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Commit c82c06ce43d3("cfg80211: Notify all User Hints To self managed wiphys")
notified all new user hints to self managed wiphy's after device registration.
But it didn't do this for anything other than cell base hints done before
registration.
This needs to be done during wiphy registration of a self managed device also,
so that the previous user settings are retained.
Fixes: c82c06ce43d3 ("cfg80211: Notify all User Hints To self managed wiphys")
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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The txq of vif is added to active_txqs list for ATF TXQ scheduling
in the function ieee80211_queue_skb(), but it was not properly removed
before freeing the txq object. It was causing use after free of the txq
objects from the active_txqs list, result was kernel panic
due to invalid memory access.
Fix kernel invalid memory access by properly removing txq object
from active_txqs list before free the object.
Signed-off-by: Bhagavathi Perumal S <bperumal@codeaurora.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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The original patch neglected to take byte order conversions
into account, fix that.
Fixes: d9bb410888ce ("mac80211: allow overriding HT STBC capabilities")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Restore SW_CRYPTO_CONTROL operation on AP_VLAN interfaces for unicast
keys, the original override was intended to be done for group keys as
those are treated specially by mac80211 and would always have been
rejected.
Now the situation is that AP_VLAN support must be enabled by the driver
if it can support it (meaning it can support software crypto GTK TX).
Thus, also simplify the code - if we get here with AP_VLAN and non-
pairwise key, software crypto must be used (driver doesn't know about
the interface) and can be used (driver must've advertised AP_VLAN if
it also uses SW_CRYPTO_CONTROL).
Fixes: db3bdcb9c3ff ("mac80211: allow AP_VLAN operation on crypto controlled devices")
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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If the RX completion indicates RX buffers errors, the RX ring will be
disabled by firmware and no packets will be received on that ring from
that point on. Recover by resetting the device.
Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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There is logic to check that the RX/TPA consumer index is the expected
index to work around a hardware problem. However, the potentially bad
consumer index is first used to index into an array to reference an entry.
This can potentially crash if the bad consumer index is beyond legal
range. Improve the logic to use the consumer index for dereferencing
after the validity check and log an error message.
Fixes: fa7e28127a5a ("bnxt_en: Add workaround to detect bad opaque in rx completion (part 2)")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make sure SKBTX_HW_TSTAMP (i.e. SOF_TIMESTAMPING_TX_HARDWARE) has been
enabled for this skb. It does fix the issue where normal socks that
aren't expecting a timestamp will not wake up on select, but when a
user does want a SOF_TIMESTAMPING_TX_HARDWARE it does work.
Signed-off-by: Paul Thomas <pthomas8589@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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qlcnic driver uses u16 to store SPEED_UKNOWN ethtool constant,
which is defined as -1, resulting in value truncation and
thus incorrect test results against SPEED_UNKNOWN.
For example, the following test will print "False":
u16 speed = SPEED_UNKNOWN;
if (speed == SPEED_UNKNOWN)
printf("True");
else
printf("False");
Change storage of speed to use u32 to avoid this issue.
Signed-off-by: Michael Zhivich <mzhivich@akamai.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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tg3 driver uses u16 to store SPEED_UKNOWN ethtool constant,
which is defined as -1, resulting in value truncation and
thus incorrect test results against SPEED_UNKNOWN.
For example, the following test will print "False":
u16 speed = SPEED_UNKNOWN;
if (speed == SPEED_UNKNOWN)
printf("True");
else
printf("False");
Change storage of speed to use u32 to avoid this issue.
Signed-off-by: Michael Zhivich <mzhivich@akamai.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When building C++ userspace code that includes ethtool.h
with "-Werror -Wall", g++ complains about signed-unsigned comparison in
ethtool_validate_speed() due to definition of SPEED_UNKNOWN as -1.
Explicitly cast SPEED_UNKNOWN to __u32 to match type of
ethtool_validate_speed() argument.
Signed-off-by: Michael Zhivich <mzhivich@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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erspan_v6 tunnels run __iptunnel_pull_header on received skbs to remove
erspan header. This can determine a possible use-after-free accessing
pkt_md pointer in ip6erspan_rcv since the packet will be 'uncloned'
running pskb_expand_head if it is a cloned gso skb (e.g if the packet has
been sent though a veth device). Fix it resetting pkt_md pointer after
__iptunnel_pull_header
Fixes: 1d7e2ed22f8d ("net: erspan: refactor existing erspan code")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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erspan tunnels run __iptunnel_pull_header on received skbs to remove
gre and erspan headers. This can determine a possible use-after-free
accessing pkt_md pointer in erspan_rcv since the packet will be 'uncloned'
running pskb_expand_head if it is a cloned gso skb (e.g if the packet has
been sent though a veth device). Fix it resetting pkt_md pointer after
__iptunnel_pull_header
Fixes: 1d7e2ed22f8d ("net: erspan: refactor existing erspan code")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In order to have control over how many bytes are read or written
the device needs to be opened in unbuffered mode.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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Three new tests added:
1. Send get random cmd, read header in 1st read, read the rest in second
read - expect success
2. Send get random cmd, read only part of the response, send another
get random command, read the response - expect success
3. Send get random cmd followed by another get random cmd, without
reading the first response - expect the second cmd to fail with -EBUSY
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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Fixes the warning reported by Clang:
security/keys/trusted.c:146:17: warning: passing an object that
undergoes default
argument promotion to 'va_start' has undefined behavior [-Wvarargs]
va_start(argp, h3);
^
security/keys/trusted.c:126:37: note: parameter of type 'unsigned
char' is declared here
unsigned char *h2, unsigned char h3, ...)
^
Specifically, it seems that both the C90 (4.8.1.1) and C11 (7.16.1.4)
standards explicitly call this out as undefined behavior:
The parameter parmN is the identifier of the rightmost parameter in
the variable parameter list in the function definition (the one just
before the ...). If the parameter parmN is declared with ... or with a
type that is not compatible with the type that results after
application of the default argument promotions, the behavior is
undefined.
Link: https://github.com/ClangBuiltLinux/linux/issues/41
Link: https://www.eskimo.com/~scs/cclass/int/sx11c.html
Suggested-by: David Laight <David.Laight@aculab.com>
Suggested-by: Denis Kenzior <denkenz@gmail.com>
Suggested-by: James Bottomley <jejb@linux.vnet.ibm.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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calc_tpm2_event_size() has an invalid signature because
it returns a 'size_t' where as its signature says that
it returns 'int'.
Cc: <stable@vger.kernel.org>
Fixes: 4d23cc323cdb ("tpm: add securityfs support for TPM 2.0 firmware event log")
Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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Allow trusted.ko to initialize w/o a TPM. This commit also adds checks
to the exported functions to fail when a TPM is not available.
Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...")
Cc: James Morris <jmorris@namei.org>
Reported-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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The poll condition should only check response_length,
because reads should only be issued if there is data to read.
The response_read flag only prevents double writes.
The problem was that the write set the response_read to false,
enqued a tpm job, and returned. Then application called poll
which checked the response_read flag and returned EPOLLIN.
Then the application called read, but got nothing.
After all that the async_work kicked in.
Added also mutex_lock around the poll check to prevent
other possible race conditions.
Fixes: 9488585b21bef0df12 ("tpm: add support for partial reads")
Reported-by: Mantas Mikulėnas <grawity@gmail.com>
Tested-by: Mantas Mikulėnas <grawity@gmail.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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tpm_chip_start/stop() should be also called for TPM 1.x devices on
suspend. Add that functionality back. Do not lock the chip because
it is unnecessary as there are no multiple threads using it when
doing the suspend.
Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
Reported-by: Paul Zimmerman <pauldzim@gmail.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Domenico Andreoli <domenico.andreoli@linux.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
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There's a significant number of reports that re-enabling ASPM causes
different issues, ranging from decreased performance to system not
booting at all. This affects only a minority of users, but the number
of affected users is big enough that we better switch off ASPM again.
This will hurt notebook users who are not affected by the issues, they
may see decreased battery runtime w/o ASPM. With the PCI core folks is
being discussed to add generic sysfs attributes to control ASPM.
Once this is in place brave enough users can re-enable ASPM on their
system.
Fixes: a99790bf5c7f ("r8169: Reinstate ASPM Support")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When moving the documentation for the ieee802154 subsystem from
plain text to rst the file pattern in the MAINTAINERS file got wrong.
Updating it here to fix scripts using this file.
Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently there is no way for the driver to signal to mac80211 that it should
schedule a TXQ even if there are no packets on the mac80211 part of that queue.
This is problematic if the driver has an internal retry queue to deal with
software A-MPDU retry.
This patch changes the behavior of ieee80211_schedule_txq to always schedule
the queue, as its only user (ath9k) seems to expect such behavior already:
it calls this function on tx status and on powersave wakeup whenever its
internal retry queue is not empty.
Also add an extra argument to ieee80211_return_txq to get the same behavior.
This fixes an issue on ath9k where tx queues with packets to retry (and no
new packets in mac80211) would not get serviced.
Fixes: 89cea7493a346 ("ath9k: Switch to mac80211 TXQ scheduling and airtime APIs")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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If we just set this to 2048, and have multiple limits you
can select from, the total number might run over and cause
a warning in cfg80211. This doesn't make sense, so we just
calculate the total max_interfaces now.
Reported-by: syzbot+8f91bd563bbff230d0ee@syzkaller.appspotmail.com
Fixes: 99e3a44bac37 ("mac80211_hwsim: allow setting iftype support")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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wiphy_{err,warn}_ratelimited will be used by rt2x00
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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When the mtu of a vrf device is set to 0, it would cause ping
failed. So I think we should limit vrf mtu in a reasonable range
to solve this problem. I set dev->min_mtu to IPV6_MIN_MTU, so it
will works for both ipv4 and ipv6. And if dev->max_mtu still be 0
can be confusing, so I set dev->max_mtu to ETH_MAX_MTU.
Here is the reproduce step:
1.Config vrf interface and set mtu to 0:
3: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel
master vrf1 state UP mode DEFAULT group default qlen 1000
link/ether 52:54:00:9e:dd:c1 brd ff:ff:ff:ff:ff:ff
2.Ping peer:
3: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel
master vrf1 state UP group default qlen 1000
link/ether 52:54:00:9e:dd:c1 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.1/16 scope global enp4s0
valid_lft forever preferred_lft forever
connect: Network is unreachable
3.Set mtu to default value, ping works:
PING 10.0.0.2 (10.0.0.2) 56(84) bytes of data.
64 bytes from 10.0.0.2: icmp_seq=1 ttl=64 time=1.88 ms
Fixes: ad49bc6361ca2 ("net: vrf: remove MTU limits for vrf device")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The commit 510ded33e075 ("slab: implement slab_root_caches list")
changes the name of the list node within "struct kmem_cache" from "list"
to "root_caches_node", but leaks_show() still use the "list" which
causes a crash when reading /proc/slab_allocators.
You need to have CONFIG_SLAB=y and CONFIG_MEMCG=y to see the problem,
because without MEMCG all slab caches are root caches, and the "list"
node happens to be the right one.
Fixes: 510ded33e075 ("slab: implement slab_root_caches list")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Tobin C. Harding <tobin@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is a follow up of the commit 0db6f8befc32 ("net/sched: fix ->get
helper of the matchall cls").
To test it:
$ cd tools/testing/selftests/tc-testing
$ ln -s ../plugin-lib/nsPlugin.py plugins/20-nsPlugin.py
$ ./tdc.py -n -e 2638
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When HOTPLUG_CPU is disabled, some fields in the smp operations
are not available or needed:
arch/arm/mach-milbeaut/platsmp.c:90:3: error: field designator 'cpu_die' does not refer to any field in type
'struct smp_operations'
.cpu_die = m10v_cpu_die,
^
arch/arm/mach-milbeaut/platsmp.c:91:3: error: field designator 'cpu_kill' does not refer to any field in type
'struct smp_operations'
.cpu_kill = m10v_cpu_kill,
^
Hide them in an #ifdef like the other platforms do.
Fixes: 9fb29c734f9e ("ARM: milbeaut: Add basic support for Milbeaut m10v SoC")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
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clang warns about statically defined DMA masks from the DMA_BIT_MASK
macro with length 64:
arch/arm/mach-iop13xx/setup.c:303:35: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
static u64 iop13xx_adma_dmamask = DMA_BIT_MASK(64);
^~~~~~~~~~~~~~~~
include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
^ ~~~
The ones in iop shouldn't really be 64 bit masks, so changing them
to what the driver can support avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
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clang warns about statically defined DMA masks from the DMA_BIT_MASK
macro with length 64:
arch/arm/plat-orion/common.c:625:29: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
.coherent_dma_mask = DMA_BIT_MASK(64),
^~~~~~~~~~~~~~~~
include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
The ones in orion shouldn't really be 64 bit masks, so changing them
to what the driver can support avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
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This reverts commit fa9463564e77067df81b0b8dec91adbbbc47bfb4.
Per Linus Walleij:
Dear ARM SoC maintainers,
can you please revert this patch. It was the wrong solution to the
wrong problem, and I must have acted in stress. Andrey fixed the
real bug in a proper way in these commits:
commit e5545c94e43b8f6599ffc01df8d1aedf18ee912a
"gpio: of: Check propname before applying "cs-gpios" quirks"
commit 7ce40277bf848391705011ba37eac2e377cbd9e6
"gpio: of: Check for "spi-cs-high" in child instead of parent node"
Signed-off-by: Olof Johansson <olof@lixom.net>
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Commit fd73403a4862 ("dt-bindings: arm: Add SMP enable-method for
Milbeaut") added support for a new cpu enable-method, but did so using
tabulations to ident. This is however invalid in the syntax, and resulted
in a failure when trying to use that schemas for validation.
Use spaces instead of tabs to indent to fix this.
Fixes: fd73403a4862 ("dt-bindings: arm: Add SMP enable-method for Milbeaut")
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Sugaya Taichi <sugaya.taichi@socionext.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
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This is similar to commit e285d5bfb7e9 ("NFC: Fix the number of pipes")
where we changed NFC_HCI_MAX_PIPES from 127 to 128.
As the comment next to the define explains, the pipe identifier is 7
bits long. The highest possible pipe is 127, but the number of possible
pipes is 128. As the code is now, then there is potential for an
out of bounds array access:
net/nfc/nci/hci.c:297 nci_hci_cmd_received() warn: array off by one?
'ndev->hci_dev->pipes[pipe]' '0-127 == 127'
Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This is similar to commit 674d9de02aa7 ("NFC: Fix possible memory
corruption when handling SHDLC I-Frame commands").
I'm not totally sure, but I think that commit description may have
overstated the danger. I was under the impression that this data came
from the firmware? If you can't trust your networking firmware, then
you're already in trouble.
Anyway, these days we add bounds checking where ever we can and we call
it kernel hardening. Better safe than sorry.
Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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While adding LASI support to QEMU, I noticed that the QEMU detection in
the kernel happens much too late. For example, when a LASI chip is found
by the kernel, it registers the LASI LED driver as well. But when we
run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so
we need to access the running_on_QEMU flag earlier than before.
This patch now makes the QEMU detection the fist task of the Linux
kernel by moving it to where the kernel enters the C-coding.
Fixes: 310d82784fb4 ("parisc: qemu idle sleep support")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.14+
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When setting the instruction pointer on PA-RISC we also need
to set the back of the instruction queue to the new offset, otherwise
we will execute on instruction from the new location, and jumping
back to the old location stored in iaoq_b.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 75ebedf1d263 ("parisc: Add HAVE_REGS_AND_STACK_ACCESS_API feature")
Cc: stable@vger.kernel.org # 4.19+
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While working on kretprobes for PA-RISC I was wondering while the
kprobes sanity test always fails on kretprobes. This is caused by
returning gpr20 instead of gpr28.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.14+
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Revert parts of commit 97d7e2e3fd8a ("parisc: Use F_EXTEND() macro in
iosapic code"). It breaks booting the 32-bit kernel on some machines.
Reported-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Sven Schnelle <svens@stackframe.org>
Fixes: 97d7e2e3fd8a ("parisc: Use F_EXTEND() macro in iosapic code")
Signed-off-by: Helge Deller <deller@gmx.de>
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Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.
This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.
The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.
However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f2655e3 -
is doing so irregardless of whether a file is seekable or not.
See
https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
https://lwn.net/Articles/180387
https://lwn.net/Articles/180396
for historic context.
The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:
kernel/power/user.c snapshot_read
fs/debugfs/file.c u32_array_read
fs/fuse/control.c fuse_conn_waiting_read + ...
drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read
arch/s390/hypfs/inode.c hypfs_read_iter
...
Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.
Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):
drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()
In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.
FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:
See
https://github.com/libfuse/osspd
https://lwn.net/Articles/308445
https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510
Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:
https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216
I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:
https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169
Let's fix this regression. The plan is:
1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
doing so would break many in-kernel nonseekable_open users which
actually use ppos in read/write handlers.
2. Add stream_open() to kernel to open stream-like non-seekable file
descriptors. Read and write on such file descriptors would never use
nor change ppos. And with that property on stream-like files read and
write will be running without taking f_pos lock - i.e. read and write
could be running simultaneously.
3. With semantic patch search and convert to stream_open all in-kernel
nonseekable_open users for which read and write actually do not
depend on ppos and where there is no other methods in file_operations
which assume @offset access.
4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
steam_open if that bit is present in filesystem open reply.
It was tempting to change fs/fuse/ open handler to use stream_open
instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
and in particular GVFS which actually uses offset in its read and
write handlers
https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481
so if we would do such a change it will break a real user.
5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
from v3.14+ (the kernel where 9c225f2655 first appeared).
This will allow to patch OSSPD and other FUSE filesystems that
provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
in their open handler and this way avoid the deadlock on all kernel
versions. This should work because fs/fuse/ ignores unknown open
flags returned from a filesystem and so passing FOPEN_STREAM to a
kernel that is not aware of this flag cannot hurt. In turn the kernel
that is not aware of FOPEN_STREAM will be < v3.14 where just
FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
write deadlock.
This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.
Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.
The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
If xace hardware reports a bad version number, the error handling code
in ace_setup() calls put_disk(), followed by queue cleanup. However, since
the disk data structure has the queue pointer set, put_disk() also
cleans and releases the queue. This results in blk_cleanup_queue()
accessing an already released data structure, which in turn may result
in a crash such as the following.
[ 10.681671] BUG: Kernel NULL pointer dereference at 0x00000040
[ 10.681826] Faulting instruction address: 0xc0431480
[ 10.682072] Oops: Kernel access of bad area, sig: 11 [#1]
[ 10.682251] BE PAGE_SIZE=4K PREEMPT Xilinx Virtex440
[ 10.682387] Modules linked in:
[ 10.682528] CPU: 0 PID: 1 Comm: swapper Tainted: G W 5.0.0-rc6-next-20190218+ #2
[ 10.682733] NIP: c0431480 LR: c043147c CTR: c0422ad8
[ 10.682863] REGS: cf82fbe0 TRAP: 0300 Tainted: G W (5.0.0-rc6-next-20190218+)
[ 10.683065] MSR: 00029000 <CE,EE,ME> CR: 22000222 XER: 00000000
[ 10.683236] DEAR: 00000040 ESR: 00000000
[ 10.683236] GPR00: c043147c cf82fc90 cf82ccc0 00000000 00000000 00000000 00000002 00000000
[ 10.683236] GPR08: 00000000 00000000 c04310bc 00000000 22000222 00000000 c0002c54 00000000
[ 10.683236] GPR16: 00000000 00000001 c09aa39c c09021b0 c09021dc 00000007 c0a68c08 00000000
[ 10.683236] GPR24: 00000001 ced6d400 ced6dcf0 c0815d9c 00000000 00000000 00000000 cedf0800
[ 10.684331] NIP [c0431480] blk_mq_run_hw_queue+0x28/0x114
[ 10.684473] LR [c043147c] blk_mq_run_hw_queue+0x24/0x114
[ 10.684602] Call Trace:
[ 10.684671] [cf82fc90] [c043147c] blk_mq_run_hw_queue+0x24/0x114 (unreliable)
[ 10.684854] [cf82fcc0] [c04315bc] blk_mq_run_hw_queues+0x50/0x7c
[ 10.685002] [cf82fce0] [c0422b24] blk_set_queue_dying+0x30/0x68
[ 10.685154] [cf82fcf0] [c0423ec0] blk_cleanup_queue+0x34/0x14c
[ 10.685306] [cf82fd10] [c054d73c] ace_probe+0x3dc/0x508
[ 10.685445] [cf82fd50] [c052d740] platform_drv_probe+0x4c/0xb8
[ 10.685592] [cf82fd70] [c052abb0] really_probe+0x20c/0x32c
[ 10.685728] [cf82fda0] [c052ae58] driver_probe_device+0x68/0x464
[ 10.685877] [cf82fdc0] [c052b500] device_driver_attach+0xb4/0xe4
[ 10.686024] [cf82fde0] [c052b5dc] __driver_attach+0xac/0xfc
[ 10.686161] [cf82fe00] [c0528428] bus_for_each_dev+0x80/0xc0
[ 10.686314] [cf82fe30] [c0529b3c] bus_add_driver+0x144/0x234
[ 10.686457] [cf82fe50] [c052c46c] driver_register+0x88/0x15c
[ 10.686610] [cf82fe60] [c09de288] ace_init+0x4c/0xac
[ 10.686742] [cf82fe80] [c0002730] do_one_initcall+0xac/0x330
[ 10.686888] [cf82fee0] [c09aafd0] kernel_init_freeable+0x34c/0x478
[ 10.687043] [cf82ff30] [c0002c6c] kernel_init+0x18/0x114
[ 10.687188] [cf82ff40] [c000f2f0] ret_from_kernel_thread+0x14/0x1c
[ 10.687349] Instruction dump:
[ 10.687435] 3863ffd4 4bfffd70 9421ffd0 7c0802a6 93c10028 7c9e2378 93e1002c 38810008
[ 10.687637] 7c7f1b78 90010034 4bfffc25 813f008c <81290040> 75290100 4182002c 80810008
[ 10.688056] ---[ end trace 13c9ff51d41b9d40 ]---
Fix the problem by setting the disk queue pointer to NULL before calling
put_disk(). A more comprehensive fix might be to rearrange the code
to check the hardware version before initializing data structures,
but I don't know if this would have undesirable side effects, and
it would increase the complexity of backporting the fix to older kernels.
Fixes: 74489a91dd43a ("Add support for Xilinx SystemACE CompactFlash interface")
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
At module load, if the selected home_node value is greater than
the available numa nodes, the system will crash in
__alloc_pages_nodemask() due to a bad paging request. Prevent this
user error crash by detecting the bad value, logging an error, and
setting g_home_node back to the default of NUMA_NO_NODE.
Signed-off-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Make sure to free the i2c adapter on the error exit path.
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: e1ab9a468e3b ("i2c: imx: improve the error handling in i2c_imx_dma_request()")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Commit 32a5ad9c2285 ("sysctl: handle overflow for file-max") hooked up
min/max values for the file-max sysctl parameter via the .extra1 and
.extra2 fields in the corresponding struct ctl_table entry.
Unfortunately, the minimum value points at the global 'zero' variable,
which is an int. This results in a KASAN splat when accessed as a long
by proc_doulongvec_minmax on 64-bit architectures:
| BUG: KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax+0x5d8/0x6a0
| Read of size 8 at addr ffff2000133d1c20 by task systemd/1
|
| CPU: 0 PID: 1 Comm: systemd Not tainted 5.1.0-rc3-00012-g40b114779944 #2
| Hardware name: linux,dummy-virt (DT)
| Call trace:
| dump_backtrace+0x0/0x228
| show_stack+0x14/0x20
| dump_stack+0xe8/0x124
| print_address_description+0x60/0x258
| kasan_report+0x140/0x1a0
| __asan_report_load8_noabort+0x18/0x20
| __do_proc_doulongvec_minmax+0x5d8/0x6a0
| proc_doulongvec_minmax+0x4c/0x78
| proc_sys_call_handler.isra.19+0x144/0x1d8
| proc_sys_write+0x34/0x58
| __vfs_write+0x54/0xe8
| vfs_write+0x124/0x3c0
| ksys_write+0xbc/0x168
| __arm64_sys_write+0x68/0x98
| el0_svc_common+0x100/0x258
| el0_svc_handler+0x48/0xc0
| el0_svc+0x8/0xc
|
| The buggy address belongs to the variable:
| zero+0x0/0x40
|
| Memory state around the buggy address:
| ffff2000133d1b00: 00 00 00 00 00 00 00 00 fa fa fa fa 04 fa fa fa
| ffff2000133d1b80: fa fa fa fa 04 fa fa fa fa fa fa fa 04 fa fa fa
| >ffff2000133d1c00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
| ^
| ffff2000133d1c80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
| ffff2000133d1d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Fix the splat by introducing a unsigned long 'zero_ul' and using that
instead.
Link: http://lkml.kernel.org/r/20190403153409.17307-1-will.deacon@arm.com
Fixes: 32a5ad9c2285 ("sysctl: handle overflow for file-max")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Christian Brauner <christian@brauner.io>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The kerneldoc misdescribes strndup_user()'s return value.
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Timur Tabi <timur@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Many of the sh CPU-types have their own plat_irq_setup() and
arch_init_clk_ops() functions, so these same (empty) functions in
arch/sh/boards/of-generic.c are not needed and cause build errors.
If there is some case where these empty functions are needed, they can
be retained by marking them as "__weak" while at the same time making
builds that do not need them succeed.
Fixes these build errors:
arch/sh/boards/of-generic.o: In function `plat_irq_setup':
(.init.text+0x134): multiple definition of `plat_irq_setup'
arch/sh/kernel/cpu/sh2/setup-sh7619.o:(.init.text+0x30): first defined here
arch/sh/boards/of-generic.o: In function `arch_init_clk_ops':
(.init.text+0x118): multiple definition of `arch_init_clk_ops'
arch/sh/kernel/cpu/sh2/clock-sh7619.o:(.init.text+0x0): first defined here
Link: http://lkml.kernel.org/r/9ee4e0c5-f100-86a2-bd4d-1d3287ceab31@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Add Tali Perry as Nuvoton NPCM maintainer, replace Brendan Higgins
Nuvoton NPCM reviewer with Benjamin Fair.
Link: http://lkml.kernel.org/r/20190328235752.334462-2-tmaimon77@gmail.com
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Benjamin Fair <benjaminfair@google.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Joe Perches <joe@perches.com>
Cc: Avi Fishman <avifishman70@gmail.com>
Cc: Patrick Venture <venture@google.com>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In the process of upstreaming architecture support for ARM/NUVOTON NPCM
include/dt-bindings/clock/nuvoton,npcm7xx-clks.h was renamed
include/dt-bindings/clock/nuvoton,npcm7xx-clock.h without updating
MAINTAINERS. This updates the MAINTAINERS pattern to match the new name
of this file.
Link: http://lkml.kernel.org/r/20190328235752.334462-1-tmaimon77@gmail.com
Fixes: 6a498e06ba22 ("MAINTAINERS: Add entry for the Nuvoton NPCM architecture")
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Reported-by: Joe Perches <joe@perches.com>
Reviewed-by: Benjamin Fair <benjaminfair@google.com>
Cc: Avi Fishman <avifishman70@gmail.com>
Cc: Mukesh Ojha <mojha@codeaurora.org>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Patrick Venture <venture@google.com>
Cc: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Since commit a983b5ebee57 ("mm: memcontrol: fix excessive complexity in
memory.stat reporting") memcg dirty and writeback counters are managed
as:
1) per-memcg per-cpu values in range of [-32..32]
2) per-memcg atomic counter
When a per-cpu counter cannot fit in [-32..32] it's flushed to the
atomic. Stat readers only check the atomic. Thus readers such as
balance_dirty_pages() may see a nontrivial error margin: 32 pages per
cpu.
Assuming 100 cpus:
4k x86 page_size: 13 MiB error per memcg
64k ppc page_size: 200 MiB error per memcg
Considering that dirty+writeback are used together for some decisions the
errors double.
This inaccuracy can lead to undeserved oom kills. One nasty case is
when all per-cpu counters hold positive values offsetting an atomic
negative value (i.e. per_cpu[*]=32, atomic=n_cpu*-32).
balance_dirty_pages() only consults the atomic and does not consider
throttling the next n_cpu*32 dirty pages. If the file_lru is in the
13..200 MiB range then there's absolutely no dirty throttling, which
burdens vmscan with only dirty+writeback pages thus resorting to oom
kill.
It could be argued that tiny containers are not supported, but it's more
subtle. It's the amount the space available for file lru that matters.
If a container has memory.max-200MiB of non reclaimable memory, then it
will also suffer such oom kills on a 100 cpu machine.
The following test reliably ooms without this patch. This patch avoids
oom kills.
$ cat test
mount -t cgroup2 none /dev/cgroup
cd /dev/cgroup
echo +io +memory > cgroup.subtree_control
mkdir test
cd test
echo 10M > memory.max
(echo $BASHPID > cgroup.procs && exec /memcg-writeback-stress /foo)
(echo $BASHPID > cgroup.procs && exec dd if=/dev/zero of=/foo bs=2M count=100)
$ cat memcg-writeback-stress.c
/*
* Dirty pages from all but one cpu.
* Clean pages from the non dirtying cpu.
* This is to stress per cpu counter imbalance.
* On a 100 cpu machine:
* - per memcg per cpu dirty count is 32 pages for each of 99 cpus
* - per memcg atomic is -99*32 pages
* - thus the complete dirty limit: sum of all counters 0
* - balance_dirty_pages() only sees atomic count -99*32 pages, which
* it max()s to 0.
* - So a workload can dirty -99*32 pages before balance_dirty_pages()
* cares.
*/
#define _GNU_SOURCE
#include <err.h>
#include <fcntl.h>
#include <sched.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <unistd.h>
static char *buf;
static int bufSize;
static void set_affinity(int cpu)
{
cpu_set_t affinity;
CPU_ZERO(&affinity);
CPU_SET(cpu, &affinity);
if (sched_setaffinity(0, sizeof(affinity), &affinity))
err(1, "sched_setaffinity");
}
static void dirty_on(int output_fd, int cpu)
{
int i, wrote;
set_affinity(cpu);
for (i = 0; i < 32; i++) {
for (wrote = 0; wrote < bufSize; ) {
int ret = write(output_fd, buf+wrote, bufSize-wrote);
if (ret == -1)
err(1, "write");
wrote += ret;
}
}
}
int main(int argc, char **argv)
{
int cpu, flush_cpu = 1, output_fd;
const char *output;
if (argc != 2)
errx(1, "usage: output_file");
output = argv[1];
bufSize = getpagesize();
buf = malloc(getpagesize());
if (buf == NULL)
errx(1, "malloc failed");
output_fd = open(output, O_CREAT|O_RDWR);
if (output_fd == -1)
err(1, "open(%s)", output);
for (cpu = 0; cpu < get_nprocs(); cpu++) {
if (cpu != flush_cpu)
dirty_on(output_fd, cpu);
}
set_affinity(flush_cpu);
if (fsync(output_fd))
err(1, "fsync(%s)", output);
if (close(output_fd))
err(1, "close(%s)", output);
free(buf);
}
Make balance_dirty_pages() and wb_over_bg_thresh() work harder to
collect exact per memcg counters. This avoids the aforementioned oom
kills.
This does not affect the overhead of memory.stat, which still reads the
single atomic counter.
Why not use percpu_counter? memcg already handles cpus going offline, so
no need for that overhead from percpu_counter. And the percpu_counter
spinlocks are more heavyweight than is required.
It probably also makes sense to use exact dirty and writeback counters
in memcg oom reports. But that is saved for later.
Link: http://lkml.kernel.org/r/20190329174609.164344-1-gthelen@google.com
Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org> [4.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The output of the PSI files show a bunch of numbers with no unit. The
psi.txt documentation file also does not indicate what units are used.
One can only find out by looking at the source code. The units are
percentage for the averages and useconds for the total. Make the
information easier to find by documenting the units in psi.txt.
Link: http://lkml.kernel.org/r/20190402193810.3450-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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