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2023-06-10Merge tag 'arm-fixes-6.4-2' of ↵Linus Torvalds1-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Arnd Bergmann: "Most of the changes this time are for the Qualcomm Snapdragon platforms. There are bug fixes for error handling in Qualcomm icc-bwmon, rpmh-rsc, ramp_controller and rmtfs driver as well as the AMD tee firmware driver and a missing initialization in the Arm ff-a firmware driver. The Qualcomm RPMh and EDAC drivers need some rework to work correctly on all supported chips. The DT fixes include: - i.MX8 fixes for gpio, pinmux and clock settings - ADS touchscreen gpio polarity settings in several machines - Address dtb warnings for caches, panel and input-enable properties on Qualcomm platforms - Incorrect data on qualcomm platforms fir SA8155P power domains, SM8550 LLCC, SC7180-lite SDRAM frequencies and SM8550 soundwire - Remoteproc firmware paths are corrected for Sony Xperia 10 IV" * tag 'arm-fixes-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (36 commits) firmware: arm_ffa: Set handle field to zero in memory descriptor ARM: dts: Fix erroneous ADS touchscreen polarities arm64: dts: imx8mn-beacon: Fix SPI CS pinmux arm64: dts: imx8-ss-dma: assign default clock rate for lpuarts arm64: dts: imx8qm-mek: correct GPIOs for USDHC2 CD and WP signals EDAC/qcom: Get rid of hardcoded register offsets EDAC/qcom: Remove superfluous return variable assignment in qcom_llcc_core_setup() arm64: dts: qcom: sm8550: Use the correct LLCC register scheme dt-bindings: cache: qcom,llcc: Fix SM8550 description arm64: dts: qcom: sc7180-lite: Fix SDRAM freq for misidentified sc7180-lite boards arm64: dts: qcom: sm8550: use uint16 for Soundwire interval soc: qcom: rpmhpd: Add SA8155P power domains arm64: dts: qcom: Split out SA8155P and use correct RPMh power domains dt-bindings: power: qcom,rpmpd: Add SA8155P soc: qcom: Rename ice to qcom_ice to avoid module name conflict soc: qcom: rmtfs: Fix error code in probe() soc: qcom: ramp_controller: Fix an error handling path in qcom_ramp_controller_probe() ARM: dts: at91: sama7g5ek: fix debounce delay property for shdwc ARM: at91: pm: fix imbalanced reference counter for ethernet devices arm64: dts: qcom: sm6375-pdx225: Fix remoteproc firmware paths ...
2023-06-08Merge tag 'net-6.4-rc6' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from can, wifi, netfilter, bluetooth and ebpf. Current release - regressions: - bpf: sockmap: avoid potential NULL dereference in sk_psock_verdict_data_ready() - wifi: iwlwifi: fix -Warray-bounds bug in iwl_mvm_wait_d3_notif() - phylink: actually fix ksettings_set() ethtool call - eth: dwmac-qcom-ethqos: fix a regression on EMAC < 3 Current release - new code bugs: - wifi: mt76: fix possible NULL pointer dereference in mt7996_mac_write_txwi() Previous releases - regressions: - netfilter: fix NULL pointer dereference in nf_confirm_cthelper - wifi: rtw88/rtw89: correct PS calculation for SUPPORTS_DYNAMIC_PS - openvswitch: fix upcall counter access before allocation - bluetooth: - fix use-after-free in hci_remove_ltk/hci_remove_irk - fix l2cap_disconnect_req deadlock - nic: bnxt_en: prevent kernel panic when receiving unexpected PHC_UPDATE event Previous releases - always broken: - core: annotate rfs lockless accesses - sched: fq_pie: ensure reasonable TCA_FQ_PIE_QUANTUM values - netfilter: add null check for nla_nest_start_noflag() in nft_dump_basechain_hook() - bpf: fix UAF in task local storage - ipv4: ping_group_range: allow GID from 2147483648 to 4294967294 - ipv6: rpl: fix route of death. - tcp: gso: really support BIG TCP - mptcp: fixes for user-space PM address advertisement - smc: avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONT - can: avoid possible use-after-free when j1939_can_rx_register fails - batman-adv: fix UaF while rescheduling delayed work - eth: qede: fix scheduling while atomic - eth: ice: make writes to /dev/gnssX synchronous" * tag 'net-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits) bnxt_en: Implement .set_port / .unset_port UDP tunnel callbacks bnxt_en: Prevent kernel panic when receiving unexpected PHC_UPDATE event bnxt_en: Skip firmware fatal error recovery if chip is not accessible bnxt_en: Query default VLAN before VNIC setup on a VF bnxt_en: Don't issue AP reset during ethtool's reset operation bnxt_en: Fix bnxt_hwrm_update_rss_hash_cfg() net: bcmgenet: Fix EEE implementation eth: ixgbe: fix the wake condition eth: bnxt: fix the wake condition lib: cpu_rmap: Fix potential use-after-free in irq_cpu_rmap_release() bpf: Add extra path pointer check to d_path helper net: sched: fix possible refcount leak in tc_chain_tmplt_add() net: sched: act_police: fix sparse errors in tcf_police_dump() net: openvswitch: fix upcall counter access before allocation net: sched: move rtm_tca_policy declaration to include file ice: make writes to /dev/gnssX synchronous net: sched: add rcu annotations around qdisc->qdisc_sleeping rfs: annotate lockless accesses to RFS sock flow table rfs: annotate lockless accesses to sk->sk_rxhash virtio_net: use control_buf for coalesce params ...
2023-06-07net: sched: add rcu annotations around qdisc->qdisc_sleepingEric Dumazet1-1/+1
syzbot reported a race around qdisc->qdisc_sleeping [1] It is time we add proper annotations to reads and writes to/from qdisc->qdisc_sleeping. [1] BUG: KCSAN: data-race in dev_graft_qdisc / qdisc_lookup_rcu read to 0xffff8881286fc618 of 8 bytes by task 6928 on cpu 1: qdisc_lookup_rcu+0x192/0x2c0 net/sched/sch_api.c:331 __tcf_qdisc_find+0x74/0x3c0 net/sched/cls_api.c:1174 tc_get_tfilter+0x18f/0x990 net/sched/cls_api.c:2547 rtnetlink_rcv_msg+0x7af/0x8c0 net/core/rtnetlink.c:6386 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmsg+0x1e3/0x270 net/socket.c:2586 __do_sys_sendmsg net/socket.c:2595 [inline] __se_sys_sendmsg net/socket.c:2593 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd write to 0xffff8881286fc618 of 8 bytes by task 6912 on cpu 0: dev_graft_qdisc+0x4f/0x80 net/sched/sch_generic.c:1115 qdisc_graft+0x7d0/0xb60 net/sched/sch_api.c:1103 tc_modify_qdisc+0x712/0xf10 net/sched/sch_api.c:1693 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6395 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmsg+0x1e3/0x270 net/socket.c:2586 __do_sys_sendmsg net/socket.c:2595 [inline] __se_sys_sendmsg net/socket.c:2593 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 6912 Comm: syz-executor.5 Not tainted 6.4.0-rc3-syzkaller-00190-g0d85b27b0cc6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/16/2023 Fixes: 3a7d0d07a386 ("net: sched: extend Qdisc with rcu") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Vlad Buslov <vladbu@nvidia.com> Acked-by: Jamal Hadi Salim<jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-07rfs: annotate lockless accesses to RFS sock flow tableEric Dumazet1-2/+5
Add READ_ONCE()/WRITE_ONCE() on accesses to the sock flow table. This also prevents a (smart ?) compiler to remove the condition in: if (table->ents[index] != newval) table->ents[index] = newval; We need the condition to avoid dirtying a shared cache line. Fixes: fec5e652e58f ("rfs: Receive Flow Steering") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-06Merge tag 'platform-drivers-x86-v6.4-4' of ↵Linus Torvalds1-5/+1
git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 Pull x86 platform driver fixes from Hans de Goede: - various Microsoft Surface support fixes - one fix for the INT3472 driver * tag 'platform-drivers-x86-v6.4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: platform/x86: int3472: Avoid crash in unregistering regulator gpio platform/surface: aggregator_tabletsw: Add support for book mode in POS subsystem platform/surface: aggregator_tabletsw: Add support for book mode in KIP subsystem platform/surface: aggregator: Allow completion work-items to be executed in parallel platform/surface: aggregator: Make to_ssam_device_driver() respect constness
2023-06-05Merge tag 'qcom-driver-fixes-for-6.4' of ↵Arnd Bergmann1-6/+0
https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux into arm/fixes Qualcomm driver fixes for 6.4 Error paths is corrected across icc-bwmon, rpmh-rsc, ramp_controller and rmtfs. The ice module is renamed qcom_ice, to avoid clashing with existing "ice" driver. SA8155P-specific RPMh power-domains are introduced to avoid the code trying to access resources that exists on SM8150, but not on SA8155P. Lastly, changes to the EDAC driver to fix an issue where the driver performs mmio based on the wrong register map. * tag 'qcom-driver-fixes-for-6.4' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux: EDAC/qcom: Get rid of hardcoded register offsets EDAC/qcom: Remove superfluous return variable assignment in qcom_llcc_core_setup() dt-bindings: cache: qcom,llcc: Fix SM8550 description soc: qcom: rpmhpd: Add SA8155P power domains dt-bindings: power: qcom,rpmpd: Add SA8155P soc: qcom: Rename ice to qcom_ice to avoid module name conflict soc: qcom: rmtfs: Fix error code in probe() soc: qcom: ramp_controller: Fix an error handling path in qcom_ramp_controller_probe() soc: qcom: rpmh-rsc: drop redundant unsigned >=0 comparision soc: qcom: icc-bwmon: fix incorrect error code passed to dev_err_probe() Link: https://lore.kernel.org/r/20230601141058.2246039-1-andersson@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-06-04Merge tag 'char-misc-6.4-rc5' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver fixes from Greg KH: "Here are a bunch of tiny char/misc/other driver fixes for 6.4-rc5 that resolve a number of reported issues. Included in here are: - iio driver fixes - fpga driver fixes - test_firmware bugfixes - fastrpc driver tiny bugfixes - MAINTAINERS file updates for some subsystems All of these have been in linux-next this past week with no reported issues" * tag 'char-misc-6.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (34 commits) test_firmware: fix the memory leak of the allocated firmware buffer test_firmware: fix a memory leak with reqs buffer test_firmware: prevent race conditions by a correct implementation of locking firmware_loader: Fix a NULL vs IS_ERR() check MAINTAINERS: Vaibhav Gupta is the new ipack maintainer dt-bindings: fpga: replace Ivan Bornyakov maintainership MAINTAINERS: update Microchip MPF FPGA reviewers misc: fastrpc: reject new invocations during device removal misc: fastrpc: return -EPIPE to invocations on device removal misc: fastrpc: Reassign memory ownership only for remote heap misc: fastrpc: Pass proper scm arguments for secure map request iio: imu: inv_icm42600: fix timestamp reset iio: adc: ad_sigma_delta: Fix IRQ issue by setting IRQ_DISABLE_UNLAZY flag dt-bindings: iio: adc: renesas,rcar-gyroadc: Fix adi,ad7476 compatible value iio: dac: mcp4725: Fix i2c_master_send() return value handling iio: accel: kx022a fix irq getting iio: bu27034: Ensure reset is written iio: dac: build ad5758 driver when AD5758 is selected iio: addac: ad74413: fix resistance input processing iio: light: vcnl4035: fixed chip ID check ...
2023-06-04Merge tag 'usb-6.4-rc5' of ↵Linus Torvalds2-0/+11
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB fixes from Greg KH: "Here are some USB driver and core fixes for 6.4-rc5. Most of these are tiny driver fixes, including: - udc driver bugfix - f_fs gadget driver bugfix - cdns3 driver bugfix - typec bugfixes But the "big" thing in here is a fix yet-again for how the USB buffers are handled from userspace when dealing with DMA issues. The changes were discussed a lot, and tested a lot, on the list, and acked by the relevant mm maintainers and have been in linux-next all this past week with no reported problems" * tag 'usb-6.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: usb: typec: tps6598x: Fix broken polling mode after system suspend/resume mm: page_table_check: Ensure user pages are not slab pages mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM usb: usbfs: Use consistent mmap functions usb: usbfs: Enforce page requirements for mmap dt-bindings: usb: snps,dwc3: Fix "snps,hsphy_interface" type usb: gadget: udc: fix NULL dereference in remove() usb: gadget: f_fs: Add unbind event before functionfs_unbind usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM
2023-06-02Merge tag 'nfsd-6.4-2' of ↵Linus Torvalds1-4/+3
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Two minor bug fixes * tag 'nfsd-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: fix double fget() bug in __write_ports_addfd() nfsd: make a copy of struct iattr before calling notify_change
2023-06-01Merge tag 'efi-fixes-for-v6.4-1' of ↵Linus Torvalds3-12/+21
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: "A few minor fixes for EFI, one of which fixes the reported boot regression when booting x86 kernels using the BIOS based loader built into the hypervisor framework on macOS. - fix harmless warning in zboot code on 'make clean' - add some missing prototypes - fix boot regressions triggered by PE/COFF header image minor version bump" * tag 'efi-fixes-for-v6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: Bump stub image version for macOS HVF compatibility efi: fix missing prototype warnings efi/libstub: zboot: Avoid eager evaluation of objcopy flags
2023-06-01Merge tag 'net-6.4-rc5' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Happy Wear a Dress Day. Fairly standard-sized batch of fixes, accounting for the lack of sub-tree submissions this week. The mlx5 IRQ fixes are notable, people were complaining about that. No fires burning. Current release - regressions: - eth: mlx5e: - multiple fixes for dynamic IRQ allocation - prevent encap offload when neigh update is running - eth: mana: fix perf regression: remove rx_cqes, tx_cqes counters Current release - new code bugs: - eth: mlx5e: DR, add missing mutex init/destroy in pattern manager Previous releases - always broken: - tcp: deny tcp_disconnect() when threads are waiting - sched: prevent ingress Qdiscs from getting installed in random locations in the hierarchy and moving around - sched: flower: fix possible OOB write in fl_set_geneve_opt() - netlink: fix NETLINK_LIST_MEMBERSHIPS length report - udp6: fix race condition in udp6_sendmsg & connect - tcp: fix mishandling when the sack compression is deferred - rtnetlink: validate link attributes set at creation time - mptcp: fix connect timeout handling - eth: stmmac: fix call trace when stmmac_xdp_xmit() is invoked - eth: amd-xgbe: fix the false linkup in xgbe_phy_status - eth: mlx5e: - fix corner cases in internal buffer configuration - drain health before unregistering devlink - usb: qmi_wwan: set DTR quirk for BroadMobi BM818 Misc: - tcp: return user_mss for TCP_MAXSEG in CLOSE/LISTEN state if user_mss set" * tag 'net-6.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (71 commits) mptcp: fix active subflow finalization mptcp: add annotations around sk->sk_shutdown accesses mptcp: fix data race around msk->first access mptcp: consolidate passive msk socket initialization mptcp: add annotations around msk->subflow accesses mptcp: fix connect timeout handling rtnetlink: add the missing IFLA_GRO_ tb check in validate_linkmsg rtnetlink: move IFLA_GSO_ tb check to validate_linkmsg rtnetlink: call validate_linkmsg in rtnl_create_link ice: recycle/free all of the fragments from multi-buffer frame net: phy: mxl-gpy: extend interrupt fix to all impacted variants net: renesas: rswitch: Fix return value in error path of xmit net: dsa: mv88e6xxx: Increase wait after reset deactivation net: ipa: Use correct value for IPA_STATUS_SIZE tcp: fix mishandling when the sack compression is deferred. net/sched: flower: fix possible OOB write in fl_set_geneve_opt() sfc: fix error unwinds in TC offload net/mlx5: Read embedded cpu after init bit cleared net/mlx5e: Fix error handling in mlx5e_refresh_tirs net/mlx5: Ensure af_desc.mask is properly initialized ...
2023-06-01fork, vhost: Use CLONE_THREAD to fix freezer/ps regressionMike Christie2-13/+3
When switching from kthreads to vhost_tasks two bugs were added: 1. The vhost worker tasks's now show up as processes so scripts doing ps or ps a would not incorrectly detect the vhost task as another process. 2. kthreads disabled freeze by setting PF_NOFREEZE, but vhost tasks's didn't disable or add support for them. To fix both bugs, this switches the vhost task to be thread in the process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that SIGKILL/STOP support is required because CLONE_THREAD requires CLONE_SIGHAND which requires those 2 signals to be supported. This is a modified version of the patch written by Mike Christie <michael.christie@oracle.com> which was a modified version of patch originally written by Linus. Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER. Including ignoring signals, setting up the register state, and having get_signal return instead of calling do_group_exit. Tidied up the vhost_task abstraction so that the definition of vhost_task only needs to be visible inside of vhost_task.c. Making it easier to review the code and tell what needs to be done where. As part of this the main loop has been moved from vhost_worker into vhost_task_fn. vhost_worker now returns true if work was done. The main loop has been updated to call get_signal which handles SIGSTOP, freezing, and collects the message that tells the thread to exit as part of process exit. This collection clears __fatal_signal_pending. This collection is not guaranteed to clear signal_pending() so clear that explicitly so the schedule() sleeps. For now the vhost thread continues to exist and run work until the last file descriptor is closed and the release function is called as part of freeing struct file. To avoid hangs in the coredump rendezvous and when killing threads in a multi-threaded exec. The coredump code and de_thread have been modified to ignore vhost threads. Remvoing the special case for exec appears to require teaching vhost_dev_flush how to directly complete transactions in case the vhost thread is no longer running. Removing the special case for coredump rendezvous requires either the above fix needed for exec or moving the coredump rendezvous into get_signal. Fixes: 6e890c5d5021 ("vhost: use vhost_tasks for worker threads") Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Co-developed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-01Merge tag 'firewire-fixes-6.4-rc4' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394 Pull firewire fix from Takashi Sakamoto: "A single patch to use a flexible array rather than a zero-length one" * tag 'firewire-fixes-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: firewire: Replace zero-length array with flexible-array member
2023-06-01firewire: Replace zero-length array with flexible-array memberGustavo A. R. Silva1-1/+1
Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: sound/firewire/amdtp-stream.c: In function ‘build_it_pkt_header’: sound/firewire/amdtp-stream.c:694:17: warning: ‘generate_cip_header’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] 694 | generate_cip_header(s, cip_header, data_block_counter, syt); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/firewire/amdtp-stream.c:694:17: note: referencing argument 2 of type ‘__be32[2]’ {aka ‘unsigned int[2]’} sound/firewire/amdtp-stream.c:667:13: note: in a call to function ‘generate_cip_header’ 667 | static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2], | ^~~~~~~~~~~~~~~~~~~ This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: https://github.com/KSPP/linux/issues/21 Link: https://github.com/KSPP/linux/issues/303 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/ZHT0V3SpvHyxCv5W@work Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2023-05-31nfsd: fix double fget() bug in __write_ports_addfd()Dan Carpenter1-4/+3
The bug here is that you cannot rely on getting the same socket from multiple calls to fget() because userspace can influence that. This is a kind of double fetch bug. The fix is to delete the svc_alien_sock() function and instead do the checking inside the svc_addsock() function. Fixes: 3064639423c4 ("nfsd: check passed socket's net matches NFSd superblock's one") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: NeilBrown <neilb@suse.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-05-30platform/surface: aggregator: Make to_ssam_device_driver() respect constnessMaximilian Luz1-5/+1
Make to_ssam_device_driver() a bit safer by replacing container_of() with container_of_const() to respect the constness of the passed in pointer, instead of silently discarding any const specifications. This change also makes it more similar to to_ssam_device(), which already uses container_of_const(). Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> Link: https://lore.kernel.org/r/20230525205041.2774947-1-luzmaximilian@gmail.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-05-29mm: page_table_check: Ensure user pages are not slab pagesRuihan Li1-0/+6
The current uses of PageAnon in page table check functions can lead to type confusion bugs between struct page and slab [1], if slab pages are accidentally mapped into the user space. This is because slab reuses the bits in struct page to store its internal states, which renders PageAnon ineffective on slab pages. Since slab pages are not expected to be mapped into the user space, this patch adds BUG_ON(PageSlab(page)) checks to make sure that slab pages are not inadvertently mapped. Otherwise, there must be some bugs in the kernel. Reported-by: syzbot+fcf1a817ceb50935ce99@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/000000000000258e5e05fae79fc1@google.com/ [1] Fixes: df4e817b7108 ("mm: page table check") Cc: <stable@vger.kernel.org> # 5.17 Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn> Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/r/20230515130958.32471-5-lrh2000@pku.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-29usb: usbfs: Enforce page requirements for mmapRuihan Li1-0/+5
The current implementation of usbdev_mmap uses usb_alloc_coherent to allocate memory pages that will later be mapped into the user space. Meanwhile, usb_alloc_coherent employs three different methods to allocate memory, as outlined below: * If hcd->localmem_pool is non-null, it uses gen_pool_dma_alloc to allocate memory; * If DMA is not available, it uses kmalloc to allocate memory; * Otherwise, it uses dma_alloc_coherent. However, it should be noted that gen_pool_dma_alloc does not guarantee that the resulting memory will be page-aligned. Furthermore, trying to map slab pages (i.e., memory allocated by kmalloc) into the user space is not resonable and can lead to problems, such as a type confusion bug when PAGE_TABLE_CHECK=y [1]. To address these issues, this patch introduces hcd_alloc_coherent_pages, which addresses the above two problems. Specifically, hcd_alloc_coherent_pages uses gen_pool_dma_alloc_align instead of gen_pool_dma_alloc to ensure that the memory is page-aligned. To replace kmalloc, hcd_alloc_coherent_pages directly allocates pages by calling __get_free_pages. Reported-by: syzbot+fcf1a817ceb50935ce99@syzkaller.appspotmail.comm Closes: https://lore.kernel.org/lkml/000000000000258e5e05fae79fc1@google.com/ [1] Fixes: f7d34b445abc ("USB: Add support for usbfs zerocopy.") Fixes: ff2437befd8f ("usb: host: Fix excessive alignment restriction for local memory allocations") Cc: stable@vger.kernel.org Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20230515130958.32471-2-lrh2000@pku.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-29Merge tag 'trace-v6.4-rc3' of ↵Linus Torvalds2-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: "User events: - Use long instead of int for storing the enable set/clear bit, as it was found that big endian machines could end up using the wrong bits. - Split allocating mm and attaching it. This keeps the allocation separate from the registration and avoids various races. - Remove RCU locking around pin_user_pages_remote() as that can schedule. The RCU protection is no longer needed with the above split of mm allocation and attaching. - Rename the "link" fields of the various structs to something more meaningful. - Add comments around user_event_mm struct usage and locking requirements. Timerlat tracer: - Fix missed wakeup of timerlat thread caused by the timerlat interrupt triggering when tracing is off. The timer interrupt handler needs to always wake up the timerlat thread regardless if tracing is enabled or not, otherwise, it will never wake up. Histograms: - Fix regression of breaking the "stacktrace" modifier for variables. That modifier cannot be used for values, but can be used for variables that are passed from one histogram to the next. This was broken when adding the restriction to values as the variable logic used the same code. - Rename the special field "stacktrace" to "common_stacktrace". Special fields (that are not actually part of the event, but can act just like event fields, like 'comm' and 'timestamp') should be prefixed with 'common_' for consistency. To keep backward compatibility, 'stacktrace' can still be used (as with the special field 'cpu'), but can be overridden if the event has a field called 'stacktrace'. - Update the synthetic event selftests to use the new name (synthetic events are created by histograms) Tracing bootup selftests: - Reorganize the code to keep artifacts of the selftests not compiled in when selftests are not configured. - Add various cond_resched() around the selftest code, as the softlock watchdog was triggering much more often. It appears that the kernel runs slower now with full debugging enabled. - While debugging ftrace with ftrace (using an instance ring buffer instead of the top level one), I found that the selftests were disabling prints to the debug instance. This should not happen, as the selftests only disable printing to the main buffer as the selftests examine the main buffer to see if it has what it expects, and prints can make the tests fail. Make the selftests only disable printing to the toplevel buffer, and leave the instance buffers alone" * tag 'trace-v6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Have function_graph selftest call cond_resched() tracing: Only make selftest conditionals affect the global_trace tracing: Make tracing_selftest_running/delete nops when not used tracing: Have tracer selftests call cond_resched() before running tracing: Move setting of tracing_selftest_running out of register_tracer() tracing/selftests: Update synthetic event selftest to use common_stacktrace tracing: Rename stacktrace field to common_stacktrace tracing/histograms: Allow variables to have some modifiers tracing/user_events: Document user_event_mm one-shot list usage tracing/user_events: Rename link fields for clarity tracing/user_events: Remove RCU lock while pinning pages tracing/user_events: Split up mm alloc and attach tracing/timerlat: Always wakeup the timerlat thread tracing/user_events: Use long vs int for atomic bit ops
2023-05-29Revert "module: error out early on concurrent load of the same module file"Linus Torvalds1-6/+0
This reverts commit 9828ed3f695a138f7add89fa2a186ababceb8006. Sadly, it does seem to cause failures to load modules. Johan Hovold reports: "This change breaks module loading during boot on the Lenovo Thinkpad X13s (aarch64). Specifically it results in indefinite probe deferral of the display and USB (ethernet) which makes it a pain to debug. Typing in the dark to acquire some logs reveals that other modules are missing as well" Since this was applied late as a "let's try this", I'm reverting it asap, and we can try to figure out what goes wrong later. The excessive parallel module loading problem is annoying, but not noticeable in normal situations, and this was only meant as an optimistic workaround for a user-space bug. One possible solution may be to do the optimistic exclusive open first, and then use a lock to serialize loading if that fails. Reported-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/lkml/ZHRpH-JXAxA6DnzR@hovoldconsulting.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-28Merge tag 'iio-fixes-for-6.4a' of ↵Greg Kroah-Hartman1-1/+1
https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-linus Jonathan writes: 1st set of IIO fixes for the 6.4 cycle. Usual mixed bag of issues in new code for this cycle and old issues that have surfaced in the last few weeks. - adi,ad_sigma_delta * Ensure irq lazy disable handing is not used as it breaks completion detection. - adi,ad4130 * Fix failure to remove clock provider. - adi,ad5758 * Wrong CONFIG variable used to control driver build. - adi,ad7192 * Fix repeated channel index by just expressing shorted channels as differential channel between a channel and itself. - adi,ad74413 * Fix error handling for resistance input processing to not fail in case of success. - rohm,bu27034 * Fix integration time in wrong units (should be seconds not usecs) * Ensure reset is actually written not detected as already set from regcache. - gts helper * Fix wrong parameter docs. * Fix integration time in wrong units (should be seconds not usecs) - fsl,imx8qxp-adc * Add missing vref-supply to binding doc (already used by driver) - fsl,imx93 * Fix sign bug in read_raw() so that error check didn't work. - inv,icm42600 * Fix reset of timestamp to work even if a particular sensor is off when the chip is first enabled. - kionix,kx022a * Fix irq get form fw node to not include the 0 value. - microchip,mcp4725 * Fix return value from i2c_master_send() handling to nto assume 0 on success. - mediatek,mt6370 * Fix incorrect scaling of a few currents on devices with particular vendor IDs. - fsl,mxs-lradc * Cleanup ordering issue fix. - renesas,rcar-adc bindings * Fix missing vendor prefix for adi,ad7476 - st,st_accel * Fix handling when no ACPI _ONT method present. - st,stm32-adc * Handle no adc-diff-channel present case (all single ended) * Handle no adc-channels present case (all differential) - ti,palmas * Fix off by one bug that could allow out of bounds read if callers provided wrong value. - ti,tmag5273 * Fix a runtime PM leak on measurement error - vishay,vcnl4035 * Correctly mask chip ID so devices with different addresses don't fail the test. * tag 'iio-fixes-for-6.4a' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (23 commits) iio: imu: inv_icm42600: fix timestamp reset iio: adc: ad_sigma_delta: Fix IRQ issue by setting IRQ_DISABLE_UNLAZY flag dt-bindings: iio: adc: renesas,rcar-gyroadc: Fix adi,ad7476 compatible value iio: dac: mcp4725: Fix i2c_master_send() return value handling iio: accel: kx022a fix irq getting iio: bu27034: Ensure reset is written iio: dac: build ad5758 driver when AD5758 is selected iio: addac: ad74413: fix resistance input processing iio: light: vcnl4035: fixed chip ID check dt-bindings: iio: imx8qxp-adc: add missing vref-supply iio: adc: stm32-adc: skip adc-channels setup if none is present iio: adc: stm32-adc: skip adc-diff-channels setup if none is present iio: adc: ad7192: Change "shorted" channels to differential iio: accel: st_accel: Fix invalid mount_matrix on devices without ACPI _ONT method iio: gts-helpers: fix integration time units iio: bu27034: Fix integration time iio: fix doc for iio_gts_find_sel_by_int_time iio: adc: palmas: fix off by one bugs iio: adc: mxs-lradc: fix the order of two cleanup operations iio: ad4130: Make sure clock provider gets removed ...
2023-05-28efi: Bump stub image version for macOS HVF compatibilityAkihiro Suda1-12/+13
The macOS hypervisor framework includes a host-side VMM called VZLinuxBootLoader [1] which implements native support for booting the Linux kernel inside a guest directly (instead of, e.g., via GRUB installed inside the guest). On x86, it incorporates a BIOS style loader that does not implement or expose EFI to the loaded kernel. However, this loader appears to fail when the 'image minor version' field in the kernel image's PE/COFF header (which is generally only used by EFI based bootloaders) is set to any value other than 0x0. [2] Commit e346bebbd36b1576 ("efi: libstub: Always enable initrd command line loader and bump version") incremented the EFI stub image minor version to convey that all EFI stub kernels now implement support for the initrd= command line option, and do so in a way where it can load initrd images from any filesystem known to the EFI firmware (as opposed to prior implementations that could only load initrds from the same volume that the kernel image was loaded from). Unfortunately, bumping the version to v1.1 triggers this issue in VZLinuxBootLoader, breaking the boot on x86. So let's keep the image minor version at 0x0, and bump the image major version instead. While at it, convert this field to a bit field, so that individual features are discoverable from it, as suggested by Linus. So let's bump the major version to v3, and document the initrd= command line loading feature as being represented by bit 1 in the mask. Note that, due to the prior interpretation as a monotonically increasing version field, loaders are still permitted to assume that the LoadFile2 initrd loading feature is supported for any major version value >= 1, even if bit 0 is not set. [1] https://developer.apple.com/documentation/virtualization/vzlinuxbootloader [2] https://lore.kernel.org/linux-efi/CAG8fp8Teu4G9JuenQrqGndFt2Gy+V4YgJ=hN1xX7AD940YKf3A@mail.gmail.com/ Fixes: e346bebbd36b1576 ("efi: libstub: Always enable initrd command ...") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217485 Signed-off-by: Akihiro Suda <suda.kyoto@gmail.com> [ardb: rewrite comment and commit log] Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-28Merge tag 'core-debugobjects-2023-05-28' of ↵Linus Torvalds2-0/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull debugobjects fixes from Thomas Gleixner: "Two fixes for debugobjects: - Prevent the allocation path from waking up kswapd. That's a long standing issue due to the GFP_ATOMIC allocation flag. As debug objects can be invoked from pretty much any context waking kswapd can end up in arbitrary lock chains versus the waitqueue lock - Correct the explicit lockdep wait-type violation in debug_object_fill_pool()" * tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: debugobjects: Don't wake up kswapd from fill_pool() debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
2023-05-27Merge tag 'for-linus-6.4-rc4-tag' of ↵Linus Torvalds1-1/+8
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: - a double free fix in the Xen pvcalls backend driver - a fix for a regression causing the MSI related sysfs entries to not being created in Xen PV guests - a fix in the Xen blkfront driver for handling insane input data better * tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/pci/xen: populate MSI sysfs entries xen/pvcalls-back: fix double frees with pvcalls_new_active_socket() xen/blkfront: Only check REQ_FUA for writes
2023-05-26EDAC/qcom: Get rid of hardcoded register offsetsManivannan Sadhasivam1-6/+0
The LLCC EDAC register offsets varies between each SoC. Hardcoding the register offsets won't work and will often result in crash due to accessing the wrong locations. Hence, get the register offsets from the LLCC driver matching the individual SoCs. Cc: <stable@vger.kernel.org> # 6.0: 5365cea199c7 ("soc: qcom: llcc: Rename reg_offset structs to reflect LLCC version") Cc: <stable@vger.kernel.org> # 6.0: c13d7d261e36 ("soc: qcom: llcc: Pass LLCC version based register offsets to EDAC driver") Cc: <stable@vger.kernel.org> # 6.0 Fixes: a6e9d7ef252c ("soc: qcom: llcc: Add configuration data for SM8450 SoC") Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Signed-off-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20230517114635.76358-3-manivannan.sadhasivam@linaro.org
2023-05-26Merge tag 'arm-fixes-6.4-1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Arnd Bergmann: "There have not been a lot of fixes for for the soc tree in 6.4, but these have been sitting here for too long. For the devicetree side, there is one minor warning fix for vexpress, the rest all all for the the NXP i.MX platforms: SoC specific bugfixes for the iMX8 clocks and its USB-3.0 gadget device, as well as board specific fixes for regulators and the phy on some of the i.MX boards. The microchip risc-v and arm32 maintainers now also add a shared maintainer file entry for the arm64 parts. The remaining fixes are all for firmware drivers, addressing mistakes in the optee, scmi and ff-a firmware driver implementation, mostly in the error handling code, incorrect use of the alloc_workqueue() interface in SCMI, and compatibility with corner cases of the firmware implementation" * tag 'arm-fixes-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: MAINTAINERS: update arm64 Microchip entries arm64: dts: imx8: fix USB 3.0 Gadget Failure in QM & QXPB0 at super speed dt-binding: cdns,usb3: Fix cdns,on-chip-buff-size type arm64: dts: colibri-imx8x: delete adc1 and dsp arm64: dts: colibri-imx8x: fix iris pinctrl configuration arm64: dts: colibri-imx8x: move pinctrl property from SoM to eval board arm64: dts: colibri-imx8x: fix eval board pin configuration arm64: dts: imx8mp: Fix video clock parents ARM: dts: imx6qdl-mba6: Add missing pvcie-supply regulator ARM: dts: imx6ull-dhcor: Set and limit the mode for PMIC buck 1, 2 and 3 arm64: dts: imx8mn-var-som: fix PHY detection bug by adding deassert delay arm64: dts: imx8mn: Fix video clock parents firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors firmware: arm_ffa: Fix FFA device names for logical partitions firmware: arm_ffa: Fix usage of partition info get count flag firmware: arm_ffa: Check if ffa_driver remove is present before executing arm64: dts: arm: add missing cache properties ARM: dts: vexpress: add missing cache properties firmware: arm_scmi: Fix incorrect alloc_workqueue() invocation optee: fix uninited async notif value
2023-05-26Merge tag 'ffa-fixes-6.4' of ↵Arnd Bergmann1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/fixes Arm FF-A fixes for v6.4 Quite a few fixes to address set of assorted issues: 1. NULL pointer dereference if the ffa driver doesn't provide remove() callback as it is currently executed unconditionally 2. FF-A core probe failure on systems with v1.0 firmware as the new partition info get count flag is used unconditionally 3. Failure to register more than one logical partition or service within the same physical partition as the device name contains only VM ID which will be same for all but each will have unique UUID. 4. Rejection of certain memory interface transmissions by the receivers (secure partitions) as few MBZ fields are non-zero due to lack of explicit re-initialization of those fields * tag 'ffa-fixes-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors firmware: arm_ffa: Fix FFA device names for logical partitions firmware: arm_ffa: Fix usage of partition info get count flag firmware: arm_ffa: Check if ffa_driver remove is present before executing Link: https://lore.kernel.org/r/20230509143453.1188753-1-sudeep.holla@arm.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-05-25Merge tag 'mlx5-fixes-2023-05-24' of ↵Jakub Kicinski1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux Saeed Mahameed says: ==================== mlx5 fixes 2023-05-24 This series includes bug fixes for the mlx5 driver. * tag 'mlx5-fixes-2023-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux: Documentation: net/mlx5: Wrap notes in admonition blocks Documentation: net/mlx5: Add blank line separator before numbered lists Documentation: net/mlx5: Use bullet and definition lists for vnic counters description Documentation: net/mlx5: Wrap vnic reporter devlink commands in code blocks net/mlx5: Fix check for allocation failure in comp_irqs_request_pci() net/mlx5: DR, Add missing mutex init/destroy in pattern manager net/mlx5e: Move Ethernet driver debugfs to profile init callback net/mlx5e: Don't attach netdev profile while handling internal error net/mlx5: Fix post parse infra to only parse every action once net/mlx5e: Use query_special_contexts cmd only once per mdev net/mlx5: fw_tracer, Fix event handling net/mlx5: SF, Drain health before removing device net/mlx5: Drain health before unregistering devlink net/mlx5e: Do not update SBCM when prio2buffer command is invalid net/mlx5e: Consider internal buffers size in port buffer calculations net/mlx5e: Prevent encap offload when neigh update is running net/mlx5e: Extract remaining tunnel encap code to dedicated file ==================== Link: https://lore.kernel.org/r/20230525034847.99268-1-saeed@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-25module: error out early on concurrent load of the same module fileLinus Torvalds1-0/+6
It turns out that udev under certain circumstances will concurrently try to load the same modules over-and-over excessively. This isn't a kernel bug, but it ends up affecting the kernel, to the point that under certain circumstances we can fail to boot, because the kernel uses a lot of memory to read all the module data all at once. Note that it isn't a memory leak, it's just basically a thundering herd problem happening at bootup with a lot of CPUs, with the worst cases then being pretty bad. Admittedly the worst situations are somewhat contrived: lots and lots of CPUs, not a lot of memory, and KASAN enabled to make it all slower and as such (unintentionally) exacerbate the problem. Luis explains: [1] "My best assessment of the situation is that each CPU in udev ends up triggering a load of duplicate set of modules, not just one, but *a lot*. Not sure what heuristics udev uses to load a set of modules per CPU." Petr Pavlu chimes in: [2] "My understanding is that udev workers are forked. An initial kmod context is created by the main udevd process but no sharing happens after the fork. It means that the mentioned memory pool logic doesn't really kick in. Multiple parallel load requests come from multiple udev workers, for instance, each handling an udev event for one CPU device and making the exactly same requests as all others are doing at the same time. The optimization idea would be to recognize these duplicate requests at the udevd/kmod level and converge them" Note that module loading has tried to mitigate this issue before, see for example commit 064f4536d139 ("module: avoid allocation if module is already present and ready"), which has a few ASCII graphs on memory use due to this same issue. However, while that noticed that the module was already loaded, and exited with an error early before spending any more time on setting up the module, it didn't handle the case of multiple concurrent module loads all being active - but not complete - at the same time. Yes, one of them will eventually win the race and finalize its copy, and the others will then notice that the module already exists and error out, but while this all happens, we have tons of unnecessary concurrent work being done. Again, the real fix is for udev to not do that (maybe it should use threads instead of fork, and have actual shared data structures and not cause duplicate work). That real fix is apparently not trivial. But it turns out that the kernel already has a pretty good model for dealing with concurrent access to the same file: the i_writecount of the inode. In fact, the module loading already indirectly uses 'i_writecount' , because 'kernel_file_read()' will in fact do ret = deny_write_access(file); if (ret) return ret; ... allow_write_access(file); around the read of the file data. We do not allow concurrent writes to the file, and return -ETXTBUSY if the file was open for writing at the same time as the module data is loaded from it. And the solution to the reader concurrency problem is to simply extend this "no concurrent writers" logic to simply be "exclusive access". Note that "exclusive" in this context isn't really some absolute thing: it's only exclusion from writers and from other "special readers" that do this writer denial. So we simply introduce a variation of that "deny_write_access()" logic that not only denies write access, but also requires that this is the _only_ such access that denies write access. Which means that you can't start loading a module that is already being loaded as a module by somebody else, or you will get the same -ETXTBSY error that you would get if there were writers around. [ It also means that you can't try to load a currently executing executable as a module, for the same reason: executables do that same "deny_write_access()" thing, and that's obviously where the whole ETXTBSY logic