The "page" pointer can be used with out being initialized.
Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When converting to atomic the state reset was done by directly calling
the functions, and before the modeset object was fully initialized.
This means the various ->dev pointers weren't set up.
this started to oops because now we're trying to derefence
drm_crtc->dev. Fix this up by entirely switching over to
drm_mode_config_reset, called once everything is set up.
Fixes: 51f644b40b4b ("drm/atomic-helper: reset vblank on crtc reset") Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Tested-by: Roland Scheidegger <sroland@vmware.com> Signed-off-by: Roland Scheidegger <sroland@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3e32cb2e0a12 ("mm: memcontrol: lockless page counters") could had
memcg->memsw->watermark and memcg->memsw->failcnt been accessed
concurrently as reported by KCSAN,
BUG: KCSAN: data-race in page_counter_try_charge / page_counter_try_charge
read to 0xffff8fb18c4cd190 of 8 bytes by task 1081 on cpu 59:
page_counter_try_charge+0x4d/0x150 mm/page_counter.c:138
try_charge+0x131/0xd50 mm/memcontrol.c:2405
__memcg_kmem_charge_memcg+0x58/0x140
__memcg_kmem_charge+0xcc/0x280
__alloc_pages_nodemask+0x1e1/0x450
alloc_pages_current+0xa6/0x120
pte_alloc_one+0x17/0xd0
__pte_alloc+0x3a/0x1f0
copy_p4d_range+0xc36/0x1990
copy_page_range+0x21d/0x360
dup_mmap+0x5f5/0x7a0
dup_mm+0xa2/0x240
copy_process+0x1b3f/0x3460
_do_fork+0xaa/0xa20
__x64_sys_clone+0x13b/0x170
do_syscall_64+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
write to 0xffff8fb18c4cd190 of 8 bytes by task 1153 on cpu 120:
page_counter_try_charge+0x5b/0x150 mm/page_counter.c:139
try_charge+0x131/0xd50 mm/memcontrol.c:2405
mem_cgroup_try_charge+0x159/0x460
mem_cgroup_try_charge_delay+0x3d/0xa0
wp_page_copy+0x14d/0x930
do_wp_page+0x107/0x7b0
__handle_mm_fault+0xce6/0xd40
handle_mm_fault+0xfc/0x2f0
do_page_fault+0x263/0x6f9
page_fault+0x34/0x40
BUG: KCSAN: data-race in page_counter_try_charge / page_counter_try_charge
write to 0xffff88809bbf2158 of 8 bytes by task 11782 on cpu 0:
page_counter_try_charge+0x100/0x170 mm/page_counter.c:129
try_charge+0x185/0xbf0 mm/memcontrol.c:2405
__memcg_kmem_charge_memcg+0x4a/0xe0 mm/memcontrol.c:2837
__memcg_kmem_charge+0xcf/0x1b0 mm/memcontrol.c:2877
__alloc_pages_nodemask+0x26c/0x310 mm/page_alloc.c:4780
read to 0xffff88809bbf2158 of 8 bytes by task 11814 on cpu 1:
page_counter_try_charge+0xef/0x170 mm/page_counter.c:129
try_charge+0x185/0xbf0 mm/memcontrol.c:2405
__memcg_kmem_charge_memcg+0x4a/0xe0 mm/memcontrol.c:2837
__memcg_kmem_charge+0xcf/0x1b0 mm/memcontrol.c:2877
__alloc_pages_nodemask+0x26c/0x310 mm/page_alloc.c:4780
Since watermark could be compared or set to garbage due to a data race
which would change the code logic, fix it by adding a pair of READ_ONCE()
and WRITE_ONCE() in those places.
The "failcnt" counter is tolerant of some degree of inaccuracy and is only
used to report stats, a data race will not be harmful, thus mark it as an
intentional data race using the data_race() macro.
Fixes: 3e32cb2e0a12 ("mm: memcontrol: lockless page counters") Reported-by: syzbot+f36cfe60b1006a94f9dc@syzkaller.appspotmail.com Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Link: http://lkml.kernel.org/r/1581519682-23594-1-git-send-email-cai@lca.pw Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
syzbot is reporting OOB read bug in vc_do_resize() [1] caused by memcpy()
based on outdated old_{rows,row_size} values, for resize_screen() can
recurse into vc_do_resize() which changes vc->vc_{cols,rows} that outdates
old_{rows,row_size} values which were saved before calling resize_screen().
Daniel Vetter explained that resize_screen() should not recurse into
fbcon_update_vcs() path due to FBINFO_MISC_USEREVENT being still set
when calling resize_screen().
Instead of masking FBINFO_MISC_USEREVENT before calling fbcon_update_vcs(),
we can remove FBINFO_MISC_USEREVENT by calling fbcon_update_vcs() only if
fb_set_var() returned 0. This change assumes that it is harmless to call
fbcon_update_vcs() when fb_set_var() returned 0 without reaching
fb_notifier_call_chain().
Some drivers do this already, but most unfortunately missed it. This
opens up bugs after driver load, before the crtc is enabled for the
first time. syzbot spotted this when loading vkms as a secondary
output. Given how many drivers are buggy it's best to solve this once
and for all in shared helper code.
Aside from moving the few existing calls to drm_crtc_vblank_reset into
helpers (i915 doesn't use helpers, so keeps its own) I think the
regression risk is minimal: atomic helpers already rely on drivers
calling drm_crtc_vblank_on/off correctly in their hooks when they
support vblanks. And driver that's failing to handle vblanks after
this is missing those calls already, and vblanks could only work by
accident when enabling a CRTC for the first time right after boot.
Big thanks to Tetsuo for helping track down what's going wrong here.
There's only a few drivers which already had the necessary call and
needed some updating:
- komeda, atmel and tidss also needed to be changed to call
__drm_atomic_helper_crtc_reset() intead of open coding it
- tegra and msm even had it in the same place already, just code
motion, and malidp already uses __drm_atomic_helper_crtc_reset().
- Laurent noticed that rcar-du and omap open-code their crtc reset and
hence would actually be broken by this patch now. So fix them up by
reusing the helpers, which brings the drm_crtc_vblank_reset() back.
Only call left is in i915, which doesn't use drm_mode_config_reset,
but has its own fastboot infrastructure. So that's the only case where
we actually want this in the driver still.
I've also reviewed all other drivers which set up vblank support with
drm_vblank_init. After the previous patch fixing mxsfb all atomic
drivers do call drm_crtc_vblank_on/off as they should, the remaining
drivers are either legacy kms or legacy dri1 drivers, so not affected
by this change to atomic helpers.
v2: Use the drm_dev_has_vblank() helper.
v3: Laurent pointed out that omap and rcar-du used drm_crtc_vblank_off
instead of drm_crtc_vblank_reset. Adjust them too.
v4: Laurent noticed that rcar-du and omap open-code their crtc reset
and hence would actually be broken by this patch now. So fix them up
by reusing the helpers, which brings the drm_crtc_vblank_reset() back.
v5: also mention rcar-du and ompadrm in the proper commit message
above (Laurent).
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Maxime Ripard <mripard@kernel.org> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Acked-by: Liviu Dudau <liviu.dudau@arm.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://syzkaller.appspot.com/bug?id=0ba17d70d062b2595e1f061231474800f076c7cb Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot+0871b14ca2e2fb64f6e3@syzkaller.appspotmail.com Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: "James (Qian) Wang" <james.qian.wang@arm.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Mihail Atanassov <mihail.atanassov@arm.com> Cc: Brian Starkey <brian.starkey@arm.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Jyri Sarha <jsarha@ti.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Rob Clark <robdclark@gmail.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: Brian Masney <masneyb@onstation.org> Cc: Emil Velikov <emil.velikov@collabora.com> Cc: zhengbin <zhengbin13@huawei.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-tegra@vger.kernel.org Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200612160056.2082681-1-daniel.vetter@ffwll.ch Signed-off-by: Sasha Levin <sashal@kernel.org>
The man page for io_uring generally claims were consistent with what
preadv2 and pwritev2 accept, but turns out there's a slight discrepancy
in how offset == -1 is handled for pipes/streams. preadv doesn't allow
it, but preadv2 does. This currently causes io_uring to return -EINVAL
if that is attempted, but we should allow that as documented.
This change makes us consistent with preadv2/pwritev2 for just passing
in a NULL ppos for streams if the offset is -1.
There's no point in using the poll handler if we can't do a nonblocking
IO attempt of the operation, since we'll need to go async anyway. In
fact this is actively harmful, as reading from eg pipes won't return 0
to indicate EOF.
If an application is doing reads on signalfd, and we arm the poll handler
because there's no data available, then the wakeup can recurse on the
tasks sighand->siglock as the signal delivery from task_work_add() will
use TWA_SIGNAL and that attempts to lock it again.
We can detect the signalfd case pretty easily by comparing the poll->head
wait_queue_head_t with the target task signalfd wait queue. Just use
normal task wakeup for this case.
The patch addresses the compliance test failures while running TDA
2.3.1.1 and TDA 2.3.1.2 of the "PD Communications Engine USB PD
Compliance MOI" test plan published in https://www.usb.org/usbc.
For a product to be Type-C compliant, it's expected that these tests
are run on usb.org certified Type-C compliance tester as mentioned in
https://www.usb.org/usbc.
While the purpose of TDA 2.3.1.1 and TDA 2.3.1.2 is to verify that
the static and dynamic electrical capabilities of a Source meet the
requirements for each PDO offered, while doing so, the tests also
monitor that the timing of the VBUS waveform versus the messages meets
the requirements for Hard Reset defined in PROT-PROC-HR-TSTR as
mentioned in step 11 of TDA.2.3.1.1 and step 15 of TDA.2.3.1.2.
TDB.2.2.13.1: PROT-PROC-HR-TSTR Procedure and Checks for Tester
Originated Hard Reset
Purpose: To perform the appropriate protocol checks relating to any
circumstance in which the Hard Reset signal is sent by the Tester.
UUT is behaving as source:
The Tester sends a Hard Reset signal.
1. Check VBUS stays within present valid voltage range for
tPSHardReset min (25ms) after last bit of Hard Reset signal.
[PROT_PROC_HR_TSTR_1]
2. Check that VBUS starts to fall below present valid voltage range by
tPSHardReset max (35ms). [PROT_PROC_HR_TSTR_2]
3. Check that VBUS reaches vSafe0V within tSafe0v max (650 ms).
[PROT_PROC_HR_TSTR_3]
4. Check that VBUS starts rising to vSafe5V after a delay of
tSrcRecover (0.66s - 1s) from reaching vSafe0V. [PROT_PROC_HR_TSTR_4]
5. Check that VBUS reaches vSafe5V within tSrcTurnOn max (275ms) of
rising above vSafe0v max (0.8V). [PROT_PROC_HR_TSTR_5] Power Delivery
Compliance Plan 139 6. Check that Source Capabilities are finished
sending within tFirstSourceCap max (250ms) of VBUS reaching vSafe5v
min. [PROT_PROC_HR_TSTR_6].
This is in line with 7.1.5 Response to Hard Resets of the USB Power
Delivery Specification Revision 3.0, Version 1.2,
"Hard Reset Signaling indicates a communication failure has occurred
and the Source Shall stop driving VCONN, Shall remove Rp from the
VCONN pin and Shall drive VBUS to vSafe0V as shown in Figure 7-9. The
USB connection May reset during a Hard Reset since the VBUS voltage
will be less than vSafe5V for an extended period of time. After
establishing the vSafe0V voltage condition on VBUS, the Source Shall
wait tSrcRecover before re-applying VCONN and restoring VBUS to
vSafe5V. A Source Shall conform to the VCONN timing as specified in
[USB Type-C 1.3]."
With the above guidelines from the spec in mind, TCPM does not turn
off VCONN while entering SRC_HARD_RESET_VBUS_OFF. The patch makes TCPM
turn off VCONN while entering SRC_HARD_RESET_VBUS_OFF and turn it back
on while entering SRC_HARD_RESET_VBUS_ON along with vbus instead of
having VCONN on through hardreset.
Also, the spec clearly states that "After establishing the vSafe0V
voltage condition on VBUS", the Source Shall wait tSrcRecover before
re-applying VCONN and restoring VBUS to vSafe5V.
TCPM does not conform to this requirement. If the TCPC driver calls
tcpm_vbus_change with vbus off signal, TCPM right away enters
SRC_HARD_RESET_VBUS_ON without waiting for tSrcRecover.
For TCPC's which are buggy/does not call tcpm_vbus_change, TCPM
assumes that the vsafe0v is instantaneous as TCPM only waits
tSrcRecover instead of waiting for tSafe0v + tSrcRecover.
This patch also fixes this behavior by making sure that TCPM waits for
tSrcRecover before transitioning into SRC_HARD_RESET_VBUS_ON when
tcpm_vbus_change is called by TCPC.
When TCPC does not call tcpm_vbus_change, TCPM assumes the worst case
i.e. tSafe0v + tSrcRecover before transitioning into
SRC_HARD_RESET_VBUS_ON.
Commit 081da1325d35 ("usb: typec: ucsi: displayport: Fix a potential race
during registration") made the ucsi code hold con->lock in
ucsi_register_displayport(). But we really don't want any interactions
with the connector to run before the port-registration process is fully
complete.
This commit moves the taking of con->lock from ucsi_register_displayport()
into ucsi_register_port() to achieve this.
Cc: stable@vger.kernel.org Fixes: 081da1325d35 ("usb: typec: ucsi: displayport: Fix a potential race during registration") Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200809141904.4317-5-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().
Push the taking of the lock down into these 2 functions, renaming
ucsi_run_command() to ucsi_send_command() which was an existing
wrapper already taking the lock for its callers.
This simplifies things for the callers and removes the difference
between ucsi_send_command() and ucsi_run_command() which has led
to various locking bugs in the past.
Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200809141904.4317-4-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1. ucsi_handle_connector_change() contains one ucsi_send_command() call,
which takes the ppm_lock for it; and one ucsi_run_command() call which
relies on the caller have taking the ppm_lock.
ucsi_handle_connector_change() does not take the lock, so the
second (ucsi_run_command) calls should also be ucsi_send_command().
2. ucsi_get_pdos() gets called from ucsi_handle_connector_change() which
does not hold the ppm_lock, so it also must use ucsi_send_command().
This commit also adds a WARN_ON(!mutex_is_locked(&ucsi->ppm_lock)); to
ucsi_run_command() to avoid similar problems getting re-introduced in
the future.
Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200809141904.4317-3-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lockdep reports an AB BA lock inversion between ucsi_init() and
ucsi_handle_connector_change():
AB order:
1. ucsi_init takes ucsi->ppm_lock (it runs with that locked for the
duration of the function)
2. usci_init eventually end up calling ucsi_register_displayport,
which takes ucsi_connector->lock
BA order:
1. ucsi_handle_connector_change work is started, takes ucsi_connector->lock
2. ucsi_handle_connector_change calls ucsi_send_command which takes
ucsi->ppm_lock
The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().
This commit fixes the AB BA lock inversion by making ucsi_init drop the
ucsi->ppm_lock before it starts registering ports; and replacing any
ucsi_run_command() calls after this point with ucsi_send_command()
(which is a wrapper around run_command taking the lock while handling
the command).
Some of the replacing of ucsi_run_command with ucsi_send_command
in the helpers used during port registration also fixes a number of
code paths after registration which call ucsi_run_command() without
holding the ppm_lock:
1. ucsi_altmode_update_active() call in ucsi/displayport.c
2. ucsi_register_altmodes() call from ucsi_handle_connector_change()
(through ucsi_partner_change())
Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200809141904.4317-2-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a new device with a specialised device driver is plugged in, the
new driver will be modprobe()'d but the driver core will attach the
"generic" driver to the device.
After that, nothing will trigger a reprobe when the modprobe()'d device
driver has finished initialising, as the device has the "generic"
driver attached to it.
Trigger a reprobe ourselves when new specialised drivers get registered.
Fixes: 88b7381a939d ("USB: Select better matching USB drivers when available") Signed-off-by: Bastien Nocera <hadess@hadess.net> Cc: stable <stable@vger.kernel.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200818110445.509668-3-hadess@hadess.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The PSZ-HA* family of USB disk drives from Sony can't handle the
REPORT OPCODES command when using the UAS protocol. This patch adds
an appropriate quirks entry.
Reported-and-tested-by: Till Dörges <doerges@pre-sense.de> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200826143229.GB400430@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cdc-acm.c:409:3: warning: Use of memory after it is freed
acm_process_notification(acm, (unsigned char *)dr);
There are three problems, the first one is that dr is not reset
The variable dr is set with
if (acm->nb_index)
dr = (struct usb_cdc_notification *)acm->notification_buffer;
But if the notification_buffer is too small it is resized with
if (acm->nb_size) {
kfree(acm->notification_buffer);
acm->nb_size = 0;
}
alloc_size = roundup_pow_of_two(expected_size);
/*
* kmalloc ensures a valid notification_buffer after a
* use of kfree in case the previous allocation was too
* small. Final freeing is done on disconnect.
*/
acm->notification_buffer =
kmalloc(alloc_size, GFP_ATOMIC);
dr should point to the new acm->notification_buffer.
The second problem is any data in the notification_buffer is lost
when the pointer is freed. In the normal case, the current data
is accumulated in the notification_buffer here.
The usb_request->zero doesn't apply for isoc. Also, if we prepare a
0-length (ZLP) TRB for the OUT direction, we need to prepare an extra
TRB to pad up to the MPS alignment. Use the same bounce buffer for the
ZLP TRB and the extra pad TRB.
The SG list may be set up with entry size more than the requested
length. Check the usb_request->length and make sure that we don't setup
the TRBs to send/receive more than requested. This case may occur when
the SG entry is allocated up to a certain minimum size, but the request
length is less than that. It can also occur when the request is reused
for a different request length.
Inadvertently the commit b1cd1b65afba ("USB: gadget: u_f: add overflow checks
to VLA macros") makes VLA macros to always return 0 due to different scope of
two variables of the same name. Obviously we need to have only one.
Fixes: b1cd1b65afba ("USB: gadget: u_f: add overflow checks to VLA macros") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Brooke Basile <brookebasile@gmail.com> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/20200826192119.56450-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some values extracted by ncm_unwrap_ntb() could possibly lead to several
different out of bounds reads of memory. Specifically the values passed
to netdev_alloc_skb_ip_align() need to be checked so that memory is not
overflowed.
Resolve this by applying bounds checking to a number of different
indexes and lengths of the structure parsing logic.
Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Brooke Basile <brookebasile@gmail.com> Acked-by: Felipe Balbi <balbi@kernel.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
size can potentially hold an overflowed value if its assigned expression
is left unchecked, leading to a smaller than needed allocation when
vla_group_size() is used by callers to allocate memory.
To fix this, add a test for saturation before declaring variables and an
overflow check to (n) * sizeof(type).
If the expression results in overflow, vla_group_size() will return SIZE_MAX.
If the function platform_get_irq() failed, the negative value
returned will not be detected here. So fix error handling in
exynos_ohci_probe(). And when get irq failed, the function
platform_get_irq() logs an error message, so remove redundant
message here.
This device does not support UAS properly and a similar entry already
exists in drivers/usb/storage/unusual_uas.h. Without this patch,
storage_probe() defers the handling of this device to UAS, which cannot
handle it either.
Tested-by: Brice Goglin <brice.goglin@gmail.com> Fixes: bc3bdb12bbb3 ("usb-storage: Disable UAS on JMicron SATA enclosure") Acked-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@vger.kernel.org> Signed-off-by: Cyril Roelandt <tipecaml@gmail.com> Link: https://lore.kernel.org/r/20200825212231.46309-1-tipecaml@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Sound Devices MixPre-D audio card suffers from the same defect
as the Sound Devices USBPre2: an endpoint shared between a normal
audio interface and a vendor-specific interface, in violation of the
USB spec. Since the USB core now treats duplicated endpoints as bugs
and ignores them, the audio endpoint isn't available and the card
can't be used for audio capture.
Along the same lines as commit bdd1b147b802 ("USB: quirks: blacklist
duplicate ep on Sound Devices USBPre2"), this patch adds a quirks
entry saying to ignore ep5in for interface 1, leaving it available for
use with standard audio interface 2.
There's another Raydium touchscreen needs the no-lpm quirk:
[ 1.339149] usb 1-9: New USB device found, idVendor=2386, idProduct=350e, bcdDevice= 0.00
[ 1.339150] usb 1-9: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1.339151] usb 1-9: Product: Raydium Touch System
[ 1.339152] usb 1-9: Manufacturer: Raydium Corporation
...
[ 6.450497] usb 1-9: can't set config #1, error -110
PNY Pro Elite USB 3.1 Gen 2 device (SSD) doesn't respond to ATA_12
pass-through command (i.e. it just hangs). If it doesn't support this
command, it should respond properly to the host. Let's just add a quirk
to be able to move forward with other operations.
The syzbot fuzzer identified a bug in the yurex driver: It passes
GFP_KERNEL as a memory-allocation flag to usb_submit_urb() at a time
when its state is TASK_INTERRUPTIBLE, not TASK_RUNNING:
[Why]
DC uses these to raise the voltage as needed for higher dispclk/dppclk
and to ensure that we have enough bandwidth to drive the displays.
There's a bug preventing these from actuially sending messages since
it's checking the actual clock (which is 0) instead of the incoming
clock (which shouldn't be 0) when deciding to send the hardmin.
[How]
Check the clocks != 0 instead of the actual clocks.
Fixes: 9ed9203c3ee7 ("drm/amd/powerplay: rv dal-pplib interface refactor powerplay part") Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation for sysfs backlight level interface requires that
values in both 'brightness' and 'actual_brightness' files are
interpreted to be in range from 0 to the value given in the
'max_brightness' file.
With amdgpu, max_brightness gives 255, and values written by the user
into 'brightness' are internally rescaled to a wider range. However,
reading from 'actual_brightness' gives the raw register value without
inverse rescaling. This causes issues for various userspace tools such
as PowerTop and systemd that expect the value to be in the correct
range.
Introduce a helper to retrieve internal backlight range. Use it to
reimplement 'convert_brightness' as 'convert_brightness_from_user' and
introduce 'convert_brightness_to_user'.
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=203905
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1242 Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alexander Monakov <amonakov@ispras.ru> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The values for "se_num" and "sh_num" come from the user in the ioctl.
They can be in the 0-255 range but if they're more than
AMDGPU_GFX_MAX_SE (4) or AMDGPU_GFX_MAX_SH_PER_SE (2) then it results in
an out of bounds read.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm: Replace drm_modeset_lock/unlock_all with DRM_MODESET_LOCK_ALL_* helpers
but it's caught by the drm_warn_on_modeset_not_all_locked() that the
legacy modeset code uses. Since this is the bkl and it's unclear
what's all protected, play it safe and grab it again for legacy
drivers.
Unfortunately this means we need to sprinkle a few more #includes
around.
Also we need to add the drm_device as a parameter to the _END macro.
Finally remove the mute_lock() from setcrtc, since that's now done by
the macro.
Cc: Alex Deucher <alexdeucher@gmail.com>
References: https://gitlab.freedesktop.org/drm/amd/-/issues/1224 Fixes: 9bcaa3fe58ab ("drm: Replace drm_modeset_lock/unlock_all with DRM_MODESET_LOCK_ALL_* helpers") Cc: Michal Orzel <michalorzel.eng@gmail.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <stable@vger.kernel.org> # v5.8+ Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200814093842.3048472-1-daniel.vetter@ffwll.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Why]
In certain cases the crtc can be NULL and returning -EINVAL causes
atomic check to fail when it shouln't. This leads to valid
configurations failing because atomic check fails.
[How]
Don't early return if crtc is null
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com>
[added stable cc] Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: 8ec046716ca8 ("drm/dp_mst: Add helper to trigger modeset on affected DSC MST CRTCs") Cc: <stable@vger.kernel.org> # v5.6+ Link: https://patchwork.freedesktop.org/patch/msgid/20200814170140.24917-1-Bhawanpreet.Lakha@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It looks like that this GPU core triggers an abort when
reading VIVS_HI_CHIP_PRODUCT_ID and/or VIVS_HI_CHIP_ECO_ID.
I looked at different versions of Vivante's kernel driver and did
not found anything about this issue or what feature flag can be
used. So go the simplest route and do not read these two registers
on the affected GPU core.
There is a race when taking a CPU offline. Current code looks like this:
native_cpu_disable()
{
...
apic_soft_disable();
/*
* Any existing set bits for pending interrupt to
* this CPU are preserved and will be sent via IPI
* to another CPU by fixup_irqs().
*/
cpu_disable_common();
{
....
/*
* Race window happens here. Once local APIC has been
* disabled any new interrupts from the device to
* the old CPU are lost
*/
fixup_irqs(); // Too late to capture anything in IRR.
...
}
}
The fix is to disable the APIC *after* cpu_disable_common().
Testing was done with a USB NIC that provided a source of frequent
interrupts. A script migrated interrupts to a specific CPU and
then took that CPU offline.
Fixes: 60dcaad5736f ("x86/hotplug: Silence APIC and NMI when CPU is dead") Reported-by: Evan Green <evgreen@chromium.org> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mathias Nyman <mathias.nyman@linux.intel.com> Tested-by: Evan Green <evgreen@chromium.org> Reviewed-by: Evan Green <evgreen@chromium.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/875zdarr4h.fsf@nanos.tec.linutronix.de/ Link: https://lore.kernel.org/r/1598501530-45821-1-git-send-email-ashok.raj@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several people reported that 5.8 broke the interrupt affinity setting
mechanism.
The consolidation of the entry code reused the regular exception entry code
for device interrupts and changed the way how the vector number is conveyed
from ptregs->orig_ax to a function argument.
The low level entry uses the hardware error code slot to push the vector
number onto the stack which is retrieved from there into a function
argument and the slot on stack is set to -1.
The reason for setting it to -1 is that the error code slot is at the
position where pt_regs::orig_ax is. A positive value in pt_regs::orig_ax
indicates that the entry came via a syscall. If it's not set to a negative
value then a signal delivery on return to userspace would try to restart a
syscall. But there are other places which rely on pt_regs::orig_ax being a
valid indicator for syscall entry.
But setting pt_regs::orig_ax to -1 has a nasty side effect vs. the
interrupt affinity setting mechanism, which was overlooked when this change
was made.
Moving interrupts on x86 happens in several steps. A new vector on a
different CPU is allocated and the relevant interrupt source is
reprogrammed to that. But that's racy and there might be an interrupt
already in flight to the old vector. So the old vector is preserved until
the first interrupt arrives on the new vector and the new target CPU. Once
that happens the old vector is cleaned up, but this cleanup still depends
on the vector number being stored in pt_regs::orig_ax, which is now -1.
That -1 makes the check for cleanup: pt_regs::orig_ax == new_vector
always false. As a consequence the interrupt is moved once, but then it
cannot be moved anymore because the cleanup of the old vector never
happens.
There would be several ways to convey the vector information to that place
in the guts of the interrupt handling, but on deeper inspection it turned
out that this check is pointless and a leftover from the old affinity model
of X86 which supported multi-CPU affinities. Under this model it was
possible that an interrupt had an old and a new vector on the same CPU, so
the vector match was required.
Under the new model the effective affinity of an interrupt is always a
single CPU from the requested affinity mask. If the affinity mask changes
then either the interrupt stays on the CPU and on the same vector when that
CPU is still in the new affinity mask or it is moved to a different CPU, but
it is never moved to a different vector on the same CPU.
Ergo the cleanup check for the matching vector number is not required and
can be removed which makes the dependency on pt_regs:orig_ax go away.
The remaining check for new_cpu == smp_processsor_id() is completely
sufficient. If it matches then the interrupt was successfully migrated and
the cleanup can proceed.
For paranoia sake add a warning into the vector assignment code to
validate that the assumption of never moving to a different vector on
the same CPU holds.
Fixes: 633260fa143 ("x86/irq: Convey vector as argument and not in ptregs") Reported-by: Alex bykov <alex.bykov@scylladb.com> Reported-by: Avi Kivity <avi@scylladb.com> Reported-by: Alexander Graf <graf@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexander Graf <graf@amazon.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87wo1ltaxz.fsf@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the current code, when the eoi callback of the exti clears the pending
bit of the current interrupt, it will first read the values of fpr and
rpr, then logically OR the corresponding bit of the interrupt number,
and finally write back to fpr and rpr.
We found through experiments that if two exti interrupts,
we call them int1/int2, arrive almost at the same time. in our scenario,
the time difference is 30 microseconds, assuming int1 is triggered first.
there will be an extreme scenario: both int's pending bit are set to 1,
the irq handle of int1 is executed first, and eoi handle is then executed,
at this moment, all pending bits are cleared, but the int 2 has not
finally been reported to the cpu yet, which eventually lost int2.
According to stm32's TRM description about rpr and fpr: Writing a 1 to this
bit will trigger a rising edge event on event x, Writing 0 has no
effect.
Therefore, when clearing the pending bit, we only need to clear the
pending bit of the irq.
Fixes: 927abfc4461e7 ("irqchip/stm32: Add stm32mp1 support with hierarchy domain") Signed-off-by: qiuguorui1 <qiuguorui1@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org # v4.18+ Link: https://lore.kernel.org/r/20200820031629.15582-1-qiuguorui1@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.
The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.
Add a check for the cpumask being empty to prevent this.
Commit 88b7381a939d ("USB: Select better matching USB drivers when
available") introduced the use of a "match" function to select a
non-generic/better driver for a particular USB device. This
unfortunately breaks the operation of usbip in general, as reported in
the kernel bugzilla with bug 208267 (linked below).
Upon inspecting the aforementioned commit, one can observe that the
original code in the usb_device_match function used to return 1
unconditionally, but the aforementioned commit makes the usb_device_match
function use identifier tables and "match" virtual functions, if either of
them are available.
Hence, this commit implements a match function for usbip that
unconditionally returns true to ensure that usbip is functional again.
This change has been verified to restore usbip functionality, with a
v5.7.y kernel on an up-to-date version of Qubes OS 4.0, which uses
usbip to redirect USB devices between VMs.
Thanks to Jonathan Dieter for the effort in bisecting this issue down
to the aforementioned commit.
The iwd daemon uses libell which sets up the skcipher operation with
two separate control messages. As the first control message is sent
without MSG_MORE, it is interpreted as an empty request.
While libell should be fixed to use MSG_MORE where appropriate, this
patch works around the bug in the kernel so that existing binaries
continue to work.
We will print a warning however.
A separate issue is that the new kernel code no longer allows the
control message to be sent twice within the same request. This
restriction is obviously incompatible with what iwd was doing (first
setting an IV and then sending the real control message). This
patch changes the kernel so that this is explicitly allowed.
Reported-by: Caleb Jorden <caljorden@hotmail.com> Fixes: f3c802a1f300 ("crypto: algif_aead - Only wake up when...") Cc: <stable@vger.kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the primary firmware node pointer is removed from a
device (set to NULL) the secondary firmware node pointer,
when it exists, is made the primary node for the device.
However, the secondary firmware node pointer of the original
primary firmware node is never cleared (set to NULL).
To avoid situation where the secondary firmware node pointer
is pointing to a non-existing object, clearing it properly
when the primary node is removed from a device in
set_primary_fwnode().
Fixes: 97badf873ab6 ("device property: Make it possible to use secondary firmware nodes") Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The bhrb_filter_map ("The Branch History Rolling Buffer") callback is
only defined in raw CPUs' power_pmu structs. The "architected" CPUs
use generic_compat_pmu, which does not have this callback, and crashes
occur if a user tries to enable branch stack for an event.
This add a NULL pointer check for bhrb_filter_map() which behaves as
if the callback returned an error.
This does not add the same check for config_bhrb() as the only caller
checks for cpuhw->bhrb_users which remains zero if bhrb_filter_map==0.
It has been reported that system-wide suspend may be aborted in the
absence of any wakeup events due to unforseen interactions of it with
the runtume PM framework.
One failing scenario is when there are multiple devices sharing an
ACPI power resource and runtime-resume needs to be carried out for
one of them during system-wide suspend (for example, because it needs
to be reconfigured before the whole system goes to sleep). In that
case, the runtime-resume of that device involves turning the ACPI
power resource "on" which in turn causes runtime-resume requests
to be queued up for all of the other devices sharing it. Those
requests go to the runtime PM workqueue which is frozen during
system-wide suspend, so they are not actually taken care of until
the resume of the whole system, but the pm_runtime_barrier()
call in __device_suspend() sees them and triggers system wakeup
events for them which then cause the system-wide suspend to be
aborted if wakeup source objects are in active use.
Of course, the logic that leads to triggering those wakeup events is
questionable in the first place, because clearly there are cases in
which a pending runtime resume request for a device is not connected
to any real wakeup events in any way (like the one above). Moreover,
it is racy, because the device may be resuming already by the time
the pm_runtime_barrier() runs and so if the driver doesn't take care
of signaling the wakeup event as appropriate, it will be lost.
However, if the driver does take care of that, the extra
pm_wakeup_event() call in the core is redundant.
Accordingly, drop the conditional pm_wakeup_event() call fron
__device_suspend() and make the latter call pm_runtime_barrier()
alone. Also modify the comment next to that call to reflect the new
code and extend it to mention the need to avoid unwanted interactions
between runtime PM and system-wide device suspend callbacks.
Fixes: 1e2ef05bb8cf8 ("PM: Limit race conditions between runtime PM and system sleep (v2)") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Utkarsh H Patel <utkarsh.h.patel@intel.com> Tested-by: Utkarsh H Patel <utkarsh.h.patel@intel.com> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled,
since it's not even supposed to be compiled otherwise, and arm64
builds without a 32bit crosscompiler will fail.
Fixes: 8d75785a8142 ("ARM64: vdso32: Install vdso32 from vdso_install") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Cc: stable@vger.kernel.org [5.4+] Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AT instructions do a translation table walk and return the result, or
the fault in PAR_EL1. KVM uses these to find the IPA when the value is
not provided by the CPU in HPFAR_EL1.
If a translation table walk causes an external abort it is taken as an
exception, even if it was due to an AT instruction. (DDI0487F.a's D5.2.11
"Synchronous faults generated by address translation instructions")
While we previously made KVM resilient to exceptions taken due to AT
instructions, the device access causes mismatched attributes, and may
occur speculatively. Prevent this, by forbidding a walk through memory
described as device at stage2. Now such AT instructions will report a
stage2 fault.
Such a fault will cause KVM to restart the guest. If the AT instructions
always walk the page tables, but guest execution uses the translation cached
in the TLB, the guest can't make forward progress until the TLB entry is
evicted. This isn't a problem, as since commit 5dcd0fdbb492 ("KVM: arm64:
Defer guest entry when an asynchronous exception is pending"), KVM will
return to the host to process IRQs allowing the rest of the system to keep
running.
Cc: stable@vger.kernel.org # <v5.3: 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending") Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sometimes re-plugging a USB device during system sleep renders the device
useless:
[ 173.418345] xhci_hcd 0000:00:14.0: Get port status 2-4 read: 0x14203e2, return 0x10262
...
[ 176.496485] usb 2-4: Waited 2000ms for CONNECT
[ 176.496781] usb usb2-port4: status 0000.0262 after resume, -19
[ 176.497103] usb 2-4: can't resume, status -19
[ 176.497438] usb usb2-port4: logical disconnect
Because PLS equals to XDEV_RESUME, xHCI driver reports U3 to usbcore,
despite of CAS bit is flagged.
So proritize CAS over XDEV_RESUME to let usbcore handle warm-reset for
the port.
tegra_xusb_init_usb_phy() should initialize "otg_usb2_port" and
"otg_usb3_port" with -EINVAL because "0" is a valid value
represents usb2 port 0 or usb3 port 0.
handler data is meant for interrupt handlers and not for storing irq chip
specific information as some devices require handler data to store internal
per interrupt information, e.g. pinctrl/GPIO chained interrupt handlers.
This obviously creates a conflict of interests and crashes the machine
because the XEN pointer is overwritten by the driver pointer.
As the XEN data is not handler specific it should be stored in
irqdesc::irq_data::chip_data instead.
A simple sed s/irq_[sg]et_handler_data/irq_[sg]et_chip_data/ cures that.
Cc: stable@vger.kernel.org Reported-by: Roman Shaposhnik <roman@zededa.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Roman Shaposhnik <roman@zededa.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/87lfi2yckt.fsf@nanos.tec.linutronix.de Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we are processing writeback for sync(2), move_expired_inodes()
didn't set any inode expiry value (older_than_this). This can result in
writeback never completing if there's steady stream of inodes added to
b_dirty_time list as writeback rechecks dirty lists after each writeback
round whether there's more work to be done. Fix the problem by using
sync(2) start time is inode expiry value when processing b_dirty_time
list similarly as for ordinarily dirtied inodes. This requires some
refactoring of older_than_this handling which simplifies the code
noticeably as a bonus.
Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") CC: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Inode's i_io_list list head is used to attach inode to several different
lists - wb->{b_dirty, b_dirty_time, b_io, b_more_io}. When flush worker
prepares a list of inodes to writeback e.g. for sync(2), it moves inodes
to b_io list. Thus it is critical for sync(2) data integrity guarantees
that inode is not requeued to any other writeback list when inode is
queued for processing by flush worker. That's the reason why
writeback_single_inode() does not touch i_io_list (unless the inode is
completely clean) and why __mark_inode_dirty() does not touch i_io_list
if I_SYNC flag is set.
However there are two flaws in the current logic:
1) When inode has only I_DIRTY_TIME set but it is already queued in b_io
list due to sync(2), concurrent __mark_inode_dirty(inode, I_DIRTY_SYNC)
can still move inode back to b_dirty list resulting in skipping
writeback of inode time stamps during sync(2).
2) When inode is on b_dirty_time list and writeback_single_inode() races
with __mark_inode_dirty() like:
writeback_single_inode() __mark_inode_dirty(inode, I_DIRTY_PAGES)
inode->i_state |= I_SYNC
__writeback_single_inode()
inode->i_state |= I_DIRTY_PAGES;
if (inode->i_state & I_SYNC)
bail
if (!(inode->i_state & I_DIRTY_ALL))
- not true so nothing done
We end up with I_DIRTY_PAGES inode on b_dirty_time list and thus
standard background writeback will not writeback this inode leading to
possible dirty throttling stalls etc. (thanks to Martijn Coenen for this
analysis).
Fix these problems by tracking whether inode is queued in b_io or
b_more_io lists in a new I_SYNC_QUEUED flag. When this flag is set, we
know flush worker has queued inode and we should not touch i_io_list.
On the other hand we also know that once flush worker is done with the
inode it will requeue the inode to appropriate dirty list. When
I_SYNC_QUEUED is not set, __mark_inode_dirty() can (and must) move inode
to appropriate dirty list.
Reported-by: Martijn Coenen <maco@android.com> Reviewed-by: Martijn Coenen <maco@android.com> Tested-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, operations on inode->i_io_list are protected by
wb->list_lock. In the following patches we'll need to maintain
consistency between inode->i_state and inode->i_io_list so change the
code so that inode->i_lock protects also all inode's i_io_list handling.
Reviewed-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> CC: stable@vger.kernel.org # Prerequisite for "writeback: Avoid skipping inode writeback" Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure we clear req->result, which was set to -EAGAIN for retry
purposes, when moving it to the reissue list. Otherwise we can end up
retrying a request more than once, which leads to weird results in
the io-wq handling (and other spots).
We have a number of "uart.port->desc.lock vs desc.lock->uart.port"
lockdep reports coming from 8250 driver; this causes a bit of trouble
to people, so let's fix it.
The problem is reverse lock order in two different call paths:
Fix this by changing the order of locks in serial8250_do_startup():
do disable_irq_nosync() first, which grabs desc->lock, and grab
uart->port after that, so that chain #1 and chain #2 have same lock
order.
Full lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.4.39 #55 Not tainted
======================================================
swapper/0/0 is trying to acquire lock: ffffffffab65b6c0 (console_owner){-...}, at: console_lock_spinning_enable+0x31/0x57
but task is already holding lock: ffff88810a8e34c0 (&irq_desc_lock_class){-.-.}, at: __report_bad_irq+0x5b/0xba
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
If the number of ports a card has is not explicitly specified, it defaults
to the rightmost 4 bits of the PCI device ID. This is prone to error since
not all PCI device IDs contain a number which corresponds to the number of
ports that card provides.
This particular case involves COMMTECH_4222PCIE, COMMTECH_4224PCIE and
COMMTECH_4228PCIE cards with device IDs 0x0022, 0x0020 and 0x0021.
Currently the multiport cards receive 2, 0 and 1 port instead of 2, 4 and
8 ports respectively.
To fix this, each Commtech Fastcom PCIe card is given a struct where the
number of ports is explicitly specified. This ensures 'board->num_ports'
is used instead of the default 'pcidev->device & 0x0f'.
Fixes: d0aeaa83f0b0 ("serial: exar: split out the exar code from 8250_pci") Signed-off-by: Valmer Huhn <valmer.huhn@concurrent-rt.com> Tested-by: Valmer Huhn <valmer.huhn@concurrent-rt.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200813165255.GC345440@icarus.concurrent-rt.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
stm32_init_port() of the stm32-usart may trigger a warning in
platform_get_irq() when the device tree specifies no wakeup interrupt.
The wakeup interrupt is usually a board-specific GPIO and the driver
functions correctly in its absence. The mainline stm32mp151.dtsi does
not specify it, so all mainline device trees trigger an unnecessary
kernel warning. Use of platform_get_irq_optional() avoids this.
pl011_probe() calls pl011_setup_port() to reserve an amba_ports[] entry,
then calls pl011_register_port() to register the uart driver with the
tty layer.
If registration of the uart driver fails, the amba_ports[] entry is not
released. If this happens 14 times (value of UART_NR macro), then all
amba_ports[] entries will have been leaked and driver probing is no
longer possible. (To be fair, that can only happen if the DeviceTree
doesn't contain alias IDs since they cause the same entry to be used for
a given port.) Fix it.
If probing of a pl011 gets deferred until after free_initmem(), an oops
ensues because pl011_console_match() is called which has been freed.
Fix by removing the __init attribute from the function and those it
calls.
Commit 10879ae5f12e ("serial: pl011: add console matching function")
introduced pl011_console_match() not just for early consoles but
regular preferred consoles, such as those added by acpi_parse_spcr().
Regular consoles may be registered after free_initmem() for various
reasons, one being deferred probing, another being dynamic enablement
of serial ports using a DeviceTree overlay.
Thus, pl011_console_match() must not be declared __init and the
functions it calls mustn't either.
Stack trace for posterity:
Unable to handle kernel paging request at virtual address 80c38b58
Internal error: Oops: 8000000d [#1] PREEMPT SMP ARM
PC is at pl011_console_match+0x0/0xfc
LR is at register_console+0x150/0x468
[<80187004>] (register_console)
[<805a8184>] (uart_add_one_port)
[<805b2b68>] (pl011_register_port)
[<805b3ce4>] (pl011_probe)
[<80569214>] (amba_probe)
[<805ca088>] (really_probe)
[<805ca2ec>] (driver_probe_device)
[<805ca5b0>] (__device_attach_driver)
[<805c8060>] (bus_for_each_drv)
[<805c9dfc>] (__device_attach)
[<805ca630>] (device_initial_probe)
[<805c90a8>] (bus_probe_device)
[<805c95a8>] (deferred_probe_work_func)
Fixes: 10879ae5f12e ("serial: pl011: add console matching function") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v4.10+ Cc: Aleksey Makarov <amakarov@marvell.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Christopher Covington <cov@codeaurora.org> Link: https://lore.kernel.org/r/f827ff09da55b8c57d316a1b008a137677b58921.1597315557.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In few older Samsung SoCs like s3c2410, s3c2412
and s3c2440, UART IP is having 2 interrupt lines.
However, in other SoCs like s3c6400, s5pv210,
exynos5433, and exynos4210 UART is having only 1
interrupt line. Due to this, "platform_get_irq(platdev, 1)"
call in the driver gives the following false-positive error:
"IRQ index 1 not found" on newer SoC's.
This patch adds the condition to check for Tx interrupt
only for the those SoC's which have 2 interrupt lines.
Tested-by: Alim Akhtar <alim.akhtar@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com> Signed-off-by: Tamseel Shams <m.shams@samsung.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200810030021.45348-1-m.shams@samsung.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vc_resize() can return with an error after failure. Change VT_RESIZEX ioctl
to save struct vc_data values that are modified and restore the original
values in case of error.
syzbot is reporting UAF bug in set_origin() from vc_do_resize() [1], for
vc_do_resize() calls kfree(vc->vc_screenbuf) before calling set_origin().
Unfortunately, in set_origin(), vc->vc_sw->con_set_origin() might access
vc->vc_pos when scroll is involved in order to manipulate cursor, but
vc->vc_pos refers already released vc->vc_screenbuf until vc->vc_pos gets
updated based on the result of vc->vc_sw->con_set_origin().
Preserving old buffer and tolerating outdated vc members until set_origin()
completes would be easier than preventing vc->vc_sw->con_set_origin() from
accessing outdated vc members.
lvs_rh_probe() can return some nonnegative value from usb_control_msg()
when it is less than "USB_DT_HUB_NONVAR_SIZE + 2" that is considered as
a failure. Make lvs_rh_probe() return -EINVAL in this case.
Found by Linux Driver Verification project (linuxtesting.org).
Add a check to fbcon_resize() to ensure that a possible change to user font
height or user font width will not allow a font data out-of-bounds access.
NOTE: must use original charcount in calculation as font charcount can
change and cannot be used to determine the font data allocated size.
can_nocow_extent and btrfs_cross_ref_exist both rely on a heuristic for
detecting a must cow condition which is not exactly accurate, but saves
unnecessary tree traversal. The incorrect assumption is that if the
extent was created in a generation smaller than the last snapshot
generation, it must be referenced by that snapshot. That is true, except
the snapshot could have since been deleted, without affecting the last
snapshot generation.
The original patch claimed a performance win from this check, but it
also leads to a bug where you are unable to use a swapfile if you ever
snapshotted the subvolume it's in. Make the check slower and more strict
for the swapon case, without modifying the general cow checks as a
compromise. Turning swap on does not seem to be a particularly
performance sensitive operation, so incurring a possibly unnecessary
btrfs_search_slot seems worthwhile for the added usability.
Note: Until the snapshot is competely cleaned after deletion,
check_committed_refs will still cause the logic to think that cow is
necessary, so the user must until 'btrfs subvolu sync' finished before
activating the swapfile swapon.
CC: stable@vger.kernel.org # 5.4+ Suggested-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a transaction aborts it can cause a memory leak of the pages array of
a block group's io_ctl structure. The following steps explain how that can
happen:
1) Transaction N is committing, currently in state TRANS_STATE_UNBLOCKED
and it's about to start writing out dirty extent buffers;
2) Transaction N + 1 already started and another task, task A, just called
btrfs_commit_transaction() on it;
3) Block group B was dirtied (extents allocated from it) by transaction
N + 1, so when task A calls btrfs_start_dirty_block_groups(), at the
very beginning of the transaction commit, it starts writeback for the
block group's space cache by calling btrfs_write_out_cache(), which
allocates the pages array for the block group's io_ctl with a call to
io_ctl_init(). Block group A is added to the io_list of transaction
N + 1 by btrfs_start_dirty_block_groups();
4) While transaction N's commit is writing out the extent buffers, it gets
an IO error and aborts transaction N, also setting the file system to
RO mode;
5) Task A has already returned from btrfs_start_dirty_block_groups(), is at
btrfs_commit_transaction() and has set transaction N + 1 state to
TRANS_STATE_COMMIT_START. Immediately after that it checks that the
filesystem was turned to RO mode, due to transaction N's abort, and
jumps to the "cleanup_transaction" label. After that we end up at
btrfs_cleanup_one_transaction() which calls btrfs_cleanup_dirty_bgs().
That helper finds block group B in the transaction's io_list but it
never releases the pages array of the block group's io_ctl, resulting in
a memory leak.
In fact at the point when we are at btrfs_cleanup_dirty_bgs(), the pages
array points to pages that were already released by us at
__btrfs_write_out_cache() through the call to io_ctl_drop_pages(). We end
up freeing the pages array only after waiting for the ordered extent to
complete through btrfs_wait_cache_io(), which calls io_ctl_free() to do
that. But in the transaction abort case we don't wait for the space cache's
ordered extent to complete through a call to btrfs_wait_cache_io(), so
that's why we end up with a memory leak - we wait for the ordered extent
to complete indirectly by shutting down the work queues and waiting for
any jobs in them to complete before returning from close_ctree().
We can solve the leak simply by freeing the pages array right after
releasing the pages (with the call to io_ctl_drop_pages()) at
__btrfs_write_out_cache(), since we will never use it anymore after that
and the pages array points to already released pages at that point, which
is currently not a problem since no one will use it after that, but not a
good practice anyway since it can easily lead to use-after-free issues.
So fix this by freeing the pages array right after releasing the pages at
__btrfs_write_out_cache().
This issue can often be reproduced with test case generic/475 from fstests
and kmemleak can detect it and reports it with the following trace:
With my new locking code dbench is so much faster that I tripped over a
transaction abort from ENOSPC. This turned out to be because
btrfs_del_dir_entries_in_log was checking for ret == -ENOSPC, but this
function sets err on error, and returns err. So instead of properly
marking the inode as needing a full commit, we were returning -ENOSPC
and aborting in __btrfs_unlink_inode. Fix this by checking the proper
variable so that we return the correct thing in the case of ENOSPC.
The ENOENT needs to be checked, because btrfs_lookup_dir_item_index()
can return -ENOENT if the dir item isn't in the tree log (which would
happen if we hadn't fsync'ed this guy). We actually handle that case in
__btrfs_unlink_inode, so it's an expected error to get back.
Fixes: 4a500fd178c8 ("Btrfs: Metadata ENOSPC handling for tree log") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com>
[ add note and comment about ENOENT ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SCHED_RESTART code path is relied to re-run queue for dispatch requests
in hctx->dispatch. Meantime the SCHED_RSTART flag is checked when adding
requests to hctx->dispatch.
memory barriers have to be used for ordering the following two pair of OPs:
1) adding requests to hctx->dispatch and checking SCHED_RESTART in
blk_mq_dispatch_rq_list()
2) clearing SCHED_RESTART and checking if there is request in hctx->dispatch
in blk_mq_sched_restart().
Without the added memory barrier, either:
1) blk_mq_sched_restart() may miss requests added to hctx->dispatch meantime
blk_mq_dispatch_rq_list() observes SCHED_RESTART, and not run queue in
dispatch side
or
2) blk_mq_dispatch_rq_list still sees SCHED_RESTART, and not run queue
in dispatch side, meantime checking if there is request in
hctx->dispatch from blk_mq_sched_restart() is missed.
IO hang in ltp/fs_fill test is reported by kernel test robot:
https://lkml.org/lkml/2020/7/26/77
Turns out it is caused by the above out-of-order OPs. And the IO hang
can't be observed any more after applying this patch.
Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Christoph Hellwig <hch@lst.de> Cc: David Jeffery <djeffery@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before this commit i2c_hid_parse() consists of the following steps:
1. Send power on cmd
2. usleep_range(1000, 5000)
3. Send reset cmd
4. Wait for reset to complete (device interrupt, or msleep(100))
5. Send power on cmd
6. Try to read HID descriptor
Notice how there is an usleep_range(1000, 5000) after the first power-on
command, but not after the second power-on command.
Testing has shown that at least on the BMAX Y13 laptop's i2c-hid touchpad,
not having a delay after the second power-on command causes the HID
descriptor to read as all zeros.
In case we hit this on other devices too, the descriptor being all zeros
can be recognized by the following message being logged many, many times:
hid-generic 0018:0911:5288.0002: unknown main item tag 0x0
At the same time as the BMAX Y13's touchpad issue was debugged,
Kai-Heng was working on debugging some issues with Goodix i2c-hid
touchpads. It turns out that these need a delay after a PWR_ON command
too, otherwise they stop working after a suspend/resume cycle.
According to Goodix a delay of minimal 60ms is needed.
Having multiple cases where we need a delay after sending the power-on
command, seems to indicate that we should always sleep after the power-on
command.
This commit fixes the mentioned issues by moving the existing 1ms sleep to
the i2c_hid_set_power() function and changing it to a 60ms sleep.
Cc: stable@vger.kernel.org BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208247 Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Reported-and-tested-by: Andrea Borgia <andrea@borgia.bo.it> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case of block device backend, if the backend supports write zeros, the
loop device will set queue flag of QUEUE_FLAG_DISCARD. However,
limits.discard_granularity isn't setup, and this way is wrong,
see the following description in Documentation/ABI/testing/sysfs-block:
A discard_granularity of 0 means that the device does not support
discard functionality.
Especially 9b15d109a6b2 ("block: improve discard bio alignment in
__blkdev_issue_discard()") starts to take q->limits.discard_granularity
for computing max discard sectors. And zero discard granularity may cause
kernel oops, or fail discard request even though the loop queue claims
discard support via QUEUE_FLAG_DISCARD.
Fix the issue by setup discard granularity and alignment.
Fixes: c52abf563049 ("loop: Better discard support for block devices") Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Xiao Ni <xni@redhat.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Evan Green <evgreen@chromium.org> Cc: Gwendal Grignou <gwendal@chromium.org> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A previous commit aligning splits to physical block sizes inadvertently
modified one return case such that that it now returns 0 length splits
when the number of sectors doesn't exceed the physical offset. This
later hits a BUG in bio_split(). Restore the previous working behavior.
Fixes: 9cc5169cd478b ("block: Improve physical block alignment of split bios") Reported-by: Eric Deal <eric.deal@wdc.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Cc: Bart Van Assche <bvanassche@acm.org> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As we can now switch from a system that isn't affected by 1418040
to a system that globally is affected, let's allow affected CPUs
to come in at a later time.
Signed-off-by: Marc Zyngier <maz@kernel.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200731173824.107480-3-maz@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Instead of dealing with erratum 1418040 on each entry and exit,
let's move the handling to __switch_to() instead, which has
several advantages:
- It can be applied when it matters (switching between 32 and 64
bit tasks).
- It is written in C (yay!)
- It can rely on static keys rather than alternatives
Signed-off-by: Marc Zyngier <maz@kernel.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200731173824.107480-2-maz@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The error path in libbpf.c:load_program() has calls to pr_warn()
which ends up for global_funcs tests to
test_global_funcs.c:libbpf_debug_print().
For the tests with no struct test_def::err_str initialized with a
string, it causes call of strstr() with NULL as the second argument
and it segfaults.
Fix it by calling strstr() only for non-NULL err_str.
Performance monitor interrupt handler checks if any counter has
overflown and calls record_and_restart() in core-book3s which invokes
perf_event_overflow() to record the sample information. Apart from
creating sample, perf_event_overflow() also does the interrupt and
period checks via perf_event_account_interrupt().
Currently we record information only if the SIAR (Sampled Instruction
Address Register) valid bit is set (using siar_valid() check) and
hence the interrupt check.
But it is possible that we do sampling for some events that are not
generating valid SIAR, and hence there is no chance to disable the
event if interrupts are more than max_samples_per_tick. This leads to
soft lockup.
Fix this by adding perf_event_account_interrupt() in the invalid SIAR
code path for a sampling event. ie if SIAR is invalid, just do
interrupt check and don't record the sample information.
In the scenario of writing sparse files, the per-inode prealloc list may
be very long, resulting in high overhead for ext4_mb_use_preallocated().
To circumvent this problem, we limit the maximum length of per-inode
prealloc list to 512 and allow users to modify it.
After patching, we observed that the sys ratio of cpu has dropped, and
the system throughput has increased significantly. We created a process
to write the sparse file, and the running time of the process on the
fixed kernel was significantly reduced, as follows:
Running time on unfixed kernel：
[root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat
real 0m2.051s
user 0m0.008s
sys 0m2.026s
Running time on fixed kernel：
[root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat
real 0m0.471s
user 0m0.004s
sys 0m0.395s
Currently when traversing all tasks, the next tid
is always increased by one. This may result in
visiting the same task multiple times in a
pid namespace.
This patch fixed the issue by seting the next
tid as pid_nr_ns(pid, ns) + 1, similar to
funciton next_tgid().
Note that `bpftool prog` actually calls a task_file bpf iterator
program to establish an association between prog/map/link/btf anon
files and processes.
In the case where the above rcu stall occured, we had a process
having 1587 tasks and each task having roughly 81305 files.
This implied 129 million bpf prog invocations. Unfortunwtely none of
these files are prog/map/link/btf files so bpf iterator/prog needs
to traverse all these files and not able to return to user space
since there are no seq_file buffer overflow.
This patch fixed the issue in bpf_seq_read() to limit the number
of visited objects. If the maximum number of visited objects is
reached, no more objects will be visited in the current syscall.
If there is nothing written in the seq_file buffer, -EAGAIN will
return to the user so user can try again.
The maximum number of visited objects is set at 1 million.
In our Intel Xeon D-2191 2.3GHZ 18-core server, bpf_seq_read()
visiting 1 million files takes around 0.18 seconds.
We did not use cond_resched() since for some iterators, e.g.,
netlink iterator, where rcu read_lock critical section spans between
consecutive seq_ops->next(), which makes impossible to do cond_resched()
in the key while loop of function bpf_seq_read().
When unloading driver by "modprobe -r amdgpu", one NULL pointer
dereference bug occurs in ras debugfs releasing. The cause is the
duplicated debugfs_remove, as drm debugfs_root dir has been cleaned
up already by drm_minor_unregister.
Every iteration of for_each_available_child_of_node() decrements
reference count of the previous node, however when control
is transferred from the middle of the loop, as in the case of
a return or break or goto, there is no decrement thus ultimately
resulting in a memory leak.
Fix a potential memory leak in gianfar.c by inserting of_node_put()
before the goto statement.
Issue found with Coccinelle.
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
projects / linux-stable / log