parameter 'int n' from bch_bucket_alloc_set() is not cleared
defined. From the code comments n is the number of buckets to alloc, but
from the code itself 'n' is the maximum cache to iterate. Indeed all the
locations where bch_bucket_alloc_set() is called, 'n' is alwasy 1.
This patch removes the confused and unnecessary 'int n' from parameter
list of bch_bucket_alloc_set(), and explicitly allocates only 1 bucket
for its caller.
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 80fca8a10b ("bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e34c8dd238 ]
Following process,
jbd2_journal_commit_transaction
// there are several dirty buffer heads in transaction->t_checkpoint_list
P1 wb_workfn
jbd2_log_do_checkpoint
if (buffer_locked(bh)) // false
__block_write_full_page
trylock_buffer(bh)
test_clear_buffer_dirty(bh)
if (!buffer_dirty(bh))
__jbd2_journal_remove_checkpoint(jh)
if (buffer_write_io_error(bh)) // false
>> bh IO error occurs <<
jbd2_cleanup_journal_tail
__jbd2_update_log_tail
jbd2_write_superblock
// The bh won't be replayed in next mount.
, which could corrupt the ext4 image, fetch a reproducer in [Link].
Since writeback process clears buffer dirty after locking buffer head,
we can fix it by try locking buffer and check dirtiness while buffer is
locked, the buffer head can be removed if it is neither dirty nor locked.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217490
Fixes: 470decc613 ("[PATCH] jbd2: initial copy of files from jbd")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230606135928.434610-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c2d6fd9d6f ]
There is a long-standing metadata corruption issue that happens from
time to time, but it's very difficult to reproduce and analyse, benefit
from the JBD2_CYCLE_RECORD option, we found out that the problem is the
checkpointing process miss to write out some buffers which are raced by
another do_get_write_access(). Looks below for detail.
jbd2_log_do_checkpoint() //transaction X
//buffer A is dirty and not belones to any transaction
__buffer_relink_io() //move it to the IO list
__flush_batch()
write_dirty_buffer()
do_get_write_access()
clear_buffer_dirty
__jbd2_journal_file_buffer()
//add buffer A to a new transaction Y
lock_buffer(bh)
//doesn't write out
__jbd2_journal_remove_checkpoint()
//finish checkpoint except buffer A
//filesystem corrupt if the new transaction Y isn't fully write out.
Due to the t_checkpoint_list walking loop in jbd2_log_do_checkpoint()
have already handles waiting for buffers under IO and re-added new
transaction to complete commit, and it also removing cleaned buffers,
this makes sure the list will eventually get empty. So it's fine to
leave buffers on the t_checkpoint_list while flushing out and completely
stop using the t_checkpoint_io_list.
Cc: stable@vger.kernel.org
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Tested-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230606135928.434610-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: e34c8dd238 ("jbd2: Fix wrongly judgement for buffer head removing while doing checkpoint")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 214eb5a4d8 ]
Now that __jbd2_journal_remove_checkpoint() can detect buffer io error
and mark journal checkpoint error, then we abort the journal later
before updating log tail to ensure the filesystem works consistently.
So we could remove other redundant buffer io error checkes.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-5-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: e34c8dd238 ("jbd2: Fix wrongly judgement for buffer head removing while doing checkpoint")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Stable-tree-only change.
Due to the way the GDS and SRSO patches flowed into the stable tree, it
was a 50% chance that the merge of the which value GDS and SRSO should
be. Of course, I lost that bet, and chose the opposite of what Linus
chose in commit 64094e7e31 ("Merge tag 'gds-for-linus-2023-08-01' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip")
Fix this up by switching the values to match what is now in Linus's tree
as that is the correct value to mirror.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 534fc31d09 upstream.
It is possible that a guest can send a packet that contains a head + 18
slots and yet has a len <= XEN_NETBACK_TX_COPY_LEN. This causes nr_slots
to underflow in xenvif_get_requests() which then causes the subsequent
loop's termination condition to be wrong, causing a buffer overrun of
queue->tx_map_ops.
Rework the code to account for the extra frag_overflow slots.
This is CVE-2023-34319 / XSA-432.
Fixes: ad7f402ae4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Upstream commit: 0e52740ffd
There was never a doubt in my mind that they would not fit into a single
u32 eventually.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1a9bcadd00 upstream.
To pick the changes from:
3b9c723ed7 ("KVM: SVM: Add support for SVM instruction address check change")
b85a0425d8 ("Enumerate AVX Vector Neural Network instructions")
fb35d30fe5 ("x86/cpufeatures: Assign dedicated feature word for CPUID_0x8000001F[EAX]")
This only causes these perf files to be rebuilt:
CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o
And addresses this perf build warning:
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
Cc: Borislav Petkov <bp@suse.de>
Cc: Kyung Min Park <kyung.min.park@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb35d30fe5 upstream.
Collect the scattered SME/SEV related feature flags into a dedicated
word. There are now five recognized features in CPUID.0x8000001F.EAX,
with at least one more on the horizon (SEV-SNP). Using a dedicated word
allows KVM to use its automagic CPUID adjustment logic when reporting
the set of supported features to userspace.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Link: https://lkml.kernel.org/r/20210122204047.2860075-2-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 69372cf012 upstream.
On systems that do not have hardware enforced cache coherency between
encrypted and unencrypted mappings of the same physical page, the
hypervisor can use the VM page flush MSR (0xc001011e) to flush the cache
contents of an SEV guest page. When a small number of pages are being
flushed, this can be used in place of issuing a WBINVD across all CPUs.
CPUID 0x8000001f_eax[2] is used to determine if the VM page flush MSR is
available. Add a CPUID feature to indicate it is supported and define the
MSR.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <f1966379e31f9b208db5257509c4a089a87d33d0.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 26ce6ec364 upstream.
Commit 3f4c8211d9 ("x86/mm: Use mm_alloc() in poking_init()") broke
the kernel for running as Xen PV guest.
It seems as if the new address space is never activated before being
used, resulting in Xen rejecting to accept the new CR3 value (the PGD
isn't pinned).
Fix that by adding the now missing call of paravirt_arch_dup_mmap() to
poking_init(). That call was previously done by dup_mm()->dup_mmap() and
it is a NOP for all cases but for Xen PV, where it is just doing the
pinning of the PGD.
Fixes: 3f4c8211d9 ("x86/mm: Use mm_alloc() in poking_init()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230109150922.10578-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 81ac7e5d74 upstream
Gather Data Sampling (GDS) is a transient execution attack using
gather instructions from the AVX2 and AVX512 extensions. This attack
allows malicious code to infer data that was previously stored in
vector registers. Systems that are not vulnerable to GDS will set the
GDS_NO bit of the IA32_ARCH_CAPABILITIES MSR. This is useful for VM
guests that may think they are on vulnerable systems that are, in
fact, not affected. Guests that are running on affected hosts where
the mitigation is enabled are protected as if they were running
on an unaffected system.
On all hosts that are not affected or that are mitigated, set the
GDS_NO bit.
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 53cf5797f1 upstream
Gather Data Sampling (GDS) is mitigated in microcode. However, on
systems that haven't received the updated microcode, disabling AVX
can act as a mitigation. Add a Kconfig option that uses the microcode
mitigation if available and disables AVX otherwise. Setting this
option has no effect on systems not affected by GDS. This is the
equivalent of setting gather_data_sampling=force.
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 553a5c03e9 upstream
The Gather Data Sampling (GDS) vulnerability allows malicious software
to infer stale data previously stored in vector registers. This may
include sensitive data such as cryptographic keys. GDS is mitigated in
microcode, and systems with up-to-date microcode are protected by
default. However, any affected system that is running with older
microcode will still be vulnerable to GDS attacks.
Since the gather instructions used by the attacker are part of the
AVX2 and AVX512 extensions, disabling these extensions prevents gather
instructions from being executed, thereby mitigating the system from
GDS. Disabling AVX2 is sufficient, but we don't have the granularity
to do this. The XCR0[2] disables AVX, with no option to just disable
AVX2.
Add a kernel parameter gather_data_sampling=force that will enable the
microcode mitigation if available, otherwise it will disable AVX on
affected systems.
This option will be ignored if cmdline mitigations=off.
This is a *big* hammer. It is known to break buggy userspace that
uses incomplete, buggy AVX enumeration. Unfortunately, such userspace
does exist in the wild:
https://www.mail-archive.com/bug-coreutils@gnu.org/msg33046.html
[ dhansen: add some more ominous warnings about disabling AVX ]
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8974eb5882 upstream
Gather Data Sampling (GDS) is a hardware vulnerability which allows
unprivileged speculative access to data which was previously stored in
vector registers.
Intel processors that support AVX2 and AVX512 have gather instructions
that fetch non-contiguous data elements from memory. On vulnerable
hardware, when a gather instruction is transiently executed and
encounters a fault, stale data from architectural or internal vector
registers may get transiently stored to the destination vector
register allowing an attacker to infer the stale data using typical
side channel techniques like cache timing attacks.
This mitigation is different from many earlier ones for two reasons.
First, it is enabled by default and a bit must be set to *DISABLE* it.
This is the opposite of normal mitigation polarity. This means GDS can
be mitigated simply by updating microcode and leaving the new control
bit alone.
Second, GDS has a "lock" bit. This lock bit is there because the
mitigation affects the hardware security features KeyLocker and SGX.
It needs to be enabled and *STAY* enabled for these features to be
mitigated against GDS.
The mitigation is enabled in the microcode by default. Disable it by
setting gather_data_sampling=off or by disabling all mitigations with
mitigations=off. The mitigation status can be checked by reading:
/sys/devices/system/cpu/vulnerabilities/gather_data_sampling
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b81fac906a upstream
Initializing the FPU during the early boot process is a pointless
exercise. Early boot is convoluted and fragile enough.
Nothing requires that the FPU is set up early. It has to be initialized
before fork_init() because the task_struct size depends on the FPU register
buffer size.
Move the initialization to arch_cpu_finalize_init() which is the perfect
place to do so.
No functional change.
This allows to remove quite some of the custom early command line parsing,
but that's subject to the next installment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.902376621@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
