Some released ACPI FW for Huawei boards describes incorrect the port IO
address range for child devices, in that it tells us the IO port max range
is 0x3fff for each child device, which is not correct. The address range
should be [e4:e8) or similar. With this incorrect upper range, the child
device IO port resources overlap.
As such, the kernel thinks that the LPC host serial device is a child of
the IPMI device:
They should both be siblings. Note that these are logical PIO addresses,
which have a direct mapping from the FW IO port ranges.
This shows up as a real issue when we enable CONFIG_KASAN and
CONFIG_DEBUG_TEST_DRIVER_REMOVE - we see use-after-free warnings in the
host removal path:
==================================================================
BUG: KASAN: use-after-free in release_resource+0x38/0xc8
Read of size 8 at addr ffff0026accdbc38 by task swapper/0/1
The issue here is that the kernel created an incorrect parent-child
resource dependency between two devices, and references the false parent
node when deleting the second child device, when it had been deleted
already.
Fix up the child device resources from FW to create proper IO port
resource relationships for broken FW.
Fields in "struct timer_rand_state" could be accessed concurrently.
Lockless plain reads and writes result in data races. Fix them by adding
pairs of READ|WRITE_ONCE(). The data races were reported by KCSAN,
BUG: KCSAN: data-race in add_timer_randomness / add_timer_randomness
write to 0xffff9f320a0a01d0 of 8 bytes by interrupt on cpu 22:
add_timer_randomness+0x100/0x190
add_timer_randomness at drivers/char/random.c:1152
add_disk_randomness+0x85/0x280
scsi_end_request+0x43a/0x4a0
scsi_io_completion+0xb7/0x7e0
scsi_finish_command+0x1ed/0x2a0
scsi_softirq_done+0x1c9/0x1d0
blk_done_softirq+0x181/0x1d0
__do_softirq+0xd9/0x57c
irq_exit+0xa2/0xc0
do_IRQ+0x8b/0x190
ret_from_intr+0x0/0x42
cpuidle_enter_state+0x15e/0x980
cpuidle_enter+0x69/0xc0
call_cpuidle+0x23/0x40
do_idle+0x248/0x280
cpu_startup_entry+0x1d/0x1f
start_secondary+0x1b2/0x230
secondary_startup_64+0xb6/0xc0
no locks held by swapper/22/0.
irq event stamp: 32871382
_raw_spin_unlock_irqrestore+0x53/0x60
_raw_spin_lock_irqsave+0x21/0x60
_local_bh_enable+0x21/0x30
irq_exit+0xa2/0xc0
read to 0xffff9f320a0a01d0 of 8 bytes by interrupt on cpu 2:
add_timer_randomness+0xe8/0x190
add_disk_randomness+0x85/0x280
scsi_end_request+0x43a/0x4a0
scsi_io_completion+0xb7/0x7e0
scsi_finish_command+0x1ed/0x2a0
scsi_softirq_done+0x1c9/0x1d0
blk_done_softirq+0x181/0x1d0
__do_softirq+0xd9/0x57c
irq_exit+0xa2/0xc0
do_IRQ+0x8b/0x190
ret_from_intr+0x0/0x42
cpuidle_enter_state+0x15e/0x980
cpuidle_enter+0x69/0xc0
call_cpuidle+0x23/0x40
do_idle+0x248/0x280
cpu_startup_entry+0x1d/0x1f
start_secondary+0x1b2/0x230
secondary_startup_64+0xb6/0xc0
no locks held by swapper/2/0.
irq event stamp: 37846304
_raw_spin_unlock_irqrestore+0x53/0x60
_raw_spin_lock_irqsave+0x21/0x60
_local_bh_enable+0x21/0x30
irq_exit+0xa2/0xc0
Reported by Kernel Concurrency Sanitizer on:
Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018
SDEI has private events that need registering and enabling on each CPU.
CPUs can come and go while we are trying to do this. SDEI tries to avoid
these problems by setting the reregister flag before the register call,
so any CPUs that come online register the event too. Sticking plaster
like this doesn't work, as if the register call fails, a CPU that
subsequently comes online will register the event before reregister
is cleared.
Take cpus_read_lock() around the register and enable calls. We don't
want surprise CPUs to do the wrong thing if they race with these calls
failing.
It's incorrect to check the channel's "busy" state without taking a lock.
That shouldn't cause any real troubles, nevertheless it's always better
not to have any race conditions in the code.
If an element is freed via RCU then recursion into BPF instrumentation
functions is not a concern. The element is already detached from the map
and the RCU callback does not hold any locks on which a kprobe, perf event
or tracepoint attached BPF program could deadlock.
Alex Shi reported the pkey macros above arch_set_user_pkey_access()
to be unused. They are unused, and even refer to a nonexistent
CONFIG option.
But, they might have served a good use, which was to ensure that
the code does not try to set values that would not fit in the
PKRU register. As it stands, a too-large 'pkey' value would
be likely to silently overflow the u32 new_pkru_bits.
Add a check to look for overflows. Also add a comment to remind
any future developer to closely examine the types used to store
pkey values if arch_max_pkey() ever changes.
This test places a kprobe to function getname_flags() in the kernel
which has the following prototype:
struct filename *getname_flags(const char __user *filename, int flags, int *empty)
The 'filename' argument points to a filename located in user space memory.
Looking at commit 88903c464321c ("tracing/probe: Add ustring type for
user-space string") the kprobe should indicate that user space memory is
accessed.
Output before:
[root@m35lp76 perf]# ./perf test 66 67
66: Use vfs_getname probe to get syscall args filenames : FAILED!
67: Check open filename arg using perf trace + vfs_getname: FAILED!
[root@m35lp76 perf]#
Output after:
[root@m35lp76 perf]# ./perf test 66 67
66: Use vfs_getname probe to get syscall args filenames : Ok
67: Check open filename arg using perf trace + vfs_getname: Ok
[root@m35lp76 perf]#
Comments from Masami Hiramatsu:
This bug doesn't happen on x86 or other archs on which user address
space and kernel address space is the same. On some arches (ppc64 in
this case?) user address space is partially or completely the same as
kernel address space.
(Yes, they switch the world when running into the kernel) In this case,
we need to use different data access functions for each space.
That is why I introduced the "ustring" type for kprobe events.
As far as I can see, Thomas's patch is sane. Thomas, could you show us
your result on your test environment?
Some USB-audio descriptors provide a bogus volume range (e.g. volume
min and max are identical), which confuses user-space.
This patch makes the driver skipping such a control element.
During the cleanup of the aggregation session, a rx handler (or release timer)
on another CPU might still hold a pointer to the reorder buffer and could
attempt to release some packets.
Clearing pointers during cleanup avoids a theoretical use-after-free bug here.
Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Sasha Levin <sashal@kernel.org>
The call to of_find_matching_node returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
Detected by coccinelle with the following warnings:
drivers/gpu/drm/omapdrm/dss/omapdss-boot-init.c:212:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 209, but without a corresponding object release within this function.
drivers/gpu/drm/omapdrm/dss/omapdss-boot-init.c:237:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 209, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Sebastian Reichel <sebastian.reichel@collabora.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: Markus Elfring <Markus.Elfring@web.de> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Link: https://patchwork.freedesktop.org/patch/msgid/1554692313-28882-2-git-send-email-wen.yang99@zte.com.cn Signed-off-by: Sasha Levin <sashal@kernel.org>
Coverity reported a memory corruption error for the fdmi attributes
routines:
CID 15768 [Memory Corruption] Out-of-bounds access on FDMI
Sloppy coding of the fmdi structures. In both the lpfc_fdmi_attr_def and
lpfc_fdmi_reg_port_list structures, a field was placed at the start of
payload that may have variable content. The field was given an arbitrary
type (uint32_t). The code then uses the field name to derive an address,
which it used in things such as memset and memcpy. The memset sizes or
memcpy lengths were larger than the arbitrary type, thus coverity reported
an error.
Fix by replacing the arbitrary fields with the real field structures
describing the payload.
Link: https://lore.kernel.org/r/20200128002312.16346-8-jsmart2021@gmail.com Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The driver is occasionally seeing the following SLI Port error, requiring
reset and reinit:
Port Status Event: ... error 1=0x52004a01, error 2=0x218
The failure means an RQ timeout. That is, the adapter had received
asynchronous receive frames, ran out of buffer slots to place the frames,
and the driver did not replenish the buffer slots before a timeout
occurred. The driver should not be so slow in replenishing buffers that a
timeout can occur.
When the driver received all the frames of a sequence, it allocates an IOCB
to put the frames in. In a situation where there was no IOCB available for
the frame of a sequence, the RQ buffer corresponding to the first frame of
the sequence was not returned to the FW. Eventually, with enough traffic
encountering the situation, the timeout occurred.
Fix by releasing the buffer back to firmware whenever there is no IOCB for
the first frame.
[mkp: typo]
Link: https://lore.kernel.org/r/20200128002312.16346-2-jsmart2021@gmail.com Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
$# read after lseek to midle of last line
$ dd if=/sys/fs/selinux/avc/cache_stats bs=180 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset
056 9115 <<<< end of last line 15605711551548 9023 9023 9056 9115 <<< whole last line once again
0+1 records in
0+1 records out
45 bytes copied, 8,7221e-05 s, 516 kB/s
$# read after lseek beyond end of of file
$ dd if=/sys/fs/selinux/avc/cache_stats bs=1000 skip=1
dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset 15605711551548 9023 9023 9056 9115 <<<< generates whole last line
0+1 records in
0+1 records out
36 bytes copied, 9,0934e-05 s, 396 kB/s
Common Criteria calls out for any action that modifies the audit trail to
be recorded. That usually is interpreted to mean insertion or removal of
rules. It is not required to log modification of the inode information
since the watch is still in effect. Additionally, if the rule is a never
rule and the underlying file is one they do not want events for, they
get an event for this bookkeeping update against their wishes.
Since no device/inode info is logged at insertion and no device/inode
information is logged on update, there is nothing meaningful being
communicated to the admin by the CONFIG_CHANGE updated_rules event. One
can assume that the rule was not "modified" because it is still watching
the intended target. If the device or inode cannot be resolved, then
audit_panic is called which is sufficient.
The correct resolution is to drop logging config_update events since
the watch is still in effect but just on another unknown inode.
Signed-off-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
sk_buff.qlen can be accessed concurrently as noticed by KCSAN,
BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg
read to 0xffff8a1b1d8a81c0 of 4 bytes by task 5371 on cpu 96:
unix_dgram_sendmsg+0x9a9/0xb70 include/linux/skbuff.h:1821
net/unix/af_unix.c:1761
____sys_sendmsg+0x33e/0x370
___sys_sendmsg+0xa6/0xf0
__sys_sendmsg+0x69/0xf0
__x64_sys_sendmsg+0x51/0x70
do_syscall_64+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
write to 0xffff8a1b1d8a81c0 of 4 bytes by task 1 on cpu 99:
__skb_try_recv_from_queue+0x327/0x410 include/linux/skbuff.h:2029
__skb_try_recv_datagram+0xbe/0x220
unix_dgram_recvmsg+0xee/0x850
____sys_recvmsg+0x1fb/0x210
___sys_recvmsg+0xa2/0xf0
__sys_recvmsg+0x66/0xf0
__x64_sys_recvmsg+0x51/0x70
do_syscall_64+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Since only the read is operating as lockless, it could introduce a logic
bug in unix_recvq_full() due to the load tearing. Fix it by adding
a lockless variant of skb_queue_len() and unix_recvq_full() where
READ_ONCE() is on the read while WRITE_ONCE() is on the write similar to
the commit d7d16a89350a ("net: add skb_queue_empty_lockless()").
Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
RIRB interrupt status getting cleared after the write pointer is read
causes a race condition, where last response(s) into RIRB may remain
unserviced by IRQ, eventually causing azx_rirb_get_response to fall
back to polling mode. Clearing the RIRB interrupt status ahead of
write pointer access ensures that this condition is avoided.
We are testing Virtual Machine with KSM on v5.4-rc2 kernel,
and found the zero_page refcount overflow.
The cause of refcount overflow is increased in try_async_pf
(get_user_page) without being decreased in mmu_set_spte()
while handling ept violation.
In kvm_release_pfn_clean(), only unreserved page will call
put_page. However, zero page is reserved.
So, as well as creating and destroy vm, the refcount of
zero page will continue to increase until it overflows.
Prefetch channel before killing sock in order to fix UAF like
BUG: KASAN: use-after-free in l2cap_sock_release+0x24c/0x290 net/bluetooth/l2cap_sock.c:1212
Read of size 8 at addr ffff8880944904a0 by task syz-fuzzer/9751
If walk_pte_range() is called with a 'end' argument that is beyond the
last page of memory (e.g. ~0UL) then the comparison between 'addr' and
'end' will always fail and the loop will be infinite. Instead change the
comparison to >= while accounting for overflow.
Link: http://lkml.kernel.org/r/20191218162402.45610-15-steven.price@arm.com Signed-off-by: Steven Price <steven.price@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Liang, Kan" <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Zong Li <zong.li@sifive.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>
If seq_file .next fuction does not change position index, read after
some lseek can generate unexpected output.
In Aug 2018 NeilBrown noticed commit 1f4aace60b0e ("fs/seq_file.c:
simplify seq_file iteration code and interface") "Some ->next functions
do not increment *pos when they return NULL... Note that such ->next
functions are buggy and should be fixed. A simple demonstration is
dd if=/proc/swaps bs=1000 skip=1
Choose any block size larger than the size of /proc/swaps. This will
always show the whole last line of /proc/swaps"
Described problem is still actual. If you make lseek into middle of
last output line following read will output end of last line and whole
last line once again.
$ dd if=/proc/swaps bs=1 # usual output
Filename Type Size Used Priority
/dev/dm-0 partition 4194812 97536 -2
104+0 records in
104+0 records out
104 bytes copied
$ dd if=/proc/swaps bs=40 skip=1 # last line was generated twice
dd: /proc/swaps: cannot skip to specified offset
v/dm-0 partition 4194812 97536 -2
/dev/dm-0 partition 4194812 97536 -2
3+1 records in
3+1 records out
131 bytes copied
There is no lock preventing both l2cap_sock_release() and
chan->ops->close() from running at the same time.
If we consider Thread A running l2cap_chan_timeout() and Thread B running
l2cap_sock_release(), expected behavior is:
A::l2cap_chan_timeout()->l2cap_chan_close()->l2cap_sock_teardown_cb()
A::l2cap_chan_timeout()->l2cap_sock_close_cb()->l2cap_sock_kill()
B::l2cap_sock_release()->sock_orphan()
B::l2cap_sock_release()->l2cap_sock_kill()
where,
sock_orphan() clears "sk->sk_socket" and l2cap_sock_teardown_cb() marks
socket as SOCK_ZAPPED.
In l2cap_sock_kill(), there is an "if-statement" that checks if both
sock_orphan() and sock_teardown() has been run i.e. sk->sk_socket is NULL
and socket is marked as SOCK_ZAPPED. Socket is killed if the condition is
satisfied.
In the race condition, following occurs:
A::l2cap_chan_timeout()->l2cap_chan_close()->l2cap_sock_teardown_cb()
B::l2cap_sock_release()->sock_orphan()
B::l2cap_sock_release()->l2cap_sock_kill()
A::l2cap_chan_timeout()->l2cap_sock_close_cb()->l2cap_sock_kill()
In this scenario, "if-statement" is true in both B::l2cap_sock_kill() and
A::l2cap_sock_kill() and we hit "refcount: underflow; use-after-free" bug.
Similar condition occurs at other places where teardown/sock_kill is
happening:
l2cap_disconnect_rsp()->l2cap_chan_del()->l2cap_sock_teardown_cb()
l2cap_disconnect_rsp()->l2cap_sock_close_cb()->l2cap_sock_kill()
Protect teardown/sock_kill and orphan/sock_kill by adding hold_lock on
l2cap channel to ensure that the socket is killed only after marked as
zapped and orphan.
test.d/ftrace/func-filter-glob.tc is failing on s390 because it has
ARCH_INLINE_SPIN_LOCK and friends set to 'y'. So the usual
__raw_spin_lock symbol isn't in the ftrace function list. Change
'*aw*lock' to '*spin*lock' which would hopefully match some of the
locking functions on all platforms.
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Add the required USB ID for running SMCWUSBT-G2 wireless adapter (SMC
"EZ Connect g").
This device uses ar5523 chipset and requires firmware to be loaded. Even
though pid of the device is 4507, this patch adds it as 4506 so that
AR5523_DEVICE_UG macro can set the AR5523_FLAG_PRE_FIRMWARE flag for pid
4507.
Signed-off-by: Mert Dirik <mertdirik@gmail.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The stacktrace code can read beyond the stack size, when it attempts to
read pt_regs from exception frames.
This can happen on normal, non-corrupt stacks. Since the unwind
information in the extable is not correct for function prologues, the
unwinding code can return data from the stack which is not actually the
caller function address, and if in_entry_text() happens to succeed on
this value, we can end up reading data from outside the task's stack
when attempting to read pt_regs, since there is no bounds check.
In this example, the stack limit is 0xeb492000, but 16 bytes outside the
stack have been read.
Fix it by adding bounds checks.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
I noticed when trying to use the trace-cmd python interface that reading the raw
buffer wasn't working for kernel_stack events. This is because it uses a
stubbed version of __dynamic_array that doesn't do the __data_loc trick and
encode the length of the array into the field. Instead it just shows up as a
size of 0. So change this to __array and set the len to FTRACE_STACK_ENTRIES
since this is what we actually do in practice and matches how user_stack_trace
works.
Currently, kmemdup is applied to the firmware data, and it invokes
kmalloc under the hood. The firmware size and patch_length are big (more
than PAGE_SIZE), and on some low-end systems (like ASUS E202SA) kmalloc
may fail to allocate a contiguous chunk under high memory usage and
fragmentation:
Many drivers don't check for errors when they get a 0xFFs response from an
MMIO load. As a result after an EEH event occurs a driver can get stuck in
a polling loop unless it some kind of internal timeout logic.
Currently EEH tries to detect and report stuck drivers by dumping a stack
trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an
already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump
would occur every few seconds if the driver was spinning in a loop. This
results in a lot of spurious stack traces in the kernel log.
Fix this by limiting it to printing one stack trace for each PE freeze. If
the driver is truely stuck the kernel's hung task detector is better suited
to reporting the probelm anyway.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com> Tested-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
Since the dma engine expects the burst length register content as
power of 2 value, the burst length needs to be converted first.
Additionally add a burst length range check to avoid corrupting unrelated
register bits.
Starting execution of a command before tracing a command may cause the
completion handler to free data while it is being traced. Fix this race by
tracing a command before it is submitted.
Cc: Bean Huo <beanhuo@micron.com> Cc: Can Guo <cang@codeaurora.org> Cc: Avri Altman <avri.altman@wdc.com> Cc: Stanley Chu <stanley.chu@mediatek.com> Cc: Tomas Winkler <tomas.winkler@intel.com> Link: https://lore.kernel.org/r/20191224220248.30138-5-bvanassche@acm.org Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Since the lrbp->cmd expression occurs multiple times, introduce a new local
variable to hold that pointer. This patch does not change any
functionality.
Cc: Bean Huo <beanhuo@micron.com> Cc: Can Guo <cang@codeaurora.org> Cc: Avri Altman <avri.altman@wdc.com> Cc: Stanley Chu <stanley.chu@mediatek.com> Cc: Tomas Winkler <tomas.winkler@intel.com> Link: https://lore.kernel.org/r/20191224220248.30138-3-bvanassche@acm.org Reviewed-by: Stanley Chu <stanley.chu@mediatek.com> Reviewed-by: Can Guo <cang@codeaurora.org> Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The original patch bringed in the "SCTP ACK tracking trace event"
feature was committed at Dec.20, 2017, it replaced jprobe usage
with trace events, and bringed in two trace events, one is
TRACE_EVENT(sctp_probe), another one is TRACE_EVENT(sctp_probe_path).
The original patch intended to trigger the trace_sctp_probe_path in
TRACE_EVENT(sctp_probe) as below code,
But I found it did not work when I did testing, and trace_sctp_probe_path
had no output, I finally found that there is trace buffer lock
operation(trace_event_buffer_reserve) in include/trace/trace_events.h:
The reason caused no output of trace_sctp_probe_path is that
trace_sctp_probe_path written in TP_fast_assign part of
TRACE_EVENT(sctp_probe), and it will be placed( { assign; } ) after the
trace_event_buffer_reserve() when compiler expands Macro,
so trace_sctp_probe_path finally can not acquire trace_event_buffer
and return no output, that is to say the nest of tracepoint entry function
is not allowed. The function call flow is:
trace_sctp_probe()
-> trace_event_raw_event_sctp_probe()
-> lock buffer
-> trace_sctp_probe_path()
-> trace_event_raw_event_sctp_probe_path() --nested
-> buffer has been locked and return no output.
This patch is to remove trace_sctp_probe_path from the TP_fast_assign
part of TRACE_EVENT(sctp_probe) to avoid the nest of entry function,
and trigger sctp_probe_path_trace in sctp_outq_sack.
After this patch, you can enable both events individually,
# cd /sys/kernel/debug/tracing
# echo 1 > events/sctp/sctp_probe/enable
# echo 1 > events/sctp/sctp_probe_path/enable
Or, you can enable all the events under sctp.
# echo 1 > events/sctp/enable
Signed-off-by: Kevin Kou <qdkevin.kou@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
This patch proposes to require marked atomic accesses surrounding
raw_write_seqcount_barrier. We reason that otherwise there is no way to
guarantee propagation nor atomicity of writes before/after the barrier
[1]. For example, consider the compiler tears stores either before or
after the barrier; in this case, readers may observe a partial value,
and because readers are unaware that writes are going on (writes are not
in a seq-writer critical section), will complete the seq-reader critical
section while having observed some partial state.
[1] https://lwn.net/Articles/793253/
This came up when designing and implementing KCSAN, because KCSAN would
flag these accesses as data-races. After careful analysis, our reasoning
as above led us to conclude that the best thing to do is to propose an
amendment to the raw_seqcount_barrier usage.
Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Omar Sandoval reported that a 4G fallocate on the realtime device causes
filesystem shutdowns due to a log reservation overflow that happens when
we log the rtbitmap updates. Factor rtbitmap/rtsummary updates into the
the tr_write and tr_itruncate log reservation calculation.
"The following reproducer results in a transaction log overrun warning
for me:
In kvm_vgic_dist_init() called from kvm_vgic_map_resources(), if
dist->vgic_model is invalid, dist->spis will be freed without set
dist->spis = NULL. And in vgicv2 resources clean up path,
__kvm_vgic_destroy() will be called to free allocated resources.
And dist->spis will be freed again in clean up chain because we
forget to set dist->spis = NULL in kvm_vgic_dist_init() failed
path. So double free would happen.
Initialization is not guaranteed to zero padding bytes so use an
explicit memset instead to avoid leaking any kernel content in any
possible padding bytes.
Link: http://lkml.kernel.org/r/dfa331c00881d61c8ee51577a082d8bebd61805c.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Dan Carpenter <error27@gmail.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.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>
It was observed Baytrail-based chromebooks could cause continuous PLL
unlocked when using playback stream and capture stream simultaneously.
Specifically, starting a capture stream after started a playback stream.
As a result, the audio data could corrupt or turn completely silent.
As the datasheet suggested, the maximum PLL lock time should be 7 msec.
The workaround resets the codec softly by toggling SHDN off and on if
PLL failed to lock for 10 msec. Notably, there is no suggested hold
time for SHDN off.
On Baytrail-based chromebooks, it would easily happen continuous PLL
unlocked if there is a 10 msec delay between SHDN off and on. Removes
the msleep().
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com> Link: https://lore.kernel.org/r/20191122073114.219945-2-tzungbi@google.com Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currenly we doesn't assume that a server may break a lease
from RWH to RW which causes us setting a wrong lease state
on a file and thus mistakenly flushing data and byte-range
locks and purging cached data on the client. This leads to
performance degradation because subsequent IOs go directly
to the server.
Fix this by propagating new lease state and epoch values
to the oplock break handler through cifsFileInfo structure
and removing the use of cifsInodeInfo flags for that. It
allows to avoid some races of several lease/oplock breaks
using those flags in parallel.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Added the fix so the if driver properly sent the abort it tries to remove
it from the firmware's list of outstanding commands regardless of the abort
status. This means that the task gets freed 'now' rather than possibly
getting freed later when the scsi layer thinks it's leaked but still valid.
Link: https://lore.kernel.org/r/20191114100910.6153-10-deepak.ukey@microchip.com Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com> Signed-off-by: peter chang <dpf@google.com> Signed-off-by: Deepak Ukey <deepak.ukey@microchip.com> Signed-off-by: Viswas G <Viswas.G@microchip.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Before this patch, gfs2_create_inode had a use-after-free for the
iopen glock in some error paths because it did this:
gfs2_glock_put(io_gl);
fail_gunlock2:
if (io_gl)
clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
In some cases, the io_gl was used for create and only had one
reference, so the glock might be freed before the clear_bit().
This patch tries to straighten it out by only jumping to the
error paths where iopen is properly set, and moving the
gfs2_glock_put after the clear_bit.
Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
With large eMMC cards, it is possible to create general purpose
partitions that are bigger than 4GB. The size member of the mmc_part
struct is only an unsigned int which overflows for gp partitions larger
than 4GB. Change this to a u64 to handle the overflow.
When a new fastmap is about to be written UBI must make sure it has a
free block for a fastmap anchor available. For this ubi_update_fastmap()
calls ubi_ensure_anchor_pebs(). This stopped working with 2e8f08deabbc
("ubi: Fix races around ubi_refill_pools()"), with this commit the wear
leveling code is blocked and can no longer produce free PEBs. UBI then
more often than not falls back to write the new fastmap anchor to the
same block it was already on which means the same erase block gets
erased during each fastmap write and wears out quite fast.
As the locking prevents us from producing the anchor PEB when we
actually need it, this patch changes the strategy for creating the
anchor PEB. We no longer create it on demand right before we want to
write a fastmap, but instead we create an anchor PEB right after we have
written a fastmap. This gives us enough time to produce a new anchor PEB
before it is needed. To make sure we have an anchor PEB for the very
first fastmap write we call ubi_ensure_anchor_pebs() during
initialisation as well.
Fixes: 2e8f08deabbc ("ubi: Fix races around ubi_refill_pools()") Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
The leaf format xattr addition helper xfs_attr3_leaf_add_work()
adjusts the block freemap in a couple places. The first update drops
the size of the freemap that the caller had already selected to
place the xattr name/value data. Before the function returns, it
also checks whether the entries array has encroached on a freemap
range by virtue of the new entry addition. This is necessary because
the entries array grows from the start of the block (but end of the
block header) towards the end of the block while the name/value data
grows from the end of the block in the opposite direction. If the
associated freemap is already empty, however, size is zero and the
subtraction underflows the field and causes corruption.
This is reproduced rarely by generic/070. The observed behavior is
that a smaller sized freemap is aligned to the end of the entries
list, several subsequent xattr additions land in larger freemaps and
the entries list expands into the smaller freemap until it is fully
consumed and then underflows. Note that it is not otherwise a
corruption for the entries array to consume an empty freemap because
the nameval list (i.e. the firstused pointer in the xattr header)
starts beyond the end of the corrupted freemap.
Update the freemap size modification to account for the fact that
the freemap entry can be empty and thus stale.
Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
We are overoptimistic about taking the fast path there; seeing
the same value in ->d_parent after having grabbed a reference
to that parent does *not* mean that it has remained our parent
all along.
That wouldn't be a big deal (in the end it is our parent and
we have grabbed the reference we are about to return), but...
the situation with barriers is messed up.
We might have hit the following sequence:
d is a dentry of /tmp/a/b
CPU1: CPU2:
parent = d->d_parent (i.e. dentry of /tmp/a)
rename /tmp/a/b to /tmp/b
rmdir /tmp/a, making its dentry negative
grab reference to parent,
end up with cached parent->d_inode (NULL)
mkdir /tmp/a, rename /tmp/b to /tmp/a/b
recheck d->d_parent, which is back to original
decide that everything's fine and return the reference we'd got.
The trouble is, caller (on CPU1) will observe dget_parent()
returning an apparently negative dentry. It actually is positive,
but CPU1 has stale ->d_inode cached.
Use d->d_seq to see if it has been moved instead of rechecking ->d_parent.
NOTE: we are *NOT* going to retry on any kind of ->d_seq mismatch;
we just go into the slow path in such case. We don't wait for ->d_seq
to become even either - again, if we are racing with renames, we
can bloody well go to slow path anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
When devm_request_irq fails, currently, the function
dma_async_device_unregister gets called. This doesn't free
the resources allocated by of_dma_controller_register.
Therefore, we have called of_dma_controller_free for this purpose.
This patch fix a lost wake-up problem caused by the race between
mca_cannibalize_lock and bch_cannibalize_unlock.
Consider two processes, A and B. Process A is executing
mca_cannibalize_lock, while process B takes c->btree_cache_alloc_lock
and is executing bch_cannibalize_unlock. The problem happens that after
process A executes cmpxchg and will execute prepare_to_wait. In this
timeslice process B executes wake_up, but after that process A executes
prepare_to_wait and set the state to TASK_INTERRUPTIBLE. Then process A
goes to sleep but no one will wake up it. This problem may cause bcache
device to dead.
As part of commit f45d1225adb0 ("tracing: Kernel access to Ftrace
instances") we exported certain functions. Here, we are adding some additional
NULL checks to ensure safe usage by users of these APIs.
link: https://bugzilla.kernel.org/show_bug.cgi?id=195657
cmd/rsp buffers are expected to be in the same ACPI region.
For Zen+ CPUs BIOS's might report two different regions, some of
them also report region sizes inconsistent with values from TPM
registers.
Work around the issue by storing ACPI regions declared for the
device in a fixed array and adding an array for pointers to
corresponding possibly allocated resources in crb_map_io function.
This data was previously held for a single resource
in struct crb_priv (iobase field) and local variable io_res in
crb_map_io function. ACPI resources array is used to find index of
corresponding region for each buffer and make the buffer size
consistent with region's length. Array of pointers to allocated
resources is used to map the region at most once.
Signed-off-by: Ivan Lazeev <ivan.lazeev@gmail.com> Tested-by: Jerry Snitselaar <jsnitsel@redhat.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
If a child device calls mfd_cell_{en,dis}able() without an appropriate
call-back being set, we are likely to encounter a panic. Avoid this
by adding suitable checking.
Signed-off-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Else there may be a double-free problem, because cfi->cfiq will
be freed by mtd_do_chip_probe() if both the two invocations of
check_cmd_set() return failure.
Signed-off-by: Hou Tao <houtao1@huawei.com> Reviewed-by: Richard Weinberger <richard@nod.at> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8057 Comm: syz-fuzzer Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
When reading sysfs nvme_info file while a remote port leaves and comes
back, a NULL pointer is encountered. The issue is due to ndlp list
corruption as the the nvme_info_show does not use the same lock as the rest
of the code.
Correct by removing the rcu_xxx_lock calls and replace by the host_lock and
phba->hbaLock spinlocks that are used by the rest of the driver. Given
we're called from sysfs, we are safe to use _irq rather than _irqsave.
Link: https://lore.kernel.org/r/20191105005708.7399-4-jsmart2021@gmail.com Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The memory chunk io_req is released by mempool_free. Accessing
io_req->start_time will result in a use after free bug. The variable
start_time is a backup of the timestamp. So, use start_time here to
avoid use after free.
There is another kHz-conversion bug in the code, resulting in integer
overflow. Although, this time the resulting value is 4294966296 and it's
close to ULONG_MAX, which is okay in this case.
Error was detected by PVS-Studio:
V512 A call of the 'sprintf' function will lead to overflow of
the buffer 'led_data->led_cdev_name'.
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua> Signed-off-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
LLVM implemented a recent "libcall optimization" that lowers calls to
`sprintf(dest, "%s", str)` where the return value is used to
`stpcpy(dest, str) - dest`.
This generally avoids the machinery involved in parsing format strings.
`stpcpy` is just like `strcpy` except it returns the pointer to the new
tail of `dest`. This optimization was introduced into clang-12.
Implement this so that we don't observe linkage failures due to missing
symbol definitions for `stpcpy`.
Similar to last year's fire drill with: commit 5f074f3e192f
("lib/string.c: implement a basic bcmp")
The kernel is somewhere between a "freestanding" environment (no full
libc) and "hosted" environment (many symbols from libc exist with the
same type, function signature, and semantics).
As Peter Anvin notes, there's not really a great way to inform the
compiler that you're targeting a freestanding environment but would like
to opt-in to some libcall optimizations (see pr/47280 below), rather
than opt-out.
Arvind notes, -fno-builtin-* behaves slightly differently between GCC
and Clang, and Clang is missing many __builtin_* definitions, which I
consider a bug in Clang and am working on fixing.
Masahiro summarizes the subtle distinction between compilers justly:
To prevent transformation from foo() into bar(), there are two ways in
Clang to do that; -fno-builtin-foo, and -fno-builtin-bar. There is
only one in GCC; -fno-buitin-foo.
(Any difference in that behavior in Clang is likely a bug from a missing
__builtin_* definition.)
Masahiro also notes:
We want to disable optimization from foo() to bar(),
but we may still benefit from the optimization from
foo() into something else. If GCC implements the same transform, we
would run into a problem because it is not -fno-builtin-bar, but
-fno-builtin-foo that disables that optimization.
In this regard, -fno-builtin-foo would be more future-proof than
-fno-built-bar, but -fno-builtin-foo is still potentially overkill. We
may want to prevent calls from foo() being optimized into calls to
bar(), but we still may want other optimization on calls to foo().
It seems that compilers today don't quite provide the fine grain control
over which libcall optimizations pseudo-freestanding environments would
prefer.
Finally, Kees notes that this interface is unsafe, so we should not
encourage its use. As such, I've removed the declaration from any
header, but it still needs to be exported to avoid linkage errors in
modules.
We found a Mic detection issue on many Lenovo laptops, those laptops
belong to differnt models and they have different audio design like
internal mic connects to the codec or PCH, they all have this problem,
the problem is if plugging a headset before powerup/reboot the
machine, after booting up, the headphone could be detected but Mic
couldn't. If we plug out and plug in the headset, both headphone and
Mic could be detected then.
Through debugging we found the codec on those laptops are same, it is
alc257, and if we don't disable the 3k pulldown in alc256_shutup(),
the issue will be fixed. So far there is no pop noise or power
consumption regression on those laptops after this change.
Cc: Kailang Yang <kailang@realtek.com> Cc: <stable@vger.kernel.org> Signed-off-by: Hui Wang <hui.wang@canonical.com> Link: https://lore.kernel.org/r/20200914065118.19238-1-hui.wang@canonical.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several people reported in the kernel bugzilla that between v4.12 and v4.13
the magic which works around broken hardware and BIOSes to find the proper
timer interrupt delivery mode stopped working for some older affected
platforms which need to fall back to ExtINT delivery mode.
The reason is that the core code changed to keep track of the masked and
disabled state of an interrupt line more accurately to avoid the expensive
hardware operations.
That broke an assumption in i8259_make_irq() which invokes
Up to v4.12 this worked because enable_irq() unconditionally unmasked the
interrupt line, but after the state tracking improvements this is not
longer the case because the IO/APIC uses lazy disabling. So the line state
is unmasked which means that enable_irq() does not call into the new irq
chip to unmask it.
In principle this is a shortcoming of the core code, but it's more than
unclear whether the core code should try to reset state. At least this
cannot be done unconditionally as that would break other existing use cases
where the chip type is changed, e.g. when changing the trigger type, but
the callers expect the state to be preserved.
As the way how check_timer() is switching the delivery modes is truly
unique, the obvious fix is to simply unmask the i8259 manually after
changing the mode to ExtINT delivery and switching the irq chip to the
legacy PIC.
Note, that the fixes tag is not really precise, but identifies the commit
which broke the assumptions in the IO/APIC and i8259 code and that's the
kernel version to which this needs to be backported.
`best_clock` is an object that may be sent out. Object `clock`
contains uninitialized bytes that are copied to `best_clock`,
which leads to memory disclosure and information leak.
When the option is RTC_PLL_GET, pll will be copied to userland
via copy_to_user. pll is initialized using mach_get_rtc_pll indirect
call and mach_get_rtc_pll is only assigned with function
q40_get_rtc_pll in arch/m68k/q40/config.c.
In function q40_get_rtc_pll, the field pll_ctrl is not initialized.
This will leak uninitialized stack content to userland.
Fix this by zeroing the uninitialized field.
As told by Catalin: "On arm64 without hardware Access Flag, copying from
user will fail because the pte is old and cannot be marked young. So we
always end up with zeroed page after fork() + CoW for pfn mappings. we
don't always have a hardware-managed access flag on arm64."
This patch fixes it by calling pte_mkyoung. Also, the parameter is
changed because vmf should be passed to cow_user_page()
Add a WARN_ON_ONCE when __copy_from_user_inatomic() returns error
in case there can be some obscure use-case (by Kirill).
If firmware reports rate_max > WMI_TPC_RATE_MAX(WMI_TPC_FINAL_RATE_MAX)
or num_tx_chain > WMI_TPC_TX_N_CHAIN, it will cause array out-of-bounds
access, so print a warning and reset to avoid memory corruption.
Tested HW: QCA9984
Tested FW: 10.4-3.9.0.2-00035
Signed-off-by: Miaoqing Pan <miaoqing@codeaurora.org> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Make dma_fence_enable_sw_signaling() behave like its
dma_fence_add_callback() and dma_fence_default_wait() counterparts and
perform the test to enable signaling under the fence->lock, along with
the action to do so. This ensure that should an implementation be trying
to flush the cb_list (by signaling) on retirement before freeing the
fence, it can do so in a race-free manner.
See also 0fc89b6802ba ("dma-fence: Simply wrap dma_fence_signal_locked
with dma_fence_signal").
v2: Refactor all 3 enable_signaling paths to use a common function.
v3: Don't argue, just keep the tracepoint in the existing spot.
Currently, the SELinux LSM prevents one from setting the
`security.selinux` xattr on an inode without a policy first being
loaded. However, this restriction is problematic: it makes it impossible
to have newly created files with the correct label before actually
loading the policy.
This is relevant in distributions like Fedora, where the policy is
loaded by systemd shortly after pivoting out of the initrd. In such
instances, all files created prior to pivoting will be unlabeled. One
then has to relabel them after pivoting, an operation which inherently
races with other processes trying to access those same files.
Going further, there are use cases for creating the entire root
filesystem on first boot from the initrd (e.g. Container Linux supports
this today[1], and we'd like to support it in Fedora CoreOS as well[2]).
One can imagine doing this in two ways: at the block device level (e.g.
laying down a disk image), or at the filesystem level. In the former,
labeling can simply be part of the image. But even in the latter
scenario, one still really wants to be able to set the right labels when
populating the new filesystem.
This patch enables this by changing behaviour in the following two ways:
1. allow `setxattr` if we're not initialized
2. don't try to set the in-core inode SID if we're not initialized;
instead leave it as `LABEL_INVALID` so that revalidation may be
attempted at a later time
Note the first hunk of this patch is mostly the same as a previously
discussed one[3], though it was part of a larger series which wasn't
accepted.
Co-developed-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Jonathan Lebon <jlebon@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
If the call to uart_add_one_port() in serial8250_register_8250_port()
fails, a half-initialized entry in the serial_8250ports[] array is left
behind.
A subsequent reprobe of the same serial port causes that entry to be
reused. Because uart->port.dev is set, uart_remove_one_port() is called
for the half-initialized entry and bails out with an error message:
The same happens on failure of mctrl_gpio_init() since commit 4a96895f74c9 ("tty/serial/8250: use mctrl_gpio helpers").
Fix by zeroing the uart->port.dev pointer in the probe error path.
The bug was introduced in v2.6.10 by historical commit befff6f5bf5f
("[SERIAL] Add new port registration/unregistration functions."):
https://git.kernel.org/tglx/history/c/befff6f5bf5f
The commit added an unconditional call to uart_remove_one_port() in
serial8250_register_port(). In v3.7, commit 835d844d1a28 ("8250_pnp:
do pnp probe before legacy probe") made that call conditional on
uart->port.dev which allows me to fix the issue by zeroing that pointer
in the error path. Thus, the present commit will fix the problem as far
back as v3.7 whereas still older versions need to also cherry-pick 835d844d1a28.
Fixes: 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v2.6.10 Cc: stable@vger.kernel.org # v2.6.10: 835d844d1a28: 8250_pnp: do pnp probe before legacy Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/b4a072013ee1a1d13ee06b4325afb19bda57ca1b.1589285873.git.lukas@wunner.de
[iwamatsu: Backported to 4.14, 4.19: adjust context] Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Aggregation effects are extremely common with wifi, cellular, and cable
modem link technologies, ACK decimation in middleboxes, and LRO and GRO
in receiving hosts. The aggregation can happen in either direction,
data or ACKs, but in either case the aggregation effect is visible
to the sender in the ACK stream.
Previously BBR's sending was often limited by cwnd under severe ACK
aggregation/decimation because BBR sized the cwnd at 2*BDP. If packets
were acked in bursts after long delays (e.g. one ACK acking 5*BDP after
5*RTT), BBR's sending was halted after sending 2*BDP over 2*RTT, leaving
the bottleneck idle for potentially long periods. Note that loss-based
congestion control does not have this issue because when facing
aggregation it continues increasing cwnd after bursts of ACKs, growing
cwnd until the buffer is full.
To achieve good throughput in the presence of aggregation effects, this
algorithm allows the BBR sender to put extra data in flight to keep the
bottleneck utilized during silences in the ACK stream that it has evidence
to suggest were caused by aggregation.
A summary of the algorithm: when a burst of packets are acked by a
stretched ACK or a burst of ACKs or both, BBR first estimates the expected
amount of data that should have been acked, based on its estimated
bandwidth. Then the surplus ("extra_acked") is recorded in a windowed-max
filter to estimate the recent level of observed ACK aggregation. Then cwnd
is increased by the ACK aggregation estimate. The larger cwnd avoids BBR
being cwnd-limited in the face of ACK silences that recent history suggests
were caused by aggregation. As a sanity check, the ACK aggregation degree
is upper-bounded by the cwnd (at the time of measurement) and a global max
of BW * 100ms. The algorithm is further described by the following
presentation:
https://datatracker.ietf.org/meeting/101/materials/slides-101-iccrg-an-update-on-bbr-work-at-google-00
In our internal testing, we observed a significant increase in BBR
throughput (measured using netperf), in a basic wifi setup.
- Host1 (sender on ethernet) -> AP -> Host2 (receiver on wifi)
- 2.4 GHz -> BBR before: ~73 Mbps; BBR after: ~102 Mbps; CUBIC: ~100 Mbps
- 5.0 GHz -> BBR before: ~362 Mbps; BBR after: ~593 Mbps; CUBIC: ~601 Mbps
Also, this code is running globally on YouTube TCP connections and produced
significant bandwidth increases for YouTube traffic.
This is based on Ian Swett's max_ack_height_ algorithm from the
QUIC BBR implementation.
Signed-off-by: Priyaranjan Jha <priyarjha@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because bbr_target_cwnd() is really a general-purpose BBR helper for
computing some volume of inflight data as a function of the estimated
BDP, refactor it into following helper functions:
- bbr_bdp()
- bbr_quantization_budget()
- bbr_inflight()
Signed-off-by: Priyaranjan Jha <priyarjha@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It only happens on our 1-vcpu instances, because there's no chance for
oom reaper to run to reclaim the to-be-killed process.
Add a cond_resched() at the upper shrink_node_memcgs() to solve this
issue, this will mean that we will get a scheduling point for each memcg
in the reclaimed hierarchy without any dependency on the reclaimable
memory in that memcg thus making it more predictable.
Suggested-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Xunlei Pang <xlpang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: http://lkml.kernel.org/r/1598495549-67324-1-git-send-email-xlpang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Julius Hemanth Pitti <jpitti@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As Documentation/kbuild/llvm.rst implies, building the kernel with a
full set of LLVM tools gets very verbose and unwieldy.
Provide a single switch LLVM=1 to use Clang and LLVM tools instead
of GCC and Binutils. You can pass it from the command line or as an
environment variable.
Please note LLVM=1 does not turn on the integrated assembler. You need
to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the
integrated assembler, I think we can make it default.
We discussed what we need, and we agreed to go with a simple boolean
flag that switches both target and host tools:
When multiple versions of LLVM are installed, I just thought supporting
LLVM_DIR=/path/to/my/llvm/bin/ might be useful.
CC = $(LLVM_DIR)clang
LD = $(LLVM_DIR)ld.lld
...
However, we can handle this by modifying PATH. So, we decided to not do
this.
- LLVM_SUFFIX
Some distributions (e.g. Debian) package specific versions of LLVM with
naming conventions that use the version as a suffix.
CC = clang$(LLVM_SUFFIX)
LD = ld.lld(LLVM_SUFFIX)
...
will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc.,
but the suffixed versions in /usr/bin/ are symlinks to binaries in
/usr/lib/llvm-#/bin/, so this can also be handled by PATH.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
[nd: hunk against Documentation/kbuild/kbuild.rst dropped due to not backporting
commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst")] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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