Currently, "NMI executing" is one the first time an outermost
NMI hits repeat_nmi and zero thereafter. Change it to be zero
each time for consistency.
This is intended to help NMI handling fail harder if it's buggy.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have a tricky bug in the nested NMI code: if we see RSP
pointing to the NMI stack on NMI entry from kernel mode, we
assume that we are executing a nested NMI.
This isn't quite true. A malicious userspace program can point
RSP at the NMI stack, issue SYSCALL, and arrange for an NMI to
happen while RSP is still pointing at the NMI stack.
Fix it with a sneaky trick. Set DF in the region of code that
the RSP check is intended to detect. IRET will clear DF
atomically.
( Note: other than paravirt, there's little need for all this
complexity. We could check RIP instead of RSP. )
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Check the repeat_nmi .. end_repeat_nmi special case first. The
next patch will rework the RSP check and, as a side effect, the
RSP check will no longer detect repeat_nmi .. end_repeat_nmi, so
we'll need this ordering of the checks.
Note: this is more subtle than it appears. The check for
repeat_nmi .. end_repeat_nmi jumps straight out of the NMI code
instead of adjusting the "iret" frame to force a repeat. This
is necessary, because the code between repeat_nmi and
end_repeat_nmi sets "NMI executing" and then writes to the
"iret" frame itself. If a nested NMI comes in and modifies the
"iret" frame while repeat_nmi is also modifying it, we'll end up
with garbage. The old code got this right, as does the new
code, but the new code is a bit more explicit.
If we were to move the check right after the "NMI executing"
check, then we'd get it wrong and have random crashes.
( Because the "NMI executing" check would jump to the code that would
modify the "iret" frame without checking if the interrupted NMI was
currently modifying it. )
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Returning to userspace is tricky: IRET can fail, and ESPFIX can
rearrange the stack prior to IRET.
The NMI nesting fixup relies on a precise stack layout and
atomic IRET. Rather than trying to teach the NMI nesting fixup
to handle ESPFIX and failed IRET, punt: run NMIs that came from
user mode on the normal kernel stack.
This will make some nested NMIs visible to C code, but the C
code is okay with that.
As a side effect, this should speed up perf: it eliminates an
RDMSR when NMIs come from user mode.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull power management and ACPI fixes from Rafael Wysocki:
"These fix two bugs in the cpufreq core (including one recent
regression), fix a 4.0 PCI regression related to the ACPI resources
management and quieten an RCU-related lockdep complaint about a
tracepoint in the suspend-to-idle code.
Specifics:
- Fix a recently introduced issue in the cpufreq policy object
reinitialization that leads to CPU offline/online breakage (Viresh
Kumar)
- Make it possible to access frequency tables of offline CPUs which
is needed by thermal management code among other things (Viresh
Kumar)
- Fix an ACPI resource management regression introduced during the
4.0 cycle that may cause incorrect resource validation results to
appear in 32-bit x86 kernels due to silent truncation of 64-bit
values to 32-bit (Jiang Liu)
- Fix up an RCU-related lockdep complaint about suspicious RCU usage
in idle caused by using a suspend tracepoint in the core suspend-
to-idle code (Rafael J Wysocki)"
* tag 'pm+acpi-4.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / PCI: Fix regressions caused by resource_size_t overflow with 32-bit kernel
cpufreq: Allow freq_table to be obtained for offline CPUs
cpufreq: Initialize the governor again while restoring policy
suspend-to-idle: Prevent RCU from complaining about tick_freeze()
Pull x86 platform driver fixes from Darren Hart:
"Fix SMBIOS call handling and hwswitch state coherency in the
dell-laptop driver. Cleanups for intel_*_ipc drivers. Details:
dell-laptop:
- Do not cache hwswitch state
- Check return value of each SMBIOS call
- Clear buffer before each SMBIOS call
intel_scu_ipc:
- Move local memory initialization out of a mutex
intel_pmc_ipc:
- Update kerneldoc formatting
- Fix compiler casting warnings"
* tag 'platform-drivers-x86-v4.2-3' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
intel_scu_ipc: move local memory initialization out of a mutex
intel_pmc_ipc: Update kerneldoc formatting
dell-laptop: Do not cache hwswitch state
dell-laptop: Check return value of each SMBIOS call
dell-laptop: Clear buffer before each SMBIOS call
intel_pmc_ipc: Fix compiler casting warnings
Pull m68knommu/coldfire fixes from Greg Ungerer:
"Contains build fixes and updates for the ColdFire defconfigs.
Specifically there is a couple of fixes that address problems building
allnoconfig. Also fix for enabling PCI bus on the M54xx family of
ColdFire"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68k: enable PCI support for m5475evb defconfig
m68k: fix io functions for ColdFire/MMU/PCI case
m68knommu: update defconfig for ColdFire m5475evb
m68knommu: update defconfig for ColdFire m5407c3
m68knommu: update defconfig for ColdFire m5307c3
m68knommu: update defconfig for ColdFire m5275evb
m68knommu: update defconfig for ColdFire m5272c3
m68knommu: update defconfig for ColdFire m5249evb
m68knommu: update defconfig for m5208evb
m68knommu: make ColdFire SoC selection a choice
m68knommu: improve the clock configuration defaults
m68knommu: force setting of CONFIG_CLOCK_FREQ for ColdFire
Pull block fixes from Jens Axboe:
"A collection of fixes from the last few weeks that should go into the
current series. This contains:
- Various fixes for the per-blkcg policy data, fixing regressions
since 4.1. From Arianna and Tejun
- Code cleanup for bcache closure macros from me. Really just
flushing this out, it's been sitting in another branch for months
- FIELD_SIZEOF cleanup from Maninder Singh
- bio integrity oops fix from Mike
- Timeout regression fix for blk-mq from Ming Lei"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: set default timeout as 30 seconds
NVMe: Reread partitions on metadata formats
bcache: don't embed 'return' statements in closure macros
blkcg: fix blkcg_policy_data allocation bug
blkcg: implement all_blkcgs list
blkcg: blkcg_css_alloc() should grab blkcg_pol_mutex while iterating blkcg_policy[]
blkcg: allow blkcg_pol_mutex to be grabbed from cgroup [file] methods
block/blk-cgroup.c: free per-blkcg data when freeing the blkcg
block: use FIELD_SIZEOF to calculate size of a field
bio integrity: do not assume bio_integrity_pool exists if bioset exists
Pull jfs fixes from David Kleikamp:
"A couple trivial fixes and an error path fix"
* tag 'jfs-4.2' of git://github.com/kleikamp/linux-shaggy:
jfs: clean up jfs_rename and fix out of order unlock
jfs: fix indentation on if statement
jfs: removed a prohibited space after opening parenthesis
* pm-cpuidle:
suspend-to-idle: Prevent RCU from complaining about tick_freeze()
* pm-cpufreq:
cpufreq: Allow freq_table to be obtained for offline CPUs
cpufreq: Initialize the governor again while restoring policy
* acpi-resources:
ACPI / PCI: Fix regressions caused by resource_size_t overflow with 32-bit kernel
It is reasonable to set default timeout of request as 30 seconds instead of
30000 ticks, which may be 300 seconds if HZ is 100, for example, some arm64
based systems may choose 100 HZ.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Fixes: c76cbbcf40 ("blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue()"
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull TPM bugfixes from James Morris.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
tpm, tpm_crb: fail when TPM2 ACPI table contents look corrupted
tpm: Fix initialization of the cdev
Pull rdma fixes from Doug Ledford:
"Mainly fix-ups for the various 4.2 items"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (24 commits)
IB/core: Destroy ocrdma_dev_id IDR on module exit
IB/core: Destroy multcast_idr on module exit
IB/mlx4: Optimize do_slave_init
IB/mlx4: Fix memory leak in do_slave_init
IB/mlx4: Optimize freeing of items on error unwind
IB/mlx4: Fix use of flow-counters for process_mad
IB/ipath: Convert use of __constant_<foo> to <foo>
IB/ipoib: Set MTU to max allowed by mode when mode changes
IB/ipoib: Scatter-Gather support in connected mode
IB/ucm: Fix bitmap wrap when devnum > IB_UCM_MAX_DEVICES
IB/ipoib: Prevent lockdep warning in __ipoib_ib_dev_flush
IB/ucma: Fix lockdep warning in ucma_lock_files
rds: rds_ib_device.refcount overflow
RDMA/nes: Fix for incorrect recording of the MAC address
RDMA/nes: Fix for resolving the neigh
RDMA/core: Fixes for port mapper client registration
IB/IPoIB: Fix bad error flow in ipoib_add_port()
IB/mlx4: Do not attemp to report HCA clock offset on VFs
IB/cm: Do not queue work to a device that's going away
IB/srp: Avoid using uninitialized variable
...
This patch has the driver automatically reread partitions if a namespace
has a separate metadata format. Previously revalidating a disk was
sufficient to get the correct capacity set on such formatted drives,
but partitions that may exist would not have been surfaced.
Reported-by: Paul Grabinar <paul.grabinar@ranbarg.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Paul Grabinar <paul.grabinar@ranbarg.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull file locking updates from Jeff Layton:
"I had thought that I was going to get away without a pull request this
cycle. There was a NFSv4 file locking problem that cropped up that I
tried to fix in the NFSv4 code alone, but that fix has turned out to
be problematic. These patches fix this in the correct way.
Note that this touches some NFSv4 code as well. Ordinarily I'd wait
for Trond to ACK this, but he's on holiday right now and the bug is
rather nasty. So I suggest we merge this and if he raises issues with
it we can sort it out when he gets back"
Acked-by: Bruce Fields <bfields@fieldses.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
[ +1 to this series fixing a 100% reproducible slab corruption +
general protection fault in my nfs-root test environment. - Dan ]
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* tag 'locks-v4.2-1' of git://git.samba.org/jlayton/linux:
locks: inline posix_lock_file_wait and flock_lock_file_wait
nfs4: have do_vfs_lock take an inode pointer
locks: new helpers - flock_lock_inode_wait and posix_lock_inode_wait
locks: have flock_lock_file take an inode pointer instead of a filp
Revert "nfs: take extra reference to fl->fl_file when running a LOCKU operation"
Pull ARC fixes from Vineet Gupta:
- Makefile changes (top-level+ARC) reinstates -O3 builds (regression
since 3.16)
- IDU intc related fixes, IRQ affinity
- patch to make bitops safer for ARC
- perf fix from Alexey to remove signed PC braino
- Futex backend gets llock/scond support
* tag 'arc-v4.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARCv2: support HS38 releases
ARC: make sure instruction_pointer() returns unsigned value
ARC: slightly refactor macros for boot logging
ARC: Add llock/scond to futex backend
arc:irqchip: prepare for drivers/irqchip/irqchip.h removal
ARC: Make ARC bitops "safer" (add anti-optimization)
ARCv2: [axs103] bump CPU frequency from 75 to 90 MHZ
ARCv2: intc: IDU: Fix potential race in installing a chained IRQ handler
ARCv2: intc: IDU: support irq affinity
ARC: fix unused var wanring
ARC: Don't memzero twice in dma_alloc_coherent for __GFP_ZERO
ARC: Override toplevel default -O2 with -O3
kbuild: Allow arch Makefiles to override {cpp,ld,c}flags
ARCv2: guard SLC DMA ops with spinlock
ARC: Kconfig: better way to disable ARC_HAS_LLSC for ARC_CPU_750D
Pull s390 fixes from Martin Schwidefsky:
"One improvement for the zcrypt driver, the quality attribute for the
hwrng device has been missing. Without it the kernel entropy seeding
will not happen automatically.
And six bug fixes, the most important one is the fix for the vector
register corruption due to machine checks"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/nmi: fix vector register corruption
s390/process: fix sfpc inline assembly
s390/dasd: fix kernel panic when alias is set offline
s390/sclp: clear upper register halves in _sclp_print_early
s390/oprofile: fix compile error
s390/sclp: fix compile error
s390/zcrypt: enable s390 hwrng to seed kernel entropy
The end of jfs_rename(), which is also used by the error paths,
included a call to IWRITE_UNLOCK(new_ip) after labels out1, out2
and out3. If we come in through these labels, IWRITE_LOCK() has not
been called yet.
In moving that call to the correct spot, I also moved some
exceptional truncate code earlier as well, since the early error
paths don't need to deal with it, and I renamed out4: to out_tx: so
a future patch by Jan Kara doesn't need to deal with renumbering or
confusing out-of-order labels.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Pull final init.h/module.h code relocation from Paul Gortmaker:
"With the release of 4.2-rc2 done, we should not be seeing any new code
added that gets upset by this small code move, and we've banked yet
another complete week of testing with this move in place on top of
4.2-rc1 via linux-next to ensure that remained true.
Given that, I'd like to put it in now so that people formulating new
work for 4.3-rc1 will be exposed to the ever so slightly stricter (but
sensible) requirements wrt. whether they are needing init.h vs.
module.h macros, even if they are not using linux-next.
The diffstat of the move is slightly asymmetrical due to needing to
leave behind a couple #ifdef in the old location and add the same ones
to the new location, but other than that, it is a 1:1 move, complete
with the module_init/exit trailing semicolon that we can't fix. That
is, until/unless someone does a tree-wide sed fix of all the
approximately 800 currently in tree users relying on it"
* tag 'module-final-v4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
module: relocate module_init from init.h to module.h
Pull tracing fix from Steven Rostedt:
"Fengguang Wu discovered a crash that happened to be because of the
branch tracer (traces unlikely and likely branches) when enabled with
certain debug options.
What happened was that various debug options like lockdep and
DEBUG_PREEMPT can cause parts of the branch tracer to recurse outside
its recursion protection. In fact, part of its recursion protection
used these features that caused the lockup. This cleans up the code a
little and makes the recursion protection a bit more robust"
* tag 'trace-v4.2-rc1-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Have branch tracer use recursive field of task struct
Andy Lutomirski
Linus Torvalds
Rafael J. Wysocki
Ming Lei
Keith Busch
Dave Kleikamp