[ Upstream commit 72349b62a5 ]
When the firmware is not responding, execution of kexec boot causes a system
hang. When firmware assertion happened, driver get notified with interrupt
vector updated in MPI configuration table. Then, the driver will read
scratchpad register and set controller_fatal_error flag to true.
Signed-off-by: Deepak Ukey <deepak.ukey@microchip.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Acked-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4a63c1ffd3 ]
For userspace to tell the difference between an random signal
and an exception, the exception must include siginfo information.
Using SEND_SIG_FORCED for SIGSEGV is thus wrong, and it will result in
userspace seeing si_code == SI_USER (like a random signal) instead of
si_code == SI_KERNEL or a more specific si_code as all exceptions
deliver.
Therefore replace force_sig_info(SIGSEGV, SEND_SIG_FORCE, current)
with force_sig(SIG_SEGV, current) which gets this right and is shorter
and easier to type.
Fixes: 791eca1010 ("uretprobes/x86: Hijack return address")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 55a3235fc7 ]
For userspace to tell the difference between a random signal and an
exception, the exception must include siginfo information.
Using SEND_SIG_FORCED for SIGILL is thus wrong, and it will result
in userspace seeing si_code == SI_USER (like a random signal) instead
of si_code == SI_KERNEL or a more specific si_code as all exceptions
deliver.
Therefore replace force_sig_info(SIGILL, SEND_SIG_FORCE, current)
with force_sig(SIG_ILL, current) which gets this right and is
shorter and easier to type.
Fixes: 014940bad8 ("uprobes/x86: Send SIGILL if arch_uprobe_post_xol() fails")
Fixes: 0b5256c7f1 ("uprobes: Send SIGILL if handle_trampoline() fails")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 86989c41b5 ]
If the first process started (aka /sbin/init) receives a SIGKILL it
will panic the system if it is delivered. Making the system unusable
and undebugable. It isn't much better if the first process started
receives SIGSTOP.
So always ignore SIGSTOP and SIGKILL sent to init.
This is done in a separate clause in sig_task_ignored as force_sig_info
can clear SIG_UNKILLABLE and this protection should work even then.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6df0580be8 ]
Various documented examples on how to set up tx99 with ath9k rely
on setting up a regular monitor interface for setting the channel.
My previous patch "ath9k: fix tx99 with monitor mode interface" made
it possible to set it up this way again. However, it was removing support
for using an active monitor interface, which is required for controlling
the bitrate as well, since the bitrate is not passed down with a regular
monitor interface.
This patch partially reverts the previous one, but keeps support for using
a regular monitor interface to keep documented steps working in cases
where the bitrate does not matter
Fixes: d9c52fd17c ("ath9k: fix tx99 with monitor mode interface")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 83ef4fb755 ]
Func jz4780_dma_desc_residue() expects the index to the next hw
descriptor as its last parameter. Caller func jz4780_dma_tx_status(),
however, applied modulus before passing it. When the current hw
descriptor was last in the list, the index passed became zero.
The resulting excess of reported residue especially caused problems
with cyclic DMA transfer clients, i.e. ALSA AIC audio output, which
rely on this for determining current DMA location within buffer.
Combined with the recent and related residue-reporting fixes, spurious
ALSA audio underruns on jz4770 hardware are now fixed.
Signed-off-by: Daniel Silsby <dansilsby@gmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c558ecd21c ]
If we make this driver depend on MACH_JZ4780, that means it can be
enabled only if we're building a kernel specially crafted for a
JZ4780-based board, while most GNU/Linux distributions will want one
generic MIPS kernel that works on multiple boards.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1ae00833e3 ]
This is needed to make the display and venc work properly.
Compare to omap3-beagle.dts.
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fa99c21ecb ]
Vendor defined U-Boot has changed the partition scheme a while ago:
* kernel partition 6MB
* file system partition uses the remainder up to end of the NAND
* increased size of the environment partition (to get an OneNAND compatible base address)
* shrink the U-Boot partition
Let's be compatible (e.g. Debian kernel built from upstream).
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8905592b6e ]
The omap dss susbystem takes the display aliases to find
out which displays exist. To enable tv-out we must define
an alias.
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fa0d7dc355 ]
needed for device variants based on GTA04 board but with
different display panel (driver).
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f6707fd624 ]
Cache nodes under the cpu node(s) is PowerMac specific according to the
comment above, so make the code enforce that.
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3b857472f3 ]
Playback of 44.1Khz contents with HDMI plugged returns
"Invalid pipe config" because HDMI paths in the FW
topology are configured to operate at 48Khz.
This patch filters out sampling rates not supported
at hdac_hdmi_create_dais() to let user space SRC
to do the converting.
Signed-off-by: Yong Zhi <yong.zhi@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 37f62c0d58 ]
This is done in order not to trig the below warning in
ieee80211_rx_napi:
WARN_ON_ONCE(softirq_count() == 0);
ieee80211_rx_napi requires that softirq's are disabled during
execution.
The High latency bus drivers (SDIO and USB) sometimes call the wmi
ep_rx_complete callback from non softirq context, resulting in a trigger
of the above warning.
Calling ieee80211_rx_ni with softirq's already disabled (e.g., from
softirq context) should be safe as the local_bh_disable and
local_bh_enable functions (called from ieee80211_rx_ni) are fully
reentrant.
Signed-off-by: Erik Stromdahl <erik.stromdahl@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ef2ecab9af ]
S5M8767 PMIC interrupt line on Exynos5250-based Arndale board has
external pull-up resistors, so disable any pull control for it in
in controller node. This fixes support for S5M8767 interrupts and
enables operation of wakeup from S5M8767 RTC alarm.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9ab708aef6 ]
In the case where lo_vag <= SGTL5000_LINE_OUT_GND_BASE, lo_vag
is set to zero and later vol_quot is computed by dividing by
lo_vag causing a division by zero error. Fix this by avoiding
a zero division and set vol_quot to zero in this specific case
so that the lowest setting for i is correctly set.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 199ba9faca ]
In gcc8, when the 3rd argument (size) of a call to strncpy() matches the
length of the first argument, the compiler warns of the possibility of an
unterminated string. Using strlcpy() forces a null at the end.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1a19c139be ]
When we receive TX response, we may release a few packets
due to a hole that was closed in the transmission window.
However, if that frame failed, we will mark all the released
frames as failed and will send multiple BARs.
This affects statistics badly, and cause unnecessary frames
transmission.
Instead, mark all the following packets as success, with the
desired result of sending a bar for the failed frame only.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 030e46e495 ]
When a read request is retried for the remaining partial
data, the response may restart from read response first
or read response only. So support those cases.
Do not advance the comp psn beyond the current wqe's last_psn
as that could skip over an entire read wqe and will cause the
req_retry() logic to set an incorrect req psn.
An example sequence is as follows:
Write PSN 40 -- this is the current WQE.
Read request PSN 41
Write PSN 42
Receive ACK PSN 42 -- this will complete the current WQE
for PSN 40, and set the comp psn to 42 which is a problem
because the read request at PSN 41 has been skipped over.
So when req_retry() tries to retransmit the read request,
it sets the req psn to 42 which is incorrect.
When retrying a read request, calculate the number of psns
completed based on the dma resid instead of the wqe first_psn.
The wqe first_psn could have moved if the read request was
retried multiple times.
Set the reth length to the dma resid to handle read retries for
the remaining partial data.
Signed-off-by: Vijay Immanuel <vijayi@attalasystems.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f8f3b7fc21 ]
Regulators, which are marked as 'on-in-suspend' seems to be critical for
board operation, thus they must not be disabled anytime. This can be
only assured by marking them as 'always-on', because otherwise some
actions of their clients might result in turning them off. This patch
restores suspend/resume operation on Peach-Pit Chromebook board. It
partially reverts 'always-on' property removal done by the commit
mentioned in the Fixes tag.
Fixes: 665c441eea ("ARM: dts: exynos: Remove unneded always-on for regulators on Peach boards")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 64858773d7 ]
This patch adds missing properties to the CODEC and sound nodes, so the
audio will work also on Snow rev5 Chromebook. This patch is an extension
to the commit e9eefc3f8c ("ARM: dts: exynos: Add missing clock and
DAI properties to the max98095 node in Snow Chromebook")
and commit 6ab569936d ("ARM: dts: exynos: Enable HDMI audio on Snow
Chromebook"). It has been reported that such changes work fine on the
rev5 board too.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
[krzk: Fixed typo in phandle to &max98090]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e33ffbd9cd ]
If the CPU DAI does not initialise rate_max, say if using
using KNOT or CONTINUOUS, then the rate_max field will be
initialised to 0. A value of zero in the rate_max field of
the hardware runtime will cause the sound card to support no
sample rates at all. Obviously this is not desired, just a
different mechanism is being used to apply the constraints. As
such update the setting of rate_max in dpcm_init_runtime_hw
to be consistent with the non-DPCM cases and set rate_max to
UINT_MAX if nothing is defined on the CPU DAI.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4f36cb36c9 ]
The GFS2_RDF_UPTODATE flag in the rgrp is used to determine when
a rgrp buffer is valid. It's cleared when the glock is invalidated,
signifying that the buffer data is now invalid. But before this
patch, function update_rgrp_lvb was setting the flag when it
determined it had a valid lvb. But that's an invalid assumption:
just because you have a valid lvb doesn't mean you have valid
buffers. After all, another node may have made the lvb valid,
and this node just fetched it from the glock via dlm.
Consider this scenario:
1. The file system is mounted with RGRPLVB option.
2. In gfs2_inplace_reserve it locks the rgrp glock EX, but thanks
to GL_SKIP, it skips the gfs2_rgrp_bh_get.
3. Since loops == 0 and the allocation target (ap->target) is
bigger than the largest known chunk of blocks in the rgrp
(rs->rs_rbm.rgd->rd_extfail_pt) it skips that rgrp and bypasses
the call to gfs2_rgrp_bh_get there as well.
4. update_rgrp_lvb sees the lvb MAGIC number is valid, so bypasses
gfs2_rgrp_bh_get, but it still sets sets GFS2_RDF_UPTODATE due
to this invalid assumption.
5. The next time update_rgrp_lvb is called, it sees the bit is set
and just returns 0, assuming both the lvb and rgrp are both
uptodate. But since this is a smaller allocation, or space has
been freed by another node, thus adjusting the lvb values,
it decides to use the rgrp for allocations, with invalid rd_free
due to the fact it was never updated.
This patch changes update_rgrp_lvb so it doesn't set the UPTODATE
flag anymore. That way, it has no choice but to fetch the latest
values.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d9c52fd17c ]
Tx99 is typically configured via a monitor mode interface, which does
not get added to the driver as a vif. Since the code currently expects
a configured virtual interface for tx99, enabling tx99 via debugfs fails.
Since the vif is not needed anyway, remove all checks for it.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
[kvalo@codeaurora.org: s/CPTCFG/CONFIG/]
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b8e131542b ]
snd_seq_system_client_init() doesn't check the errors returned from
its port creations. Let's do it properly and handle the error paths.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7417844b63 ]
When REGULATORY_COUNTRY_IE_IGNORE is set, __reg_process_hint_country_ie()
ignores the country code change request from __cfg80211_connect_result()
via regulatory_hint_country_ie().
After Disconnect, similar to above, country code should not be reset to
world when country IE ignore is set. But this is violated and restore of
regulatory settings is invoked by cfg80211_disconnect_work via
regulatory_hint_disconnect().
To address this, avoid regulatory restore from regulatory_hint_disconnect()
when COUNTRY_IE_IGNORE is set.
Note: Currently, restore_regulatory_settings() takes care of clearing
beacon hints. But in the proposed change, regulatory restore is avoided.
Therefore, explicitly clear beacon hints when DISABLE_BEACON_HINTS
is not set.
Signed-off-by: Rajeev Kumar Sirasanagandla <rsirasan@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f128fa41f ]
The "frames" variable is unsigned so the error handling doesn't work
properly.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bd1d395070 ]
When continuously running wifi up/down sequence, the napi poll
can be scheduled after the CE buffers being freed by ath10k_pci_flush
Steps:
In a certain condition, during wifi down below scenario might occur.
ath10k_stop->ath10k_hif_stop->napi_schedule->ath10k_pci_flush->napi_poll(napi_synchronize).
In the above scenario, CE buffer entries will be freed up and become NULL in
ath10k_pci_flush. And the napi_poll has been invoked after the flush process
and it will try to get the skb from the CE buffer entry and perform some action on that.
Since the CE buffer already cleaned by pci flush this action will create NULL
pointer dereference and trigger below kernel panic.
Unable to handle kernel NULL pointer dereference at virtual address 0000005c
PC is at ath10k_pci_htt_rx_cb+0x64/0x3ec [ath10k_pci]
ath10k_pci_htt_rx_cb [ath10k_pci]
ath10k_ce_per_engine_service+0x74/0xc4 [ath10k_pci]
ath10k_ce_per_engine_service [ath10k_pci]
ath10k_ce_per_engine_service_any+0x74/0x80 [ath10k_pci]
ath10k_ce_per_engine_service_any [ath10k_pci]
ath10k_pci_napi_poll+0x48/0xec [ath10k_pci]
ath10k_pci_napi_poll [ath10k_pci]
net_rx_action+0xac/0x160
net_rx_action
__do_softirq+0xdc/0x208
__do_softirq
irq_exit+0x84/0xe0
irq_exit
__handle_domain_irq+0x80/0xa0
__handle_domain_irq
gic_handle_irq+0x38/0x5c
gic_handle_irq
__irq_usr+0x44/0x60
Tested on QCA4019 and firmware version 10.4.3.2.1.1-00010
Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0362f326d8 upstream.
An exiting task might belong to an offline cgroup. In this case an
attempt to grab a cgroup reference from the task can end up with an
infinite loop in hugetlb_cgroup_charge_cgroup(), because neither the
cgroup will become online, neither the task will be migrated to a live
cgroup.
Fix this by switching over to css_tryget(). As css_tryget_online()
can't guarantee that the cgroup won't go offline, in most cases the
check doesn't make sense. In this particular case users of
hugetlb_cgroup_charge_cgroup() are not affected by this change.
A similar problem is described by commit 18fa84a2db ("cgroup: Use
css_tryget() instead of css_tryget_online() in task_get_css()").
Link: http://lkml.kernel.org/r/20191106225131.3543616-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00d484f354 upstream.
We've encountered a rcu stall in get_mem_cgroup_from_mm():
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 33-....: (21000 ticks this GP) idle=6c6/1/0x4000000000000002 softirq=35441/35441 fqs=5017
(t=21031 jiffies g=324821 q=95837) NMI backtrace for cpu 33
<...>
RIP: 0010:get_mem_cgroup_from_mm+0x2f/0x90
<...>
__memcg_kmem_charge+0x55/0x140
__alloc_pages_nodemask+0x267/0x320
pipe_write+0x1ad/0x400
new_sync_write+0x127/0x1c0
__kernel_write+0x4f/0xf0
dump_emit+0x91/0xc0
writenote+0xa0/0xc0
elf_core_dump+0x11af/0x1430
do_coredump+0xc65/0xee0
get_signal+0x132/0x7c0
do_signal+0x36/0x640
exit_to_usermode_loop+0x61/0xd0
do_syscall_64+0xd4/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The problem is caused by an exiting task which is associated with an
offline memcg. We're iterating over and over in the do {} while
(!css_tryget_online()) loop, but obviously the memcg won't become online
and the exiting task won't be migrated to a live memcg.
Let's fix it by switching from css_tryget_online() to css_tryget().
As css_tryget_online() cannot guarantee that the memcg won't go offline,
the check is usually useless, except some rare cases when for example it
determines if something should be presented to a user.
A similar problem is described by commit 18fa84a2db ("cgroup: Use
css_tryget() instead of css_tryget_online() in task_get_css()").
Johannes:
: The bug aside, it doesn't matter whether the cgroup is online for the
: callers. It used to matter when offlining needed to evacuate all charges
: from the memcg, and so needed to prevent new ones from showing up, but we
: don't care now.
Link: http://lkml.kernel.org/r/20191106225131.3543616-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeeb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e7120d79e upstream.
For both PASID-based-Device-TLB Invalidate Descriptor and
Device-TLB Invalidate Descriptor, the Physical Function Source-ID
value is split according to this layout:
PFSID[3:0] is set at offset 12 and PFSID[15:4] is put at offset 52.
Fix the part laid out at offset 52.
Fixes: 0f725561e1 ("iommu/vt-d: Add definitions for PFSID")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: stable@vger.kernel.org # v4.19+
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 762c69685f upstream.
We need to get the underlying dentry of parent; sure, absent the races
it is the parent of underlying dentry, but there's nothing to prevent
losing a timeslice to preemtion in the middle of evaluation of
lower_dentry->d_parent->d_inode, having another process move lower_dentry
around and have its (ex)parent not pinned anymore and freed on memory
pressure. Then we regain CPU and try to fetch ->d_inode from memory
that is freed by that point.
dentry->d_parent *is* stable here - it's an argument of ->lookup() and
we are guaranteed that it won't be moved anywhere until we feed it
to d_add/d_splice_alias. So we safely go that way to get to its
underlying dentry.
Cc: stable@vger.kernel.org # since 2009 or so
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e72b9dd6a5 upstream.
lower_dentry can't go from positive to negative (we have it pinned),
but it *can* go from negative to positive. So fetching ->d_inode
into a local variable, doing a blocking allocation, checking that
now ->d_inode is non-NULL and feeding the value we'd fetched
earlier to a function that won't accept NULL is not a good idea.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
