Now that all the code is in place provide a Kconfig option allowing users
to enable BTI for the kernel if their toolchain supports it, defaulting it
on since this has security benefits. This is a separate configuration
option since we currently don't support secondary CPUs that lack BTI if
the boot CPU supports it.
Code generation issues mean that current GCC 9 versions are not able to
produce usable BTI binaries so we disable support for building with GCC
versions prior to 10, once a fix is backported to GCC 9 the dependencies
will be updated.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-8-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
When the kernel is built for BTI and running on a system which supports
make all executable text guarded pages to ensure that loadable module
and JITed BPF code is protected by BTI.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-7-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
In order to extend the protection offered by BTI to all code executing in
kernel mode we need to annotate JITed BPF code appropriately for BTI. To
do this we need to add a landing pad to the start of each BPF function and
also immediately after the function prologue if we are emitting a function
which can be tail called. Jumps within BPF functions are all to immediate
offsets and therefore do not require landing pads.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-6-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Now that the kernel is built with BTI annotations enable the feature by
setting the GP bit in the stage 1 translation tables. This is done
based on the features supported by the boot CPU so that we do not need
to rewrite the translation tables.
In order to avoid potential issues on big.LITTLE systems when there are
a mix of BTI and non-BTI capable CPUs in the system when we have enabled
kernel mode BTI we change BTI to be a _STRICT_BOOT_CPU_FEATURE when we
have kernel BTI. This will prevent any CPUs that don't support BTI
being started if the boot CPU supports BTI rather than simply not using
BTI as we do when supporting BTI only in userspace. The main concern is
the possibility of BTYPE being preserved by a CPU that does not
implement BTI when a thread is migrated to it resulting in an incorrect
state which could generate an exception when the thread migrates back to
a CPU that does support BTI. If we encounter practical systems which
mix BTI and non-BTI CPUs we will need to revisit this implementation.
Since we currently do not generate landing pads in the BPF JIT we only
map the base kernel text in this way.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
When the kernel is built for BTI override SYM_FUNC_START and related macros
to add a BTI landing pad to the start of all global functions, ensuring that
they are BTI safe. The ; at the end of the BTI_x macros is for the
benefit of the macro-generated functions in xen-hypercall.S.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
When running with BTI enabled we need to ask the compiler to enable
generation of BTI landing pads beyond those generated as a result of
pointer authentication instructions being landing pads. Since the two
features are practically speaking unlikely to be used separately we
will make kernel mode BTI depend on pointer authentication in order
to simplify the Makefile.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Document the fact that we enable pointer authentication protection for
leaf functions since there is some narrow potential for ROP protection
benefits and little overhead has been observed.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200506195138.22086-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAl6yqbIUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroObBQf+NH9DCs6X92YggAoNpJl6uSIOX35X
ErdWqYj80Xx95QU73aMukjs3Zqxe6WfYI9jPEOD8SDUZzZlVfIA35D8BYlqt1c5R
A2K2ebTQbZ+j487QTUPbEvEivyxyVSozwvOdKBfL5kv0D9Cn2STyjVjmguUoCp9n
VztmwbwpSZdOnexRSolwAWuyOriYbvpV12cIZpcMGrjL67yZPv8UyCxxJplDCLlB
1c8tvGI2Md8apE/YZDqlCFh3H4YBQsact8uOoyY8cXKO/xIAsZOI+Dhm/cQAhGDk
QIQqv/hkM4HPvOXQluwIau4Cx+Fl05xY/ggtQt4z/8yml2pOw8PKmwziZA==
=60QX
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Bugfixes, mostly for ARM and AMD, and more documentation.
Slightly bigger than usual because I couldn't send out what was
pending for rc4, but there is nothing worrisome going on. I have more
fixes pending for guest debugging support (gdbstub) but I will send
them next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
KVM: X86: Declare KVM_CAP_SET_GUEST_DEBUG properly
KVM: selftests: Fix build for evmcs.h
kvm: x86: Use KVM CPU capabilities to determine CR4 reserved bits
KVM: VMX: Explicitly clear RFLAGS.CF and RFLAGS.ZF in VM-Exit RSB path
docs/virt/kvm: Document configuring and running nested guests
KVM: s390: Remove false WARN_ON_ONCE for the PQAP instruction
kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts
KVM: x86: Fixes posted interrupt check for IRQs delivery modes
KVM: SVM: fill in kvm_run->debug.arch.dr[67]
KVM: nVMX: Replace a BUG_ON(1) with BUG() to squash clang warning
KVM: arm64: Fix 32bit PC wrap-around
KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
KVM: arm64: Save/restore sp_el0 as part of __guest_enter
KVM: arm64: Delete duplicated label in invalid_vector
KVM: arm64: vgic-its: Fix memory leak on the error path of vgic_add_lpi()
KVM: arm64: vgic-v3: Retire all pending LPIs on vcpu destroy
KVM: arm: vgic-v2: Only use the virtual state when userspace accesses pending bits
KVM: arm: vgic: Only use the virtual state when userspace accesses enable bits
KVM: arm: vgic: Synchronize the whole guest on GIC{D,R}_I{S,C}ACTIVER read
KVM: arm64: PSCI: Forbid 64bit functions for 32bit guests
...
led_classdev_unregister() already has the very same check, so,
drop a duplicate in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
led_classdev_unregister() already has the very same check, so,
drop a duplicate in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
led_classdev_unregister() already has the very same check, so,
drop a duplicate in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
do_splice() is used by io_uring, as will be do_tee(). Move f_mode
checks from sys_{splice,tee}() to do_{splice,tee}(), so they're
enforced for io_uring as well.
Fixes: 7d67af2c01 ("io_uring: add splice(2) support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit
21b5ee59ef ("x86/cpu/amd: Enable the fixed Instructions Retired
counter IRPERF")
mistakenly added erratum #1054 as an OS Visible Workaround (OSVW) ID 0.
Erratum #1054 is not OSVW ID 0 [1], so make it a legacy erratum.
There would never have been a false positive on older hardware that
has OSVW bit 0 set, since the IRPERF feature was not available.
However, save a couple of RDMSR executions per thread, on modern
system configurations that correctly set non-zero values in their
OSVW_ID_Length MSRs.
[1] Revision Guide for AMD Family 17h Models 00h-0Fh Processors. The
revision guide is available from the bugzilla link below.
Fixes: 21b5ee59ef ("x86/cpu/amd: Enable the fixed Instructions Retired counter IRPERF")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200417143356.26054-1-kim.phillips@amd.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
When CONFIG_ARM_PSCI_FW is disabled but CONFIG_HAVE_ARM_SMCCC is enabled,
arm-scmi runs into a link failure:
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/smc.o: in function `smc_send_message':
smc.c:(.text+0x200): undefined reference to `arm_smccc_1_1_get_conduit'
Change from HAVE_ARM_SMCCC to ARM_PSCI_FW config dependency for now.
We rely on PSCI bindings anyways for the conduit and this should be
fine.
Link: https://lore.kernel.org/r/20200507144905.11397-1-sudeep.holla@arm.com
Fixes: 1dc6558062 ("firmware: arm_scmi: Add smc/hvc transport")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
iget_flags is unused in xfs_imap_to_bp(). Remove the parameter and
fix up the callers.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Both types control shutdown messaging and neither is used in the
current codebase.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Introduce an error tag to randomly fail async buffer writes. This is
primarily to facilitate testing of the XFS error configuration
mechanism.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The stale parameter was used to control the now unused shutdown
parameter of xfs_trans_ail_remove().
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Now that the functions and callers of
xfs_trans_ail_[remove|delete]() have been fixed up appropriately,
the only difference between the two is the shutdown behavior. There
are only a few callers of the _remove() variant, so make the
shutdown conditional on the parameter and combine the two functions.
Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The shutdown parameter of xfs_trans_ail_remove() is no longer used.
The remaining callers use it for items that legitimately might not
be in the AIL or from contexts where AIL state has already been
checked. Remove the unnecessary parameter and fix up the callers.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Various intent log items call xfs_trans_ail_remove() with a log I/O
error shutdown type, but this helper historically checks whether an
item is in the AIL before calling xfs_trans_ail_delete(). This means
the shutdown check is essentially a no-op for users of
xfs_trans_ail_remove().
It is possible that some items might not be AIL resident when the
AIL remove attempt occurs, but this should be isolated to cases
where the filesystem has already shutdown. For example, this
includes abort of the transaction committing the intent and I/O
error of the iclog buffer committing the intent to the log.
Therefore, update these callsites to use xfs_trans_ail_delete() to
provide AIL state validation for the common path of items being
released and removed when associated done items commit to the
physical log.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Several callers acquire the lock just prior to the call. Callers
that require ->ail_lock for other purposes already check IN_AIL
state and thus don't require the additional shutdown check in the
helper. Push the lock down into xfs_trans_ail_delete(), open code
the instances that still acquire it, and remove the unnecessary ailp
parameter.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The dquot flush handler effectively aborts the dquot flush if the
filesystem is already shut down, but doesn't actually shut down if
the flush fails. Update xfs_qm_dqflush() to consistently abort the
dquot flush and shutdown the fs if the flush fails with an
unexpected error.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The pre-flush dquot verification in xfs_qm_dqflush() duplicates the
read verifier by checking the dquot in the on-disk buffer. Instead,
verify the in-core variant before it is flushed to the buffer.
Fixes: 7224fa482a ("xfs: add full xfs_dqblk verifier")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
At unmount time, XFS emits an alert for every in-core buffer that
might have undergone a write error. In practice this behavior is
probably reasonable given that the filesystem is likely short lived
once I/O errors begin to occur consistently. Under certain test or
otherwise expected error conditions, this can spam the logs and slow
down the unmount.
Now that we have a ratelimit mechanism specifically for buffer
alerts, reuse it for the per-buffer alerts in xfs_wait_buftarg().
Also lift the final repair message out of the loop so it always
prints and assert that the metadata error handling code has shut
down the fs.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
XFS has some inconsistent log message rate limiting with respect to
buffer alerts. The metadata I/O error notification uses the generic
ratelimited alert, the buffer push code uses a custom rate limit and
the similar quiesce time failure checks are not rate limited at all
(when they should be).
The custom rate limit defined in the buf item code is specifically
crafted for buffer alerts. It is more aggressive than generic rate
limiting code because it must accommodate a high frequency of I/O
error events in a relative short timeframe.
Factor out the custom rate limit state from the buf item code into a
per-buftarg rate limit so various alerts are limited based on the
target. Define a buffer alert helper function and use it for the
buffer alerts that are already ratelimited.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The buffer write failure flag is intended to control the internal
write retry that XFS has historically implemented to help mitigate
the severity of transient I/O errors. The flag is set when a buffer
is resubmitted from the I/O completion path due to a previous
failure. It is checked on subsequent I/O completions to skip the
internal retry and fall through to the higher level configurable
error handling mechanism. The flag is cleared in the synchronous and
delwri submission paths and also checked in various places to log
write failure messages.
There are a couple minor problems with the current usage of this
flag. One is that we issue an internal retry after every submission
from xfsaild due to how delwri submission clears the flag. This
results in double the expected or configured number of write
attempts when under sustained failures. Another more subtle issue is
that the flag is never cleared on successful I/O completion. This
can cause xfs_wait_buftarg() to suggest that dirty buffers are being
thrown away due to the existence of the flag, when the reality is
that the flag might still be set because the write succeeded on the
retry.
Clear the write failure flag on successful I/O completion to address
both of these problems. This means that the internal retry attempt
occurs once since the last time a buffer write failed and that
various other contexts only see the flag set when the immediately
previous write attempt has failed.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The shutdown check in xfs_iflush() duplicates checks down in the
buffer code. If the fs is shut down, xfs_trans_read_buf_map() always
returns an error and falls into the same error path. Remove the
unnecessary check along with the warning in xfs_imap_to_bp()
that generates excessive noise in the log if the fs is shut down.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The inode flush code has several layers of error handling between
the inode and cluster flushing code. If the inode flush fails before
acquiring the backing buffer, the inode flush is aborted. If the
cluster flush fails, the current inode flush is aborted and the
cluster buffer is failed to handle the initial inode and any others
that might have been attached before the error.
Since xfs_iflush() is the only caller of xfs_iflush_cluster(), the
error handling between the two can be condensed in the top-level
function. If we update xfs_iflush_int() to always fall through to
the log item update and attach the item completion handler to the
buffer, any errors that occur after the first call to
xfs_iflush_int() can be handled with a buffer I/O failure.
Lift the error handling from xfs_iflush_cluster() into xfs_iflush()
and consolidate with the existing error handling. This also replaces
the need to release the buffer because failing the buffer with
XBF_ASYNC drops the current reference.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
We use the same buffer I/O failure code in a few different places.
It's not much code, but it's not necessarily self-explanatory.
Factor it into a helper and document it in one place.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Flush locked log items whose underlying buffers fail metadata
writeback are tagged with a special flag to indicate that the flush
lock is already held. This is currently implemented in the type
specific ->iop_push() callback, but the processing required for such
items is not type specific because we're only doing basic state
management on the underlying buffer.
Factor the failed log item handling out of the inode and dquot
->iop_push() callbacks and open code the buffer resubmit helper into
a single helper called from xfsaild_push_item(). This provides a
generic mechanism for handling failed metadata buffer writeback with
a bit less code.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Kristen found a hang in objtool when building with -ffunction-sections.
It was caused by evergreen_pcie_gen2_enable.cold() being laid out
immediately before evergreen_pcie_gen2_enable(). Since their "pfunc" is
always the same, find_jump_table() got into an infinite loop because it
didn't recognize the boundary between the two functions.
Fix that with a new prev_insn_same_sym() helper, which doesn't cross
subfunction boundaries.
Reported-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/378b51c9d9c894dc3294bc460b4b0869e950b7c5.1588110291.git.jpoimboe@redhat.com
The DIOREAD_NOLOCK flag has been cleared when doing the test_opt
that is meaningless, so remove the unnecessary test_opt for DIOREAD_NOLOCK.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Link: https://lore.kernel.org/r/1586751862-19437-1-git-send-email-kaixuxia@tencent.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
it doesn't actually exist...
Test: builds and 'git grep tcp_default_init_rwnd' comes up empty
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we fill up a receive VQ, try_fill_recv currently tries to count
kicks using a 64 bit stats counter. Turns out, on a 32 bit kernel that
uses a seqcount. sequence counts are "lock" constructs where you need to
make sure that writers are serialized.
In turn, this means that we mustn't run two try_fill_recv concurrently.
Which of course we don't. We do run try_fill_recv sometimes from a
softirq napi context, and sometimes from a fully preemptible context,
but the later always runs with napi disabled.
However, when it comes to the seqcount, lockdep is trying to enforce the
rule that the same lock isn't accessed from preemptible and softirq
context - it doesn't know about napi being enabled/disabled. This causes
a false-positive warning:
WARNING: inconsistent lock state
...
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
As a work around, shut down the warning by switching
to u64_stats_update_begin_irqsave - that works by disabling
interrupts on 32 bit only, is a NOP on 64 bit.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bdi_dev_name is not a fast path function, move it out of line. This
prepares for using it from modular callers without having to export
an implementation detail like bdi_unknown_name.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Simplify the bdi name to mirror what we are doing elsewhere, and
drop them name in favor of just using a number. This avoids a
potentially very long bdi name.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The '==' expression itself is bool, no need to convert it to bool again.
This fixes the following coccicheck warning:
arch/x86/net/bpf_jit_comp32.c:1478:50-55: WARNING: conversion to bool not needed here
arch/x86/net/bpf_jit_comp32.c:1479:50-55: WARNING: conversion to bool not needed here
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200506140352.37154-1-yanaijie@huawei.com
Fix the following coccicheck warning:
include/linux/kgdb.h:301:54-55: WARNING: return of 0/1 in function
'kgdb_nmi_poll_knock' with return type bool
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200507110649.37426-1-yanaijie@huawei.com
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Kernel doc does not understand POD variables to be referred to.
.../debug_core.c:73: warning: cannot understand function prototype:
'int kgdb_connected; '
Convert kernel doc to pure comment.
Fixes: dc7d552705 ("kgdb: core")
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Currently there is a small window where a badly timed migration could
cause in_dbg_master() to spuriously return true. Specifically if we
migrate to a new core after reading the processor id and the previous
core takes a breakpoint then we will evaluate true if we read
kgdb_active before we get the IPI to bring us to halt.
Fix this by checking irqs_disabled() first. Interrupts are always
disabled when we are executing the kgdb trap so this is an acceptable
prerequisite. This also allows us to replace raw_smp_processor_id()
with smp_processor_id() since the short circuit logic will prevent
warnings from PREEMPT_DEBUG.
Fixes: dcc7871128 ("kgdb: core changes to support kdb")
Suggested-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200506164223.2875760-1-daniel.thompson@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
TPAUSE instructs the processor to enter an implementation-dependent
optimized state. The instruction execution wakes up when the time-stamp
counter reaches or exceeds the implicit EDX:EAX 64-bit input value.
The instruction execution also wakes up due to the expiration of
the operating system time-limit or by an external interrupt
or exceptions such as a debug exception or a machine check exception.
TPAUSE offers a choice of two lower power states:
1. Light-weight power/performance optimized state C0.1
2. Improved power/performance optimized state C0.2
This way, it can save power with low wake-up latency in comparison to
spinloop based delay. The selection between the two is governed by the
input register.
TPAUSE is available on processors with X86_FEATURE_WAITPKG.
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1587757076-30337-4-git-send-email-kyung.min.park@intel.com
Refactor code to make it easier to add a new model specific function to
delay for a number of cycles.
No functional change.
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1587757076-30337-3-git-send-email-kyung.min.park@intel.com
The naming conventions in the delay code are confusing at best.
All delay variants use a loops argument and or variable which originates
from the original delay_loop() implementation. But all variants except
delay_loop() are based on TSC cycles.
Rename the argument to cycles and make it type u64 to avoid these weird
expansions to u64 in the functions.
Rename MWAITX_MAX_LOOPS to MWAITX_MAX_WAIT_CYCLES for the same reason
and fixup the comment of delay_mwaitx() as well.
Mark the delay_fn function pointer __ro_after_init and fixup the comment
for it.
No functional change and preparation for the upcoming TPAUSE based delay
variant.
[ Kyung Min Park: Added __init to use_tsc_delay() ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1587757076-30337-2-git-send-email-kyung.min.park@intel.com
LLVM's unwinder depends on the .eh_frame_hdr being present for
unwinding. However, when compiling Linux with GCC, the section
is not present in the vdso library object and when compiling
with Clang, it is present, but it has zero length.
With GCC the problem was not spotted because libgcc unwinder does
not require the .eh_frame_hdr section to be present.
Add --eh-frame-hdr to ldflags to correctly generate and populate
the section for both GCC and LLVM.
Fixes: 28b1a824a4 ("arm64: vdso: Substitute gettimeofday() with C implementation")
Reported-by: Tamas Zsoldos <tamas.zsoldos@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Tamas Zsoldos <tamas.zsoldos@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200507104049.47834-1-vincenzo.frascino@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
No users anywhere in the kernel tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Not-acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Russ Anderson <rja@hpe.com>
Link: https://lkml.kernel.org/r/20200504171527.2845224-12-hch@lst.de
Neither this functions nor the helpers used to implement it are used
anywhere in the kernel tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Not-acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Russ Anderson <rja@hpe.com>
Link: https://lkml.kernel.org/r/20200504171527.2845224-10-hch@lst.de
Merge two helpers only used by uv_send_IPI_one() into the main function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Not-acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Russ Anderson <rja@hpe.com>
Link: https://lkml.kernel.org/r/20200504171527.2845224-9-hch@lst.de
