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atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)
Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.
The variable nlm_lockowner.count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
**Important note for maintainers:
Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts.
The full comparison can be seen in
https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon
in state to be merged to the documentation tree.
Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.
For the nlm_lockowner.count it might make a difference
in following places:
- nlm_put_lockowner(): decrement in refcount_dec_and_lock() only
provides RELEASE ordering, control dependency on success and
holds a spin lock on success vs. fully ordered atomic counterpart.
No changes in spin lock guarantees.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)
Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.
The variable nsm_handle.sm_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
**Important note for maintainers:
Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts.
The full comparison can be seen in
https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon
in state to be merged to the documentation tree.
Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.
For the nsm_handle.sm_count it might make a difference
in following places:
- nsm_release(): decrement in refcount_dec_and_lock() only
provides RELEASE ordering, control dependency on success
and holds a spin lock on success vs. fully ordered atomic
counterpart. No change for the spin lock guarantees.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)
Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.
The variable nlm_host.h_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
**Important note for maintainers:
Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts.
The full comparison can be seen in
https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon
in state to be merged to the documentation tree.
Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.
For the nlm_host.h_count it might make a difference
in following places:
- nlmsvc_release_host(): decrement in refcount_dec()
provides RELEASE ordering, while original atomic_dec()
was fully unordered. Since the change is for better, it
should not matter.
- nlmclnt_release_host(): decrement in refcount_dec_and_test() only
provides RELEASE ordering and control dependency on success
vs. fully ordered atomic counterpart. It doesn't seem to
matter in this case since object freeing happens under mutex
lock anyway.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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Currently when falling back to doing I/O through the MDS (via
pnfs_{read|write}_through_mds), the client frees the nfs_pgio_header
without releasing the reference taken on the dreq
via pnfs_generic_pg_{read|write}pages -> nfs_pgheader_init ->
nfs_direct_pgio_init. It then takes another reference on the dreq via
nfs_generic_pg_pgios -> nfs_pgheader_init -> nfs_direct_pgio_init and
as a result the requester will become stuck in inode_dio_wait. Once
that happens, other processes accessing the inode will become stuck as
well.
Ensure that pnfs_read_through_mds() and pnfs_write_through_mds() clean
up correctly by calling hdr->completion_ops->completion() instead of
calling hdr->release() directly.
This can be reproduced (sometimes) by performing "storage failover
takeover" commands on NetApp filer while doing direct I/O from a client.
This can also be reproduced using SystemTap to simulate a failure while
doing direct I/O from a client (from Dave Wysochanski
<dwysocha@redhat.com>):
stap -v -g -e 'probe module("nfs_layout_nfsv41_files").function("nfs4_fl_prepare_ds").return { $return=NULL; exit(); }'
Suggested-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Fixes: 1ca018d28d ("pNFS: Fix a memory leak when attempted pnfs fails")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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PNFS block/SCSI layouts should gracefully handle cases where block devices
are not available when a layout is retrieved, or the block devices are
removed while the client holds a layout.
While setting up a layout segment, keep a record of an unavailable or
un-parsable block device in cache with a flag so that subsequent layouts do
not spam the server with GETDEVINFO. We can reuse the current
NFS_DEVICEID_UNAVAILABLE handling with one variation: instead of reusing
the device, we will discard it and send a fresh GETDEVINFO after the
timeout, since the lookup and validation of the device occurs within the
GETDEVINFO response handling.
A lookup of a layout segment that references an unavailable device will
return a segment with the NFS_LSEG_UNAVAILABLE flag set. This will allow
the pgio layer to mark the layout with the appropriate fail bit, which
forces subsequent IO to the MDS, and prevents spamming the server with
LAYOUTGET, LAYOUTRETURN.
Finally, when IO to a block device fails, look up the block device(s)
referenced by the pgio header, and mark them as unavailable.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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If there's an error doing I/O to block device, and the client resends the
I/O to the MDS, the MDS must recall the layout from the client before
processing the I/O. Let's preempt that exchange by returning the layout
before falling back to the MDS when there's an error.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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The blocklayout module contains the client support for both block and SCSI
layouts. Add a module alias for the SCSI layout type so that the module
will be loaded for SCSI layouts.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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nfs_pgio_rpcsetup() is always called with an offset of 0, so we should be
able to drop the arguement altogether.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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There are 2 comments in the NFSv4 code which suggest that
SIGLOST should possibly be sent to a process. In these
cases a lock has been lost.
The current practice is to set NFS_LOCK_LOST so that
read/write returns EIO when a lock is lost.
So change these comments to code when sets NFS_LOCK_LOST.
One case is when lock recovery after apparent server restart
fails with NFS4ERR_DENIED, NFS4ERR_RECLAIM_BAD, or
NFS4ERRO_RECLAIM_CONFLICT. The other case is when a lock
attempt as part of lease recovery fails with NFS4ERR_DENIED.
In an ideal world, these should not happen. However I have
a packet trace showing an NFSv4.1 session getting
NFS4ERR_BADSESSION after an extended network parition. The
NFSv4.1 client treats this like server reboot until/unless
it get NFS4ERR_NO_GRACE, in which case it switches over to
"nograce" recovery mode. In this network trace, the client
attempts to recover a lock and the server (incorrectly)
reports NFS4ERR_DENIED rather than NFS4ERR_NO_GRACE. This
leads to the ineffective comment and the client then
continues to write using the OPEN stateid.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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This code can never be used as the IS_AUTOMOUNT(inode)
case has already been handled.
So remove it to avoid confusion.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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Support the query flags AT_STATX_FORCE_SYNC by forcing an attribute
revalidation, and AT_STATX_DONT_SYNC by returning cached attributes
only.
Use the mask to optimise away server revalidation for attributes
that are not being requested by the user.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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The LOOKUPP operation was inserted into the nfs4_procedures array
rather than being appended, which put /proc/net/rpc/nfs out of
whack, and broke the nfsstat utility.
Fix by moving the LOOKUPP operation to the end of the array, and
by ensuring that it keeps the same length whether or not NFSV4.1
and NFSv4.2 are compiled in.
Fixes: 5b5faaf6df734 ("nfs4: add NFSv4 LOOKUPP handlers")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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Convert CLOSE so that it specifies the correct stateid and
inode for the error handling.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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Convert CLOSE so that it specifies the correct stateid, state and
inode for the error handling.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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The commit list can get very large, and so we need a cond_resched()
in nfs_commit_release_pages() in order to ensure we don't hog the CPU
for excessive periods of time.
Reported-by: Mike Galbraith <efault@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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One of the limitations of pm_runtime_force_suspend/resume() is that
if a parent driver wants to use these functions, all of its child
drivers generally have to do that too because of the parent usage
counter manipulations necessary to get the correct state of the parent
during system-wide transitions to the working state (system resume).
However, that limitation turns out to be artificial, so remove it.
Namely, pm_runtime_force_suspend() only needs to update the children
counter of its parent (if there's is a parent) when the device can
stay in suspend after the subsequent system resume transition, as
that counter is correct already otherwise. Now, if the parent's
children counter is not updated, it is not necessary to increment
the parent's usage counter in that case any more, as long as the
children counters of devices are checked along with their usage
counters in order to decide whether or not the devices may be left
in suspend after the subsequent system resume transition.
Accordingly, modify pm_runtime_force_suspend() to only call
pm_runtime_set_suspended() for devices whose usage and children
counters are at the "no references" level (the runtime PM status
of the device needs to be updated to "suspended" anyway in case
this function is called once again for the same device during the
transition under way), drop the parent usage counter incrementation
from it and update pm_runtime_force_resume() to compensate for these
changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
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There are problems with calling pm_runtime_force_suspend/resume()
to "stop" and "start" devices in genpd_finish_suspend() and
genpd_resume_noirq() (and in analogous hibernation-specific genpd
callbacks) after commit 122a22377a3d (PM / Domains: Stop/start
devices during system PM suspend/resume in genpd) as those routines
do much more than just "stopping" and "starting" devices (which was
the stated purpose of that commit) unnecessarily and may not play
well with system-wide PM driver callbacks.
First, consider the pm_runtime_force_suspend() in
genpd_finish_suspend(). If the current runtime PM status of the
device is "suspended", that function most likely does the right thing
by ignoring the device, because it should have been "stopped" already
and whatever needed to be done to deactivate it shoud have been done.
In turn, if the runtime PM status of the device is "active",
genpd_runtime_suspend() is called for it (indirectly) and (1) runs
the ->runtime_suspend callback provided by the device's driver
(assuming no bus type with ->runtime_suspend of its own), (2) "stops"
the device and (3) checks if the domain can be powered down, and then
(4) the device's runtime PM status is changed to "suspended". Out of
the four actions above (1) is not necessary and it may be outright
harmful, (3) is pointless and (4) is questionable. The only
operation that needs to be carried out here is (2).
The reason why (1) is not necessary is because the system-wide
PM callbacks provided by the device driver for the transition in
question have been run and they should have taken care of the
driver's part of device suspend already. Moreover, it may be
harmful, because the ->runtime_suspend callback may want to
access the device which is partially suspended at that point
and may not be responsive. Also, system-wide PM callbacks may
have been run already (in the previous phases of the system
transition under way) for the device's parent or for its supplier
devices (if any) and the device may not be accessible because of
that.
There also is no reason to do (3), because genpd_finish_suspend()
will repeat it anyway, and (4) potentially causes confusion to ensue
during the subsequent system transition to the working state.
Consider pm_runtime_force_resume() in genpd_resume_noirq() now.
It runs genpd_runtime_resume() for all devices with runtime PM
status set to "suspended", which includes all of the devices
whose runtime PM status was changed by pm_runtime_force_suspend()
before and may include some devices already suspended when the
pm_runtime_force_suspend() was running, which may be confusing. The
genpd_runtime_resume() first tries to power up the domain, which
(again) is pointless, because genpd_resume_noirq() has done that
already. Then, it "starts" the device and runs the ->runtime_resume
callback (from the driver, say) for it. If all is well, the device
is left with the runtime PM status set to "active".
Unfortunately, running the driver's ->runtime_resume callback
before its system-wide PM callbacks and possibly before some
system-wide PM callbacks of the parent device's driver (let
alone supplier drivers) is asking for trouble, especially if
the device had been suspended before pm_runtime_force_suspend()
ran previously or if the callbacks in question expect to be run
back-to-back with their suspend-side counterparts. It also should
not be necessary, because the system-wide PM driver callbacks that
will be invoked for the device subsequently should take care of
resuming it just fine.
[Running the driver's ->runtime_resume callback in the "noirq"
phase of the transition to the working state may be problematic
even for devices whose drivers do use pm_runtime_force_resume()
in (or as) their system-wide PM callbacks if they have suppliers
other than their parents, because it may cause the supplier to
be resumed after the consumer in some cases.]
Because of the above, modify genpd as follows:
1. Change genpd_finish_suspend() to only "stop" devices with
runtime PM status set to "active" (without invoking runtime PM
callbacks for them, changing their runtime PM status and so on).
That doesn't change the handling of devices whose drivers use
pm_runtime_force_suspend/resume() in (or as) their system-wide
PM callbacks and addresses the issues described above for the
other devices.
2. Change genpd_resume_noirq() to only "start" devices with
runtime PM status set to "active" (without invoking runtime PM
callbacks for them, changing their runtime PM status and so on).
Again, that doesn't change the handling of devices whose drivers
use pm_runtime_force_suspend/resume() in (or as) their system-wide
PM callbacks and addresses the described issues for the other
devices. Devices with runtime PM status set to "suspended"
are not started with the assumption that they will be resumed
later, either by pm_runtime_force_resume() or via runtime PM.
3. Change genpd_restore_noirq() to follow genpd_resume_noirq().
That causes devices already suspended before hibernation to be
left alone (which also is the case without the change) and
avoids running the ->runtime_resume driver callback too early
for the other devices.
4. Change genpd_freeze_noirq() and genpd_thaw_noirq() in accordance
with the above modifications.
Fixes: 122a22377a3d (PM / Domains: Stop/start devices during system PM suspend/resume in genpd)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
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The PAUSE instruction is currently used in the retpoline and RSB filling
macros as a speculation trap. The use of PAUSE was originally suggested
because it showed a very, very small difference in the amount of
cycles/time used to execute the retpoline as compared to LFENCE. On AMD,
the PAUSE instruction is not a serializing instruction, so the pause/jmp
loop will use excess power as it is speculated over waiting for return
to mispredict to the correct target.
The RSB filling macro is applicable to AMD, and, if software is unable to
verify that LFENCE is serializing on AMD (possible when running under a
hypervisor), the generic retpoline support will be used and, so, is also
applicable to AMD. Keep the current usage of PAUSE for Intel, but add an
LFENCE instruction to the speculation trap for AMD.
The same sequence has been adopted by GCC for the GCC generated retpolines.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Kees Cook <keescook@google.com>
Link: https://lkml.kernel.org/r/20180113232730.31060.36287.stgit@tlendack-t1.amdoffice.net
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On context switch from a shallow call stack to a deeper one, as the CPU
does 'ret' up the deeper side it may encounter RSB entries (predictions for
where the 'ret' goes to) which were populated in userspace.
This is problematic if neither SMEP nor KPTI (the latter of which marks
userspace pages as NX for the kernel) are active, as malicious code in
userspace may then be executed speculatively.
Overwrite the CPU's return prediction stack with calls which are predicted
to return to an infinite loop, to "capture" speculation if this
happens. This is required both for retpoline, and also in conjunction with
IBRS for !SMEP && !KPTI.
On Skylake+ the problem is slightly different, and an *underflow* of the
RSB may cause errant branch predictions to occur. So there it's not so much
overwrite, as *filling* the RSB to attempt to prevent it getting
empty. This is only a partial solution for Skylake+ since there are many
other conditions which may result in the RSB becoming empty. The full
solution on Skylake+ is to use IBRS, which will prevent the problem even
when the RSB becomes empty. With IBRS, the RSB-stuffing will not be
required on context switch.
[ tglx: Added missing vendor check and slighty massaged comments and
changelog ]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515779365-9032-1-git-send-email-dwmw@amazon.co.uk
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Currently KASAN doesn't panic in case it don't have enough memory
to boot. Instead, it crashes in some random place:
kernel BUG at arch/x86/mm/physaddr.c:27!
RIP: 0010:__phys_addr+0x268/0x276
Call Trace:
kasan_populate_shadow+0x3f2/0x497
kasan_init+0x12e/0x2b2
setup_arch+0x2825/0x2a2c
start_kernel+0xc8/0x15f4
x86_64_start_reservations+0x2a/0x2c
x86_64_start_kernel+0x72/0x75
secondary_startup_64+0xa5/0xb0
Use memblock_virt_alloc_try_nid() for allocations without failure
fallback. It will panic with an out of memory message.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
Cc: Alexander Potapenko <glider@google.com>
Cc: lkp@01.org
Link: https://lkml.kernel.org/r/20180110153602.18919-1-aryabinin@virtuozzo.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixlet from Thomas Gleixner.
Remove a warning about lack of compiler support for retpoline that most
people can't do anything about, so it just annoys them needlessly.
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/retpoline: Remove compile time warning
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"One fix for an oops at boot if we take a hotplug interrupt before we
are ready to handle it.
The bulk is patches to implement mitigation for Meltdown, see the
change logs for more details.
Thanks to: Nicholas Piggin, Michael Neuling, Oliver O'Halloran, Jon
Masters, Jose Ricardo Ziviani, David Gibson"
* tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/powernv: Check device-tree for RFI flush settings
powerpc/pseries: Query hypervisor for RFI flush settings
powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti
powerpc/64s: Add support for RFI flush of L1-D cache
powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
powerpc/64s: Simple RFI macro conversions
powerpc/64: Add macros for annotating the destination of rfid/hrfid
powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper
powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ
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When the timer base is checked for expired timers then the deferrable base
must be checked as well. This was missed when making the deferrable base
independent of base::nohz_active.
Fixes: ced6d5c11d3e ("timers: Use deferrable base independent of base::nohz_active")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Cc: rt@linutronix.de
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due to some JITs doing if (src_reg == 0) check in 64-bit mode
for div/mod operations mask upper 32-bits of src register
before doing the check
Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT")
Fixes: 7a12b5031c6b ("sparc64: Add eBPF JIT.")
Reported-by: syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler
does not have retpoline support. Linus rationale for this is:
It's wrong because it will just make people turn off RETPOLINE, and the
asm updates - and return stack clearing - that are independent of the
compiler are likely the most important parts because they are likely the
ones easiest to target.
And it's annoying because most people won't be able to do anything about
it. The number of people building their own compiler? Very small. So if
their distro hasn't got a compiler yet (and pretty much nobody does), the
warning is just annoying crap.
It is already properly reported as part of the sysfs interface. The
compile-time warning only encourages bad things.
Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support")
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Link: https://lkml.kernel.org/r/CA+55aFzWgquv4i6Mab6bASqYXg3ErV3XDFEYf=GEcCDQg5uAtw@mail.gmail.com
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With this change, PCI devices can be detected and used inside a non-root
cell.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/e8d19494b96b68a749bcac514795d864ad9c28c3.1511770314.git.jan.kiszka@siemens.com
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The typical I/O interrupts in non-root cells are MSI-based. However, the
platform UARTs do not support MSI. In order to run a non-root cell that
shall use one of them, the standard IOAPIC must be registered and 1:1
routing for IRQ 3 and 4 set up.
If an IOAPIC is not available, the boot loader clears standard_ioapic in
the setup data, so registration is skipped. If the guest is not allowed to
to use one of those pins, Jailhouse will simply ignore the access.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/90d942dda9d48a8046e00bb3c1bb6757c83227be.1511770314.git.jan.kiszka@siemens.com
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Jailhouse provides no guest-initiated restart. So, do not even try to.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/ef8a0ef95c2b17c21066e5f28ea56b58bf7eaa82.1511770314.git.jan.kiszka@siemens.com
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Jailhouse support does not depend on ACPI, and does not even use it. But
if it should be enabled, avoid warning about its absence in the
platform.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/939687007cbd7643b02fd330e8616e7e5944063f.1511770314.git.jan.kiszka@siemens.com
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Non-root cells do not have CMOS access, thus the warm reset cannot be
enabled. There is no RTC, thus also no wall clock. Furthermore, there
are no ISA IRQs and no PIC.
Also disable probing of i8042 devices that are typically blocked for
non-root cells. In theory, access could also be granted to a non-root
cell, provided the root cell is not using the devices. But there is no
concrete scenario in sight, and disabling probing over Jailhouse allows
to build generic kernels that keep CONFIG_SERIO enabled for use in
normal systems.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/39b68cc2c496501c9d95e6f40e5d76e3053c3908.1511770314.git.jan.kiszka@siemens.com
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Get the precalibrated frequencies for the TSC and the APIC timer from
the Jailhouse platform info and set the kernel values accordingly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/b2557426332fc337a74d3141cb920f7dce9ad601.1511770314.git.jan.kiszka@siemens.com
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Jailhouse exposes the PMTIMER as only reference clock to all cells. Pick
up its address from the setup data. Allow to enable the Linux support of
it by relaxing its strict dependency on ACPI.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/6d5c3fadd801eb3fba9510e2d3db14a9c404a1a0.1511770314.git.jan.kiszka@siemens.com
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Register the APIC which Jailhouse always exposes at 0xfee00000 if in
xAPIC mode or via MSRs as x2APIC. The latter is only available if it was
already activated because there is no support for switching its mode
during runtime.
Jailhouse requires the APIC to be operated in phys-flat mode. Ensure
that this mode is selected by Linux.
The available CPUs are taken from the setup data structure that the
loader filled and registered with the kernel.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/8b2255da0a9856c530293a67aa9d6addfe102a2b.1511770314.git.jan.kiszka@siemens.com
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The Jailhouse hypervisor is able to statically partition a multicore
system into multiple so-called cells. Linux is used as boot loader and
continues to run in the root cell after Jailhouse is enabled. Linux can
also run in non-root cells.
Jailhouse does not emulate usual x86 devices. It also provides no
complex ACPI but basic platform information that the boot loader
forwards via setup data. This adds the infrastructure to detect when
running in a non-root cell so that the platform can be configured as
required in succeeding steps.
Support is limited to x86-64 so far, primarily because no boot loader
stub exists for i386 and, thus, we wouldn't be able to test the 32-bit
path.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/7f823d077b38b1a70c526b40b403f85688c137d3.1511770314.git.jan.kiszka@siemens.com
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MP_IRQDIR_* constants pointed in the right direction but remained unused so
far: It's cleaner to use symbolic values for the IRQ flags in the MP config
table. That also saves some comments.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/60809926663a1d38e2a5db47d020d6e2e7a70019.1511770314.git.jan.kiszka@siemens.com
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Allow to turn off the setup of BIOS-managed warm reset via a new flag in
x86_legacy_features. Besides the UV1, the upcoming jailhose guest support
needs this switched off.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/44376558129d70a2c1527959811371ef4b82e829.1511770314.git.jan.kiszka@siemens.com
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As the comment already stated, there is no need for setting up LDR (and
DFR) in physflat mode as it remains unused (see SDM, 10.6.2.1).
flat_init_apic_ldr only served as a placeholder for a nop operation so
far, causing no harm.
That will change when running over the Jailhouse hypervisor. Here we
must not touch LDR in a way that destroys the mapping originally set up
by the Linux root cell. Jailhouse enforces this setting in order to
efficiently validate any IPI requests sent by a cell.
Avoid a needless clash caused by flat_init_apic_ldr by installing a true
nop handler.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/f9867d294cdae4d45ed89d3a2e6adb524f4f6794.1511770314.git.jan.kiszka@siemens.com
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Because the return value of cpu_timer_sample_group() is not checked,
compilers and static checkers can legitimately warn about a potential use
of the uninitialized variable 'now'. This is not a runtime issue as all call
sites hand in valid clock ids.
Also cpu_timer_sample_group() is invoked unconditionally even when the
result is not used because *oldval is NULL.
Make the invocation conditional and check the return value.
[ tglx: Massage changelog ]
Signed-off-by: Max R. P. Grossmann <m@max.pm>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/20180108190157.10048-1-m@max.pm
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Without TSC_KNOWN_FREQ the TSC clocksource is registered so late that the
kernel first switches to the HPET. Using HPET on large CPU count machines is
undesirable.
Therefore register a tsc-early clocksource using the preliminary tsc_khz
from quick calibration. Then when the final TSC calibration is done, it
can switch to the tuned frequency.
The only notably problem is that the real tsc clocksource must be marked
with CLOCK_SOURCE_VALID_FOR_HRES, otherwise it will not be selected when
unregistering tsc-early. tsc-early cannot be left registered, because then
the clocksource code would fall back to it when we tsc clocksource is
marked unstable later.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20171222092243.431585460@infradead.org
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Even without a PIC/PIT the legacy timer interrupt is required for HPET in
legacy replacement mode.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.382623763@infradead.org
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Zhang Rui reported that a Surface Pro 4 will fail to boot with
lapic=notscdeadline. Part of the problem is that that machine doesn't have
a PIT.
If, for some reason, the TSC init has to fall back to TSC calibration, it
relies on the PIT to be present.
Allow TSC calibration to reliably fall back to HPET.
The below results in an accurate TSC measurement when forced on a IVB:
tsc: Unable to calibrate against PIT
tsc: No reference (HPET/PMTIMER) available
tsc: Unable to calibrate against PIT
tsc: using HPET reference calibration
tsc: Detected 2792.451 MHz processor
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.333145937@infradead.org
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const variables must use __initconst, not __initdata.
Fix this up for the IDT tables, which got it consistently wrong.
Fixes: 16bc18d895ce ("x86/idt: Move 32-bit idt_descr to C code")
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171222001821.2157-7-andi@firstfloor.org
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Mark the C exception handler functions that are directly called through
exception tables visible. LTO needs to know they are accessed from assembler.
[ tglx: Mopped up the wrecked argument alignment. Sigh.... ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171222001821.2157-6-andi@firstfloor.org
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__const_udelay is marked inline, and LTO will happily inline it everywhere
Dropping the inline saves ~44k text in a LTO build.
13999560 1740864 1499136 17239560 1070e08 vmlinux-with-udelay-inline
13954764 1736768 1499136 17190668 1064f0c vmlinux-wo-udelay-inline
Inlining it has no advantage in general, so its the right thing to do.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171222001821.2157-2-andi@firstfloor.org
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The Kryo CPUs are also affected by the Falkor 1003 errata, so
we need to do the same workaround on Kryo CPUs. The MIDR is
slightly more complicated here, where the PART number is not
always the same when looking at all the bits from 15 to 4. Drop
the lower 8 bits and just look at the top 4 to see if it's '2'
and then consider those as Kryo CPUs. This covers all the
combinations without having to list them all out.
Fixes: 38fd94b0275c ("arm64: Work around Falkor erratum 1003")
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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Currently the early assembler page table code assumes that precisely
1xpgd, 1xpud, 1xpmd are sufficient to represent the early kernel text
mappings.
Unfortunately this is rarely the case when running with a 16KB granule,
and we also run into limits with 4KB granule when building much larger
kernels.
This patch re-writes the early page table logic to compute indices of
mappings for each level of page table, and if multiple indices are
required, the next-level page table is scaled up accordingly.
Also the required size of the swapper_pg_dir is computed at link time
to cover the mapping [KIMAGE_ADDR + VOFFSET, _end]. When KASLR is
enabled, an extra page is set aside for each level that may require extra
entries at runtime.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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The trampoline page tables are positioned after the early page tables in
the kernel linker script.
As we are about to change the early page table logic to resolve the
swapper size at link time as opposed to compile time, the
SWAPPER_DIR_SIZE variable (currently used to locate the trampline)
will be rendered unsuitable for low level assembler.
This patch solves this issue by moving the trampoline before the PAN
page tables. The offset to the trampoline from ttbr1 can then be
expressed by: PAGE_SIZE + RESERVED_TTBR0_SIZE, which is available to the
entry assembler.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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