Greetings:
Sending via plain text email -- apologies if you receive this twice.
If this isn't the process for reporting a regression in a LTS kernel per https://www.kernel.org/doc/html/latest/admin-guide/reporting-issues.html, I'm happy to follow another process.
Kernel 6.1.149 introduced a regression, at least on our ARM Cortex A57-based platforms, via commit 8f4dc4e54eed4bebb18390305eb1f721c00457e1 in arch/arm64/kernel/fpsimd.c where booting KVM VMs eventually leads to a spinlock recursion BUG and crash of the box.
Reverting that commit via the below reverts to the old (working) behavior:
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 837d1937300a57..bc42163a7fd1f0 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1851,10 +1851,10 @@ void fpsimd_save_and_flush_cpu_state(void)
if (!system_supports_fpsimd())
return;
WARN_ON(preemptible());
- get_cpu_fpsimd_context();
+ __get_cpu_fpsimd_context();
fpsimd_save();
fpsimd_flush_cpu_state();
- put_cpu_fpsimd_context();
+ __put_cpu_fpsimd_context();
}
#ifdef CONFIG_KERNEL_MODE_NEON
It's not entirely clear to me if this is specific to our firmware, specific to ARM Cortex A57, or more systemic as we lack sufficiently differentiated hardware to know. I've tested on the latest 6.1 kernel in addition to the one in the log below and have also tested a number of firmware versions available for these boxes.
Steps to reproduce:
Boot VM in qemu-system-aarch64 with "-accel kvm" and "-cpu host" flags set -- no other arguments seem to matter
Generate CPU load in VM
Kernel log:
[sjc1] root@si-compute-kvm-e0fff70016b4:/# [ 805.905413] BUG: spinlock recursion on CPU#7, CPU 3/KVM/57616
[ 805.905452] lock: 0xffff3045ef850240, .magic: dead4ead, .owner: CPU 3/KVM/57616, .owner_cpu: 7
[ 805.905477] CPU: 7 PID: 57616 Comm: CPU 3/KVM Tainted: G O 6.1.152 #1
[ 805.905495] Hardware name: SoftIron SoftIron Platform Mainboard/SoftIron Platform Mainboard, BIOS 1.31 May 11 2023
[ 805.905516] Call trace:
[ 805.905524] dump_backtrace+0xe4/0x110
[ 805.905538] show_stack+0x20/0x30
[ 805.905548] dump_stack_lvl+0x6c/0x88
[ 805.905561] dump_stack+0x18/0x34
[ 805.905571] spin_dump+0x98/0xac
[ 805.905583] do_raw_spin_lock+0x70/0x128
[ 805.905596] _raw_spin_lock+0x18/0x28
[ 805.905607] raw_spin_rq_lock_nested+0x18/0x28
[ 805.905620] update_blocked_averages+0x70/0x550
[ 805.905634] run_rebalance_domains+0x50/0x70
[ 805.905645] handle_softirqs+0x198/0x328
[ 805.905659] __do_softirq+0x1c/0x28
[ 805.905669] ____do_softirq+0x18/0x28
[ 805.905680] call_on_irq_stack+0x30/0x48
[ 805.905691] do_softirq_own_stack+0x24/0x30
[ 805.905703] do_softirq+0x74/0x90
[ 805.905714] __local_bh_enable_ip+0x64/0x80
[ 805.905727] fpsimd_save_and_flush_cpu_state+0x5c/0x68
[ 805.905740] kvm_arch_vcpu_put_fp+0x4c/0x88
[ 805.905752] kvm_arch_vcpu_put+0x28/0x88
[ 805.905764] kvm_sched_out+0x38/0x58
[ 805.905774] __schedule+0x55c/0x6c8
[ 805.905786] schedule+0x60/0xa8
[ 805.905796] kvm_vcpu_block+0x5c/0x90
[ 805.905807] kvm_vcpu_halt+0x440/0x468
[ 805.905818] kvm_vcpu_wfi+0x3c/0x70
[ 805.905828] kvm_handle_wfx+0x18c/0x1f0
[ 805.905840] handle_exit+0xb8/0x148
[ 805.905851] kvm_arch_vcpu_ioctl_run+0x6c4/0x7b0
[ 805.905863] kvm_vcpu_ioctl+0x1d0/0x8b8
[ 805.905874] __arm64_sys_ioctl+0x9c/0xe0
[ 805.905886] invoke_syscall+0x78/0x108
[ 805.905899] el0_svc_common.constprop.3+0xb4/0xf8
[ 805.905912] do_el0_svc+0x78/0x88
[ 805.905922] el0_svc+0x48/0x78
[ 805.905932] el0t_64_sync_handler+0x40/0xc0
[ 805.905943] el0t_64_sync+0x18c/0x190
[ 806.048300] hrtimer: interrupt took 2976 ns
[ 826.924613] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
SoC 0 became not ready
SoC 0 became ready
Thanks,
--
Kenneth Van Alstyne, Jr.
This is the start of the stable review cycle for the 6.6.109 release.
There are 91 patches in this series, all will be posted as a response
to this one. If anyone has any issues with these being applied, please
let me know.
Responses should be made by Thu, 02 Oct 2025 14:37:59 +0000.
Anything received after that time might be too late.
The whole patch series can be found in one patch at:
https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.6.109-rc…
or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.6.y
and the diffstat can be found below.
thanks,
greg k-h
-------------
Pseudo-Shortlog of commits:
Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Linux 6.6.109-rc1
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: remove some #defines that are only expanded once
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: simplify the variants of clamp()
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: move all the clamp() definitions after the min/max() ones
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: reduce the #define expansion of min(), max() and clamp()
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: update some comments
David Laight <David.Laight(a)ACULAB.COM>
minmax.h: add whitespace around operators and after commas
Linus Torvalds <torvalds(a)linux-foundation.org>
minmax: fix up min3() and max3() too
Linus Torvalds <torvalds(a)linux-foundation.org>
minmax: improve macro expansion and type checking
Linus Torvalds <torvalds(a)linux-foundation.org>
minmax: don't use max() in situations that want a C constant expression
Linus Torvalds <torvalds(a)linux-foundation.org>
minmax: simplify min()/max()/clamp() implementation
Linus Torvalds <torvalds(a)linux-foundation.org>
minmax: make generic MIN() and MAX() macros available everywhere
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: add validation for ring_len param
Justin Bronder <jsbronder(a)cold-front.org>
i40e: increase max descriptors for XL710
Nirmoy Das <nirmoyd(a)nvidia.com>
drm/ast: Use msleep instead of mdelay for edid read
Hans de Goede <hansg(a)kernel.org>
gpiolib: Extend software-node support to support secondary software-nodes
Jan Kara <jack(a)suse.cz>
loop: Avoid updating block size under exclusive owner
David Hildenbrand <david(a)redhat.com>
mm/migrate_device: don't add folio to be freed to LRU in migrate_device_finalize()
Kefeng Wang <wangkefeng.wang(a)huawei.com>
mm: migrate_device: use more folio in migrate_device_finalize()
Florian Fainelli <florian.fainelli(a)broadcom.com>
ARM: bcm: Select ARM_GIC_V3 for ARCH_BRCMSTB
Nathan Chancellor <nathan(a)kernel.org>
s390/cpum_cf: Fix uninitialized warning after backport of ce971233242b
Thomas Zimmermann <tzimmermann(a)suse.de>
fbcon: Fix OOB access in font allocation
Samasth Norway Ananda <samasth.norway.ananda(a)oracle.com>
fbcon: fix integer overflow in fbcon_do_set_font
Jinjiang Tu <tujinjiang(a)huawei.com>
mm/hugetlb: fix folio is still mapped when deleted
Eric Biggers <ebiggers(a)kernel.org>
kmsan: fix out-of-bounds access to shadow memory
Zhen Ni <zhen.ni(a)easystack.cn>
afs: Fix potential null pointer dereference in afs_put_server
Nobuhiro Iwamatsu <iwamatsu(a)nigauri.org>
ARM: dts: socfpga: sodia: Fix mdio bus probe and PHY address
Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
tracing: dynevent: Add a missing lockdown check on dynevent
Eric Biggers <ebiggers(a)kernel.org>
crypto: af_alg - Fix incorrect boolean values in af_alg_ctx
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: improve VF MAC filters accounting
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: add mask to apply valid bits for itr_idx
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: add max boundary check for VF filters
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: fix validation of VF state in get resources
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: fix input validation logic for action_meta
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: fix idx validation in config queues msg
Lukasz Czapnik <lukasz.czapnik(a)intel.com>
i40e: fix idx validation in i40e_validate_queue_map
Amit Chaudhari <amitchaudhari(a)mac.com>
HID: asus: add support for missing PX series fn keys
Sang-Heon Jeon <ekffu200098(a)gmail.com>
smb: client: fix wrong index reference in smb2_compound_op()
Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
futex: Prevent use-after-free during requeue-PI
Zabelin Nikita <n.zabelin(a)mt-integration.ru>
drm/gma500: Fix null dereference in hdmi teardown
Dan Carpenter <dan.carpenter(a)linaro.org>
octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()
Vladimir Oltean <vladimir.oltean(a)nxp.com>
net: dsa: lantiq_gswip: suppress -EINVAL errors for bridge FDB entries added to the CPU port
Vladimir Oltean <vladimir.oltean(a)nxp.com>
net: dsa: lantiq_gswip: move gswip_add_single_port_br() call to port_setup()
Martin Schiller <ms(a)dev.tdt.de>
net: dsa: lantiq_gswip: do also enable or disable cpu port
Ido Schimmel <idosch(a)nvidia.com>
selftests: fib_nexthops: Fix creation of non-FDB nexthops
Ido Schimmel <idosch(a)nvidia.com>
nexthop: Forbid FDB status change while nexthop is in a group
Jason Baron <jbaron(a)akamai.com>
net: allow alloc_skb_with_frags() to use MAX_SKB_FRAGS
Alok Tiwari <alok.a.tiwari(a)oracle.com>
bnxt_en: correct offset handling for IPv6 destination address
Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
vhost: Take a reference on the task in struct vhost_task.
Luiz Augusto von Dentz <luiz.von.dentz(a)intel.com>
Bluetooth: hci_event: Fix UAF in hci_acl_create_conn_sync
Luiz Augusto von Dentz <luiz.von.dentz(a)intel.com>
Bluetooth: hci_sync: Fix hci_resume_advertising_sync
Petr Malat <oss(a)malat.biz>
ethernet: rvu-af: Remove slash from the driver name
Stéphane Grosjean <stephane.grosjean(a)hms-networks.com>
can: peak_usb: fix shift-out-of-bounds issue
Vincent Mailhol <mailhol(a)kernel.org>
can: mcba_usb: populate ndo_change_mtu() to prevent buffer overflow
Vincent Mailhol <mailhol(a)kernel.org>
can: sun4i_can: populate ndo_change_mtu() to prevent buffer overflow
Vincent Mailhol <mailhol(a)kernel.org>
can: hi311x: populate ndo_change_mtu() to prevent buffer overflow
Vincent Mailhol <mailhol(a)kernel.org>
can: etas_es58x: populate ndo_change_mtu() to prevent buffer overflow
Sabrina Dubroca <sd(a)queasysnail.net>
xfrm: xfrm_alloc_spi shouldn't use 0 as SPI
Leon Hwang <leon.hwang(a)linux.dev>
bpf: Reject bpf_timer for PREEMPT_RT
Geert Uytterhoeven <geert+renesas(a)glider.be>
can: rcar_can: rcar_can_resume(): fix s2ram with PSCI
James Guan <guan_yufei(a)163.com>
wifi: virt_wifi: Fix page fault on connect
Stefan Metzmacher <metze(a)samba.org>
smb: server: don't use delayed_work for post_recv_credits_work
Christian Loehle <christian.loehle(a)arm.com>
cpufreq: Initialize cpufreq-based invariance before subsys
Jihed Chaibi <jihed.chaibi.dev(a)gmail.com>
ARM: dts: kirkwood: Fix sound DAI cells for OpenRD clients
Peng Fan <peng.fan(a)nxp.com>
arm64: dts: imx8mp: Correct thermal sensor index
Hugh Dickins <hughd(a)google.com>
mm: folio_may_be_lru_cached() unless folio_test_large()
Hugh Dickins <hughd(a)google.com>
mm/gup: local lru_add_drain() to avoid lru_add_drain_all()
Hugh Dickins <hughd(a)google.com>
mm/gup: check ref_count instead of lru before migration
Shivank Garg <shivankg(a)amd.com>
mm: add folio_expected_ref_count() for reference count calculation
David Hildenbrand <david(a)redhat.com>
mm/gup: revert "mm: gup: fix infinite loop within __get_longterm_locked"
Or Har-Toov <ohartoov(a)nvidia.com>
IB/mlx5: Fix obj_type mismatch for SRQ event subscriptions
qaqland <anguoli(a)uniontech.com>
ALSA: usb-audio: Add mute TLV for playback volumes on more devices
Cryolitia PukNgae <cryolitia(a)uniontech.com>
ALSA: usb-audio: move mixer_quirks' min_mute into common quirk
noble.yang <noble.yang(a)comtrue-inc.com>
ALSA: usb-audio: Add DSD support for Comtrue USB Audio device
Heikki Krogerus <heikki.krogerus(a)linux.intel.com>
i2c: designware: Add quirk for Intel Xe
Benoît Monin <benoit.monin(a)bootlin.com>
mmc: sdhci-cadence: add Mobileye eyeQ support
Jiayi Li <lijiayi(a)kylinos.cn>
usb: core: Add 0x prefix to quirks debug output
Takashi Iwai <tiwai(a)suse.de>
ALSA: usb-audio: Fix build with CONFIG_INPUT=n
Chen Ni <nichen(a)iscas.ac.cn>
ALSA: usb-audio: Convert comma to semicolon
Kerem Karabay <kekrby(a)gmail.com>
HID: multitouch: specify that Apple Touch Bar is direct
Kerem Karabay <kekrby(a)gmail.com>
HID: multitouch: take cls->maxcontacts into account for Apple Touch Bar even without a HID_DG_CONTACTMAX field
Kerem Karabay <kekrby(a)gmail.com>
HID: multitouch: support getting the tip state from HID_DG_TOUCH fields in Apple Touch Bar
Kerem Karabay <kekrby(a)gmail.com>
HID: multitouch: Get the contact ID from HID_DG_TRANSDUCER_INDEX fields in case of Apple Touch Bar
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
ALSA: usb-audio: Add mixer quirk for Sony DualSense PS5
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
ALSA: usb-audio: Remove unneeded wmb() in mixer_quirks
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
ALSA: usb-audio: Simplify NULL comparison in mixer_quirks
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
ALSA: usb-audio: Avoid multiple assignments in mixer_quirks
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
ALSA: usb-audio: Drop unnecessary parentheses in mixer_quirks
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
ALSA: usb-audio: Fix block comments in mixer_quirks
Takashi Sakamoto <o-takashi(a)sakamocchi.jp>
firewire: core: fix overlooked update of subsystem ABI version
Alok Tiwari <alok.a.tiwari(a)oracle.com>
scsi: ufs: mcq: Fix memory allocation checks for SQE and CQE
-------------
Diffstat:
Makefile | 4 +-
.../dts/intel/socfpga/socfpga_cyclone5_sodia.dts | 6 +-
.../boot/dts/marvell/kirkwood-openrd-client.dts | 2 +-
arch/arm/mach-bcm/Kconfig | 1 +
arch/arm64/boot/dts/freescale/imx8mp.dtsi | 4 +-
arch/s390/kernel/perf_cpum_cf.c | 4 +-
arch/um/drivers/mconsole_user.c | 2 +
drivers/block/loop.c | 40 ++-
drivers/cpufreq/cpufreq.c | 20 +-
drivers/edac/skx_common.h | 1 -
drivers/firewire/core-cdev.c | 2 +-
drivers/gpio/gpiolib.c | 19 +-
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 +
.../gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c | 2 +
drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h | 14 +-
.../drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c | 2 +
.../gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_0_ppt.c | 3 +
.../gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c | 3 +
drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 2 +-
drivers/gpu/drm/ast/ast_dp.c | 2 +-
drivers/gpu/drm/gma500/oaktrail_hdmi.c | 2 +-
drivers/gpu/drm/radeon/evergreen_cs.c | 2 +
drivers/hid/hid-asus.c | 3 +
drivers/hid/hid-multitouch.c | 45 +++-
drivers/hwmon/adt7475.c | 24 +-
drivers/i2c/busses/i2c-designware-platdrv.c | 7 +-
drivers/infiniband/hw/mlx5/devx.c | 1 +
drivers/input/touchscreen/cyttsp4_core.c | 2 +-
drivers/irqchip/irq-sun6i-r.c | 2 +-
drivers/media/dvb-frontends/stv0367_priv.h | 3 +
drivers/mmc/host/sdhci-cadence.c | 11 +
drivers/net/can/rcar/rcar_can.c | 8 +-
drivers/net/can/spi/hi311x.c | 1 +
drivers/net/can/sun4i_can.c | 1 +
drivers/net/can/usb/etas_es58x/es58x_core.c | 3 +-
drivers/net/can/usb/etas_es58x/es58x_devlink.c | 2 +-
drivers/net/can/usb/mcba_usb.c | 1 +
drivers/net/can/usb/peak_usb/pcan_usb_core.c | 2 +-
drivers/net/dsa/lantiq_gswip.c | 41 +--
drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c | 2 +-
drivers/net/ethernet/intel/i40e/i40e.h | 4 +-
drivers/net/ethernet/intel/i40e/i40e_ethtool.c | 25 +-
drivers/net/ethernet/intel/i40e/i40e_main.c | 26 +-
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 110 ++++----
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.h | 3 +-
drivers/net/ethernet/marvell/octeontx2/af/cgx.c | 3 +-
.../net/ethernet/marvell/octeontx2/nic/otx2_tc.c | 2 +-
drivers/net/fjes/fjes_main.c | 4 +-
drivers/net/wireless/virtual/virt_wifi.c | 4 +-
drivers/nfc/pn544/i2c.c | 2 -
drivers/platform/x86/sony-laptop.c | 1 -
drivers/scsi/isci/init.c | 6 +-
.../pci/hive_isp_css_include/math_support.h | 5 -
drivers/ufs/core/ufs-mcq.c | 4 +-
drivers/usb/core/quirks.c | 2 +-
drivers/video/fbdev/core/fbcon.c | 13 +-
fs/afs/server.c | 3 +-
fs/btrfs/tree-checker.c | 2 +-
fs/hugetlbfs/inode.c | 10 +-
fs/smb/client/smb2inode.c | 2 +-
fs/smb/server/transport_rdma.c | 18 +-
include/crypto/if_alg.h | 2 +-
include/linux/compiler.h | 9 +
include/linux/minmax.h | 234 +++++++++-------
include/linux/mm.h | 55 ++++
include/linux/swap.h | 10 +
include/net/bluetooth/hci_core.h | 21 ++
kernel/bpf/verifier.c | 4 +
kernel/futex/requeue.c | 6 +-
kernel/trace/preemptirq_delay_test.c | 2 -
kernel/trace/trace_dynevent.c | 4 +
kernel/vhost_task.c | 3 +-
lib/btree.c | 1 -
lib/decompress_unlzma.c | 2 +
lib/vsprintf.c | 2 +-
mm/gup.c | 28 +-
mm/kmsan/core.c | 10 +-
mm/kmsan/kmsan_test.c | 16 ++
mm/migrate_device.c | 42 ++-
mm/mlock.c | 6 +-
mm/swap.c | 4 +-
mm/zsmalloc.c | 2 -
net/bluetooth/hci_event.c | 26 +-
net/bluetooth/hci_sync.c | 7 +
net/core/skbuff.c | 2 +-
net/ipv4/nexthop.c | 7 +
net/xfrm/xfrm_state.c | 3 +
sound/usb/mixer_quirks.c | 295 +++++++++++++++++++--
sound/usb/quirks.c | 24 +-
sound/usb/usbaudio.h | 4 +
tools/testing/selftests/mm/mremap_test.c | 2 +
tools/testing/selftests/net/fib_nexthops.sh | 12 +-
tools/testing/selftests/seccomp/seccomp_bpf.c | 2 +
93 files changed, 1031 insertions(+), 363 deletions(-)
From: xu xin <xu.xin16(a)zte.com.cn>
This series aim to fix exec/fork inheritance and introduce ksm-utils tools
including ksm-set and ksm-get, you can see the detail in PATCH 1.
Problem
=======
In some extreme scenarios, however, this inheritance of MMF_VM_MERGE_ANY during
exec/fork can fail. For example, when the scanning frequency of ksmd is tuned
extremely high, a process carrying MMF_VM_MERGE_ANY may still fail to pass it to
the newly exec'd process. This happens because ksm_execve() is executed too early
in the do_execve flow (prematurely adding the new mm_struct to the ksm_mm_slot list).
As a result, before do_execve completes, ksmd may have already performed a scan and
found that this new mm_struct has no VM_MERGEABLE VMAs, thus clearing its
MMF_VM_MERGE_ANY flag. Consequently, when the new program executes, the flag
MMF_VM_MERGE_ANY inheritance fails!
Reproduce
========
Prepare ksm-utils in the prerequisite PATCH, and simply do as follows
echo 1 > /sys/kernel/mm/ksm/run;
echo 2000 > /sys/kernel/mm/ksm/pages_to_scan;
echo 0 > /sys/kernel/mm/ksm/sleep_millisecs;
ksm-set -s on [NEW_PROGRAM_BIN] &
ksm-get -a -e
you can see like this:
Pid Comm Merging_pages Ksm_zero_pages Ksm_profit Ksm_mergeable Ksm_merge_any
206 NEW_PROGRAM_BIN 7680 0 30965760 yes no
Note:
If the first time don't reproduce the issue, pkill NEW_PROGRAM_BIN and try run it
again. Usually, we can reproduce it in 5 times.
Root reason
===========
The commit d7597f59d1d33 ("mm: add new api to enable ksm per process") clear the
flag MMF_VM_MERGE_ANY when ksmd found no VM_MERGEABLE VMAs.
xu xin (2):
tools: add ksm-utils tools
mm/ksm: fix exec/fork inheritance support for prctl
mm/ksm.c | 8 +-
tools/mm/Makefile | 12 +-
tools/mm/ksm-utils/Makefile | 10 +
tools/mm/ksm-utils/ksm-get.c | 397 +++++++++++++++++++++++++++++++++++
tools/mm/ksm-utils/ksm-set.c | 144 +++++++++++++
5 files changed, 567 insertions(+), 4 deletions(-)
create mode 100644 tools/mm/ksm-utils/Makefile
create mode 100644 tools/mm/ksm-utils/ksm-get.c
create mode 100644 tools/mm/ksm-utils/ksm-set.c
--
2.25.1
In of_unittest_pci_node_verify(), when the add parameter is false,
device_find_any_child() obtains a reference to a child device. This
function implicitly calls get_device() to increment the device's
reference count before returning the pointer. However, the caller
fails to properly release this reference by calling put_device(),
leading to a device reference count leak. Add put_device() in the else
branch immediately after child_dev is no longer needed.
As the comment of device_find_any_child states: "NOTE: you will need
to drop the reference with put_device() after use".
Found by code review.
Cc: stable(a)vger.kernel.org
Fixes: 26409dd04589 ("of: unittest: Add pci_dt_testdrv pci driver")
Signed-off-by: Ma Ke <make24(a)iscas.ac.cn>
---
Changes in v2:
- modified the put_device() location as suggestions.
---
drivers/of/unittest.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index e3503ec20f6c..388e9ec2cccf 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -4300,6 +4300,7 @@ static int of_unittest_pci_node_verify(struct pci_dev *pdev, bool add)
unittest(!np, "Child device tree node is not removed\n");
child_dev = device_find_any_child(&pdev->dev);
unittest(!child_dev, "Child device is not removed\n");
+ put_device(child_dev);
}
failed:
--
2.17.1