In kvm_mmu_notifier_invalidate_range_start(), tlbs_dirty is used as:
need_tlb_flush |= kvm->tlbs_dirty;
with need_tlb_flush's type being int and tlbs_dirty's type being long.
It means that tlbs_dirty is always used as int and the higher 32 bits
is useless. We need to check tlbs_dirty in a correct way and this
change checks it directly without propagating it to need_tlb_flush.
Note: it's _extremely_ unlikely this neglecting of higher 32 bits can
cause problems in practice. It would require encountering tlbs_dirty
on a 4 billion count boundary, and KVM would need to be using shadow
paging or be running a nested guest.
Cc: stable@vger.kernel.org Fixes: a4ee1ca4a36e ("KVM: MMU: delay flush all tlbs on sync_page path") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20201217154118.16497-1-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sudip: adjust context] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function uses a goto-based loop, which may lead to an earlier error
getting discarded by a later iteration. Exit this ad-hoc loop when an
error was encountered.
The out-of-memory error path additionally fails to fill a structure
field looked at by xen_blkbk_unmap_prepare() before inspecting the
handle which does get properly set (to BLKBACK_INVALID_HANDLE).
Since the earlier exiting from the ad-hoc loop requires the same field
filling (invalidation) as that on the out-of-memory path, fold both
paths. While doing so, drop the pr_alert(), as extra log messages aren't
going to help the situation (the kernel will log oom conditions already
anyway).
In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.
In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.
In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.
Failure of the kernel part of the mapping operation should also be
indicated as an error to the caller, or else it may assume the
respective kernel VA is okay to access.
Furthermore gnttab_map_refs() failing still requires recording
successfully mapped handles, so they can be unmapped subsequently. This
in turn requires there to be a way to tell full hypercall failure from
partial success - preset map_op status fields such that they won't
"happen" to look as if the operation succeeded.
Also again use GNTST_okay instead of implying its value (zero).
We may not skip setting the field in the unmap structure when
GNTMAP_device_map is in use - such an unmap would fail to release the
respective resources (a page ref in the hypervisor). Otoh the field
doesn't need setting at all when GNTMAP_device_map is not in use.
To record the value for unmapping, we also better don't use our local
p2m: In particular after a subsequent change it may not have got updated
for all the batch elements. Instead it can simply be taken from the
respective map's results.
We can additionally avoid playing this game altogether for the kernel
part of the mappings in (x86) PV mode.
Its sibling (set_foreign_p2m_mapping()) as well as the sibling of its
only caller (gnttab_map_refs()) don't clean up after themselves in case
of error. Higher level callers are expected to do so. However, in order
for that to really clean up any partially set up state, the operation
should not terminate upon encountering an entry in unexpected state. It
is particularly relevant to notice here that set_foreign_p2m_mapping()
would skip setting up a p2m entry if its grant mapping failed, but it
would continue to set up further p2m entries as long as their mappings
succeeded.
Arguably down the road set_foreign_p2m_mapping() may want its page state
related WARN_ON() also converted to an error return.
gcc 5 supports a new -mcount-record option to generate ftrace
tables directly. This avoids the need to run record_mcount
manually.
Use this option when available.
So far doesn't use -mcount-nop, which also exists now.
This is needed to make ftrace work with LTO because the
normal record-mcount script doesn't run over the link
time output.
It should also improve build times slightly in the general
case. Link: http://lkml.kernel.org/r/20171127213423.27218-12-andi@firstfloor.org Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
20bf2b378729 ("x86/build: Disable CET instrumentation in the kernel")
disabled CET instrumentation which gets added by default by the Ubuntu
gcc9 and 10 by default, but did that only for 64-bit builds. It would
still fail when building a 32-bit target. So disable CET for all x86
builds.
Fixes: 20bf2b378729 ("x86/build: Disable CET instrumentation in the kernel") Reported-by: AC <achirvasub@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: AC <achirvasub@gmail.com> Link: https://lkml.kernel.org/r/YCCIgMHkzh/xT4ex@arch-chirva.localdomain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In vsock_shutdown() we touched some socket fields without holding the
socket lock, such as 'state' and 'sk_flags'.
Also, after the introduction of multi-transport, we are accessing
'vsk->transport' in vsock_send_shutdown() without holding the lock
and this call can be made while the connection is in progress, so
the transport can change in the meantime.
To avoid issues, we hold the socket lock when we enter in
vsock_shutdown() and release it when we leave.
Among the transports that implement the 'shutdown' callback, only
hyperv_transport acquired the lock. Since the caller now holds it,
we no longer take it.
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent netif_tx_disable() running concurrently with dev_watchdog() by
taking the device global xmit lock. Otherwise, the recommended:
netif_carrier_off(dev);
netif_tx_disable(dev);
driver shutdown sequence can happen after the watchdog has already
checked carrier, resulting in possible false alarms. This is because
netif_tx_lock() only sets the frozen bit without maintaining the locks
on the individual queues.
Fixes: c3f26a269c24 ("netdev: Fix lockdep warnings in multiqueue configurations.") Signed-off-by: Edwin Peer <edwin.peer@broadcom.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Originally the procedure of the ULPI transaction finish detection has been
developed as a simple busy-loop with just decrementing counter and no
delays. It's wrong since on different systems the loop will take a
different time to complete. So if the system bus and CPU are fast enough
to overtake the ULPI bus and the companion PHY reaction, then we'll get to
take a false timeout error. Fix this by converting the busy-loop procedure
to take the standard bus speed, address value and the registers access
mode into account for the busy-loop delay calculation.
Here is the way the fix works. It's known that the ULPI bus is clocked
with 60MHz signal. In accordance with [1] the ULPI bus protocol is created
so to spend 5 and 6 clock periods for immediate register write and read
operations respectively, and 6 and 7 clock periods - for the extended
register writes and reads. Based on that we can easily pre-calculate the
time which will be needed for the controller to perform a requested IO
operation. Note we'll still preserve the attempts counter in case if the
DWC USB3 controller has got some internals delays.
[1] UTMI+ Low Pin Interface (ULPI) Specification, Revision 1.1,
October 20, 2004, pp. 30 - 36.
When both --reap and --update flag are specified, there's a code
path at which the entry to be updated is reaped beforehand,
which then leads to kernel crash. Reap only entries which won't be
updated.
Fixes kernel bugzilla #207773.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207773 Reported-by: Reindl Harald <h.reindl@thelounge.net> Fixes: 0079c5aee348 ("netfilter: xt_recent: add an entry reaper") Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
With kaslr the kernel image is placed at a random place, so starting the
bottom-up allocation with the kernel_end can result in an allocation
failure and a warning like this one:
At the same time, the kernel image is protected with memblock_reserve(),
so we can just start searching at PAGE_SIZE. In this case the bottom-up
allocation has the same chances to success as a top-down allocation, so
there is no reason to fallback in the case of a failure. All together it
simplifies the logic.
Link: https://lkml.kernel.org/r/20201217201214.3414100-2-guro@fb.com Fixes: 8fabc623238e ("powerpc: Ensure that swiotlb buffer is allocated from low memory") Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Wonhyuk Yang <vvghjk1234@gmail.com> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Sysbot has reported a warning where a kmalloc() attempt exceeds the
maximum limit. This has been identified as corruption of the xattr_ids
count when reading the xattr id lookup table.
This patch adds a number of additional sanity checks to detect this
corruption and others.
1. It checks for a corrupted xattr index read from the inode. This could
be because the metadata block is uncompressed, or because the
"compression" bit has been corrupted (turning a compressed block
into an uncompressed block). This would cause an out of bounds read.
2. It checks against corruption of the xattr_ids count. This can either
lead to the above kmalloc failure, or a smaller than expected
table to be read.
3. It checks the contents of the index table for corruption.
Sysbot has reported an "slab-out-of-bounds read" error which has been
identified as being caused by a corrupted "ino_num" value read from the
inode. This could be because the metadata block is uncompressed, or
because the "compression" bit has been corrupted (turning a compressed
block into an uncompressed block).
This patch adds additional sanity checks to detect this, and the
following corruption.
1. It checks against corruption of the inodes count. This can either
lead to a larger table to be read, or a smaller than expected
table to be read.
In the case of a too large inodes count, this would often have been
trapped by the existing sanity checks, but this patch introduces
a more exact check, which can identify too small values.
2. It checks the contents of the index table for corruption.
Sysbot has reported a number of "slab-out-of-bounds reads" and
"use-after-free read" errors which has been identified as being caused
by a corrupted index value read from the inode. This could be because
the metadata block is uncompressed, or because the "compression" bit has
been corrupted (turning a compressed block into an uncompressed block).
This patch adds additional sanity checks to detect this, and the
following corruption.
1. It checks against corruption of the ids count. This can either
lead to a larger table to be read, or a smaller than expected
table to be read.
In the case of a too large ids count, this would often have been
trapped by the existing sanity checks, but this patch introduces
a more exact check, which can identify too small values.
2. It checks the contents of the index table for corruption.
Without memcg, there is a one-to-one mapping between the bdi and
bdi_writeback structures. In this world, things are fairly
straightforward; the first thing bdi_unregister() does is to shutdown
the bdi_writeback structure (or wb), and part of that writeback ensures
that no other work queued against the wb, and that the wb is fully
drained.
With memcg, however, there is a one-to-many relationship between the bdi
and bdi_writeback structures; that is, there are multiple wb objects
which can all point to a single bdi. There is a refcount which prevents
the bdi object from being released (and hence, unregistered). So in
theory, the bdi_unregister() *should* only get called once its refcount
goes to zero (bdi_put will drop the refcount, and when it is zero,
release_bdi gets called, which calls bdi_unregister).
Unfortunately, del_gendisk() in block/gen_hd.c never got the memo about
the Brave New memcg World, and calls bdi_unregister directly. It does
this without informing the file system, or the memcg code, or anything
else. This causes the root wb associated with the bdi to be
unregistered, but none of the memcg-specific wb's are shutdown. So when
one of these wb's are woken up to do delayed work, they try to
dereference their wb->bdi->dev to fetch the device name, but
unfortunately bdi->dev is now NULL, thanks to the bdi_unregister()
called by del_gendisk(). As a result, *boom*.
Fortunately, it looks like the rest of the writeback path is perfectly
happy with bdi->dev and bdi->owner being NULL, so the simplest fix is to
create a bdi_dev_name() function which can handle bdi->dev being NULL.
This also allows us to bulletproof the writeback tracepoints to prevent
them from dereferencing a NULL pointer and crashing the kernel if one is
tracing with memcg's enabled, and an iSCSI device dies or a USB storage
stick is pulled.
The most common way of triggering this will be hotremoval of a device
while writeback with memcg enabled is going on. It was triggering
several times a day in a heavily loaded production environment.
In file included from ./arch/powerpc/include/asm/paca.h:15,
from ./arch/powerpc/include/asm/current.h:13,
from ./include/linux/thread_info.h:21,
from ./include/asm-generic/preempt.h:5,
from ./arch/powerpc/include/generated/asm/preempt.h:1,
from ./include/linux/preempt.h:78,
from ./include/linux/spinlock.h:51,
from fs/fs-writeback.c:19:
In function 'strncpy',
inlined from 'perf_trace_writeback_page_template' at
./include/trace/events/writeback.h:56:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified
bound 32 equals destination size [-Wstringop-truncation]
return __builtin_strncpy(p, q, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix it by using the new strscpy_pad() which was introduced in "lib/string:
Add strscpy_pad() function" and will always be NUL-terminated instead of
strncpy(). Also, change strlcpy() to use strscpy_pad() in this file for
consistency.
Link: http://lkml.kernel.org/r/1564075099-27750-1-git-send-email-cai@lca.pw Fixes: 455b2864686d ("writeback: Initial tracing support") Fixes: 028c2dd184c0 ("writeback: Add tracing to balance_dirty_pages") Fixes: e84d0a4f8e39 ("writeback: trace event writeback_queue_io") Fixes: b48c104d2211 ("writeback: trace event bdi_dirty_ratelimit") Fixes: cc1676d917f3 ("writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()") Fixes: 9fb0a7da0c52 ("writeback: add more tracepoints") Signed-off-by: Qian Cai <cai@lca.pw> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Tobin C. Harding <tobin@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Nitin Gote <nitin.r.gote@intel.com> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Cc: Stephen Kitt <steve@sk2.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
We have a function to copy strings safely and we have a function to copy
strings and zero the tail of the destination (if source string is
shorter than destination buffer) but we do not have a function to do
both at once. This means developers must write this themselves if they
desire this functionality. This is a chore, and also leaves us open to
off by one errors unnecessarily.
Add a function that calls strscpy() then memset()s the tail to zero if
the source string is shorter than the destination buffer.
When handling an auth_gss downcall, it's possible to get 0-length
opaque object for the acceptor. In the case of a 0-length XDR
object, make sure simple_get_netobj() fills in dest->data = NULL,
and does not continue to kmemdup() which will set
dest->data = ZERO_SIZE_PTR for the acceptor.
The trace event code can handle NULL but not ZERO_SIZE_PTR for a
string, and so without this patch the rpcgss_context trace event
will crash the kernel as follows:
Remove duplicated helper functions to parse opaque XDR objects
and place inside new file net/sunrpc/auth_gss/auth_gss_internal.h.
In the new file carry the license and copyright from the source file
net/sunrpc/auth_gss/auth_gss.c. Finally, update the comment inside
include/linux/sunrpc/xdr.h since lockd is not the only user of
struct xdr_netobj.
If we get into a problem severe enough to attempt a reprobe,
we schedule a worker to do that. However, if the problem gets
more severe and the device is actually destroyed before this
worker has a chance to run, we use a free device. Bump up the
reference count of the device until the worker runs to avoid
this situation.
xfrm_probe_algs() probes kernel crypto modules and changes the
availability of struct xfrm_algo_desc. But there is a small window
where ealg->available and aalg->available get changed between
count_ah_combs()/count_esp_combs() and dump_ah_combs()/dump_esp_combs(),
in this case we may allocate a smaller skb but later put a larger
amount of data and trigger the panic in skb_put().
Fix this by relaxing the checks when counting the size, that is,
skipping the test of ->available. We may waste some memory for a few
of sizeof(struct sadb_comb), but it is still much better than a panic.
On some archs, the idle task can call into cpu_suspend(). The cpu_suspend()
will disable or pause function graph tracing, as there's some paths in
bringing down the CPU that can have issues with its return address being
modified. The task_struct structure has a "tracing_graph_pause" atomic
counter, that when set to something other than zero, the function graph
tracer will not modify the return address.
The problem is that the tracing_graph_pause counter is initialized when the
function graph tracer is enabled. This can corrupt the counter for the idle
task if it is suspended in these architectures.
CPU 1 CPU 2
----- -----
do_idle()
cpu_suspend()
pause_graph_tracing()
task_struct->tracing_graph_pause++ (0 -> 1)
The file /sys/kernel/tracing/events/enable is used to enable all events by
echoing in "1", or disabling all events when echoing in "0". To know if all
events are enabled, disabled, or some are enabled but not all of them,
cating the file should show either "1" (all enabled), "0" (all disabled), or
"X" (some enabled but not all of them). This works the same as the "enable"
files in the individule system directories (like tracing/events/sched/enable).
But when all events are enabled, the top level "enable" file shows "X". The
reason is that its checking the "ftrace" events, which are special events
that only exist for their format files. These include the format for the
function tracer events, that are enabled when the function tracer is
enabled, but not by the "enable" file. The check includes these events,
which will always be disabled, and even though all true events are enabled,
the top level "enable" file will show "X" instead of "1".
To fix this, have the check test the event's flags to see if it has the
"IGNORE_ENABLE" flag set, and if so, not test it.
Cc: stable@vger.kernel.org Fixes: 553552ce1796c ("tracing: Combine event filter_active and enable into single flags field") Reported-by: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calling acpi_thermal_check() from acpi_thermal_notify() directly
is problematic if _TMP triggers Notify () on the thermal zone for
which it has been evaluated (which happens on some systems), because
it causes a new acpi_thermal_notify() invocation to be queued up
every time and if that takes place too often, an indefinite number of
pending work items may accumulate in kacpi_notify_wq over time.
Besides, it is not really useful to queue up a new invocation of
acpi_thermal_check() if one of them is pending already.
For these reasons, rework acpi_thermal_notify() to queue up a thermal
check instead of calling acpi_thermal_check() directly and only allow
one thermal check to be pending at a time. Moreover, only allow one
acpi_thermal_check_fn() instance at a time to run
thermal_zone_device_update() for one thermal zone and make it return
early if it sees other instances running for the same thermal zone.
While at it, fold acpi_thermal_check() into acpi_thermal_check_fn(),
as it is only called from there after the other changes made here.
[This issue appears to have been exposed by commit 6d25be5782e4
("sched/core, workqueues: Distangle worker accounting from rq
lock"), but it is unclear why it was not visible earlier.]
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208877 Reported-by: Stephen Berman <stephen.berman@gmx.net> Diagnosed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Stephen Berman <stephen.berman@gmx.net> Cc: All applicable <stable@vger.kernel.org>
[bigeasy: Backported to v4.4.y, use atomic_t instead of refcount_t] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jan Kiszka reported that the x2apic_wrmsr_fence() function uses a plain
MFENCE while the Intel SDM (10.12.3 MSR Access in x2APIC Mode) calls for
MFENCE; LFENCE.
Short summary: we have special MSRs that have weaker ordering than all
the rest. Add fencing consistent with current SDM recommendations.
This is not known to cause any issues in practice, only in theory.
Longer story below:
The reason the kernel uses a different semantic is that the SDM changed
(roughly in late 2017). The SDM changed because folks at Intel were
auditing all of the recommended fences in the SDM and realized that the
x2apic fences were insufficient.
Why was the pain MFENCE judged insufficient?
WRMSR itself is normally a serializing instruction. No fences are needed
because the instruction itself serializes everything.
But, there are explicit exceptions for this serializing behavior written
into the WRMSR instruction documentation for two classes of MSRs:
IA32_TSC_DEADLINE and the X2APIC MSRs.
Back to x2apic: WRMSR is *not* serializing in this specific case.
But why is MFENCE insufficient? MFENCE makes writes visible, but
only affects load/store instructions. WRMSR is unfortunately not a
load/store instruction and is unaffected by MFENCE. This means that a
non-serializing WRMSR could be reordered by the CPU to execute before
the writes made visible by the MFENCE have even occurred in the first
place.
This means that an x2apic IPI could theoretically be triggered before
there is any (visible) data to process.
Does this affect anything in practice? I honestly don't know. It seems
quite possible that by the time an interrupt gets to consume the (not
yet) MFENCE'd data, it has become visible, mostly by accident.
To be safe, add the SDM-recommended fences for all x2apic WRMSRs.
This also leaves open the question of the _other_ weakly-ordered WRMSR:
MSR_IA32_TSC_DEADLINE. While it has the same ordering architecture as
the x2APIC MSRs, it seems substantially less likely to be a problem in
practice. While writes to the in-memory Local Vector Table (LVT) might
theoretically be reordered with respect to a weakly-ordered WRMSR like
TSC_DEADLINE, the SDM has this to say:
In x2APIC mode, the WRMSR instruction is used to write to the LVT
entry. The processor ensures the ordering of this write and any
subsequent WRMSR to the deadline; no fencing is required.
But, that might still leave xAPIC exposed. The safest thing to do for
now is to add the extra, recommended LFENCE.
[ bp: Massage commit message, fix typos, drop accidentally added
newline to tools/arch/x86/include/asm/barrier.h. ]
Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200305174708.F77040DD@viggo.jf.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With retpolines disabled, some configurations of GCC, and specifically
the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation
to the kernel by default. That breaks certain tracing scenarios by
adding a superfluous ENDBR64 instruction before the fentry call, for
functions which can be called indirectly.
CET instrumentation isn't currently necessary in the kernel, as CET is
only supported in user space. Disable it unconditionally and move it
into the x86's Makefile as CET/CFI... enablement should be a per-arch
decision anyway.
[ bp: Massage and extend commit message. ]
Fixes: 29be86d7f9cb ("kbuild: add -fcf-protection=none when using retpoline flags") Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Cc: <stable@vger.kernel.org> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The page_huge_active() can be called from scan_movable_pages() which do
not hold a reference count to the HugeTLB page. So when we call
page_huge_active() from scan_movable_pages(), the HugeTLB page can be
freed parallel. Then we will trigger a BUG_ON which is in the
page_huge_active() when CONFIG_DEBUG_VM is enabled. Just remove the
VM_BUG_ON_PAGE.
Link: https://lkml.kernel.org/r/20210115124942.46403-6-songmuchun@bytedance.com Fixes: 7e1f049efb86 ("mm: hugetlb: cleanup using paeg_huge_active()") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we isolate a HugeTLB page on CPU0. Meanwhile, we free it to the
buddy allocator on CPU1. Then, we can trigger a BUG_ON on CPU0, because
it is already freed to the buddy allocator.
Link: https://lkml.kernel.org/r/20210115124942.46403-5-songmuchun@bytedance.com Fixes: c8721bbbdd36 ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a new hugetlb page is allocated during fallocate it will not be
marked as active (set_page_huge_active) which will result in a later
isolate_huge_page failure when the page migration code would like to
move that page. Such a failure would be unexpected and wrong.
Only export set_page_huge_active, just leave clear_page_huge_active as
static. Because there are no external users.
Link: https://lkml.kernel.org/r/20210115124942.46403-3-songmuchun@bytedance.com Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Building with gcc 4.9.2 reveals a latent bug in the PCI accessors
for Footbridge platforms, which causes a fatal alignment fault
while accessing IO memory. Fix this by making the assembly volatile.
Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Assuming
- //HOST/a is mounted on /mnt
- //HOST/b is mounted on /mnt/b
On a slow connection, running 'df' and killing it while it's
processing /mnt/b can make cifs_get_inode_info() returns -ERESTARTSYS.
This triggers the following chain of events:
=> the dentry revalidation fail
=> dentry is put and released
=> superblock associated with the dentry is put
=> /mnt/b is unmounted
This patch makes cifs_d_revalidate() return the error instead of 0
(invalid) when cifs_revalidate_dentry() fails, except for ENOENT (file
deleted) and ESTALE (file recreated).
Signed-off-by: Aurelien Aptel <aaptel@suse.com> Suggested-by: Shyam Prasad N <nspmangalore@gmail.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com> CC: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Our system encountered a re-init error when re-registering same kretprobe,
where the kretprobe_instance in rp->free_instances is illegally accessed
after re-init.
Implementation to avoid re-registration has been introduced for kprobe
before, but lags for register_kretprobe(). We must check if kprobe has
been re-registered before re-initializing kretprobe, otherwise it will
destroy the data struct of kretprobe registered, which can lead to memory
leak, system crash, also some unexpected behaviors.
We use check_kprobe_rereg() to check if kprobe has been re-registered
before running register_kretprobe()'s body, for giving a warning message
and terminate registration process.
Link: https://lkml.kernel.org/r/20210128124427.2031088-1-bobo.shaobowang@huawei.com Cc: stable@vger.kernel.org Fixes: 1f0ab40976460 ("kprobes: Prevent re-registration of the same kprobe")
[ The above commit should have been done for kretprobes too ] Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the driver uses .sta_add, station entries are only uploaded after the sta
is in assoc state. Fix early station rate table updates by deferring them
until the sta has been uploaded.
Cc: stable@vger.kernel.org Signed-off-by: Felix Fietkau <nbd@nbd.name> Link: https://lore.kernel.org/r/20210201083324.3134-1-nbd@nbd.name
[use rcu_access_pointer() instead since we won't dereference here] Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dwc2_hsotg_process_req_status uses ep_from_windex() to retrieve
the endpoint for the index provided in the wIndex request param.
In a test-case with a rndis gadget running and sending a malformed
packet to it like:
dev.ctrl_transfer(
0x82, # bmRequestType
0x00, # bRequest
0x0000, # wValue
0x0001, # wIndex
0x00 # wLength
)
it is possible to cause a crash:
This happens because ep_from_windex wants to compare the endpoint
direction even if index_to_ep() didn't return an endpoint due to
the direction not matching.
The fix is easy insofar that the actual direction check is already
happening when calling index_to_ep() which will return NULL if there
is no endpoint for the targeted direction, so the offending check
can go away completely.
Some devices, such as the Winbond Electronics Corp. Virtual Com Port
(Vendor=0416, ProdId=5011), lockup when usb_set_interface() or
usb_clear_halt() are called. This device has only a single
altsetting, so it should not be necessary to call usb_set_interface().
Acked-by: Pete Zaitcev <zaitcev@redhat.com> Signed-off-by: Jeremy Figgins <kernel@jeremyfiggins.com> Link: https://lore.kernel.org/r/YAy9kJhM/rG8EQXC@watson Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/elfcore.c only contains weak symbols, which triggers a bug with
clang in combination with recordmcount:
Cannot find symbol for section 2: .text.
kernel/elfcore.o: failed
Move the empty stubs into linux/elfcore.h as inline functions. As only
two architectures use these, just use the architecture specific Kconfig
symbols to key off the declaration.
CONFIG_MIPS32_N32=y but CONFIG_BINFMT_ELF disabled results in the
following linker errors:
arch/mips/built-in.o: In function `elf_core_dump':
binfmt_elfn32.c:(.text+0x23dbc): undefined reference to `elf_core_extra_phdrs'
binfmt_elfn32.c:(.text+0x246e4): undefined reference to `elf_core_extra_data_size'
binfmt_elfn32.c:(.text+0x248d0): undefined reference to `elf_core_write_extra_phdrs'
binfmt_elfn32.c:(.text+0x24ac4): undefined reference to `elf_core_write_extra_data'
CONFIG_MIPS32_O32=y but CONFIG_BINFMT_ELF disabled results in the following
linker errors:
arch/mips/built-in.o: In function `elf_core_dump':
binfmt_elfo32.c:(.text+0x28a04): undefined reference to `elf_core_extra_phdrs'
binfmt_elfo32.c:(.text+0x29330): undefined reference to `elf_core_extra_data_size'
binfmt_elfo32.c:(.text+0x2951c): undefined reference to `elf_core_write_extra_phdrs'
binfmt_elfo32.c:(.text+0x29710): undefined reference to `elf_core_write_extra_data'
This is because binfmt_elfn32 and binfmt_elfo32 are using symbols from
elfcore but for these configurations elfcore will not be built.
Fixed by making elfcore selectable by a separate config symbol which
unlike the current mechanism can also be used from other directories
than kernel/, then having each flavor of ELF that relies on elfcore.o,
select it in Kconfig, including CONFIG_MIPS32_N32 and CONFIG_MIPS32_O32
which fixes this issue.
Link: http://lkml.kernel.org/r/20160520141705.GA1913@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When sending a packet, we will prepend it with an LAPB header.
This modifies the shared parts of a cloned skb, so we should copy the
skb rather than just clone it, before we prepend the header.
In "Documentation/networking/driver.rst" (the 2nd point), it states
that drivers shouldn't modify the shared parts of a cloned skb when
transmitting.
The "dev_queue_xmit_nit" function in "net/core/dev.c", which is called
when an skb is being sent, clones the skb and sents the clone to
AF_PACKET sockets. Because the LAPB drivers first remove a 1-byte
pseudo-header before handing over the skb to us, if we don't copy the
skb before prepending the LAPB header, the first byte of the packets
received on AF_PACKET sockets can be corrupted.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xie He <xie.he.0141@gmail.com> Acked-by: Martin Schiller <ms@dev.tdt.de> Link: https://lore.kernel.org/r/20210201055706.415842-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Sasha Levin [Fri, 5 Feb 2021 17:47:02 +0000 (12:47 -0500)]
stable: clamp SUBLEVEL in 4.4 and 4.9
Right now SUBLEVEL is overflowing, and some userspace may start treating
4.9.256 as 4.10. While out of tree modules have different ways of
extracting the version number (and we're generally ok with breaking
them), we do care about breaking userspace and it would appear that this
overflow might do just that.
Our rules around userspace ABI in the stable kernel are pretty simple:
we don't break it. Thus, while userspace may be checking major/minor, it
shouldn't be doing anything with sublevel.
This patch applies a big band-aid to the 4.9 and 4.4 kernels in the form
of clamping their sublevel to 255.
The clamp is done for the purpose of LINUX_VERSION_CODE only, and
extracting the version number from the Makefile or "make kernelversion"
will continue to work as intended.
We might need to do it later in newer trees, but maybe we'll have a
better solution by then, so I'm ignoring that problem for now.
While testing live partition mobility, we have observed occasional crashes
of the Linux partition. What we've seen is that during the live migration,
for specific configurations with large amounts of memory, slow network
links, and workloads that are changing memory a lot, the partition can end
up being suspended for 30 seconds or longer. This resulted in the following
scenario:
CPU 0 CPU 1
------------------------------- ----------------------------------
scsi_queue_rq migration_store
-> blk_mq_start_request -> rtas_ibm_suspend_me
-> blk_add_timer -> on_each_cpu(rtas_percpu_suspend_me
_______________________________________V
|
V
-> IPI from CPU 1
-> rtas_percpu_suspend_me
-> __rtas_suspend_last_cpu
Normally, the SCMD_STATE_COMPLETE bit would protect against the command
completion and the timeout, but that doesn't work here, since we don't
check that at all in the SCSI_MLQUEUE_HOST_BUSY path.
In this case we end up calling scsi_queue_insert on a request that has
already been queued, or possibly even freed, and we crash.
The patch below simply increases the default I/O timeout to avoid this race
condition. This is also the timeout value that nearly all IBM SAN storage
recommends setting as the default value.
A race condition exists between the response handler getting called because
of exchange_mgr_reset() (which clears out all the active XIDs) and the
response we get via an interrupt.
Sequence of events:
rport ba0200: Port timeout, state PLOGI
rport ba0200: Port entered PLOGI state from PLOGI state
xid 1052: Exchange timer armed : 20000 msecs  xid timer armed here
rport ba0200: Received LOGO request while in state PLOGI
rport ba0200: Delete port
rport ba0200: work event 3
rport ba0200: lld callback ev 3
bnx2fc: rport_event_hdlr: event = 3, port_id = 0xba0200
bnx2fc: ba0200 - rport not created Yet!!
/* Here we reset any outstanding exchanges before
freeing rport using the exch_mgr_reset() */
xid 1052: Exchange timer canceled
/* Here we got two responses for one xid */
xid 1052: invoking resp(), esb 20000000 state 3
xid 1052: invoking resp(), esb 20000000 state 3
xid 1052: fc_rport_plogi_resp() : ep->resp_active 2
xid 1052: fc_rport_plogi_resp() : ep->resp_active 2
Skip the response if the exchange is already completed.
Lee Jones [Thu, 4 Feb 2021 17:29:03 +0000 (17:29 +0000)]
futex: Handle faults correctly for PI futexes
From: Thomas Gleixner <tglx@linutronix.de>
fixup_pi_state_owner() tries to ensure that the state of the rtmutex,
pi_state and the user space value related to the PI futex are consistent
before returning to user space. In case that the user space value update
faults and the fault cannot be resolved by faulting the page in via
fault_in_user_writeable() the function returns with -EFAULT and leaves
the rtmutex and pi_state owner state inconsistent.
A subsequent futex_unlock_pi() operates on the inconsistent pi_state and
releases the rtmutex despite not owning it which can corrupt the RB tree of
the rtmutex and cause a subsequent kernel stack use after free.
It was suggested to loop forever in fixup_pi_state_owner() if the fault
cannot be resolved, but that results in runaway tasks which is especially
undesired when the problem happens due to a programming error and not due
to malice.
As the user space value cannot be fixed up, the proper solution is to make
the rtmutex and the pi_state consistent so both have the same owner. This
leaves the user space value out of sync. Any subsequent operation on the
futex will fail because the 10th rule of PI futexes (pi_state owner and
user space value are consistent) has been violated.
As a consequence this removes the inept attempts of 'fixing' the situation
in case that the current task owns the rtmutex when returning with an
unresolvable fault by unlocking the rtmutex which left pi_state::owner and
rtmutex::owner out of sync in a different and only slightly less dangerous
way.
Fixes: 1b7558e457ed ("futexes: fix fault handling in futex_lock_pi") Reported-by: gzobqq@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Too many gotos already and an upcoming fix would make it even more
unreadable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No point in open coding it. This way it gains the extra sanity checks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Updating pi_state::owner is done at several places with the same
code. Provide a function for it and use that at the obvious places.
This is also a preparation for a bug fix to avoid yet another copy of the
same code or alternatively introducing a completely unpenetratable mess of
gotos.
Originally-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If that unexpected case of inconsistent arguments ever happens then the
futex state is left completely inconsistent and the printk is not really
helpful. Replace it with a warning and make the state consistent.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
/* At this point, we've returned -ETIMEDOUT to userspace, but the
* futex word shows waiter to be the owner, and the pi_mutex has
* stealer as the owner */
futex_lock(LOCK_PI, uaddr2)
-> bails with EDEADLK, futex word says we're owner.
removes from fixup_owner() looks to be just what is needed. And indeed
it is -- I completely missed that requeue_pi could also result in this
case. So we need to restore that, except that subsequent patches, like
commit:
16ffa12d7425 ("futex: Pull rt_mutex_futex_unlock() out from under hb->lock")
changed all the locking rules. Even without that, the sequence:
- raw_spin_lock_irq(&q->pi_state->pi_mutex.wait_lock);
- owner = rt_mutex_owner(&q->pi_state->pi_mutex);
- if (!owner)
- owner = rt_mutex_next_owner(&q->pi_state->pi_mutex);
- raw_spin_unlock_irq(&q->pi_state->pi_mutex.wait_lock);
- ret = fixup_pi_state_owner(uaddr, q, owner);
already suggests there were races; otherwise we'd never have to look
at next_owner.
So instead of doing 3 consecutive wait_lock sections with who knows
what races, we do it all in a single section. Additionally, the usage
of pi_state->owner in fixup_owner() was only safe because only the
rt_mutex owner would modify it, which this additional case wrecks.
Luckily the values can only change away and not to the value we're
testing, this means we can do a speculative test and double check once
we have the wait_lock.
Fixes: 73d786bd043e ("futex: Rework inconsistent rt_mutex/futex_q state") Reported-by: Julia Cartwright <julia@ni.com> Reported-by: Gratian Crisan <gratian.crisan@ni.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Julia Cartwright <julia@ni.com> Tested-by: Gratian Crisan <gratian.crisan@ni.com> Cc: Darren Hart <dvhart@infradead.org> Link: https://lkml.kernel.org/r/20171208124939.7livp7no2ov65rrc@hirez.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Lee: Back-ported to solve a dependency] Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a weird state in the futex_unlock_pi() path when it interleaves
with a concurrent futex_lock_pi() at the point where it drops hb->lock.
In this case, it can happen that the rt_mutex wait_list and the futex_q
disagree on pending waiters, in particular rt_mutex will find no pending
waiters where futex_q thinks there are. In this case the rt_mutex unlock
code cannot assign an owner.
The futex side fixup code has to cleanup the inconsistencies with quite a
bunch of interesting corner cases.
Simplify all this by changing wake_futex_pi() to return -EAGAIN when this
situation occurs. This then gives the futex_lock_pi() code the opportunity
to continue and the retried futex_unlock_pi() will now observe a coherent
state.
The only problem is that this breaks RT timeliness guarantees. That
is, consider the following scenario:
T1 and T2 are both pinned to CPU0. prio(T2) > prio(T1)
CPU0
T1
lock_pi()
queue_me() <- Waiter is visible
preemption
T2
unlock_pi()
loops with -EAGAIN forever
Which is undesirable for PI primitives. Future patches will rectify
this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: dvhart@infradead.org Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170322104151.850383690@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[Lee: Back-ported to solve a dependency] Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Put the device to avoid resource leak on path that the polling flag is
invalid.
Fixes: a831b9132065 ("NFC: Do not return EBUSY when stopping a poll that's already stopped") Signed-off-by: Pan Bian <bianpan2016@163.com> Link: https://lore.kernel.org/r/20210121153745.122184-1-bianpan2016@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Goto to the label put_dev instead of the label error to fix potential
resource leak on path that the target index is invalid.
Fixes: c4fbb6515a4d ("NFC: The core part should generate the target index") Signed-off-by: Pan Bian <bianpan2016@163.com> Link: https://lore.kernel.org/r/20210121152748.98409-1-bianpan2016@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit c40aaaac1018 ("iommu/vt-d: Gracefully handle DMAR units
with no supported address widths") dmar.c needs struct iommu_device to
be selected. We can drop this dependency by not dereferencing struct
iommu_device if IOMMU_API is not selected and by reusing the information
stored in iommu->drhd->ignored instead.
This fixes the following build error when IOMMU_API is not selected:
drivers/iommu/dmar.c: In function ‘free_iommu’:
drivers/iommu/dmar.c:1139:41: error: ‘struct iommu_device’ has no member named ‘ops’
1139 | if (intel_iommu_enabled && iommu->iommu.ops) {
^
Fixes: c40aaaac1018 ("iommu/vt-d: Gracefully handle DMAR units with no supported address widths") Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lore.kernel.org/r/20201013073055.11262-1-brgl@bgdev.pl Signed-off-by: Joerg Roedel <jroedel@suse.de>
[ - context change due to moving drivers/iommu/dmar.c to
drivers/iommu/intel/dmar.c
- set the drhr in the iommu like in upstream commit b1012ca8dc4f
("iommu/vt-d: Skip TE disabling on quirky gfx dedicated iommu") ] Signed-off-by: Filippo Sironi <sironi@amazon.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of bailing out completely, such a unit can still be used for
interrupt remapping.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/linux-iommu/549928db2de6532117f36c9c810373c14cf76f51.camel@infradead.org/ Signed-off-by: Joerg Roedel <jroedel@suse.de>
[ - context change due to moving drivers/iommu/dmar.c to
drivers/iommu/intel/dmar.c
- remove the unused err_unmap label
- use iommu->iommu_dev instead of iommu->iommu.ops to decide whether
when freeing ] Signed-off-by: Filippo Sironi <sironi@amazon.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The "bec" struct isn't necessarily always initialized. For example, the
mcp251xfd_get_berr_counter() function doesn't initialize anything if the
interface is down.
Fixes: 52c793f24054 ("can: netlink support for bus-error reporting and counters") Link: https://lore.kernel.org/r/YAkaRdRJncsJO8Ve@mwanda Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
syzbot reported a crash that happened when changing the interface
type around a lot, and while it might have been easy to fix just
the symptom there, a little deeper investigation found that really
the reason is that we allowed packets to be transmitted while in
the middle of changing the interface type.
Disallow TX by stopping the queues while changing the type.
The max_recv_sge value is wrongly reported when calling query_qp, This is
happening due to a typo when assigning the max_recv_sge value, the value
of sq_max_sges was assigned instead of rq_max_sges.
Fixes: 3e5c02c9ef9a ("iw_cxgb4: Support query_qp() verb") Link: https://lore.kernel.org/r/20210114191423.423529-1-kamalheib1@gmail.com Signed-off-by: Kamal Heib <kamalheib1@gmail.com> Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Analysis revealed offending code is when accessing:
replay_esn->bmp[nr] |= (1U << bitnr);
with 'nr' being 0x07fffffa.
This happened in an SMP system when reordering of packets was present;
A packet arrived with a "too old" sequence number (outside the window,
i.e 'diff > replay_window'), and therefore the following calculation:
bitnr = replay_esn->replay_window - (diff - pos);
yields a negative result, but since bitnr is u32 we get a large unsigned
quantity (in crash dump above: 0xffffff4b seen in ecx).
This was supposed to be protected by xfrm_input()'s former call to:
if (x->repl->check(x, skb, seq)) {
However, the state's spinlock x->lock is *released* after '->check()'
is performed, and gets re-acquired before '->advance()' - which gives a
chance for a different core to update the xfrm state, e.g. by advancing
'replay_esn->seq' when it encounters more packets - leading to a
'diff > replay_window' situation when original core continues to
xfrm_replay_advance_bmp().
An attempt to fix this issue was suggested in commit bcf66bf54aab
("xfrm: Perform a replay check after return from async codepaths"),
by calling 'x->repl->recheck()' after lock is re-acquired, but fix
applied only to asyncronous crypto algorithms.
Augment the fix, by *always* calling 'recheck()' - irrespective if we're
using async crypto.
Fixes: 0ebea8ef3559 ("[IPSEC]: Move state lock into x->type->input") Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Otherwise, the newly create element shows no timeout when listing the
ruleset. If the set definition does not specify a default timeout, then
the set element only shows the expiration time, but not the timeout.
This is a problem when restoring a stateful ruleset listing since it
skips the timeout policy entirely.
Fixes: 22fe54d5fefc ("netfilter: nf_tables: add support for dynamic set updates") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the kernel is configured to use the Thumb-2 instruction set
"suspend-to-memory" fails to resume. Observed on a Colibri iMX6ULL
(i.MX 6ULL) and Apalis iMX6 (i.MX 6Q).
It looks like the CPU resumes unconditionally in ARM instruction mode
and then chokes on the presented Thumb-2 code it should execute.
Fix this by using the arm instruction set for all code in
suspend-imx6.S.
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com> Fixes: df595746fa69 ("ARM: imx: add suspend in ocram support for i.mx6q") Acked-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--> preemption (unrelated wakeup of some other higher prio task, e.g. timer)
switch_to(other_task)
return to user
sys_futex()
loop infinite as above
Just for the fun of it the futex exit cleanup could trigger the wakeup
itself before the task sets its futex state to DEAD.
To cure this, the handling of the exiting owner is changed so:
- A refcount is held on the task
- The task pointer is stored in a caller visible location
- The caller drops all locks (hash bucket, mmap_sem) and blocks
on task::futex_exit_mutex. When the mutex is acquired then
the exiting task has completed the cleanup and the state
is consistent and can be reevaluated.
This is not a pretty solution, but there is no choice other than returning
an error code to user space, which would break the state consistency
guarantee and open another can of problems including regressions.
For stable backports the preparatory commits ac31c7ff8624 .. ba31c1a48538
are required as well, but for anything older than 5.3.y the backports are
going to be provided when this hits mainline as the other dependencies for
those kernels are definitely not stable material.
Fixes: 778e9a9c3e71 ("pi-futex: fix exit races and locking problems") Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Stable Team <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20191106224557.041676471@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mutex will be used in subsequent changes to replace the busy looping of
a waiter when the futex owner is currently executing the exit cleanup to
prevent a potential live lock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.845798895@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
exec() attempts to handle potentially held futexes gracefully by running
the futex exit handling code like exit() does.
The current implementation has no protection against concurrent incoming
waiters. The reason is that the futex state cannot be set to
FUTEX_STATE_DEAD after the cleanup because the task struct is still active
and just about to execute the new binary.
While its arguably buggy when a task holds a futex over exec(), for
consistency sake the state handling can at least cover the actual futex
exit cleanup section. This provides state consistency protection accross
the cleanup. As the futex state of the task becomes FUTEX_STATE_OK after the
cleanup has been finished, this cannot prevent subsequent attempts to
attach to the task in case that the cleanup was not successfull in mopping
up all leftovers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.753355618@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of relying on PF_EXITING use an explicit state for the futex exit
and set it in the futex exit function. This moves the smp barrier and the
lock/unlock serialization into the futex code.
As with the DEAD state this is restricted to the exit path as exec
continues to use the same task struct.
This allows to simplify that logic in a next step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.539409004@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Setting task::futex_state in do_exit() is rather arbitrarily placed for no
reason. Move it into the futex code.
Note, this is only done for the exit cleanup as the exec cleanup cannot set
the state to FUTEX_STATE_DEAD because the task struct is still in active
use.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.439511191@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To allow separate handling of the futex exit state in the futex exit code
for exit and exec, split futex_mm_release() into two functions and invoke
them from the corresponding exit/exec_mm_release() callsites.
Preparatory only, no functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.332094221@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The futex exit handling relies on PF_ flags. That's suboptimal as it
requires a smp_mb() and an ugly lock/unlock of the exiting tasks pi_lock in
the middle of do_exit() to enforce the observability of PF_EXITING in the
futex code.
Add a futex_state member to task_struct and convert the PF_EXITPIDONE logic
over to the new state. The PF_EXITING dependency will be cleaned up in a
later step.
This prepares for handling various futex exit issues later.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.149449274@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The futex exit handling is #ifdeffed into mm_release() which is not pretty
to begin with. But upcoming changes to address futex exit races need to add
more functionality to this exit code.
Split it out into a function, move it into futex code and make the various
futex exit functions static.
Preparatory only and no functional change.
Folded build fix from Borislav.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.049705556@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are going to share the compat_sys_futex() handler between 64-bit
architectures and 32-bit architectures that need to deal with both 32-bit
and 64-bit time_t, and this is easier if both entry points are in the
same file.
In fact, most other system call handlers do the same thing these days, so
let's follow the trend here and merge all of futex_compat.c into futex.c.
In the process, a few minor changes have to be done to make sure everything
still makes sense: handle_futex_death() and futex_cmpxchg_enabled() become
local symbol, and the compat version of the fetch_robust_entry() function
gets renamed to compat_fetch_robust_entry() to avoid a symbol clash.
This is intended as a purely cosmetic patch, no behavior should
change.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Lee: Back-ported to satisfy a build dependency] Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>