After fixing the tail_lsn vs cache flush race, generic/482 continued
to fail in a similar way where cache flushes were missing before
iclog FUA writes. Tracing of iclog state changes during the fsstress
workload portion of the test (via xlog_iclog* events) indicated that
iclog writes were coming from two sources - CIL pushes and log
forces (due to fsync/O_SYNC operations). All of the cases where a
recovery problem was triggered indicated that the log force was the
source of the iclog write that was not preceeded by a cache flush.
This was an oversight in the modifications made in commit
eef983ffea ("xfs: journal IO cache flush reductions"). Log forces
for fsync imply a data device cache flush has been issued if an
iclog was flushed to disk and is indicated to the caller via the
log_flushed parameter so they can elide the device cache flush if
the journal issued one.
The change in eef983ffea results in iclogs only issuing a cache
flush if XLOG_ICL_NEED_FLUSH is set on the iclog, but this was not
added to the iclogs that the log force code flushes to disk. Hence
log forces are no longer guaranteeing that a cache flush is issued,
hence opening up a potential on-disk ordering failure.
Log forces should also set XLOG_ICL_NEED_FUA as well to ensure that
the actual iclogs it forces to the journal are also on stable
storage before it returns to the caller.
This patch introduces the xlog_force_iclog() helper function to
encapsulate the process of taking a reference to an iclog, switching
its state if WANT_SYNC and flushing it to stable storage correctly.
Both xfs_log_force() and xfs_log_force_lsn() are converted to use
it, as is xlog_unmount_write() which has an elaborate method of
doing exactly the same "write this iclog to stable storage"
operation.
Further, if the log force code needs to wait on a iclog in the
WANT_SYNC state, it needs to ensure that iclog also results in a
cache flush being issued. This covers the case where the iclog
contains the commit record of the CIL flush that the log force
triggered, but it hasn't been written yet because there is still an
active reference to the iclog.
Note: this whole cache flush whack-a-mole patch is a result of log
forces still being iclog state centric rather than being CIL
sequence centric. Most of this nasty code will go away in future
when log forces are converted to wait on CIL sequence push
completion rather than iclog completion. With the CIL push algorithm
guaranteeing that the CIL checkpoint is fully on stable storage when
it completes, we no longer need to iterate iclogs and push them to
ensure a CIL sequence push has completed and so all this nasty iclog
iteration and flushing code will go away.
Fixes: eef983ffea ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
We force iclogs in several places - we need them all to have the
same cache flush semantics, so start by factoring out the iclog
force into a common helper.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
There is a race between the new CIL async data device metadata IO
completion cache flush and the log tail in the iclog the flush
covers being updated. This can be seen by repeating generic/482 in a
loop and eventually log recovery fails with a failures such as this:
XFS (dm-3): Starting recovery (logdev: internal)
XFS (dm-3): bad inode magic/vsn daddr 228352 #0 (magic=0)
XFS (dm-3): Metadata corruption detected at xfs_inode_buf_verify+0x180/0x190, xfs_inode block 0x37c00 xfs_inode_buf_verify
XFS (dm-3): Unmount and run xfs_repair
XFS (dm-3): First 128 bytes of corrupted metadata buffer:
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
XFS (dm-3): metadata I/O error in "xlog_recover_items_pass2+0x55/0xc0" at daddr 0x37c00 len 32 error 117
Analysis of the logwrite replay shows that there were no writes to
the data device between the FUA @ write 124 and the FUA at write @
125, but log recovery @ 125 failed. The difference was the one log
write @ 125 moved the tail of the log forwards from (1,8) to (1,32)
and so the inode create intent in (1,8) was not replayed and so the
inode cluster was zero on disk when replay of the first inode item
in (1,32) was attempted.
What this meant was that the journal write that occurred at @ 125
did not ensure that metadata completed before the iclog was written
was correctly on stable storage. The tail of the log moved forward,
so IO must have been completed between the two iclog writes. This
means that there is a race condition between the unconditional async
cache flush in the CIL push work and the tail LSN that is written to
the iclog. This happens like so:
CIL push work AIL push work
------------- -------------
Add to committing list
start async data dev cache flush
.....
<flush completes>
<all writes to old tail lsn are stable>
xlog_write
.... push inode create buffer
<start IO>
.....
xlog_write(commit record)
.... <IO completes>
log tail moves
xlog_assign_tail_lsn()
start_lsn == commit_lsn
<no iclog preflush!>
xlog_state_release_iclog
__xlog_state_release_iclog()
<writes *new* tail_lsn into iclog>
xlog_sync()
....
submit_bio()
<tail in log moves forward without flushing written metadata>
Essentially, this can only occur if the commit iclog is issued
without a cache flush. If the iclog bio is submitted with
REQ_PREFLUSH, then it will guarantee that all the completed IO is
one stable storage before the iclog bio with the new tail LSN in it
is written to the log.
IOWs, the tail lsn that is written to the iclog needs to be sampled
*before* we issue the cache flush that guarantees all IO up to that
LSN has been completed.
To fix this without giving up the performance advantage of the
flush/FUA optimisations (e.g. g/482 runtime halves with 5.14-rc1
compared to 5.13), we need to ensure that we always issue a cache
flush if the tail LSN changes between the initial async flush and
the commit record being written. THis requires sampling the tail_lsn
before we start the flush, and then passing the sampled tail LSN to
xlog_state_release_iclog() so it can determine if the the tail LSN
has changed while writing the checkpoint. If the tail LSN has
changed, then it needs to set the NEED_FLUSH flag on the iclog and
we'll issue another cache flush before writing the iclog.
Fixes: eef983ffea ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Fold __xlog_state_release_iclog into its only caller to prepare
make an upcoming fix easier.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The recent journal flush/FUA changes replaced the flushing of the
data device on every iclog write with an up-front async data device
cache flush. Unfortunately, the assumption of which this was based
on has been proven incorrect by the flush vs log tail update
ordering issue. As the fix for that issue uses the
XLOG_ICL_NEED_FLUSH flag to indicate that data device needs a cache
flush, we now need to (once again) ensure that an iclog write to
external logs that need a cache flush to be issued actually issue a
cache flush to the data device as well as the log device.
Fixes: eef983ffea ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
We incorrectly flush the log device instead of the data device when
trying to ensure metadata is correctly on disk before writing the
unmount record.
Fixes: eef983ffea ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The Go runtime uses r30 for some special value called 'g'. It assumes
that value will remain unchanged even when calling VDSO functions.
Although r30 is non-volatile across function calls, the callee is free
to use it, as long as the callee saves the value and restores it before
returning.
It used to be true by accident that the VDSO didn't use r30, because the
VDSO was hand-written asm. When we switched to building the VDSO from C
the compiler started using r30, at least in some builds, leading to
crashes in Go. eg:
~/go/src$ ./all.bash
Building Go cmd/dist using /usr/lib/go-1.16. (go1.16.2 linux/ppc64le)
Building Go toolchain1 using /usr/lib/go-1.16.
go build os/exec: /usr/lib/go-1.16/pkg/tool/linux_ppc64le/compile: signal: segmentation fault
go build reflect: /usr/lib/go-1.16/pkg/tool/linux_ppc64le/compile: signal: segmentation fault
go tool dist: FAILED: /usr/lib/go-1.16/bin/go install -gcflags=-l -tags=math_big_pure_go compiler_bootstrap bootstrap/cmd/...: exit status 1
There are patches in flight to fix Go[1], but until they are released
and widely deployed we can workaround it in the VDSO by avoiding use of
r30.
Note this only works with GCC, clang does not support -ffixed-rN.
1: https://go-review.googlesource.com/c/go/+/328110
Fixes: ab037dd87a ("powerpc/vdso: Switch VDSO to generic C implementation.")
Cc: stable@vger.kernel.org # v5.11+
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210729131244.2595519-1-mpe@ellerman.id.au
With commit c9f3401313 ("powerpc: Always enable queued spinlocks for
64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always
enabled on ppc64le, external modules that use spinlock APIs are
failing.
ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor'
Before the above commit, modules were able to build without any
issues. Also this problem is not seen on other architectures. This
problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in
the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by
default and only enabled in certain conditions like
CONFIG_DEBUG_SPINLOCKS is set in the kernel config.
#include <linux/module.h>
spinlock_t spLock;
static int __init spinlock_test_init(void)
{
spin_lock_init(&spLock);
spin_lock(&spLock);
spin_unlock(&spLock);
return 0;
}
static void __exit spinlock_test_exit(void)
{
printk("spinlock_test unloaded\n");
}
module_init(spinlock_test_init);
module_exit(spinlock_test_exit);
MODULE_DESCRIPTION ("spinlock_test");
MODULE_LICENSE ("non-GPL");
MODULE_AUTHOR ("Srikar Dronamraju");
Given that spin locks are one of the basic facilities for module code,
this effectively makes it impossible to build/load almost any non GPL
modules on ppc64le.
This was first reported at https://github.com/openzfs/zfs/issues/11172
Currently shared_processor is exported as GPL only symbol.
Fix this for parity with other architectures by exposing
shared_processor to non-GPL modules too.
Fixes: 14c73bd344 ("powerpc/vcpu: Assume dedicated processors as non-preempt")
Cc: stable@vger.kernel.org # v5.5+
Reported-by: marc.c.dionne@gmail.com
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210729060449.292780-1-srikar@linux.vnet.ibm.com
Building with -Warray-bounds on systems with 64K pages there's a
warning:
fs/btrfs/disk-io.c: In function ‘csum_tree_block’:
fs/btrfs/disk-io.c:226:34: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds]
226 | kaddr = page_address(buf->pages[i]);
| ~~~~~~~~~~^~~
./include/linux/mm.h:1630:48: note: in definition of macro ‘page_address’
1630 | #define page_address(page) lowmem_page_address(page)
| ^~~~
In file included from fs/btrfs/ctree.h:32,
from fs/btrfs/disk-io.c:23:
fs/btrfs/extent_io.h:98:15: note: while referencing ‘pages’
98 | struct page *pages[1];
| ^~~~~
The compiler has no way to know that in that case the nodesize is exactly
PAGE_SIZE, so the resulting number of pages will be correct (1).
Let's use num_extent_pages that makes the case nodesize == PAGE_SIZE
explicitly 1.
Reported-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit fixes a functional regression introduced by the commit 82f09a637d
("HID: ft260: improve error handling of ft260_hid_feature_report_get()")
when upon USB disconnect, the FTDI FT260 i2c device is still available within
the /dev folder.
In my company's product, where the host USB to FT260 USB connection is
hard-wired in the PCB, the issue is not reproducible. To reproduce it, I used
the VirtualBox Ubuntu 20.04 VM and the UMFT260EV1A development module for the
FTDI FT260 chip:
Plug the UMFT260EV1A module into a USB port and attach it to VM.
The VM shows 2 i2c devices under the /dev:
michael@michael-VirtualBox:~$ ls /dev/i2c-*
/dev/i2c-0 /dev/i2c-1
The i2c-0 is not related to the FTDI FT260:
michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-0/name
SMBus PIIX4 adapter at 4100
The i2c-1 is created by hid-ft260.ko:
michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-1/name
FT260 usb-i2c bridge on hidraw1
Now, detach the FTDI FT260 USB device from VM. We expect the /dev/i2c-1
to disappear, but it's still here:
michael@michael-VirtualBox:~$ ls /dev/i2c-*
/dev/i2c-0 /dev/i2c-1
And the kernel log shows:
[ +0.001202] usb 2-2: USB disconnect, device number 3
[ +0.000109] ft260 0003:0403:6030.0002: failed to retrieve system status
[ +0.000316] ft260 0003:0403:6030.0003: failed to retrieve system status
It happens because the commit 82f09a637d changed the ft260_get_system_config()
return logic. This caused the ft260_is_interface_enabled() to exit with error
upon the FT260 device USB disconnect, which in turn, aborted the ft260_remove()
before deleting the FT260 i2c device and cleaning its sysfs stuff.
This commit restores the FT260 USB removal functionality and improves the
ft260_is_interface_enabled() code to handle correctly all chip modes defined
by the device interface configuration pins DCNF0 and DCNF1.
Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Acked-by: Aaron Jones (FTDI-UK) <aaron.jones@ftdichip.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The memory reserved by console/PALcode or non-volatile memory is not added
to memblock.memory.
Since commit fa3354e4ea (mm: free_area_init: use maximal zone PFNs rather
than zone sizes) the initialization of the memory map relies on the
accuracy of memblock.memory to properly calculate zone sizes. The holes in
memblock.memory caused by absent regions reserved by the firmware cause
incorrect initialization of struct pages which leads to BUG() during the
initial page freeing:
BUG: Bad page state in process swapper pfn:2ffc53
page:fffffc000ecf14c0 refcount:0 mapcount:1 mapping:0000000000000000 index:0x0
flags: 0x0()
raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-03841-gfa3354e4ea39-dirty #26
fffffc0001b5bd68 fffffc0001b5be80 fffffc00011cd148 fffffc000ecf14c0
fffffc00019803df fffffc0001b5be80 fffffc00011ce340 fffffc000ecf14c0
0000000000000000 fffffc0001b5be80 fffffc0001b482c0 fffffc00027d6618
fffffc00027da7d0 00000000002ff97a 0000000000000000 fffffc0001b5be80
fffffc00011d1abc fffffc000ecf14c0 fffffc0002d00000 fffffc0001b5be80
fffffc0001b2350c 0000000000300000 fffffc0001b48298 fffffc0001b482c0
Trace:
[<fffffc00011cd148>] bad_page+0x168/0x1b0
[<fffffc00011ce340>] free_pcp_prepare+0x1e0/0x290
[<fffffc00011d1abc>] free_unref_page+0x2c/0xa0
[<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30
[<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30
[<fffffc000101001c>] _stext+0x1c/0x20
Fix this by registering the reserved ranges in memblock.memory.
Link: https://lore.kernel.org/lkml/20210726192311.uffqnanxw3ac5wwi@ivybridge
Fixes: fa3354e4ea ("mm: free_area_init: use maximal zone PFNs rather than zone sizes")
Reported-by: Matt Turner <mattst88@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
- Fix vbt port mask
- Fix around reading the right DSC disable fuse in display_ver 10
- Split display version 9 and 10 in intel_setup_outputs
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEbSBwaO7dZQkcLOKj+mJfZA7rE8oFAmEBetMACgkQ+mJfZA7r
E8r3gwgAnGKsblTbSYahQp8syGDgsVZ9/lykUWCrzk+oRfkZmpQrkclEQmCkVe9t
QliEK4aLdEB5FHvpgsNaxArVbU9PiDbFJ9HRGjNV5HlNavvvEFCoD92iegqrDWAu
l79VySq5umeTczf7yGJ8+wygh11lVe7RCeUu5iZUD5LdngNJe/ukkMU5Mxad+xok
iHFKm8UpDDWm+9SfT0Nuf68NdZlM57AQumtLExWeMwypgDahr/r/A2wMiGS0XXdc
wikAOodB5y664TMGclfZNbF6OIEEX1awuHsB3uxQBmYWui+DuROD12D6VOkPmhF8
7dVu17jXvh8e9Mva2eAJ4AlJRc9r2w==
=OV5Z
-----END PGP SIGNATURE-----
Merge tag 'drm-intel-fixes-2021-07-28' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes
Display related fixes:
- Fix vbt port mask
- Fix around reading the right DSC disable fuse in display_ver 10
- Split display version 9 and 10 in intel_setup_outputs
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YQF63ruuE72x2T45@intel.com
Daniel Borkmann says:
====================
pull-request: bpf 2021-07-29
The following pull-request contains BPF updates for your *net* tree.
We've added 9 non-merge commits during the last 14 day(s) which contain
a total of 20 files changed, 446 insertions(+), 138 deletions(-).
The main changes are:
1) Fix UBSAN out-of-bounds splat for showing XDP link fdinfo, from Lorenz Bauer.
2) Fix insufficient Spectre v4 mitigation in BPF runtime, from Daniel Borkmann,
Piotr Krysiuk and Benedict Schlueter.
3) Batch of fixes for BPF sockmap found under stress testing, from John Fastabend.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Spectre v4 gadgets make use of memory disambiguation, which is a set of
techniques that execute memory access instructions, that is, loads and
stores, out of program order; Intel's optimization manual, section 2.4.4.5:
A load instruction micro-op may depend on a preceding store. Many
microarchitectures block loads until all preceding store addresses are
known. The memory disambiguator predicts which loads will not depend on
any previous stores. When the disambiguator predicts that a load does
not have such a dependency, the load takes its data from the L1 data
cache. Eventually, the prediction is verified. If an actual conflict is
detected, the load and all succeeding instructions are re-executed.
af86ca4e30 ("bpf: Prevent memory disambiguation attack") tried to mitigate
this attack by sanitizing the memory locations through preemptive "fast"
(low latency) stores of zero prior to the actual "slow" (high latency) store
of a pointer value such that upon dependency misprediction the CPU then
speculatively executes the load of the pointer value and retrieves the zero
value instead of the attacker controlled scalar value previously stored at
that location, meaning, subsequent access in the speculative domain is then
redirected to the "zero page".
The sanitized preemptive store of zero prior to the actual "slow" store is
done through a simple ST instruction based on r10 (frame pointer) with
relative offset to the stack location that the verifier has been tracking
on the original used register for STX, which does not have to be r10. Thus,
there are no memory dependencies for this store, since it's only using r10
and immediate constant of zero; hence af86ca4e30 /assumed/ a low latency
operation.
However, a recent attack demonstrated that this mitigation is not sufficient
since the preemptive store of zero could also be turned into a "slow" store
and is thus bypassed as well:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
31: (7b) *(u64 *)(r10 -16) = r2
// r9 will remain "fast" register, r10 will become "slow" register below
32: (bf) r9 = r10
// JIT maps BPF reg to x86 reg:
// r9 -> r15 (callee saved)
// r10 -> rbp
// train store forward prediction to break dependency link between both r9
// and r10 by evicting them from the predictor's LRU table.
33: (61) r0 = *(u32 *)(r7 +24576)
34: (63) *(u32 *)(r7 +29696) = r0
35: (61) r0 = *(u32 *)(r7 +24580)
36: (63) *(u32 *)(r7 +29700) = r0
37: (61) r0 = *(u32 *)(r7 +24584)
38: (63) *(u32 *)(r7 +29704) = r0
39: (61) r0 = *(u32 *)(r7 +24588)
40: (63) *(u32 *)(r7 +29708) = r0
[...]
543: (61) r0 = *(u32 *)(r7 +25596)
544: (63) *(u32 *)(r7 +30716) = r0
// prepare call to bpf_ringbuf_output() helper. the latter will cause rbp
// to spill to stack memory while r13/r14/r15 (all callee saved regs) remain
// in hardware registers. rbp becomes slow due to push/pop latency. below is
// disasm of bpf_ringbuf_output() helper for better visual context:
//
// ffffffff8117ee20: 41 54 push r12
// ffffffff8117ee22: 55 push rbp
// ffffffff8117ee23: 53 push rbx
// ffffffff8117ee24: 48 f7 c1 fc ff ff ff test rcx,0xfffffffffffffffc
// ffffffff8117ee2b: 0f 85 af 00 00 00 jne ffffffff8117eee0 <-- jump taken
// [...]
// ffffffff8117eee0: 49 c7 c4 ea ff ff ff mov r12,0xffffffffffffffea
// ffffffff8117eee7: 5b pop rbx
// ffffffff8117eee8: 5d pop rbp
// ffffffff8117eee9: 4c 89 e0 mov rax,r12
// ffffffff8117eeec: 41 5c pop r12
// ffffffff8117eeee: c3 ret
545: (18) r1 = map[id:4]
547: (bf) r2 = r7
548: (b7) r3 = 0
549: (b7) r4 = 4
550: (85) call bpf_ringbuf_output#194288
// instruction 551 inserted by verifier \
551: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
// storing map value pointer r7 at fp-16 | since value of r10 is "slow".
552: (7b) *(u64 *)(r10 -16) = r7 /
// following "fast" read to the same memory location, but due to dependency
// misprediction it will speculatively execute before insn 551/552 completes.
553: (79) r2 = *(u64 *)(r9 -16)
// in speculative domain contains attacker controlled r2. in non-speculative
// domain this contains r7, and thus accesses r7 +0 below.
554: (71) r3 = *(u8 *)(r2 +0)
// leak r3
As can be seen, the current speculative store bypass mitigation which the
verifier inserts at line 551 is insufficient since /both/, the write of
the zero sanitation as well as the map value pointer are a high latency
instruction due to prior memory access via push/pop of r10 (rbp) in contrast
to the low latency read in line 553 as r9 (r15) which stays in hardware
registers. Thus, architecturally, fp-16 is r7, however, microarchitecturally,
fp-16 can still be r2.
Initial thoughts to address this issue was to track spilled pointer loads
from stack and enforce their load via LDX through r10 as well so that /both/
the preemptive store of zero /as well as/ the load use the /same/ register
such that a dependency is created between the store and load. However, this
option is not sufficient either since it can be bypassed as well under
speculation. An updated attack with pointer spill/fills now _all_ based on
r10 would look as follows:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
[...]
// longer store forward prediction training sequence than before.
2062: (61) r0 = *(u32 *)(r7 +25588)
2063: (63) *(u32 *)(r7 +30708) = r0
2064: (61) r0 = *(u32 *)(r7 +25592)
2065: (63) *(u32 *)(r7 +30712) = r0
2066: (61) r0 = *(u32 *)(r7 +25596)
2067: (63) *(u32 *)(r7 +30716) = r0
// store the speculative load address (scalar) this time after the store
// forward prediction training.
2068: (7b) *(u64 *)(r10 -16) = r2
// preoccupy the CPU store port by running sequence of dummy stores.
2069: (63) *(u32 *)(r7 +29696) = r0
2070: (63) *(u32 *)(r7 +29700) = r0
2071: (63) *(u32 *)(r7 +29704) = r0
2072: (63) *(u32 *)(r7 +29708) = r0
2073: (63) *(u32 *)(r7 +29712) = r0
2074: (63) *(u32 *)(r7 +29716) = r0
2075: (63) *(u32 *)(r7 +29720) = r0
2076: (63) *(u32 *)(r7 +29724) = r0
2077: (63) *(u32 *)(r7 +29728) = r0
2078: (63) *(u32 *)(r7 +29732) = r0
2079: (63) *(u32 *)(r7 +29736) = r0
2080: (63) *(u32 *)(r7 +29740) = r0
2081: (63) *(u32 *)(r7 +29744) = r0
2082: (63) *(u32 *)(r7 +29748) = r0
2083: (63) *(u32 *)(r7 +29752) = r0
2084: (63) *(u32 *)(r7 +29756) = r0
2085: (63) *(u32 *)(r7 +29760) = r0
2086: (63) *(u32 *)(r7 +29764) = r0
2087: (63) *(u32 *)(r7 +29768) = r0
2088: (63) *(u32 *)(r7 +29772) = r0
2089: (63) *(u32 *)(r7 +29776) = r0
2090: (63) *(u32 *)(r7 +29780) = r0
2091: (63) *(u32 *)(r7 +29784) = r0
2092: (63) *(u32 *)(r7 +29788) = r0
2093: (63) *(u32 *)(r7 +29792) = r0
2094: (63) *(u32 *)(r7 +29796) = r0
2095: (63) *(u32 *)(r7 +29800) = r0
2096: (63) *(u32 *)(r7 +29804) = r0
2097: (63) *(u32 *)(r7 +29808) = r0
2098: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; same as before, also including the
// sanitation store with 0 from the current mitigation by the verifier.
2099: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
2100: (7b) *(u64 *)(r10 -16) = r7 | since store unit is still busy.
// load from stack intended to bypass stores.
2101: (79) r2 = *(u64 *)(r10 -16)
2102: (71) r3 = *(u8 *)(r2 +0)
// leak r3
[...]
Looking at the CPU microarchitecture, the scheduler might issue loads (such
as seen in line 2101) before stores (line 2099,2100) because the load execution
units become available while the store execution unit is still busy with the
sequence of dummy stores (line 2069-2098). And so the load may use the prior
stored scalar from r2 at address r10 -16 for speculation. The updated attack
may work less reliable on CPU microarchitectures where loads and stores share
execution resources.
This concludes that the sanitizing with zero stores from af86ca4e30 ("bpf:
Prevent memory disambiguation attack") is insufficient. Moreover, the detection
of stack reuse from af86ca4e30 where previously data (STACK_MISC) has been
written to a given stack slot where a pointer value is now to be stored does
not have sufficient coverage as precondition for the mitigation either; for
several reasons outlined as follows:
1) Stack content from prior program runs could still be preserved and is
therefore not "random", best example is to split a speculative store
bypass attack between tail calls, program A would prepare and store the
oob address at a given stack slot and then tail call into program B which
does the "slow" store of a pointer to the stack with subsequent "fast"
read. From program B PoV such stack slot type is STACK_INVALID, and
therefore also must be subject to mitigation.
2) The STACK_SPILL must not be coupled to register_is_const(&stack->spilled_ptr)
condition, for example, the previous content of that memory location could
also be a pointer to map or map value. Without the fix, a speculative
store bypass is not mitigated in such precondition and can then lead to
a type confusion in the speculative domain leaking kernel memory near
these pointer types.
While brainstorming on various alternative mitigation possibilities, we also
stumbled upon a retrospective from Chrome developers [0]:
[...] For variant 4, we implemented a mitigation to zero the unused memory
of the heap prior to allocation, which cost about 1% when done concurrently
and 4% for scavenging. Variant 4 defeats everything we could think of. We
explored more mitigations for variant 4 but the threat proved to be more
pervasive and dangerous than we anticipated. For example, stack slots used
by the register allocator in the optimizing compiler could be subject to
type confusion, leading to pointer crafting. Mitigating type confusion for
stack slots alone would have required a complete redesign of the backend of
the optimizing compiler, perhaps man years of work, without a guarantee of
completeness. [...]
From BPF side, the problem space is reduced, however, options are rather
limited. One idea that has been explored was to xor-obfuscate pointer spills
to the BPF stack:
[...]
// preoccupy the CPU store port by running sequence of dummy stores.
[...]
2106: (63) *(u32 *)(r7 +29796) = r0
2107: (63) *(u32 *)(r7 +29800) = r0
2108: (63) *(u32 *)(r7 +29804) = r0
2109: (63) *(u32 *)(r7 +29808) = r0
2110: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; xored with random 'secret' value
// of 943576462 before store ...
2111: (b4) w11 = 943576462
2112: (af) r11 ^= r7
2113: (7b) *(u64 *)(r10 -16) = r11
2114: (79) r11 = *(u64 *)(r10 -16)
2115: (b4) w2 = 943576462
2116: (af) r2 ^= r11
// ... and restored with the same 'secret' value with the help of AX reg.
2117: (71) r3 = *(u8 *)(r2 +0)
[...]
While the above would not prevent speculation, it would make data leakage
infeasible by directing it to random locations. In order to be effective
and prevent type confusion under speculation, such random secret would have
to be regenerated for each store. The additional complexity involved for a
tracking mechanism that prevents jumps such that restoring spilled pointers
would not get corrupted is not worth the gain for unprivileged. Hence, the
fix in here eventually opted for emitting a non-public BPF_ST | BPF_NOSPEC
instruction which the x86 JIT translates into a lfence opcode. Inserting the
latter in between the store and load instruction is one of the mitigations
options [1]. The x86 instruction manual notes:
[...] An LFENCE that follows an instruction that stores to memory might
complete before the data being stored have become globally visible. [...]
The latter meaning that the preceding store instruction finished execution
and the store is at minimum guaranteed to be in the CPU's store queue, but
it's not guaranteed to be in that CPU's L1 cache at that point (globally
visible). The latter would only be guaranteed via sfence. So the load which
is guaranteed to execute after the lfence for that local CPU would have to
rely on store-to-load forwarding. [2], in section 2.3 on store buffers says:
[...] For every store operation that is added to the ROB, an entry is
allocated in the store buffer. This entry requires both the virtual and
physical address of the target. Only if there is no free entry in the store
buffer, the frontend stalls until there is an empty slot available in the
store buffer again. Otherwise, the CPU can immediately continue adding
subsequent instructions to the ROB and execute them out of order. On Intel
CPUs, the store buffer has up to 56 entries. [...]
One small upside on the fix is that it lifts constraints from af86ca4e30
where the sanitize_stack_off relative to r10 must be the same when coming
from different paths. The BPF_ST | BPF_NOSPEC gets emitted after a BPF_STX
or BPF_ST instruction. This happens either when we store a pointer or data
value to the BPF stack for the first time, or upon later pointer spills.
The former needs to be enforced since otherwise stale stack data could be
leaked under speculation as outlined earlier. For non-x86 JITs the BPF_ST |
BPF_NOSPEC mapping is currently optimized away, but others could emit a
speculation barrier as well if necessary. For real-world unprivileged
programs e.g. generated by LLVM, pointer spill/fill is only generated upon
register pressure and LLVM only tries to do that for pointers which are not
used often. The program main impact will be the initial BPF_ST | BPF_NOSPEC
sanitation for the STACK_INVALID case when the first write to a stack slot
occurs e.g. upon map lookup. In future we might refine ways to mitigate
the latter cost.
[0] https://arxiv.org/pdf/1902.05178.pdf
[1] https://msrc-blog.microsoft.com/2018/05/21/analysis-and-mitigation-of-speculative-store-bypass-cve-2018-3639/
[2] https://arxiv.org/pdf/1905.05725.pdf
Fixes: af86ca4e30 ("bpf: Prevent memory disambiguation attack")
Fixes: f7cf25b202 ("bpf: track spill/fill of constants")
Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.
This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.
The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.
Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
We lost parsing of backupuid in the switch to new mount API.
Add it back.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: <stable@vger.kernel.org> # v5.11+
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAmEBWkcACgkQnJ2qBz9k
QNlc2Af/dJBIzZmwPiqW/3vg8/2NihuKnhlkR0ytF5pGswDiZ/3jpNoapz53UeMy
is73PwCqrBYII923Q//+TsiRSGELbmo5nY+xRKlAmg4yovVti+/fgkg2sYdHLfz5
SwMpZjtpqnJ6sfKY6wnN4nXJ0JfGR6Q52wfMWmYQbpQaHLPy1XVUBmKKh+TKwuqy
5S7OhYQ/sml3pdlHhQ5AoG0glgM12DiC5DvqJjwThWmZbsGNfpOw578XC9suCdKJ
6/Wvxm2KiKcltoSb/5LzRTOSIJNtBX7XXwUQewRXnXclEbZYhb5cob/HBkoAU0Nw
4LxVXzxnF3SDwx1thtkgoJ6qUclDWg==
=/q9+
-----END PGP SIGNATURE-----
Merge tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext2 and reiserfs fixes from Jan Kara:
"A fix for the ext2 conversion to kmap_local() and two reiserfs
hardening fixes"
* tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
reiserfs: check directory items on read from disk
fs/ext2: Avoid page_address on pages returned by ext2_get_page
reiserfs: add check for root_inode in reiserfs_fill_super
Highlights:
-amd-pmc fixes
-think-lmi fixes
-Various new hardware-ids
The following is an automated git shortlog grouped by driver:
amd-pmc:
- Fix undefined reference to __udivdi3
- Fix missing unlock on error in amd_pmc_send_cmd()
- Use return code on suspend
- Add new acpi id for future PMC controllers
- Add support for ACPI ID AMDI0006
- Add support for logging s0ix counters
- Add support for logging SMU metrics
- call dump registers only once
- Fix SMU firmware reporting mechanism
- Fix command completion code
gigabyte-wmi:
- add support for B550 Aorus Elite V2
intel-hid:
- add Alder Lake ACPI device ID
think-lmi:
- Fix possible mem-leaks on tlmi_analyze() error-exit
- Split kobject_init() and kobject_add() calls
- Move pending_reboot_attr to the attributes sysfs dir
- Add pending_reboot support
wireless-hotkey:
- remove hardcoded "hp" from the error message
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEEuvA7XScYQRpenhd+kuxHeUQDJ9wFAmEBMfkUHGhkZWdvZWRl
QHJlZGhhdC5jb20ACgkQkuxHeUQDJ9yZ4AgAiYKZubpQ4CflNZ3PkSHtL8rb3Pqy
lfM/bkTKi2u718yDMSxQrBslXxXsjyuzQ9/F2kxm21YL8R5G66QTXqayWFFPjtvo
7iiBv7JzP6vD132TwTiKZj6XRu2d0kXIbwGiK+nddXfOvDFwAMXiKDevVXqHXA2q
llxDLEHYzst3JynJMsD3uaZiDw309DU++ElX0hCBEAnkJ0rVnPTcKbEys74hmRph
0D3GFkZKsHFcuvPUK6tC8fwLvV3fQaTVxp17cmE6b5OhADJSSQoJWjiMe7kFNnHk
9WrSCUfd2bXJqNBEpSmNuJ9L5I9zTCqrjwWFf126fdp1c1I1DUfw6LvLlg==
=iuFO
-----END PGP SIGNATURE-----
Merge tag 'platform-drivers-x86-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver fixes from Hans de Goede:
"A set of bug-fixes and new hardware ids.
Highlights:
- amd-pmc fixes
- think-lmi fixes
- various new hardware-ids"
* tag 'platform-drivers-x86-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
platform/x86: gigabyte-wmi: add support for B550 Aorus Elite V2
platform/x86: intel-hid: add Alder Lake ACPI device ID
platform/x86: think-lmi: Fix possible mem-leaks on tlmi_analyze() error-exit
platform/x86: think-lmi: Split kobject_init() and kobject_add() calls
platform/x86: think-lmi: Move pending_reboot_attr to the attributes sysfs dir
platform/x86: amd-pmc: Fix undefined reference to __udivdi3
platform/x86: amd-pmc: Fix missing unlock on error in amd_pmc_send_cmd()
platform/x86: wireless-hotkey: remove hardcoded "hp" from the error message
platform/x86: amd-pmc: Use return code on suspend
platform/x86: amd-pmc: Add new acpi id for future PMC controllers
platform/x86: amd-pmc: Add support for ACPI ID AMDI0006
platform/x86: amd-pmc: Add support for logging s0ix counters
platform/x86: amd-pmc: Add support for logging SMU metrics
platform/x86: amd-pmc: call dump registers only once
platform/x86: amd-pmc: Fix SMU firmware reporting mechanism
platform/x86: amd-pmc: Fix command completion code
platform/x86: think-lmi: Add pending_reboot support
This file was given GPL-2.0 license. But LGPL-2.1 makes more sense
as it needs to be used by libraries outside of the kernel source tree.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
unix_gc() assumes that candidate sockets can never gain an external
reference (i.e. be installed into an fd) while the unix_gc_lock is
held. Except for MSG_PEEK this is guaranteed by modifying inflight
count under the unix_gc_lock.
MSG_PEEK does not touch any variable protected by unix_gc_lock (file
count is not), yet it needs to be serialized with garbage collection.
Do this by locking/unlocking unix_gc_lock:
1) increment file count
2) lock/unlock barrier to make sure incremented file count is visible
to garbage collection
3) install file into fd
This is a lock barrier (unlike smp_mb()) that ensures that garbage
collection is run completely before or completely after the barrier.
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When removing a writeable device in __btrfs_free_extra_devids, the rw
device count should be decremented.
This error was caught by Syzbot which reported a warning in
close_fs_devices:
WARNING: CPU: 1 PID: 9355 at fs/btrfs/volumes.c:1168 close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168
Modules linked in:
CPU: 0 PID: 9355 Comm: syz-executor552 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168
RSP: 0018:ffffc9000333f2f0 EFLAGS: 00010293
RAX: ffffffff8365f5c3 RBX: 0000000000000001 RCX: ffff888029afd4c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88802846f508 R08: ffffffff8365f525 R09: ffffed100337d128
R10: ffffed100337d128 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888019be8868 R14: 1ffff1100337d10d R15: 1ffff1100337d10a
FS: 00007f6f53828700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000047c410 CR3: 00000000302a6000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_close_devices+0xc9/0x450 fs/btrfs/volumes.c:1180
open_ctree+0x8e1/0x3968 fs/btrfs/disk-io.c:3693
btrfs_fill_super fs/btrfs/super.c:1382 [inline]
btrfs_mount_root+0xac5/0xc60 fs/btrfs/super.c:1749
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1498
fc_mount fs/namespace.c:993 [inline]
vfs_kern_mount+0xc9/0x160 fs/namespace.c:1023
btrfs_mount+0x3d3/0xb50 fs/btrfs/super.c:1809
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x196f/0x2be0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
Because fs_devices->rw_devices was not 0 after
closing all devices. Here is the call trace that was observed:
btrfs_mount_root():
btrfs_scan_one_device():
device_list_add(); <---------------- device added
btrfs_open_devices():
open_fs_devices():
btrfs_open_one_device(); <-------- writable device opened,
rw device count ++
btrfs_fill_super():
open_ctree():
btrfs_free_extra_devids():
__btrfs_free_extra_devids(); <--- writable device removed,
rw device count not decremented
fail_tree_roots:
btrfs_close_devices():
close_fs_devices(); <------- rw device count off by 1
As a note, prior to commit cf89af146b ("btrfs: dev-replace: fail
mount if we don't have replace item with target device"), rw_devices
was decremented on removing a writable device in
__btrfs_free_extra_devids only if the BTRFS_DEV_STATE_REPLACE_TGT bit
was not set for the device. However, this check does not need to be
reinstated as it is now redundant and incorrect.
In __btrfs_free_extra_devids, we skip removing the device if it is the
target for replacement. This is done by checking whether device->devid
== BTRFS_DEV_REPLACE_DEVID. Since BTRFS_DEV_STATE_REPLACE_TGT is set
only on the device with devid BTRFS_DEV_REPLACE_DEVID, no devices
should have the BTRFS_DEV_STATE_REPLACE_TGT bit set after the check,
and so it's redundant to test for that bit.
Additionally, following commit 82372bc816 ("Btrfs: make
the logic of source device removing more clear"), rw_devices is
incremented whenever a writeable device is added to the alloc
list (including the target device in btrfs_dev_replace_finishing), so
all removals of writable devices from the alloc list should also be
accompanied by a decrement to rw_devices.
Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Fixes: cf89af146b ("btrfs: dev-replace: fail mount if we don't have replace item with target device")
CC: stable@vger.kernel.org # 5.10+
Tested-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When checking if we need to log the new name of a renamed inode, we are
checking if the inode and its parent inode have been logged before, and if
not we don't log the new name. The check however is buggy, as it directly
compares the logged_trans field of the inodes versus the ID of the current
transaction. The problem is that logged_trans is a transient field, only
stored in memory and never persisted in the inode item, so if an inode
was logged before, evicted and reloaded, its logged_trans field is set to
a value of 0, meaning the check will return false and the new name of the
renamed inode is not logged. If the old parent directory was previously
fsynced and we deleted the logged directory entries corresponding to the
old name, we end up with a log that when replayed will delete the renamed
inode.
The following example triggers the problem:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ mkdir /mnt/A
$ mkdir /mnt/B
$ echo -n "hello world" > /mnt/A/foo
$ sync
# Add some new file to A and fsync directory A.
$ touch /mnt/A/bar
$ xfs_io -c "fsync" /mnt/A
# Now trigger inode eviction. We are only interested in triggering
# eviction for the inode of directory A.
$ echo 2 > /proc/sys/vm/drop_caches
# Move foo from directory A to directory B.
# This deletes the directory entries for foo in A from the log, and
# does not add the new name for foo in directory B to the log, because
# logged_trans of A is 0, which is less than the current transaction ID.
$ mv /mnt/A/foo /mnt/B/foo
# Now make an fsync to anything except A, B or any file inside them,
# like for example create a file at the root directory and fsync this
# new file. This syncs the log that contains all the changes done by
# previous rename operation.
$ touch /mnt/baz
$ xfs_io -c "fsync" /mnt/baz
<power fail>
# Mount the filesystem and replay the log.
$ mount /dev/sdc /mnt
# Check the filesystem content.
$ ls -1R /mnt
/mnt/:
A
B
baz
/mnt/A:
bar
/mnt/B:
$
# File foo is gone, it's neither in A/ nor in B/.
Fix this by using the inode_logged() helper at btrfs_log_new_name(), which
safely checks if an inode was logged before in the current transaction.
A test case for fstests will follow soon.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In compression write endio sequence, the range which the compressed_bio
writes is marked as uptodate if the last bio of the compressed (sub)bios
is completed successfully. There could be previous bio which may
have failed which is recorded in cb->errors.
Set the writeback range as uptodate only if cb->errors is zero, as opposed
to checking only the last bio's status.
Backporting notes: in all versions up to 4.4 the last argument is always
replaced by "!cb->errors".
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The current assumption that methods to read PCH FIVR attributes will
return integer, is not correct. There is no good way to return integer
as negative numbers are also valid.
These read methods return a package of integers. The first integer returns
status, which is 0 on success and any other value for failure. When the
returned status is zero, then the second integer returns the actual value.
This change fixes this issue by replacing acpi_evaluate_integer() with
acpi_evaluate_object() and use acpi_extract_package() to extract results.
Fixes: 2ce6324ead ("ACPI: DPTF: Add PCH FIVR participant driver")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The commit 0ec4e55e9f ("ACPI: resources: Add checks for ACPI IRQ
override") introduces regression on some platforms, at least it makes
the UART can't get correct irq setting on two different platforms,
and it makes the kernel can't bootup on these two platforms.
This reverts commit 0ec4e55e9f.
Regression-discuss: https://bugzilla.kernel.org/show_bug.cgi?id=213031
Reported-by: PGNd <pgnet.dev@gmail.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For pure poll requests, it doesn't remove the second poll wait entry
when it's done, neither after vfs_poll() or in the poll completion
handler. We should remove the second poll wait entry.
And we use io_poll_remove_double() rather than io_poll_remove_waitqs()
since the latter has some redundant logic.
Fixes: 88e41cf928 ("io_uring: add multishot mode for IORING_OP_POLL_ADD")
Cc: stable@vger.kernel.org # 5.13+
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210728030322.12307-1-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some setups, like SCSI, can throw spurious -EAGAIN off the softirq
completion path. Normally we expect this to happen inline as part
of submission, but apparently SCSI has a weird corner case where it
can happen as part of normal completions.
This should be solved by having the -EAGAIN bubble back up the stack
as part of submission, but previous attempts at this failed and we're
not just quite there yet. Instead we currently use REQ_F_REISSUE to
handle this case.
For now, catch it in io_rw_should_reissue() and prevent a reissue
from a bogus path.
Cc: stable@vger.kernel.org
Reported-by: Fabian Ebner <f.ebner@proxmox.com>
Tested-by: Fabian Ebner <f.ebner@proxmox.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Replace pci_enable_device() with pcim_enable_device(),
pci_disable_device() and pci_release_regions() will be
called in release automatically.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
using same source and destination ip/port for flow hash calculation
within the two directions.
Signed-off-by: zhang kai <zhangkaiheb@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The `input_mt_get_slot_by_key` function may return a negative value
if an error occurs (e.g. running out of slots). If this occurs we
should really avoid reporting any data for the slot.
Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Commit 670e90924b ("HID: wacom: support named keys on older devices")
added support for sending named events from the soft buttons on the
24HDT and 27QHDT. In the process, however, it inadvertantly disabled the
touchscreen of the 24HDT and 27QHDT by default. The
`wacom_set_shared_values` function would normally enable touch by default
but because it checks the state of the non-shared `has_mute_touch_switch`
flag and `wacom_setup_touch_input_capabilities` sets the state of the
/shared/ version, touch ends up being disabled by default.
This patch sets the non-shared flag, letting `wacom_set_shared_values`
take care of copying the value over to the shared version and setting
the default touch state to "on".
Fixes: 670e90924b ("HID: wacom: support named keys on older devices")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There is a spelling mistake in the Kconfig text. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The Keychron K1 wireless keyboard has a set of Apple-like function keys
and an Fn key that works like on an Apple bluetooth keyboard. It
identifies as an Apple Alu RevB ANSI keyboard (05ac:024f) over USB and
BT. Use hid-apple for it so the Fn key and function keys work correctly.
Signed-off-by: Haochen Tong <i@hexchain.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There is a missing space in "relyingon".
Add it.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There is a use after free memory corruption during module exit:
- nfcsim_exit()
- nfcsim_device_free(dev0)
- nfc_digital_unregister_device()
This iterates over command queue and frees all commands,
- dev->up = false
- nfcsim_link_shutdown()
- nfcsim_link_recv_wake()
This wakes the sleeping thread nfcsim_link_recv_skb().
- nfcsim_link_recv_skb()
Wake from wait_event_interruptible_timeout(),
call directly the deb->cb callback even though (dev->up == false),
- digital_send_cmd_complete()
Dereference of "struct digital_cmd" cmd which was freed earlier by
nfc_digital_unregister_device().
This causes memory corruption shortly after (with unrelated stack
trace):
nfc nfc0: NFC: nfcsim_recv_wq: Device is down
llcp: nfc_llcp_recv: err -19
nfc nfc1: NFC: nfcsim_recv_wq: Device is down
BUG: unable to handle page fault for address: ffffffffffffffed
Call Trace:
fsnotify+0x54b/0x5c0
__fsnotify_parent+0x1fe/0x300
? vfs_write+0x27c/0x390
vfs_write+0x27c/0x390
ksys_write+0x63/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
KASAN report:
BUG: KASAN: use-after-free in digital_send_cmd_complete+0x16/0x50
Write of size 8 at addr ffff88800a05f720 by task kworker/0:2/71
Workqueue: events nfcsim_recv_wq [nfcsim]
Call Trace:
dump_stack_lvl+0x45/0x59
print_address_description.constprop.0+0x21/0x140
? digital_send_cmd_complete+0x16/0x50
? digital_send_cmd_complete+0x16/0x50
kasan_report.cold+0x7f/0x11b
? digital_send_cmd_complete+0x16/0x50
? digital_dep_link_down+0x60/0x60
digital_send_cmd_complete+0x16/0x50
nfcsim_recv_wq+0x38f/0x3d5 [nfcsim]
? nfcsim_in_send_cmd+0x4a/0x4a [nfcsim]
? lock_is_held_type+0x98/0x110
? finish_wait+0x110/0x110
? rcu_read_lock_sched_held+0x9c/0xd0
? rcu_read_lock_bh_held+0xb0/0xb0
? lockdep_hardirqs_on_prepare+0x12e/0x1f0
This flow of calling digital_send_cmd_complete() callback on driver exit
is specific to nfcsim which implements reading and sending work queues.
Since the NFC digital device was unregistered, the callback should not
be called.
Fixes: 204bddcb50 ("NFC: nfcsim: Make use of the Digital layer")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace pci_enable_device() with pcim_enable_device(),
pci_disable_device() and pci_release_regions() will be
called in release automatically.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As Ben Hutchings noticed, this check should have been inverted: the call
returns true in case of success.
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 0c5dc070ff ("sctp: validate from_addr_param return")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the function s3fwrn5_fw_download(), the 'ret' is not assigned,
so the correct value should be given in dev_err function.
Fixes: a0302ff590 ("nfc: s3fwrn5: remove unnecessary label")
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEGhZs6bAKwk/OTgTpSD+KveBX+j4FAmEAkk4ACgkQSD+KveBX
+j6hFgf/eIRpqg3mivOXjwo3LF34cP02OBStbb5S5S2MFX60n8Z1GXew42I01iON
zUv6RRmtgJiWHedWUYaXnPHE3hqXlX7Vr2fuBXlNJdPG87jZBBK5FLfQCSPBmcyQ
ZK778uSlgarBL3kGwPkPLLwMypMgHpTCkvCb9RIOD2HzXPCjftP4IBQwEEV2zyaj
d7mtbndGeOyRyEh2RO7ABdJNIAta3Z6EfZCe61mYhVg6c49fkoZlX4/vdX5FhtZM
Pvode2ReD49vigpvfDpSSFea6W+qWtTz83/J9Dbnt8byLdzY5VKm3hanv7o41ksg
FyLHz08HPJjP6Mwikel/ZyG5Bb5FFw==
=lD83
-----END PGP SIGNATURE-----
Merge tag 'mlx5-fixes-2021-07-27' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux
Saeed Mahameed says:
====================
mlx5 fixes 2021-07-27
This series introduces some fixes to mlx5 driver.
Please pull and let me know if there is any problem.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
blkdev_get_no_open acquires a reference to the block_device through
the block device inode and then tries to acquire a device model
reference to the gendisk. But at this point the disk migh already
be freed (although the race is free). Fix this by only freeing the
gendisk from the whole device bdevs ->free_inode callback as well.
Fixes: 22ae8ce8b8 ("block: simplify bdev/disk lookup in blkdev_get")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210722075402.983367-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
iocg_wake_fn() open-codes wait_queue_entry removal and wakeup because it
wants the wq_entry to be always removed whether it ended up waking the
task or not. finish_wait() tests whether wq_entry needs removal without
grabbing the wait_queue lock and expects the waker to use
list_del_init_careful() after all waking operations are complete, which
iocg_wake_fn() didn't do. The operation order was wrong and the regular
list_del_init() was used.
The result is that if a waiter wakes up racing the waker, it can free pop
the wq_entry off stack before the waker is still looking at it, which can
lead to a backtrace like the following.
[7312084.588951] general protection fault, probably for non-canonical address 0x586bf4005b2b88: 0000 [#1] SMP
...
[7312084.647079] RIP: 0010:queued_spin_lock_slowpath+0x171/0x1b0
...
[7312084.858314] Call Trace:
[7312084.863548] _raw_spin_lock_irqsave+0x22/0x30
[7312084.872605] try_to_wake_up+0x4c/0x4f0
[7312084.880444] iocg_wake_fn+0x71/0x80
[7312084.887763] __wake_up_common+0x71/0x140
[7312084.895951] iocg_kick_waitq+0xe8/0x2b0
[7312084.903964] ioc_rqos_throttle+0x275/0x650
[7312084.922423] __rq_qos_throttle+0x20/0x30
[7312084.930608] blk_mq_make_request+0x120/0x650
[7312084.939490] generic_make_request+0xca/0x310
[7312084.957600] submit_bio+0x173/0x200
[7312084.981806] swap_readpage+0x15c/0x240
[7312084.989646] read_swap_cache_async+0x58/0x60
[7312084.998527] swap_cluster_readahead+0x201/0x320
[7312085.023432] swapin_readahead+0x2df/0x450
[7312085.040672] do_swap_page+0x52f/0x820
[7312085.058259] handle_mm_fault+0xa16/0x1420
[7312085.066620] do_page_fault+0x2c6/0x5c0
[7312085.074459] page_fault+0x2f/0x40
Fix it by switching to list_del_init_careful() and putting it at the end.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Rik van Riel <riel@surriel.com>
Fixes: 7caa47151a ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The result of __dev_get_by_index() is not checked for NULL and then gets
dereferenced immediately.
Also, __dev_get_by_index() must be called while holding either RTNL lock
or @dev_base_lock, which isn't satisfied by mlx5e_hairpin_get_mdev() or
its callers. This makes the underlying hlist_for_each_entry() loop not
safe, and can have adverse effects in itself.
Fix by using dev_get_by_index() and handling nullptr return value when
ifindex device is not found. Update mlx5e_hairpin_get_mdev() callers to
check for possible PTR_ERR() result.
Fixes: 77ab67b7f0 ("net/mlx5e: Basic setup of hairpin object")
Addresses-Coverity: ("Dereference null return value")
Signed-off-by: Dima Chumak <dchumak@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
When fw_fatal reporter reports an error, the firmware in not responding.
Unload the device to ensure that the driver closes all its resources,
even if recovery is not due (user disabled auto-recovery or reporter is
in grace period). On successful recovery the device is loaded back up.
Fixes: b3bd076f75 ("net/mlx5: Report devlink health on FW fatal issues")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Set the correct pci-device pointer to the ptp-RQ. This allows access to
dma_mask and avoids allocation request with wrong pci-device.
Fixes: a099da8ffc ("net/mlx5e: Add RQ to PTP channel")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Dave Chinner