commit e64d5fa504 upstream.
During hibernation process, once thaw() stage completes, the MHI endpoint
devices will be in M0 state post recovery. After that, the devices will be
powered down so that the system can enter the target sleep state. During
this stage, the PCI core will put the devices in D3hot. But this transition
is allowed by the MHI spec. The devices can only enter D3hot when it is in
M3 state.
So for fixing this issue, let's add the poweroff() callback that will get
executed before putting the system in target sleep state during
hibernation. This callback will power down the device properly so that it
could be restored during restore() or thaw() stage.
Cc: stable@vger.kernel.org
Fixes: 5f0c2ee1fe ("bus: mhi: pci-generic: Fix hibernation")
Reported-by: Hemant Kumar <quic_hemantk@quicinc.com>
Suggested-by: Hemant Kumar <quic_hemantk@quicinc.com>
Link: https://lore.kernel.org/r/20220405125907.5644-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 637674fa40 upstream.
The EndRun PTP/1588 dual serial port device is based on the Oxford
Semiconductor OXPCIe952 UART device with the PCI vendor:device ID set
for EndRun Technologies and is therefore driven by a fixed 62.5MHz clock
input derived from the 100MHz PCI Express clock. The clock rate is
divided by the oversampling rate of 16 as it is supplied to the baud
rate generator, yielding the baud base of 3906250.
Replace the incorrect baud base of 4000000 with the right value of
3906250 then, complementing commit 6cbe45d8ac ("serial: 8250: Correct
the clock for OxSemi PCIe devices").
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable <stable@kernel.org>
Fixes: 1bc8cde46a ("8250_pci: Added driver for Endrun Technologies PTP PCIe card.")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181515270.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0e4deb56b0 upstream.
The current timeout for draining the tx fifo in RS485 mode is calculated by
multiplying the time it takes to transmit one character (with the given
baud rate) with the maximal number of characters in the tx queue.
This timeout is too short for two reasons:
First when calculating the time to transmit one character integer division
is used which may round down the result in case of a remainder of the
division.
Fix this by rounding up the division result.
Second the hardware may need additional time (e.g for first putting the
characters from the fifo into the shift register) before the characters are
actually put onto the wire.
To be on the safe side double the current maximum number of iterations
that are used to wait for the queue draining.
Fixes: 8d47923772 ("serial: amba-pl011: add RS485 support")
Cc: stable@vger.kernel.org
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Link: https://lore.kernel.org/r/20220408233503.7251-1-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ee82c6e41 upstream.
Commit 76821e222c ("serial: imx: ensure that RX irqs are off if RX is
off") accidentally enabled overrun interrupts unconditionally when
deferring DMA enable until after the receiver has been enabled during
startup.
Fix this by using the DMA-initialised instead of DMA-enabled flag to
determine whether overrun interrupts should be enabled.
Note that overrun interrupts are already accounted for in
imx_uart_clear_rx_errors() when using DMA since commit 41d98b5da9
("serial: imx-serial - update RX error counters when DMA is used").
Fixes: 76821e222c ("serial: imx: ensure that RX irqs are off if RX is off")
Cc: stable@vger.kernel.org # 4.17
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220411081957.7846-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c7428dbddc upstream.
If the user sets the usb_request's no_interrupt, then there will be no
completion event for the request. Currently the driver incorrectly uses
the event status of a different request to report the status for a
request with no_interrupt. The dwc3 driver needs to check the TRB status
associated with the request when reporting its status.
Note: this is only applicable to missed_isoc TRB completion status, but
the other status are also listed for completeness/documentation.
Fixes: 6d8a019614 ("usb: dwc3: gadget: check for Missed Isoc from event status")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/db2c80108286cfd108adb05bad52138b78d7c3a7.1650673655.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab7aa2866d upstream.
If the PHY controller node has a "port" dwc3 tries to find an
extcon device even when "usb-role-switch" is present. This happens
because dwc3_get_extcon() sees that "port" node and then calls
extcon_find_edev_by_node() which will always return EPROBE_DEFER
in that case.
On the other hand, even if an extcon was present and dwc3_get_extcon()
was successful it would still be ignored in favor of "usb-role-switch".
Let's just first check if "usb-role-switch" is configured in the device
tree and directly use it instead and only try to look for an extcon
device otherwise.
Fixes: 8a0a137997 ("usb: dwc3: Registering a role switch in the DRD code.")
Cc: stable <stable@kernel.org>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20220411155300.9766-1-sven@svenpeter.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bf95c4d463 upstream.
If any function like UVC is deactivating gadget as part of composition
switch which results in not calling pullup enablement, it is not getting
enabled after switch to new composition due to this deactivation flag
not cleared. This results in USB enumeration not happening after switch
to new USB composition. Hence clear deactivation flag inside gadget
structure in configfs_composite_unbind() before switch to new USB
composition.
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: Dan Vacura <w36195@motorola.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20220413211038.72797-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 71d471e3fa upstream.
During the uvcg_video_pump() process, if an error occurs and
uvcg_queue_cancel() is called, the buffer queue will be cleared out, but
the current marker (queue->buf_used) of the active buffer (no longer
active) is not reset. On the next iteration of uvcg_video_pump() the
stale buf_used count will be used and the logic of min((unsigned
int)len, buf->bytesused - queue->buf_used) may incorrectly calculate a
nbytes size, causing an invalid memory access.
[80802.185460][ T315] configfs-gadget gadget: uvc: VS request completed
with status -18.
[80802.185519][ T315] configfs-gadget gadget: uvc: VS request completed
with status -18.
...
uvcg_queue_cancel() is called and the queue is cleared out, but the
marker queue->buf_used is not reset.
...
[80802.262328][ T8682] Unable to handle kernel paging request at virtual
address ffffffc03af9f000
...
...
[80802.263138][ T8682] Call trace:
[80802.263146][ T8682] __memcpy+0x12c/0x180
[80802.263155][ T8682] uvcg_video_pump+0xcc/0x1e0
[80802.263165][ T8682] process_one_work+0x2cc/0x568
[80802.263173][ T8682] worker_thread+0x28c/0x518
[80802.263181][ T8682] kthread+0x160/0x170
[80802.263188][ T8682] ret_from_fork+0x10/0x18
[80802.263198][ T8682] Code: a8c12829 a88130cb a8c130
Fixes: d692522577 ("usb: gadget/uvc: Port UVC webcam gadget to use videobuf2 framework")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20220331184024.23918-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0543e4e885 upstream.
Since commit ae8709b296 ("USB: core: Make do_proc_control() and
do_proc_bulk() killable") if a device has the USB_QUIRK_DELAY_CTRL_MSG
quirk set, it will temporarily block all other URBs (e.g. interrupts)
while sleeping due to a control.
This results in noticeable delays when, for example, a userspace usbfs
application is sending URB interrupts at a high rate to a keyboard and
simultaneously updates the lock indicators using controls. Interrupts
with direction set to IN are also affected by this, meaning that
delivery of HID reports (containing scancodes) to the usbfs application
is delayed as well.
This patch fixes the regression by calling msleep() while the device
mutex is unlocked, as was the case originally with usb_control_msg().
Fixes: ae8709b296 ("USB: core: Make do_proc_control() and do_proc_bulk() killable")
Cc: stable <stable@kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
Link: https://lore.kernel.org/r/3e299e2a-13b9-ddff-7fee-6845e868bc06@tasossah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3a26787dac upstream.
When the driver fails to enable the regulator 'vid', we will get the
following splat:
[ 79.955610] WARNING: CPU: 5 PID: 441 at drivers/regulator/core.c:2257 _regulator_put+0x3ec/0x4e0
[ 79.959641] RIP: 0010:_regulator_put+0x3ec/0x4e0
[ 79.967570] Call Trace:
[ 79.967773] <TASK>
[ 79.967951] regulator_put+0x1f/0x30
[ 79.968254] devres_release_group+0x319/0x3d0
[ 79.968608] i2c_device_probe+0x766/0x940
Fix this by disabling the 'vdd' regulator when failing to enable 'vid'
regulator.
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Link: https://lore.kernel.org/r/20220409034849.3717231-2-zheyuma97@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 33597f0c48 upstream.
The first U3 wake signal by the host may be lost if the USB 3 connection is
tunneled over USB4, with a runtime suspended USB4 host, and firmware
implemented connection manager.
Specs state the host must wait 100ms (tU3WakeupRetryDelay) before
resending a U3 wake signal if device doesn't respond, leading to U3 -> U0
link transition times around 270ms in the tunneled case.
Fixes: 0200b9f790 ("xhci: Wait until link state trainsits to U0 after setting USB_SS_PORT_LS_U0")
Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220408134823.2527272-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dc92944a01 upstream.
While rebooting, XHCI controller and its bus device will be shut down
in order by .shutdown callback. Stopping roothubs polling in
xhci_shutdown() can prevent XHCI driver from accessing port status
after its bus device shutdown.
Take PCIe XHCI controller as example, if XHCI driver doesn't stop roothubs
polling, XHCI driver may access PCIe BAR register for port status after
parent PCIe root port driver is shutdown and cause PCIe bus error.
[check shared hcd exist before stopping its roothub polling -Mathias]
Cc: stable@vger.kernel.org
Signed-off-by: Henry Lin <henryl@nvidia.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220408134823.2527272-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e23e50e7ac upstream.
The sizeof(struct whitehat_dr_info) can be 4 bytes under CONFIG_AEABI=n
due to "-mabi=apcs-gnu", even though it has a single u8:
whiteheat_private {
__u8 mcr; /* 0 1 */
/* size: 4, cachelines: 1, members: 1 */
/* padding: 3 */
/* last cacheline: 4 bytes */
};
The result is technically harmless, as both the source and the
destinations are currently the same allocation size (4 bytes) and don't
use their padding, but if anything were to ever be added after the
"mcr" member in "struct whiteheat_private", it would be overwritten. The
structs both have a single u8 "mcr" member, but are 4 bytes in padded
size. The memcpy() destination was explicitly targeting the u8 member
(size 1) with the length of the whole structure (size 4), triggering
the memcpy buffer overflow warning:
In file included from include/linux/string.h:253,
from include/linux/bitmap.h:11,
from include/linux/cpumask.h:12,
from include/linux/smp.h:13,
from include/linux/lockdep.h:14,
from include/linux/spinlock.h:62,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:6,
from include/linux/slab.h:15,
from drivers/usb/serial/whiteheat.c:17:
In function 'fortify_memcpy_chk',
inlined from 'firm_send_command' at drivers/usb/serial/whiteheat.c:587:4:
include/linux/fortify-string.h:328:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
328 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Instead, just assign the one byte directly.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202204142318.vDqjjSFn-lkp@intel.com
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220421001234.2421107-1-keescook@chromium.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 456244aeec upstream.
Issue description:
When an OTG port has been switched to device role and then switch back
to host role again, the USB 3.0 Host (XHCI) will not be able to detect
"plug in event of a connected USB 2.0/1.0 ((Highspeed and Fullspeed)
devices until system reboot.
Root cause and Solution:
There is a condition checking flag "ssusb->otg_switch.is_u3_drd" in
toggle_opstate(). At the end of role switch procedure, toggle_opstate()
will be called to set DC_SESSION and SOFT_CONN bit. If "is_u3_drd" was
set and switched the role to USB host 3.0, bit DC_SESSION and SOFT_CONN
will be skipped hence caused the port cannot detect connected USB 2.0
(Highspeed and Fullspeed) devices. Simply remove the condition check to
solve this issue.
Fixes: d0ed062a8b ("usb: mtu3: dual-role mode support")
Cc: stable@vger.kernel.org
Tested-by: Fabien Parent <fparent@baylibre.com>
Reviewed-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Signed-off-by: Tainping Fang <tianping.fang@mediatek.com>
Link: https://lore.kernel.org/r/20220419081245.21015-1-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 13c6a37d40 upstream.
This test tries to pass a PTR_TO_BTF_ID_OR_NULL to the release function,
which would trigger a out of bounds access without the fix in commit
45ce4b4f90 ("bpf: Fix crash due to out of bounds access into reg2btf_ids.")
but after the fix, it should only index using base_type(reg->type),
which should be less than __BPF_REG_TYPE_MAX, and also not permit any
type flags to be set for the reg->type.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220220023138.2224652-1-memxor@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fe673d3f5b upstream
Instead of using GUP, make fault_in_safe_writeable() actually force a
'handle_mm_fault()' using the same fixup_user_fault() machinery that
futexes already use.
Using the GUP machinery meant that fault_in_safe_writeable() did not do
everything that a real fault would do, ranging from not auto-expanding
the stack segment, to not updating accessed or dirty flags in the page
tables (GUP sets those flags on the pages themselves).
The latter causes problems on architectures (like s390) that do accessed
bit handling in software, which meant that fault_in_safe_writeable()
didn't actually do all the fault handling it needed to, and trying to
access the user address afterwards would still cause faults.
Reported-and-tested-by: Andreas Gruenbacher <agruenba@redhat.com>
Fixes: cdd591fc86 ("iov_iter: Introduce fault_in_iov_iter_writeable")
Link: https://lore.kernel.org/all/CAHc6FU5nP+nziNGG0JAF1FUx-GV7kKFvM7aZuU_XD2_1v4vnvg@mail.gmail.com/
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ca93e44bfb upstream
Some users recently reported that MariaDB was getting a read corruption
when using io_uring on top of btrfs. This started to happen in 5.16,
after commit 51bd9563b6 ("btrfs: fix deadlock due to page faults
during direct IO reads and writes"). That changed btrfs to use the new
iomap flag IOMAP_DIO_PARTIAL and to disable page faults before calling
iomap_dio_rw(). This was necessary to fix deadlocks when the iovector
corresponds to a memory mapped file region. That type of scenario is
exercised by test case generic/647 from fstests.
For this MariaDB scenario, we attempt to read 16K from file offset X
using IOCB_NOWAIT and io_uring. In that range we have 4 extents, each
with a size of 4K, and what happens is the following:
1) btrfs_direct_read() disables page faults and calls iomap_dio_rw();
2) iomap creates a struct iomap_dio object, its reference count is
initialized to 1 and its ->size field is initialized to 0;
3) iomap calls btrfs_dio_iomap_begin() with file offset X, which finds
the first 4K extent, and setups an iomap for this extent consisting
of a single page;
4) At iomap_dio_bio_iter(), we are able to access the first page of the
buffer (struct iov_iter) with bio_iov_iter_get_pages() without
triggering a page fault;
5) iomap submits a bio for this 4K extent
(iomap_dio_submit_bio() -> btrfs_submit_direct()) and increments
the refcount on the struct iomap_dio object to 2; The ->size field
of the struct iomap_dio object is incremented to 4K;
6) iomap calls btrfs_iomap_begin() again, this time with a file
offset of X + 4K. There we setup an iomap for the next extent
that also has a size of 4K;
7) Then at iomap_dio_bio_iter() we call bio_iov_iter_get_pages(),
which tries to access the next page (2nd page) of the buffer.
This triggers a page fault and returns -EFAULT;
8) At __iomap_dio_rw() we see the -EFAULT, but we reset the error
to 0 because we passed the flag IOMAP_DIO_PARTIAL to iomap and
the struct iomap_dio object has a ->size value of 4K (we submitted
a bio for an extent already). The 'wait_for_completion' variable
is not set to true, because our iocb has IOCB_NOWAIT set;
9) At the bottom of __iomap_dio_rw(), we decrement the reference count
of the struct iomap_dio object from 2 to 1. Because we were not
the only ones holding a reference on it and 'wait_for_completion' is
set to false, -EIOCBQUEUED is returned to btrfs_direct_read(), which
just returns it up the callchain, up to io_uring;
10) The bio submitted for the first extent (step 5) completes and its
bio endio function, iomap_dio_bio_end_io(), decrements the last
reference on the struct iomap_dio object, resulting in calling
iomap_dio_complete_work() -> iomap_dio_complete().
11) At iomap_dio_complete() we adjust the iocb->ki_pos from X to X + 4K
and return 4K (the amount of io done) to iomap_dio_complete_work();
12) iomap_dio_complete_work() calls the iocb completion callback,
iocb->ki_complete() with a second argument value of 4K (total io
done) and the iocb with the adjust ki_pos of X + 4K. This results
in completing the read request for io_uring, leaving it with a
result of 4K bytes read, and only the first page of the buffer
filled in, while the remaining 3 pages, corresponding to the other
3 extents, were not filled;
13) For the application, the result is unexpected because if we ask
to read N bytes, it expects to get N bytes read as long as those
N bytes don't cross the EOF (i_size).
MariaDB reports this as an error, as it's not expecting a short read,
since it knows it's asking for read operations fully within the i_size
boundary. This is typical in many applications, but it may also be
questionable if they should react to such short reads by issuing more
read calls to get the remaining data. Nevertheless, the short read
happened due to a change in btrfs regarding how it deals with page
faults while in the middle of a read operation, and there's no reason
why btrfs can't have the previous behaviour of returning the whole data
that was requested by the application.
The problem can also be triggered with the following simple program:
/* Get O_DIRECT */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <liburing.h>
int main(int argc, char *argv[])
{
char *foo_path;
struct io_uring ring;
struct io_uring_sqe *sqe;
struct io_uring_cqe *cqe;
struct iovec iovec;
int fd;
long pagesize;
void *write_buf;
void *read_buf;
ssize_t ret;
int i;
if (argc != 2) {
fprintf(stderr, "Use: %s <directory>\n", argv[0]);
return 1;
}
foo_path = malloc(strlen(argv[1]) + 5);
if (!foo_path) {
fprintf(stderr, "Failed to allocate memory for file path\n");
return 1;
}
strcpy(foo_path, argv[1]);
strcat(foo_path, "/foo");
/*
* Create file foo with 2 extents, each with a size matching
* the page size. Then allocate a buffer to read both extents
* with io_uring, using O_DIRECT and IOCB_NOWAIT. Before doing
* the read with io_uring, access the first page of the buffer
* to fault it in, so that during the read we only trigger a
* page fault when accessing the second page of the buffer.
*/
fd = open(foo_path, O_CREAT | O_TRUNC | O_WRONLY |
O_DIRECT, 0666);
if (fd == -1) {
fprintf(stderr,
"Failed to create file 'foo': %s (errno %d)",
strerror(errno), errno);
return 1;
}
pagesize = sysconf(_SC_PAGE_SIZE);
ret = posix_memalign(&write_buf, pagesize, 2 * pagesize);
if (ret) {
fprintf(stderr, "Failed to allocate write buffer\n");
return 1;
}
memset(write_buf, 0xab, pagesize);
memset(write_buf + pagesize, 0xcd, pagesize);
/* Create 2 extents, each with a size matching page size. */
for (i = 0; i < 2; i++) {
ret = pwrite(fd, write_buf + i * pagesize, pagesize,
i * pagesize);
if (ret != pagesize) {
fprintf(stderr,
"Failed to write to file, ret = %ld errno %d (%s)\n",
ret, errno, strerror(errno));
return 1;
}
ret = fsync(fd);
if (ret != 0) {
fprintf(stderr, "Failed to fsync file\n");
return 1;
}
}
close(fd);
fd = open(foo_path, O_RDONLY | O_DIRECT);
if (fd == -1) {
fprintf(stderr,
"Failed to open file 'foo': %s (errno %d)",
strerror(errno), errno);
return 1;
}
ret = posix_memalign(&read_buf, pagesize, 2 * pagesize);
if (ret) {
fprintf(stderr, "Failed to allocate read buffer\n");
return 1;
}
/*
* Fault in only the first page of the read buffer.
* We want to trigger a page fault for the 2nd page of the
* read buffer during the read operation with io_uring
* (O_DIRECT and IOCB_NOWAIT).
*/
memset(read_buf, 0, 1);
ret = io_uring_queue_init(1, &ring, 0);
if (ret != 0) {
fprintf(stderr, "Failed to create io_uring queue\n");
return 1;
}
sqe = io_uring_get_sqe(&ring);
if (!sqe) {
fprintf(stderr, "Failed to get io_uring sqe\n");
return 1;
}
iovec.iov_base = read_buf;
iovec.iov_len = 2 * pagesize;
io_uring_prep_readv(sqe, fd, &iovec, 1, 0);
ret = io_uring_submit_and_wait(&ring, 1);
if (ret != 1) {
fprintf(stderr,
"Failed at io_uring_submit_and_wait()\n");
return 1;
}
ret = io_uring_wait_cqe(&ring, &cqe);
if (ret < 0) {
fprintf(stderr, "Failed at io_uring_wait_cqe()\n");
return 1;
}
printf("io_uring read result for file foo:\n\n");
printf(" cqe->res == %d (expected %d)\n", cqe->res, 2 * pagesize);
printf(" memcmp(read_buf, write_buf) == %d (expected 0)\n",
memcmp(read_buf, write_buf, 2 * pagesize));
io_uring_cqe_seen(&ring, cqe);
io_uring_queue_exit(&ring);
return 0;
}
When running it on an unpatched kernel:
$ gcc io_uring_test.c -luring
$ mkfs.btrfs -f /dev/sda
$ mount /dev/sda /mnt/sda
$ ./a.out /mnt/sda
io_uring read result for file foo:
cqe->res == 4096 (expected 8192)
memcmp(read_buf, write_buf) == -205 (expected 0)
After this patch, the read always returns 8192 bytes, with the buffer
filled with the correct data. Although that reproducer always triggers
the bug in my test vms, it's possible that it will not be so reliable
on other environments, as that can happen if the bio for the first
extent completes and decrements the reference on the struct iomap_dio
object before we do the atomic_dec_and_test() on the reference at
__iomap_dio_rw().
Fix this in btrfs by having btrfs_dio_iomap_begin() return -EAGAIN
whenever we try to satisfy a non blocking IO request (IOMAP_NOWAIT flag
set) over a range that spans multiple extents (or a mix of extents and
holes). This avoids returning success to the caller when we only did
partial IO, which is not optimal for writes and for reads it's actually
incorrect, as the caller doesn't expect to get less bytes read than it has
requested (unless EOF is crossed), as previously mentioned. This is also
the type of behaviour that xfs follows (xfs_direct_write_iomap_begin()),
even though it doesn't use IOMAP_DIO_PARTIAL.
A test case for fstests will follow soon.
Link: https://lore.kernel.org/linux-btrfs/CABVffEM0eEWho+206m470rtM0d9J8ue85TtR-A_oVTuGLWFicA@mail.gmail.com/
Link: https://lore.kernel.org/linux-btrfs/CAHF2GV6U32gmqSjLe=XKgfcZAmLCiH26cJ2OnHGp5x=VAH4OHQ@mail.gmail.com/
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 51bd9563b6 upstream
If we do a direct IO read or write when the buffer given by the user is
memory mapped to the file range we are going to do IO, we end up ending
in a deadlock. This is triggered by the new test case generic/647 from
fstests.
For a direct IO read we get a trace like this:
[967.872718] INFO: task mmap-rw-fault:12176 blocked for more than 120 seconds.
[967.874161] Not tainted 5.14.0-rc7-btrfs-next-95 #1
[967.874909] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[967.875983] task:mmap-rw-fault state:D stack: 0 pid:12176 ppid: 11884 flags:0x00000000
[967.875992] Call Trace:
[967.875999] __schedule+0x3ca/0xe10
[967.876015] schedule+0x43/0xe0
[967.876020] wait_extent_bit.constprop.0+0x1eb/0x260 [btrfs]
[967.876109] ? do_wait_intr_irq+0xb0/0xb0
[967.876118] lock_extent_bits+0x37/0x90 [btrfs]
[967.876150] btrfs_lock_and_flush_ordered_range+0xa9/0x120 [btrfs]
[967.876184] ? extent_readahead+0xa7/0x530 [btrfs]
[967.876214] extent_readahead+0x32d/0x530 [btrfs]
[967.876253] ? lru_cache_add+0x104/0x220
[967.876255] ? kvm_sched_clock_read+0x14/0x40
[967.876258] ? sched_clock_cpu+0xd/0x110
[967.876263] ? lock_release+0x155/0x4a0
[967.876271] read_pages+0x86/0x270
[967.876274] ? lru_cache_add+0x125/0x220
[967.876281] page_cache_ra_unbounded+0x1a3/0x220
[967.876291] filemap_fault+0x626/0xa20
[967.876303] __do_fault+0x36/0xf0
[967.876308] __handle_mm_fault+0x83f/0x15f0
[967.876322] handle_mm_fault+0x9e/0x260
[967.876327] __get_user_pages+0x204/0x620
[967.876332] ? get_user_pages_unlocked+0x69/0x340
[967.876340] get_user_pages_unlocked+0xd3/0x340
[967.876349] internal_get_user_pages_fast+0xbca/0xdc0
[967.876366] iov_iter_get_pages+0x8d/0x3a0
[967.876374] bio_iov_iter_get_pages+0x82/0x4a0
[967.876379] ? lock_release+0x155/0x4a0
[967.876387] iomap_dio_bio_actor+0x232/0x410
[967.876396] iomap_apply+0x12a/0x4a0
[967.876398] ? iomap_dio_rw+0x30/0x30
[967.876414] __iomap_dio_rw+0x29f/0x5e0
[967.876415] ? iomap_dio_rw+0x30/0x30
[967.876420] ? lock_acquired+0xf3/0x420
[967.876429] iomap_dio_rw+0xa/0x30
[967.876431] btrfs_file_read_iter+0x10b/0x140 [btrfs]
[967.876460] new_sync_read+0x118/0x1a0
[967.876472] vfs_read+0x128/0x1b0
[967.876477] __x64_sys_pread64+0x90/0xc0
[967.876483] do_syscall_64+0x3b/0xc0
[967.876487] entry_SYSCALL_64_after_hwframe+0x44/0xae
[967.876490] RIP: 0033:0x7fb6f2c038d6
[967.876493] RSP: 002b:00007fffddf586b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000011
[967.876496] RAX: ffffffffffffffda RBX: 0000000000001000 RCX: 00007fb6f2c038d6
[967.876498] RDX: 0000000000001000 RSI: 00007fb6f2c17000 RDI: 0000000000000003
[967.876499] RBP: 0000000000001000 R08: 0000000000000003 R09: 0000000000000000
[967.876501] R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000003
[967.876502] R13: 0000000000000000 R14: 00007fb6f2c17000 R15: 0000000000000000
This happens because at btrfs_dio_iomap_begin() we lock the extent range
and return with it locked - we only unlock in the endio callback, at
end_bio_extent_readpage() -> endio_readpage_release_extent(). Then after
iomap called the btrfs_dio_iomap_begin() callback, it triggers the page
faults that resulting in reading the pages, through the readahead callback
btrfs_readahead(), and through there we end to attempt to lock again the
same extent range (or a subrange of what we locked before), resulting in
the deadlock.
For a direct IO write, the scenario is a bit different, and it results in
trace like this:
[1132.442520] run fstests generic/647 at 2021-08-31 18:53:35
[1330.349355] INFO: task mmap-rw-fault:184017 blocked for more than 120 seconds.
[1330.350540] Not tainted 5.14.0-rc7-btrfs-next-95 #1
[1330.351158] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[1330.351900] task:mmap-rw-fault state:D stack: 0 pid:184017 ppid:183725 flags:0x00000000
[1330.351906] Call Trace:
[1330.351913] __schedule+0x3ca/0xe10
[1330.351930] schedule+0x43/0xe0
[1330.351935] btrfs_start_ordered_extent+0x108/0x1c0 [btrfs]
[1330.352020] ? do_wait_intr_irq+0xb0/0xb0
[1330.352028] btrfs_lock_and_flush_ordered_range+0x8c/0x120 [btrfs]
[1330.352064] ? extent_readahead+0xa7/0x530 [btrfs]
[1330.352094] extent_readahead+0x32d/0x530 [btrfs]
[1330.352133] ? lru_cache_add+0x104/0x220
[1330.352135] ? kvm_sched_clock_read+0x14/0x40
[1330.352138] ? sched_clock_cpu+0xd/0x110
[1330.352143] ? lock_release+0x155/0x4a0
[1330.352151] read_pages+0x86/0x270
[1330.352155] ? lru_cache_add+0x125/0x220
[1330.352162] page_cache_ra_unbounded+0x1a3/0x220
[1330.352172] filemap_fault+0x626/0xa20
[1330.352176] ? filemap_map_pages+0x18b/0x660
[1330.352184] __do_fault+0x36/0xf0
[1330.352189] __handle_mm_fault+0x1253/0x15f0
[1330.352203] handle_mm_fault+0x9e/0x260
[1330.352208] __get_user_pages+0x204/0x620
[1330.352212] ? get_user_pages_unlocked+0x69/0x340
[1330.352220] get_user_pages_unlocked+0xd3/0x340
[1330.352229] internal_get_user_pages_fast+0xbca/0xdc0
[1330.352246] iov_iter_get_pages+0x8d/0x3a0
[1330.352254] bio_iov_iter_get_pages+0x82/0x4a0
[1330.352259] ? lock_release+0x155/0x4a0
[1330.352266] iomap_dio_bio_actor+0x232/0x410
[1330.352275] iomap_apply+0x12a/0x4a0
[1330.352278] ? iomap_dio_rw+0x30/0x30
[1330.352292] __iomap_dio_rw+0x29f/0x5e0
[1330.352294] ? iomap_dio_rw+0x30/0x30
[1330.352306] btrfs_file_write_iter+0x238/0x480 [btrfs]
[1330.352339] new_sync_write+0x11f/0x1b0
[1330.352344] ? NF_HOOK_LIST.constprop.0.cold+0x31/0x3e
[1330.352354] vfs_write+0x292/0x3c0
[1330.352359] __x64_sys_pwrite64+0x90/0xc0
[1330.352365] do_syscall_64+0x3b/0xc0
[1330.352369] entry_SYSCALL_64_after_hwframe+0x44/0xae
[1330.352372] RIP: 0033:0x7f4b0a580986
[1330.352379] RSP: 002b:00007ffd34d75418 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
[1330.352382] RAX: ffffffffffffffda RBX: 0000000000001000 RCX: 00007f4b0a580986
[1330.352383] RDX: 0000000000001000 RSI: 00007f4b0a3a4000 RDI: 0000000000000003
[1330.352385] RBP: 00007f4b0a3a4000 R08: 0000000000000003 R09: 0000000000000000
[1330.352386] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
[1330.352387] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Unlike for reads, at btrfs_dio_iomap_begin() we return with the extent
range unlocked, but later when the page faults are triggered and we try
to read the extents, we end up btrfs_lock_and_flush_ordered_range() where
we find the ordered extent for our write, created by the iomap callback
btrfs_dio_iomap_begin(), and we wait for it to complete, which makes us
deadlock since we can't complete the ordered extent without reading the
pages (the iomap code only submits the bio after the pages are faulted
in).
Fix this by setting the nofault attribute of the given iov_iter and retry
the direct IO read/write if we get an -EFAULT error returned from iomap.
For reads, also disable page faults completely, this is because when we
read from a hole or a prealloc extent, we can still trigger page faults
due to the call to iov_iter_zero() done by iomap - at the moment, it is
oblivious to the value of the ->nofault attribute of an iov_iter.
We also need to keep track of the number of bytes written or read, and
pass it to iomap_dio_rw(), as well as use the new flag IOMAP_DIO_PARTIAL.
This depends on the iov_iter and iomap changes introduced in commit
c03098d4b9 ("Merge tag 'gfs2-v5.15-rc5-mmap-fault' of
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2").
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b01b2d72da upstream
Also disable page faults during direct I/O requests and implement a
similar kind of retry logic as in the buffered I/O case.
The retry logic in the direct I/O case differs from the buffered I/O
case in the following way: direct I/O doesn't provide the kinds of
consistency guarantees between concurrent reads and writes that buffered
I/O provides, so once we lose the inode glock while faulting in user
pages, we always resume the operation. We never need to return a
partial read or write.
This locking problem was originally reported by Jan Kara. Linus came up
with the idea of disabling page faults. Many thanks to Al Viro and
Matthew Wilcox for their feedback.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3337ab08d0 upstream
Introduce a new nofault flag to indicate to iov_iter_get_pages not to
fault in user pages.
This is implemented by passing the FOLL_NOFAULT flag to get_user_pages,
which causes get_user_pages to fail when it would otherwise fault in a
page. We'll use the ->nofault flag to prevent iomap_dio_rw from faulting
in pages when page faults are not allowed.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55b8fe703b upstream
Introduce a new FOLL_NOFAULT flag that causes get_user_pages to return
-EFAULT when it would otherwise trigger a page fault. This is roughly
similar to FOLL_FAST_ONLY but available on all architectures, and less
fragile.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4fdccaa0d1 upstream
Add a done_before argument to iomap_dio_rw that indicates how much of
the request has already been transferred. When the request succeeds, we
report that done_before additional bytes were tranferred. This is
useful for finishing a request asynchronously when part of the request
has already been completed synchronously.
We'll use that to allow iomap_dio_rw to be used with page faults
disabled: when a page fault occurs while submitting a request, we
synchronously complete the part of the request that has already been
submitted. The caller can then take care of the page fault and call
iomap_dio_rw again for the rest of the request, passing in the number of
bytes already tranferred.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 97308f8b0d upstream
In iomap_dio_rw, when iomap_apply returns an -EFAULT error and the
IOMAP_DIO_PARTIAL flag is set, complete the request synchronously and
return a partial result. This allows the caller to deal with the page
fault and retry the remainder of the request.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 42c498c18a upstream
When a user copy fails in one of the helpers of iomap_dio_rw, fail with
-EFAULT instead of returning 0. This matches what iomap_dio_bio_actor
returns when it gets an -EFAULT from bio_iov_iter_get_pages. With these
changes, iomap_dio_actor now consistently fails with -EFAULT when a user
page cannot be faulted in.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00bfe02f47 upstream
In the .read_iter and .write_iter file operations, we're accessing
user-space memory while holding the inode glock. There is a possibility
that the memory is mapped to the same file, in which case we'd recurse
on the same glock.
We could detect and work around this simple case of recursive locking,
but more complex scenarios exist that involve multiple glocks,
processes, and cluster nodes, and working around all of those cases
isn't practical or even possible.
Avoid these kinds of problems by disabling page faults while holding the
inode glock. If a page fault would occur, we either end up with a
partial read or write or with -EFAULT if nothing could be read or
written. In either case, we know that we're not done with the
operation, so we indicate that we're willing to give up the inode glock
and then we fault in the missing pages. If that made us lose the inode
glock, we return a partial read or write. Otherwise, we resume the
operation.
This locking problem was originally reported by Jan Kara. Linus came up
with the idea of disabling page faults. Many thanks to Al Viro and
Matthew Wilcox for their feedback.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b223f7065 upstream
Now that gfs2_file_buffered_write is the only remaining user of
ip->i_gh, we can move the glock holder to the stack (or rather, use the
one we already have on the stack); there is no need for keeping the
holder in the inode anymore.
This is slightly complicated by the fact that we're using ip->i_gh for
the statfs inode in gfs2_file_buffered_write as well. Writing to the
statfs inode isn't very common, so allocate the statfs holder
dynamically when needed.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b924bdab74 upstream
So far, for buffered writes, we were taking the inode glock in
gfs2_iomap_begin and dropping it in gfs2_iomap_end with the intention of
not holding the inode glock while iomap_write_actor faults in user
pages. It turns out that iomap_write_actor is called inside iomap_begin
... iomap_end, so the user pages were still faulted in while holding the
inode glock and the locking code in iomap_begin / iomap_end was
completely pointless.
Move the locking into gfs2_file_buffered_write instead. We'll take care
of the potential deadlocks due to faulting in user pages while holding a
glock in a subsequent patch.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
