169e77764a
Core ---- - Introduce XDP multi-buffer support, allowing the use of XDP with jumbo frame MTUs and combination with Rx coalescing offloads (LRO). - Speed up netns dismantling (5x) and lower the memory cost a little. Remove unnecessary per-netns sockets. Scope some lists to a netns. Cut down RCU syncing. Use batch methods. Allow netdev registration to complete out of order. - Support distinguishing timestamp types (ingress vs egress) and maintaining them across packet scrubbing points (e.g. redirect). - Continue the work of annotating packet drop reasons throughout the stack. - Switch netdev error counters from an atomic to dynamically allocated per-CPU counters. - Rework a few preempt_disable(), local_irq_save() and busy waiting sections problematic on PREEMPT_RT. - Extend the ref_tracker to allow catching use-after-free bugs. BPF --- - Introduce "packing allocator" for BPF JIT images. JITed code is marked read only, and used to be allocated at page granularity. Custom allocator allows for more efficient memory use, lower iTLB pressure and prevents identity mapping huge pages from getting split. - Make use of BTF type annotations (e.g. __user, __percpu) to enforce the correct probe read access method, add appropriate helpers. - Convert the BPF preload to use light skeleton and drop the user-mode-driver dependency. - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling its use as a packet generator. - Allow local storage memory to be allocated with GFP_KERNEL if called from a hook allowed to sleep. - Introduce fprobe (multi kprobe) to speed up mass attachment (arch bits to come later). - Add unstable conntrack lookup helpers for BPF by using the BPF kfunc infra. - Allow cgroup BPF progs to return custom errors to user space. - Add support for AF_UNIX iterator batching. - Allow iterator programs to use sleepable helpers. - Support JIT of add, and, or, xor and xchg atomic ops on arm64. - Add BTFGen support to bpftool which allows to use CO-RE in kernels without BTF info. - Large number of libbpf API improvements, cleanups and deprecations. Protocols --------- - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev. - Adjust TSO packet sizes based on min_rtt, allowing very low latency links (data centers) to always send full-sized TSO super-frames. - Make IPv6 flow label changes (AKA hash rethink) more configurable, via sysctl and setsockopt. Distinguish between server and client behavior. - VxLAN support to "collect metadata" devices to terminate only configured VNIs. This is similar to VLAN filtering in the bridge. - Support inserting IPv6 IOAM information to a fraction of frames. - Add protocol attribute to IP addresses to allow identifying where given address comes from (kernel-generated, DHCP etc.) - Support setting socket and IPv6 options via cmsg on ping6 sockets. - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS. Define dscp_t and stop taking ECN bits into account in fib-rules. - Add support for locked bridge ports (for 802.1X). - tun: support NAPI for packets received from batched XDP buffs, doubling the performance in some scenarios. - IPv6 extension header handling in Open vSwitch. - Support IPv6 control message load balancing in bonding, prevent neighbor solicitation and advertisement from using the wrong port. Support NS/NA monitor selection similar to existing ARP monitor. - SMC - improve performance with TCP_CORK and sendfile() - support auto-corking - support TCP_NODELAY - MCTP (Management Component Transport Protocol) - add user space tag control interface - I2C binding driver (as specified by DMTF DSP0237) - Multi-BSSID beacon handling in AP mode for WiFi. - Bluetooth: - handle MSFT Monitor Device Event - add MGMT Adv Monitor Device Found/Lost events - Multi-Path TCP: - add support for the SO_SNDTIMEO socket option - lots of selftest cleanups and improvements - Increase the max PDU size in CAN ISOTP to 64 kB. Driver API ---------- - Add HW counters for SW netdevs, a mechanism for devices which offload packet forwarding to report packet statistics back to software interfaces such as tunnels. - Select the default NIC queue count as a fraction of number of physical CPU cores, instead of hard-coding to 8. - Expose devlink instance locks to drivers. Allow device layer of drivers to use that lock directly instead of creating their own which always runs into ordering issues in devlink callbacks. - Add header/data split indication to guide user space enabling of TCP zero-copy Rx. - Allow configuring completion queue event size. - Refactor page_pool to enable fragmenting after allocation. - Add allocation and page reuse statistics to page_pool. - Improve Multiple Spanning Trees support in the bridge to allow reuse of topologies across VLANs, saving HW resources in switches. - DSA (Distributed Switch Architecture): - replay and offload of host VLAN entries - offload of static and local FDB entries on LAG interfaces - FDB isolation and unicast filtering New hardware / drivers ---------------------- - Ethernet: - LAN937x T1 PHYs - Davicom DM9051 SPI NIC driver - Realtek RTL8367S, RTL8367RB-VB switch and MDIO - Microchip ksz8563 switches - Netronome NFP3800 SmartNICs - Fungible SmartNICs - MediaTek MT8195 switches - WiFi: - mt76: MediaTek mt7916 - mt76: MediaTek mt7921u USB adapters - brcmfmac: Broadcom BCM43454/6 - Mobile: - iosm: Intel M.2 7360 WWAN card Drivers ------- - Convert many drivers to the new phylink API built for split PCS designs but also simplifying other cases. - Intel Ethernet NICs: - add TTY for GNSS module for E810T device - improve AF_XDP performance - GTP-C and GTP-U filter offload - QinQ VLAN support - Mellanox Ethernet NICs (mlx5): - support xdp->data_meta - multi-buffer XDP - offload tc push_eth and pop_eth actions - Netronome Ethernet NICs (nfp): - flow-independent tc action hardware offload (police / meter) - AF_XDP - Other Ethernet NICs: - at803x: fiber and SFP support - xgmac: mdio: preamble suppression and custom MDC frequencies - r8169: enable ASPM L1.2 if system vendor flags it as safe - macb/gem: ZynqMP SGMII - hns3: add TX push mode - dpaa2-eth: software TSO - lan743x: multi-queue, mdio, SGMII, PTP - axienet: NAPI and GRO support - Mellanox Ethernet switches (mlxsw): - source and dest IP address rewrites - RJ45 ports - Marvell Ethernet switches (prestera): - basic routing offload - multi-chain TC ACL offload - NXP embedded Ethernet switches (ocelot & felix): - PTP over UDP with the ocelot-8021q DSA tagging protocol - basic QoS classification on Felix DSA switch using dcbnl - port mirroring for ocelot switches - Microchip high-speed industrial Ethernet (sparx5): - offloading of bridge port flooding flags - PTP Hardware Clock - Other embedded switches: - lan966x: PTP Hardward Clock - qca8k: mdio read/write operations via crafted Ethernet packets - Qualcomm 802.11ax WiFi (ath11k): - add LDPC FEC type and 802.11ax High Efficiency data in radiotap - enable RX PPDU stats in monitor co-exist mode - Intel WiFi (iwlwifi): - UHB TAS enablement via BIOS - band disablement via BIOS - channel switch offload - 32 Rx AMPDU sessions in newer devices - MediaTek WiFi (mt76): - background radar detection - thermal management improvements on mt7915 - SAR support for more mt76 platforms - MBSSID and 6 GHz band on mt7915 - RealTek WiFi: - rtw89: AP mode - rtw89: 160 MHz channels and 6 GHz band - rtw89: hardware scan - Bluetooth: - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS) - Microchip CAN (mcp251xfd): - multiple RX-FIFOs and runtime configurable RX/TX rings - internal PLL, runtime PM handling simplification - improve chip detection and error handling after wakeup Signed-off-by: Jakub Kicinski <kuba@kernel.org> -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmI7YBcACgkQMUZtbf5S IrveSBAAmSNJlUK6vPsnNzs7IhsZnfI/AUjm2TCLZnlhKttbpI4A/4Pohk33V7RS FGX7f8kjEfhUwrIiLDgeCnztNHRECrCmk6aZc/jLEvecmTauJ+f6kjShkDY/wix+ AkPHmrZnQeLPAEVuljDdV+sL6ik08+zQL7PazIYHsaSKKC0MGQptRwcri8PLRAKE KPBAhVhleq2rAZ/ntprSN52F4Af6rpFTrPIWuN8Bqdbc9dy5094LT0mpOOWYvgr3 /DLvvAPuLemwyIQkjWknVKBRUAQcmNPC+BY3J8K3LRaiNhekGqOFan46BfqP+k2J 6DWu0Qrp2yWt4BMOeEToZR5rA6v5suUAMIBu8PRZIDkINXQMlIxHfGjZyNm0rVfw 7edNri966yus9OdzwPa32MIG3oC6PnVAwYCJAjjBMNS8sSIkp7wgHLkgWN4UFe2H K/e6z8TLF4UQ+zFM0aGI5WZ+9QqWkTWEDF3R3OhdFpGrznna0gxmkOeV2YvtsgxY cbS0vV9Zj73o+bYzgBKJsw/dAjyLdXoHUGvus26VLQ78S/VGunVKtItwoxBAYmZo krW964qcC89YofzSi8RSKLHuEWtNWZbVm8YXr75u6jpr5GhMBu0CYefLs+BuZcxy dw8c69cGneVbGZmY2J3rBhDkchbuICl8vdUPatGrOJAoaFdYKuw= =ELpe -----END PGP SIGNATURE----- Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "The sprinkling of SPI drivers is because we added a new one and Mark sent us a SPI driver interface conversion pull request. Core ---- - Introduce XDP multi-buffer support, allowing the use of XDP with jumbo frame MTUs and combination with Rx coalescing offloads (LRO). - Speed up netns dismantling (5x) and lower the memory cost a little. Remove unnecessary per-netns sockets. Scope some lists to a netns. Cut down RCU syncing. Use batch methods. Allow netdev registration to complete out of order. - Support distinguishing timestamp types (ingress vs egress) and maintaining them across packet scrubbing points (e.g. redirect). - Continue the work of annotating packet drop reasons throughout the stack. - Switch netdev error counters from an atomic to dynamically allocated per-CPU counters. - Rework a few preempt_disable(), local_irq_save() and busy waiting sections problematic on PREEMPT_RT. - Extend the ref_tracker to allow catching use-after-free bugs. BPF --- - Introduce "packing allocator" for BPF JIT images. JITed code is marked read only, and used to be allocated at page granularity. Custom allocator allows for more efficient memory use, lower iTLB pressure and prevents identity mapping huge pages from getting split. - Make use of BTF type annotations (e.g. __user, __percpu) to enforce the correct probe read access method, add appropriate helpers. - Convert the BPF preload to use light skeleton and drop the user-mode-driver dependency. - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling its use as a packet generator. - Allow local storage memory to be allocated with GFP_KERNEL if called from a hook allowed to sleep. - Introduce fprobe (multi kprobe) to speed up mass attachment (arch bits to come later). - Add unstable conntrack lookup helpers for BPF by using the BPF kfunc infra. - Allow cgroup BPF progs to return custom errors to user space. - Add support for AF_UNIX iterator batching. - Allow iterator programs to use sleepable helpers. - Support JIT of add, and, or, xor and xchg atomic ops on arm64. - Add BTFGen support to bpftool which allows to use CO-RE in kernels without BTF info. - Large number of libbpf API improvements, cleanups and deprecations. Protocols --------- - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev. - Adjust TSO packet sizes based on min_rtt, allowing very low latency links (data centers) to always send full-sized TSO super-frames. - Make IPv6 flow label changes (AKA hash rethink) more configurable, via sysctl and setsockopt. Distinguish between server and client behavior. - VxLAN support to "collect metadata" devices to terminate only configured VNIs. This is similar to VLAN filtering in the bridge. - Support inserting IPv6 IOAM information to a fraction of frames. - Add protocol attribute to IP addresses to allow identifying where given address comes from (kernel-generated, DHCP etc.) - Support setting socket and IPv6 options via cmsg on ping6 sockets. - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS. Define dscp_t and stop taking ECN bits into account in fib-rules. - Add support for locked bridge ports (for 802.1X). - tun: support NAPI for packets received from batched XDP buffs, doubling the performance in some scenarios. - IPv6 extension header handling in Open vSwitch. - Support IPv6 control message load balancing in bonding, prevent neighbor solicitation and advertisement from using the wrong port. Support NS/NA monitor selection similar to existing ARP monitor. - SMC - improve performance with TCP_CORK and sendfile() - support auto-corking - support TCP_NODELAY - MCTP (Management Component Transport Protocol) - add user space tag control interface - I2C binding driver (as specified by DMTF DSP0237) - Multi-BSSID beacon handling in AP mode for WiFi. - Bluetooth: - handle MSFT Monitor Device Event - add MGMT Adv Monitor Device Found/Lost events - Multi-Path TCP: - add support for the SO_SNDTIMEO socket option - lots of selftest cleanups and improvements - Increase the max PDU size in CAN ISOTP to 64 kB. Driver API ---------- - Add HW counters for SW netdevs, a mechanism for devices which offload packet forwarding to report packet statistics back to software interfaces such as tunnels. - Select the default NIC queue count as a fraction of number of physical CPU cores, instead of hard-coding to 8. - Expose devlink instance locks to drivers. Allow device layer of drivers to use that lock directly instead of creating their own which always runs into ordering issues in devlink callbacks. - Add header/data split indication to guide user space enabling of TCP zero-copy Rx. - Allow configuring completion queue event size. - Refactor page_pool to enable fragmenting after allocation. - Add allocation and page reuse statistics to page_pool. - Improve Multiple Spanning Trees support in the bridge to allow reuse of topologies across VLANs, saving HW resources in switches. - DSA (Distributed Switch Architecture): - replay and offload of host VLAN entries - offload of static and local FDB entries on LAG interfaces - FDB isolation and unicast filtering New hardware / drivers ---------------------- - Ethernet: - LAN937x T1 PHYs - Davicom DM9051 SPI NIC driver - Realtek RTL8367S, RTL8367RB-VB switch and MDIO - Microchip ksz8563 switches - Netronome NFP3800 SmartNICs - Fungible SmartNICs - MediaTek MT8195 switches - WiFi: - mt76: MediaTek mt7916 - mt76: MediaTek mt7921u USB adapters - brcmfmac: Broadcom BCM43454/6 - Mobile: - iosm: Intel M.2 7360 WWAN card Drivers ------- - Convert many drivers to the new phylink API built for split PCS designs but also simplifying other cases. - Intel Ethernet NICs: - add TTY for GNSS module for E810T device - improve AF_XDP performance - GTP-C and GTP-U filter offload - QinQ VLAN support - Mellanox Ethernet NICs (mlx5): - support xdp->data_meta - multi-buffer XDP - offload tc push_eth and pop_eth actions - Netronome Ethernet NICs (nfp): - flow-independent tc action hardware offload (police / meter) - AF_XDP - Other Ethernet NICs: - at803x: fiber and SFP support - xgmac: mdio: preamble suppression and custom MDC frequencies - r8169: enable ASPM L1.2 if system vendor flags it as safe - macb/gem: ZynqMP SGMII - hns3: add TX push mode - dpaa2-eth: software TSO - lan743x: multi-queue, mdio, SGMII, PTP - axienet: NAPI and GRO support - Mellanox Ethernet switches (mlxsw): - source and dest IP address rewrites - RJ45 ports - Marvell Ethernet switches (prestera): - basic routing offload - multi-chain TC ACL offload - NXP embedded Ethernet switches (ocelot & felix): - PTP over UDP with the ocelot-8021q DSA tagging protocol - basic QoS classification on Felix DSA switch using dcbnl - port mirroring for ocelot switches - Microchip high-speed industrial Ethernet (sparx5): - offloading of bridge port flooding flags - PTP Hardware Clock - Other embedded switches: - lan966x: PTP Hardward Clock - qca8k: mdio read/write operations via crafted Ethernet packets - Qualcomm 802.11ax WiFi (ath11k): - add LDPC FEC type and 802.11ax High Efficiency data in radiotap - enable RX PPDU stats in monitor co-exist mode - Intel WiFi (iwlwifi): - UHB TAS enablement via BIOS - band disablement via BIOS - channel switch offload - 32 Rx AMPDU sessions in newer devices - MediaTek WiFi (mt76): - background radar detection - thermal management improvements on mt7915 - SAR support for more mt76 platforms - MBSSID and 6 GHz band on mt7915 - RealTek WiFi: - rtw89: AP mode - rtw89: 160 MHz channels and 6 GHz band - rtw89: hardware scan - Bluetooth: - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS) - Microchip CAN (mcp251xfd): - multiple RX-FIFOs and runtime configurable RX/TX rings - internal PLL, runtime PM handling simplification - improve chip detection and error handling after wakeup" * tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits) llc: fix netdevice reference leaks in llc_ui_bind() drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool ice: don't allow to run ice_send_event_to_aux() in atomic ctx ice: fix 'scheduling while atomic' on aux critical err interrupt net/sched: fix incorrect vlan_push_eth dest field net: bridge: mst: Restrict info size queries to bridge ports net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init() drivers: net: xgene: Fix regression in CRC stripping net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT net: dsa: fix missing host-filtered multicast addresses net/mlx5e: Fix build warning, detected write beyond size of field iwlwifi: mvm: Don't fail if PPAG isn't supported selftests/bpf: Fix kprobe_multi test. Revert "rethook: x86: Add rethook x86 implementation" Revert "arm64: rethook: Add arm64 rethook implementation" Revert "powerpc: Add rethook support" Revert "ARM: rethook: Add rethook arm implementation" netdevice: add missing dm_private kdoc net: bridge: mst: prevent NULL deref in br_mst_info_size() selftests: forwarding: Use same VRF for port and VLAN upper ...
1821 lines
45 KiB
C
1821 lines
45 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/kernel/exit.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/sched/autogroup.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/stat.h>
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#include <linux/sched/task.h>
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#include <linux/sched/task_stack.h>
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#include <linux/sched/cputime.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/capability.h>
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#include <linux/completion.h>
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#include <linux/personality.h>
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#include <linux/tty.h>
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#include <linux/iocontext.h>
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#include <linux/key.h>
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#include <linux/cpu.h>
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#include <linux/acct.h>
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#include <linux/tsacct_kern.h>
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#include <linux/file.h>
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#include <linux/fdtable.h>
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#include <linux/freezer.h>
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#include <linux/binfmts.h>
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#include <linux/nsproxy.h>
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#include <linux/pid_namespace.h>
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#include <linux/ptrace.h>
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#include <linux/profile.h>
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#include <linux/mount.h>
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#include <linux/proc_fs.h>
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#include <linux/kthread.h>
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#include <linux/mempolicy.h>
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#include <linux/taskstats_kern.h>
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#include <linux/delayacct.h>
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#include <linux/cgroup.h>
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#include <linux/syscalls.h>
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#include <linux/signal.h>
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#include <linux/posix-timers.h>
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#include <linux/cn_proc.h>
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#include <linux/mutex.h>
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#include <linux/futex.h>
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#include <linux/pipe_fs_i.h>
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#include <linux/audit.h> /* for audit_free() */
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#include <linux/resource.h>
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#include <linux/task_io_accounting_ops.h>
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#include <linux/tracehook.h>
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#include <linux/fs_struct.h>
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#include <linux/init_task.h>
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#include <linux/perf_event.h>
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#include <trace/events/sched.h>
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#include <linux/hw_breakpoint.h>
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#include <linux/oom.h>
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#include <linux/writeback.h>
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#include <linux/shm.h>
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#include <linux/kcov.h>
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#include <linux/random.h>
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#include <linux/rcuwait.h>
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#include <linux/compat.h>
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#include <linux/io_uring.h>
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#include <linux/kprobes.h>
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#include <linux/rethook.h>
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#include <linux/uaccess.h>
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#include <asm/unistd.h>
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#include <asm/mmu_context.h>
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static void __unhash_process(struct task_struct *p, bool group_dead)
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{
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nr_threads--;
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detach_pid(p, PIDTYPE_PID);
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if (group_dead) {
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detach_pid(p, PIDTYPE_TGID);
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detach_pid(p, PIDTYPE_PGID);
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detach_pid(p, PIDTYPE_SID);
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list_del_rcu(&p->tasks);
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list_del_init(&p->sibling);
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__this_cpu_dec(process_counts);
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}
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list_del_rcu(&p->thread_group);
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list_del_rcu(&p->thread_node);
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}
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/*
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* This function expects the tasklist_lock write-locked.
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*/
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static void __exit_signal(struct task_struct *tsk)
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{
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struct signal_struct *sig = tsk->signal;
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bool group_dead = thread_group_leader(tsk);
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struct sighand_struct *sighand;
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struct tty_struct *tty;
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u64 utime, stime;
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sighand = rcu_dereference_check(tsk->sighand,
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lockdep_tasklist_lock_is_held());
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spin_lock(&sighand->siglock);
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#ifdef CONFIG_POSIX_TIMERS
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posix_cpu_timers_exit(tsk);
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if (group_dead)
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posix_cpu_timers_exit_group(tsk);
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#endif
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if (group_dead) {
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tty = sig->tty;
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sig->tty = NULL;
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} else {
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/*
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* If there is any task waiting for the group exit
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* then notify it:
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*/
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if (sig->notify_count > 0 && !--sig->notify_count)
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wake_up_process(sig->group_exec_task);
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if (tsk == sig->curr_target)
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sig->curr_target = next_thread(tsk);
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}
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add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
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sizeof(unsigned long long));
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/*
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* Accumulate here the counters for all threads as they die. We could
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* skip the group leader because it is the last user of signal_struct,
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* but we want to avoid the race with thread_group_cputime() which can
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* see the empty ->thread_head list.
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*/
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task_cputime(tsk, &utime, &stime);
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write_seqlock(&sig->stats_lock);
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sig->utime += utime;
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sig->stime += stime;
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sig->gtime += task_gtime(tsk);
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sig->min_flt += tsk->min_flt;
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sig->maj_flt += tsk->maj_flt;
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sig->nvcsw += tsk->nvcsw;
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sig->nivcsw += tsk->nivcsw;
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sig->inblock += task_io_get_inblock(tsk);
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sig->oublock += task_io_get_oublock(tsk);
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task_io_accounting_add(&sig->ioac, &tsk->ioac);
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sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
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sig->nr_threads--;
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__unhash_process(tsk, group_dead);
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write_sequnlock(&sig->stats_lock);
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/*
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* Do this under ->siglock, we can race with another thread
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* doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
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*/
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flush_sigqueue(&tsk->pending);
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tsk->sighand = NULL;
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spin_unlock(&sighand->siglock);
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__cleanup_sighand(sighand);
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clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
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if (group_dead) {
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flush_sigqueue(&sig->shared_pending);
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tty_kref_put(tty);
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}
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}
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static void delayed_put_task_struct(struct rcu_head *rhp)
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{
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struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
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kprobe_flush_task(tsk);
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rethook_flush_task(tsk);
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perf_event_delayed_put(tsk);
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trace_sched_process_free(tsk);
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put_task_struct(tsk);
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}
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void put_task_struct_rcu_user(struct task_struct *task)
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{
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if (refcount_dec_and_test(&task->rcu_users))
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call_rcu(&task->rcu, delayed_put_task_struct);
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}
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|
|
void release_task(struct task_struct *p)
|
|
{
|
|
struct task_struct *leader;
|
|
struct pid *thread_pid;
|
|
int zap_leader;
|
|
repeat:
|
|
/* don't need to get the RCU readlock here - the process is dead and
|
|
* can't be modifying its own credentials. But shut RCU-lockdep up */
|
|
rcu_read_lock();
|
|
dec_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
|
|
rcu_read_unlock();
|
|
|
|
cgroup_release(p);
|
|
|
|
write_lock_irq(&tasklist_lock);
|
|
ptrace_release_task(p);
|
|
thread_pid = get_pid(p->thread_pid);
|
|
__exit_signal(p);
|
|
|
|
/*
|
|
* If we are the last non-leader member of the thread
|
|
* group, and the leader is zombie, then notify the
|
|
* group leader's parent process. (if it wants notification.)
|
|
*/
|
|
zap_leader = 0;
|
|
leader = p->group_leader;
|
|
if (leader != p && thread_group_empty(leader)
|
|
&& leader->exit_state == EXIT_ZOMBIE) {
|
|
/*
|
|
* If we were the last child thread and the leader has
|
|
* exited already, and the leader's parent ignores SIGCHLD,
|
|
* then we are the one who should release the leader.
|
|
*/
|
|
zap_leader = do_notify_parent(leader, leader->exit_signal);
|
|
if (zap_leader)
|
|
leader->exit_state = EXIT_DEAD;
|
|
}
|
|
|
|
write_unlock_irq(&tasklist_lock);
|
|
seccomp_filter_release(p);
|
|
proc_flush_pid(thread_pid);
|
|
put_pid(thread_pid);
|
|
release_thread(p);
|
|
put_task_struct_rcu_user(p);
|
|
|
|
p = leader;
|
|
if (unlikely(zap_leader))
|
|
goto repeat;
|
|
}
|
|
|
|
int rcuwait_wake_up(struct rcuwait *w)
|
|
{
|
|
int ret = 0;
|
|
struct task_struct *task;
|
|
|
|
rcu_read_lock();
|
|
|
|
/*
|
|
* Order condition vs @task, such that everything prior to the load
|
|
* of @task is visible. This is the condition as to why the user called
|
|
* rcuwait_wake() in the first place. Pairs with set_current_state()
|
|
* barrier (A) in rcuwait_wait_event().
|
|
*
|
|
* WAIT WAKE
|
|
* [S] tsk = current [S] cond = true
|
|
* MB (A) MB (B)
|
|
* [L] cond [L] tsk
|
|
*/
|
|
smp_mb(); /* (B) */
|
|
|
|
task = rcu_dereference(w->task);
|
|
if (task)
|
|
ret = wake_up_process(task);
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rcuwait_wake_up);
|
|
|
|
/*
|
|
* Determine if a process group is "orphaned", according to the POSIX
|
|
* definition in 2.2.2.52. Orphaned process groups are not to be affected
|
|
* by terminal-generated stop signals. Newly orphaned process groups are
|
|
* to receive a SIGHUP and a SIGCONT.
|
|
*
|
|
* "I ask you, have you ever known what it is to be an orphan?"
|
|
*/
|
|
static int will_become_orphaned_pgrp(struct pid *pgrp,
|
|
struct task_struct *ignored_task)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
|
|
if ((p == ignored_task) ||
|
|
(p->exit_state && thread_group_empty(p)) ||
|
|
is_global_init(p->real_parent))
|
|
continue;
|
|
|
|
if (task_pgrp(p->real_parent) != pgrp &&
|
|
task_session(p->real_parent) == task_session(p))
|
|
return 0;
|
|
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
|
|
|
|
return 1;
|
|
}
|
|
|
|
int is_current_pgrp_orphaned(void)
|
|
{
|
|
int retval;
|
|
|
|
read_lock(&tasklist_lock);
|
|
retval = will_become_orphaned_pgrp(task_pgrp(current), NULL);
|
|
read_unlock(&tasklist_lock);
|
|
|
|
return retval;
|
|
}
|
|
|
|
static bool has_stopped_jobs(struct pid *pgrp)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
|
|
if (p->signal->flags & SIGNAL_STOP_STOPPED)
|
|
return true;
|
|
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check to see if any process groups have become orphaned as
|
|
* a result of our exiting, and if they have any stopped jobs,
|
|
* send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
|
|
*/
|
|
static void
|
|
kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
|
|
{
|
|
struct pid *pgrp = task_pgrp(tsk);
|
|
struct task_struct *ignored_task = tsk;
|
|
|
|
if (!parent)
|
|
/* exit: our father is in a different pgrp than
|
|
* we are and we were the only connection outside.
|
|
*/
|
|
parent = tsk->real_parent;
|
|
else
|
|
/* reparent: our child is in a different pgrp than
|
|
* we are, and it was the only connection outside.
|
|
*/
|
|
ignored_task = NULL;
|
|
|
|
if (task_pgrp(parent) != pgrp &&
|
|
task_session(parent) == task_session(tsk) &&
|
|
will_become_orphaned_pgrp(pgrp, ignored_task) &&
|
|
has_stopped_jobs(pgrp)) {
|
|
__kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
|
|
__kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
|
|
}
|
|
}
|
|
|
|
static void coredump_task_exit(struct task_struct *tsk)
|
|
{
|
|
struct core_state *core_state;
|
|
|
|
/*
|
|
* Serialize with any possible pending coredump.
|
|
* We must hold siglock around checking core_state
|
|
* and setting PF_POSTCOREDUMP. The core-inducing thread
|
|
* will increment ->nr_threads for each thread in the
|
|
* group without PF_POSTCOREDUMP set.
|
|
*/
|
|
spin_lock_irq(&tsk->sighand->siglock);
|
|
tsk->flags |= PF_POSTCOREDUMP;
|
|
core_state = tsk->signal->core_state;
|
|
spin_unlock_irq(&tsk->sighand->siglock);
|
|
if (core_state) {
|
|
struct core_thread self;
|
|
|
|
self.task = current;
|
|
if (self.task->flags & PF_SIGNALED)
|
|
self.next = xchg(&core_state->dumper.next, &self);
|
|
else
|
|
self.task = NULL;
|
|
/*
|
|
* Implies mb(), the result of xchg() must be visible
|
|
* to core_state->dumper.
|
|
*/
|
|
if (atomic_dec_and_test(&core_state->nr_threads))
|
|
complete(&core_state->startup);
|
|
|
|
for (;;) {
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
if (!self.task) /* see coredump_finish() */
|
|
break;
|
|
freezable_schedule();
|
|
}
|
|
__set_current_state(TASK_RUNNING);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG
|
|
/*
|
|
* A task is exiting. If it owned this mm, find a new owner for the mm.
|
|
*/
|
|
void mm_update_next_owner(struct mm_struct *mm)
|
|
{
|
|
struct task_struct *c, *g, *p = current;
|
|
|
|
retry:
|
|
/*
|
|
* If the exiting or execing task is not the owner, it's
|
|
* someone else's problem.
|
|
*/
|
|
if (mm->owner != p)
|
|
return;
|
|
/*
|
|
* The current owner is exiting/execing and there are no other
|
|
* candidates. Do not leave the mm pointing to a possibly
|
|
* freed task structure.
|
|
*/
|
|
if (atomic_read(&mm->mm_users) <= 1) {
|
|
WRITE_ONCE(mm->owner, NULL);
|
|
return;
|
|
}
|
|
|
|
read_lock(&tasklist_lock);
|
|
/*
|
|
* Search in the children
|
|
*/
|
|
list_for_each_entry(c, &p->children, sibling) {
|
|
if (c->mm == mm)
|
|
goto assign_new_owner;
|
|
}
|
|
|
|
/*
|
|
* Search in the siblings
|
|
*/
|
|
list_for_each_entry(c, &p->real_parent->children, sibling) {
|
|
if (c->mm == mm)
|
|
goto assign_new_owner;
|
|
}
|
|
|
|
/*
|
|
* Search through everything else, we should not get here often.
|
|
*/
|
|
for_each_process(g) {
|
|
if (g->flags & PF_KTHREAD)
|
|
continue;
|
|
for_each_thread(g, c) {
|
|
if (c->mm == mm)
|
|
goto assign_new_owner;
|
|
if (c->mm)
|
|
break;
|
|
}
|
|
}
|
|
read_unlock(&tasklist_lock);
|
|
/*
|
|
* We found no owner yet mm_users > 1: this implies that we are
|
|
* most likely racing with swapoff (try_to_unuse()) or /proc or
|
|
* ptrace or page migration (get_task_mm()). Mark owner as NULL.
|
|
*/
|
|
WRITE_ONCE(mm->owner, NULL);
|
|
return;
|
|
|
|
assign_new_owner:
|
|
BUG_ON(c == p);
|
|
get_task_struct(c);
|
|
/*
|
|
* The task_lock protects c->mm from changing.
|
|
* We always want mm->owner->mm == mm
|
|
*/
|
|
task_lock(c);
|
|
/*
|
|
* Delay read_unlock() till we have the task_lock()
|
|
* to ensure that c does not slip away underneath us
|
|
*/
|
|
read_unlock(&tasklist_lock);
|
|
if (c->mm != mm) {
|
|
task_unlock(c);
|
|
put_task_struct(c);
|
|
goto retry;
|
|
}
|
|
WRITE_ONCE(mm->owner, c);
|
|
task_unlock(c);
|
|
put_task_struct(c);
|
|
}
|
|
#endif /* CONFIG_MEMCG */
|
|
|
|
/*
|
|
* Turn us into a lazy TLB process if we
|
|
* aren't already..
|
|
*/
|
|
static void exit_mm(void)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
exit_mm_release(current, mm);
|
|
if (!mm)
|
|
return;
|
|
sync_mm_rss(mm);
|
|
mmap_read_lock(mm);
|
|
mmgrab(mm);
|
|
BUG_ON(mm != current->active_mm);
|
|
/* more a memory barrier than a real lock */
|
|
task_lock(current);
|
|
/*
|
|
* When a thread stops operating on an address space, the loop
|
|
* in membarrier_private_expedited() may not observe that
|
|
* tsk->mm, and the loop in membarrier_global_expedited() may
|
|
* not observe a MEMBARRIER_STATE_GLOBAL_EXPEDITED
|
|
* rq->membarrier_state, so those would not issue an IPI.
|
|
* Membarrier requires a memory barrier after accessing
|
|
* user-space memory, before clearing tsk->mm or the
|
|
* rq->membarrier_state.
|
|
*/
|
|
smp_mb__after_spinlock();
|
|
local_irq_disable();
|
|
current->mm = NULL;
|
|
membarrier_update_current_mm(NULL);
|
|
enter_lazy_tlb(mm, current);
|
|
local_irq_enable();
|
|
task_unlock(current);
|
|
mmap_read_unlock(mm);
|
|
mm_update_next_owner(mm);
|
|
mmput(mm);
|
|
if (test_thread_flag(TIF_MEMDIE))
|
|
exit_oom_victim();
|
|
}
|
|
|
|
static struct task_struct *find_alive_thread(struct task_struct *p)
|
|
{
|
|
struct task_struct *t;
|
|
|
|
for_each_thread(p, t) {
|
|
if (!(t->flags & PF_EXITING))
|
|
return t;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static struct task_struct *find_child_reaper(struct task_struct *father,
|
|
struct list_head *dead)
|
|
__releases(&tasklist_lock)
|
|
__acquires(&tasklist_lock)
|
|
{
|
|
struct pid_namespace *pid_ns = task_active_pid_ns(father);
|
|
struct task_struct *reaper = pid_ns->child_reaper;
|
|
struct task_struct *p, *n;
|
|
|
|
if (likely(reaper != father))
|
|
return reaper;
|
|
|
|
reaper = find_alive_thread(father);
|
|
if (reaper) {
|
|
pid_ns->child_reaper = reaper;
|
|
return reaper;
|
|
}
|
|
|
|
write_unlock_irq(&tasklist_lock);
|
|
|
|
list_for_each_entry_safe(p, n, dead, ptrace_entry) {
|
|
list_del_init(&p->ptrace_entry);
|
|
release_task(p);
|
|
}
|
|
|
|
zap_pid_ns_processes(pid_ns);
|
|
write_lock_irq(&tasklist_lock);
|
|
|
|
return father;
|
|
}
|
|
|
|
/*
|
|
* When we die, we re-parent all our children, and try to:
|
|
* 1. give them to another thread in our thread group, if such a member exists
|
|
* 2. give it to the first ancestor process which prctl'd itself as a
|
|
* child_subreaper for its children (like a service manager)
|
|
* 3. give it to the init process (PID 1) in our pid namespace
|
|
*/
|
|
static struct task_struct *find_new_reaper(struct task_struct *father,
|
|
struct task_struct *child_reaper)
|
|
{
|
|
struct task_struct *thread, *reaper;
|
|
|
|
thread = find_alive_thread(father);
|
|
if (thread)
|
|
return thread;
|
|
|
|
if (father->signal->has_child_subreaper) {
|
|
unsigned int ns_level = task_pid(father)->level;
|
|
/*
|
|
* Find the first ->is_child_subreaper ancestor in our pid_ns.
|
|
* We can't check reaper != child_reaper to ensure we do not
|
|
* cross the namespaces, the exiting parent could be injected
|
|
* by setns() + fork().
|
|
* We check pid->level, this is slightly more efficient than
|
|
* task_active_pid_ns(reaper) != task_active_pid_ns(father).
|
|
*/
|
|
for (reaper = father->real_parent;
|
|
task_pid(reaper)->level == ns_level;
|
|
reaper = reaper->real_parent) {
|
|
if (reaper == &init_task)
|
|
break;
|
|
if (!reaper->signal->is_child_subreaper)
|
|
continue;
|
|
thread = find_alive_thread(reaper);
|
|
if (thread)
|
|
return thread;
|
|
}
|
|
}
|
|
|
|
return child_reaper;
|
|
}
|
|
|
|
/*
|
|
* Any that need to be release_task'd are put on the @dead list.
|
|
*/
|
|
static void reparent_leader(struct task_struct *father, struct task_struct *p,
|
|
struct list_head *dead)
|
|
{
|
|
if (unlikely(p->exit_state == EXIT_DEAD))
|
|
return;
|
|
|
|
/* We don't want people slaying init. */
|
|
p->exit_signal = SIGCHLD;
|
|
|
|
/* If it has exited notify the new parent about this child's death. */
|
|
if (!p->ptrace &&
|
|
p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
|
|
if (do_notify_parent(p, p->exit_signal)) {
|
|
p->exit_state = EXIT_DEAD;
|
|
list_add(&p->ptrace_entry, dead);
|
|
}
|
|
}
|
|
|
|
kill_orphaned_pgrp(p, father);
|
|
}
|
|
|
|
/*
|
|
* This does two things:
|
|
*
|
|
* A. Make init inherit all the child processes
|
|
* B. Check to see if any process groups have become orphaned
|
|
* as a result of our exiting, and if they have any stopped
|
|
* jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
|
|
*/
|
|
static void forget_original_parent(struct task_struct *father,
|
|
struct list_head *dead)
|
|
{
|
|
struct task_struct *p, *t, *reaper;
|
|
|
|
if (unlikely(!list_empty(&father->ptraced)))
|
|
exit_ptrace(father, dead);
|
|
|
|
/* Can drop and reacquire tasklist_lock */
|
|
reaper = find_child_reaper(father, dead);
|
|
if (list_empty(&father->children))
|
|
return;
|
|
|
|
reaper = find_new_reaper(father, reaper);
|
|
list_for_each_entry(p, &father->children, sibling) {
|
|
for_each_thread(p, t) {
|
|
RCU_INIT_POINTER(t->real_parent, reaper);
|
|
BUG_ON((!t->ptrace) != (rcu_access_pointer(t->parent) == father));
|
|
if (likely(!t->ptrace))
|
|
t->parent = t->real_parent;
|
|
if (t->pdeath_signal)
|
|
group_send_sig_info(t->pdeath_signal,
|
|
SEND_SIG_NOINFO, t,
|
|
PIDTYPE_TGID);
|
|
}
|
|
/*
|
|
* If this is a threaded reparent there is no need to
|
|
* notify anyone anything has happened.
|
|
*/
|
|
if (!same_thread_group(reaper, father))
|
|
reparent_leader(father, p, dead);
|
|
}
|
|
list_splice_tail_init(&father->children, &reaper->children);
|
|
}
|
|
|
|
/*
|
|
* Send signals to all our closest relatives so that they know
|
|
* to properly mourn us..
|
|
*/
|
|
static void exit_notify(struct task_struct *tsk, int group_dead)
|
|
{
|
|
bool autoreap;
|
|
struct task_struct *p, *n;
|
|
LIST_HEAD(dead);
|
|
|
|
write_lock_irq(&tasklist_lock);
|
|
forget_original_parent(tsk, &dead);
|
|
|
|
if (group_dead)
|
|
kill_orphaned_pgrp(tsk->group_leader, NULL);
|
|
|
|
tsk->exit_state = EXIT_ZOMBIE;
|
|
if (unlikely(tsk->ptrace)) {
|
|
int sig = thread_group_leader(tsk) &&
|
|
thread_group_empty(tsk) &&
|
|
!ptrace_reparented(tsk) ?
|
|
tsk->exit_signal : SIGCHLD;
|
|
autoreap = do_notify_parent(tsk, sig);
|
|
} else if (thread_group_leader(tsk)) {
|
|
autoreap = thread_group_empty(tsk) &&
|
|
do_notify_parent(tsk, tsk->exit_signal);
|
|
} else {
|
|
autoreap = true;
|
|
}
|
|
|
|
if (autoreap) {
|
|
tsk->exit_state = EXIT_DEAD;
|
|
list_add(&tsk->ptrace_entry, &dead);
|
|
}
|
|
|
|
/* mt-exec, de_thread() is waiting for group leader */
|
|
if (unlikely(tsk->signal->notify_count < 0))
|
|
wake_up_process(tsk->signal->group_exec_task);
|
|
write_unlock_irq(&tasklist_lock);
|
|
|
|
list_for_each_entry_safe(p, n, &dead, ptrace_entry) {
|
|
list_del_init(&p->ptrace_entry);
|
|
release_task(p);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_STACK_USAGE
|
|
static void check_stack_usage(void)
|
|
{
|
|
static DEFINE_SPINLOCK(low_water_lock);
|
|
static int lowest_to_date = THREAD_SIZE;
|
|
unsigned long free;
|
|
|
|
free = stack_not_used(current);
|
|
|
|
if (free >= lowest_to_date)
|
|
return;
|
|
|
|
spin_lock(&low_water_lock);
|
|
if (free < lowest_to_date) {
|
|
pr_info("%s (%d) used greatest stack depth: %lu bytes left\n",
|
|
current->comm, task_pid_nr(current), free);
|
|
lowest_to_date = free;
|
|
}
|
|
spin_unlock(&low_water_lock);
|
|
}
|
|
#else
|
|
static inline void check_stack_usage(void) {}
|
|
#endif
|
|
|
|
void __noreturn do_exit(long code)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
int group_dead;
|
|
|
|
WARN_ON(tsk->plug);
|
|
|
|
kcov_task_exit(tsk);
|
|
|
|
coredump_task_exit(tsk);
|
|
ptrace_event(PTRACE_EVENT_EXIT, code);
|
|
|
|
validate_creds_for_do_exit(tsk);
|
|
|
|
io_uring_files_cancel();
|
|
exit_signals(tsk); /* sets PF_EXITING */
|
|
|
|
/* sync mm's RSS info before statistics gathering */
|
|
if (tsk->mm)
|
|
sync_mm_rss(tsk->mm);
|
|
acct_update_integrals(tsk);
|
|
group_dead = atomic_dec_and_test(&tsk->signal->live);
|
|
if (group_dead) {
|
|
/*
|
|
* If the last thread of global init has exited, panic
|
|
* immediately to get a useable coredump.
|
|
*/
|
|
if (unlikely(is_global_init(tsk)))
|
|
panic("Attempted to kill init! exitcode=0x%08x\n",
|
|
tsk->signal->group_exit_code ?: (int)code);
|
|
|
|
#ifdef CONFIG_POSIX_TIMERS
|
|
hrtimer_cancel(&tsk->signal->real_timer);
|
|
exit_itimers(tsk->signal);
|
|
#endif
|
|
if (tsk->mm)
|
|
setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
|
|
}
|
|
acct_collect(code, group_dead);
|
|
if (group_dead)
|
|
tty_audit_exit();
|
|
audit_free(tsk);
|
|
|
|
tsk->exit_code = code;
|
|
taskstats_exit(tsk, group_dead);
|
|
|
|
exit_mm();
|
|
|
|
if (group_dead)
|
|
acct_process();
|
|
trace_sched_process_exit(tsk);
|
|
|
|
exit_sem(tsk);
|
|
exit_shm(tsk);
|
|
exit_files(tsk);
|
|
exit_fs(tsk);
|
|
if (group_dead)
|
|
disassociate_ctty(1);
|
|
exit_task_namespaces(tsk);
|
|
exit_task_work(tsk);
|
|
exit_thread(tsk);
|
|
|
|
/*
|
|
* Flush inherited counters to the parent - before the parent
|
|
* gets woken up by child-exit notifications.
|
|
*
|
|
* because of cgroup mode, must be called before cgroup_exit()
|
|
*/
|
|
perf_event_exit_task(tsk);
|
|
|
|
sched_autogroup_exit_task(tsk);
|
|
cgroup_exit(tsk);
|
|
|
|
/*
|
|
* FIXME: do that only when needed, using sched_exit tracepoint
|
|
*/
|
|
flush_ptrace_hw_breakpoint(tsk);
|
|
|
|
exit_tasks_rcu_start();
|
|
exit_notify(tsk, group_dead);
|
|
proc_exit_connector(tsk);
|
|
mpol_put_task_policy(tsk);
|
|
#ifdef CONFIG_FUTEX
|
|
if (unlikely(current->pi_state_cache))
|
|
kfree(current->pi_state_cache);
|
|
#endif
|
|
/*
|
|
* Make sure we are holding no locks:
|
|
*/
|
|
debug_check_no_locks_held();
|
|
|
|
if (tsk->io_context)
|
|
exit_io_context(tsk);
|
|
|
|
if (tsk->splice_pipe)
|
|
free_pipe_info(tsk->splice_pipe);
|
|
|
|
if (tsk->task_frag.page)
|
|
put_page(tsk->task_frag.page);
|
|
|
|
validate_creds_for_do_exit(tsk);
|
|
exit_task_stack_account(tsk);
|
|
|
|
check_stack_usage();
|
|
preempt_disable();
|
|
if (tsk->nr_dirtied)
|
|
__this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
|
|
exit_rcu();
|
|
exit_tasks_rcu_finish();
|
|
|
|
lockdep_free_task(tsk);
|
|
do_task_dead();
|
|
}
|
|
|
|
void __noreturn make_task_dead(int signr)
|
|
{
|
|
/*
|
|
* Take the task off the cpu after something catastrophic has
|
|
* happened.
|
|
*
|
|
* We can get here from a kernel oops, sometimes with preemption off.
|
|
* Start by checking for critical errors.
|
|
* Then fix up important state like USER_DS and preemption.
|
|
* Then do everything else.
|
|
*/
|
|
struct task_struct *tsk = current;
|
|
|
|
if (unlikely(in_interrupt()))
|
|
panic("Aiee, killing interrupt handler!");
|
|
if (unlikely(!tsk->pid))
|
|
panic("Attempted to kill the idle task!");
|
|
|
|
if (unlikely(in_atomic())) {
|
|
pr_info("note: %s[%d] exited with preempt_count %d\n",
|
|
current->comm, task_pid_nr(current),
|
|
preempt_count());
|
|
preempt_count_set(PREEMPT_ENABLED);
|
|
}
|
|
|
|
/*
|
|
* We're taking recursive faults here in make_task_dead. Safest is to just
|
|
* leave this task alone and wait for reboot.
|
|
*/
|
|
if (unlikely(tsk->flags & PF_EXITING)) {
|
|
pr_alert("Fixing recursive fault but reboot is needed!\n");
|
|
futex_exit_recursive(tsk);
|
|
tsk->exit_state = EXIT_DEAD;
|
|
refcount_inc(&tsk->rcu_users);
|
|
do_task_dead();
|
|
}
|
|
|
|
do_exit(signr);
|
|
}
|
|
|
|
SYSCALL_DEFINE1(exit, int, error_code)
|
|
{
|
|
do_exit((error_code&0xff)<<8);
|
|
}
|
|
|
|
/*
|
|
* Take down every thread in the group. This is called by fatal signals
|
|
* as well as by sys_exit_group (below).
|
|
*/
|
|
void
|
|
do_group_exit(int exit_code)
|
|
{
|
|
struct signal_struct *sig = current->signal;
|
|
|
|
if (sig->flags & SIGNAL_GROUP_EXIT)
|
|
exit_code = sig->group_exit_code;
|
|
else if (sig->group_exec_task)
|
|
exit_code = 0;
|
|
else if (!thread_group_empty(current)) {
|
|
struct sighand_struct *const sighand = current->sighand;
|
|
|
|
spin_lock_irq(&sighand->siglock);
|
|
if (sig->flags & SIGNAL_GROUP_EXIT)
|
|
/* Another thread got here before we took the lock. */
|
|
exit_code = sig->group_exit_code;
|
|
else if (sig->group_exec_task)
|
|
exit_code = 0;
|
|
else {
|
|
sig->group_exit_code = exit_code;
|
|
sig->flags = SIGNAL_GROUP_EXIT;
|
|
zap_other_threads(current);
|
|
}
|
|
spin_unlock_irq(&sighand->siglock);
|
|
}
|
|
|
|
do_exit(exit_code);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/*
|
|
* this kills every thread in the thread group. Note that any externally
|
|
* wait4()-ing process will get the correct exit code - even if this
|
|
* thread is not the thread group leader.
|
|
*/
|
|
SYSCALL_DEFINE1(exit_group, int, error_code)
|
|
{
|
|
do_group_exit((error_code & 0xff) << 8);
|
|
/* NOTREACHED */
|
|
return 0;
|
|
}
|
|
|
|
struct waitid_info {
|
|
pid_t pid;
|
|
uid_t uid;
|
|
int status;
|
|
int cause;
|
|
};
|
|
|
|
struct wait_opts {
|
|
enum pid_type wo_type;
|
|
int wo_flags;
|
|
struct pid *wo_pid;
|
|
|
|
struct waitid_info *wo_info;
|
|
int wo_stat;
|
|
struct rusage *wo_rusage;
|
|
|
|
wait_queue_entry_t child_wait;
|
|
int notask_error;
|
|
};
|
|
|
|
static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
|
|
{
|
|
return wo->wo_type == PIDTYPE_MAX ||
|
|
task_pid_type(p, wo->wo_type) == wo->wo_pid;
|
|
}
|
|
|
|
static int
|
|
eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
|
|
{
|
|
if (!eligible_pid(wo, p))
|
|
return 0;
|
|
|
|
/*
|
|
* Wait for all children (clone and not) if __WALL is set or
|
|
* if it is traced by us.
|
|
*/
|
|
if (ptrace || (wo->wo_flags & __WALL))
|
|
return 1;
|
|
|
|
/*
|
|
* Otherwise, wait for clone children *only* if __WCLONE is set;
|
|
* otherwise, wait for non-clone children *only*.
|
|
*
|
|
* Note: a "clone" child here is one that reports to its parent
|
|
* using a signal other than SIGCHLD, or a non-leader thread which
|
|
* we can only see if it is traced by us.
|
|
*/
|
|
if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
|
|
* read_lock(&tasklist_lock) on entry. If we return zero, we still hold
|
|
* the lock and this task is uninteresting. If we return nonzero, we have
|
|
* released the lock and the system call should return.
|
|
*/
|
|
static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
|
|
{
|
|
int state, status;
|
|
pid_t pid = task_pid_vnr(p);
|
|
uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
|
|
struct waitid_info *infop;
|
|
|
|
if (!likely(wo->wo_flags & WEXITED))
|
|
return 0;
|
|
|
|
if (unlikely(wo->wo_flags & WNOWAIT)) {
|
|
status = (p->signal->flags & SIGNAL_GROUP_EXIT)
|
|
? p->signal->group_exit_code : p->exit_code;
|
|
get_task_struct(p);
|
|
read_unlock(&tasklist_lock);
|
|
sched_annotate_sleep();
|
|
if (wo->wo_rusage)
|
|
getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
|
|
put_task_struct(p);
|
|
goto out_info;
|
|
}
|
|
/*
|
|
* Move the task's state to DEAD/TRACE, only one thread can do this.
|
|
*/
|
|
state = (ptrace_reparented(p) && thread_group_leader(p)) ?
|
|
EXIT_TRACE : EXIT_DEAD;
|
|
if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)
|
|
return 0;
|
|
/*
|
|
* We own this thread, nobody else can reap it.
|
|
*/
|
|
read_unlock(&tasklist_lock);
|
|
sched_annotate_sleep();
|
|
|
|
/*
|
|
* Check thread_group_leader() to exclude the traced sub-threads.
|
|
*/
|
|
if (state == EXIT_DEAD && thread_group_leader(p)) {
|
|
struct signal_struct *sig = p->signal;
|
|
struct signal_struct *psig = current->signal;
|
|
unsigned long maxrss;
|
|
u64 tgutime, tgstime;
|
|
|
|
/*
|
|
* The resource counters for the group leader are in its
|
|
* own task_struct. Those for dead threads in the group
|
|
* are in its signal_struct, as are those for the child
|
|
* processes it has previously reaped. All these
|
|
* accumulate in the parent's signal_struct c* fields.
|
|
*
|
|
* We don't bother to take a lock here to protect these
|
|
* p->signal fields because the whole thread group is dead
|
|
* and nobody can change them.
|
|
*
|
|
* psig->stats_lock also protects us from our sub-theads
|
|
* which can reap other children at the same time. Until
|
|
* we change k_getrusage()-like users to rely on this lock
|
|
* we have to take ->siglock as well.
|
|
*
|
|
* We use thread_group_cputime_adjusted() to get times for
|
|
* the thread group, which consolidates times for all threads
|
|
* in the group including the group leader.
|
|
*/
|
|
thread_group_cputime_adjusted(p, &tgutime, &tgstime);
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
write_seqlock(&psig->stats_lock);
|
|
psig->cutime += tgutime + sig->cutime;
|
|
psig->cstime += tgstime + sig->cstime;
|
|
psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime;
|
|
psig->cmin_flt +=
|
|
p->min_flt + sig->min_flt + sig->cmin_flt;
|
|
psig->cmaj_flt +=
|
|
p->maj_flt + sig->maj_flt + sig->cmaj_flt;
|
|
psig->cnvcsw +=
|
|
p->nvcsw + sig->nvcsw + sig->cnvcsw;
|
|
psig->cnivcsw +=
|
|
p->nivcsw + sig->nivcsw + sig->cnivcsw;
|
|
psig->cinblock +=
|
|
task_io_get_inblock(p) +
|
|
sig->inblock + sig->cinblock;
|
|
psig->coublock +=
|
|
task_io_get_oublock(p) +
|
|
sig->oublock + sig->coublock;
|
|
maxrss = max(sig->maxrss, sig->cmaxrss);
|
|
if (psig->cmaxrss < maxrss)
|
|
psig->cmaxrss = maxrss;
|
|
task_io_accounting_add(&psig->ioac, &p->ioac);
|
|
task_io_accounting_add(&psig->ioac, &sig->ioac);
|
|
write_sequnlock(&psig->stats_lock);
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
}
|
|
|
|
if (wo->wo_rusage)
|
|
getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
|
|
status = (p->signal->flags & SIGNAL_GROUP_EXIT)
|
|
? p->signal->group_exit_code : p->exit_code;
|
|
wo->wo_stat = status;
|
|
|
|
if (state == EXIT_TRACE) {
|
|
write_lock_irq(&tasklist_lock);
|
|
/* We dropped tasklist, ptracer could die and untrace */
|
|
ptrace_unlink(p);
|
|
|
|
/* If parent wants a zombie, don't release it now */
|
|
state = EXIT_ZOMBIE;
|
|
if (do_notify_parent(p, p->exit_signal))
|
|
state = EXIT_DEAD;
|
|
p->exit_state = state;
|
|
write_unlock_irq(&tasklist_lock);
|
|
}
|
|
if (state == EXIT_DEAD)
|
|
release_task(p);
|
|
|
|
out_info:
|
|
infop = wo->wo_info;
|
|
if (infop) {
|
|
if ((status & 0x7f) == 0) {
|
|
infop->cause = CLD_EXITED;
|
|
infop->status = status >> 8;
|
|
} else {
|
|
infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
|
|
infop->status = status & 0x7f;
|
|
}
|
|
infop->pid = pid;
|
|
infop->uid = uid;
|
|
}
|
|
|
|
return pid;
|
|
}
|
|
|
|
static int *task_stopped_code(struct task_struct *p, bool ptrace)
|
|
{
|
|
if (ptrace) {
|
|
if (task_is_traced(p) && !(p->jobctl & JOBCTL_LISTENING))
|
|
return &p->exit_code;
|
|
} else {
|
|
if (p->signal->flags & SIGNAL_STOP_STOPPED)
|
|
return &p->signal->group_exit_code;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* wait_task_stopped - Wait for %TASK_STOPPED or %TASK_TRACED
|
|
* @wo: wait options
|
|
* @ptrace: is the wait for ptrace
|
|
* @p: task to wait for
|
|
*
|
|
* Handle sys_wait4() work for %p in state %TASK_STOPPED or %TASK_TRACED.
|
|
*
|
|
* CONTEXT:
|
|
* read_lock(&tasklist_lock), which is released if return value is
|
|
* non-zero. Also, grabs and releases @p->sighand->siglock.
|
|
*
|
|
* RETURNS:
|
|
* 0 if wait condition didn't exist and search for other wait conditions
|
|
* should continue. Non-zero return, -errno on failure and @p's pid on
|
|
* success, implies that tasklist_lock is released and wait condition
|
|
* search should terminate.
|
|
*/
|
|
static int wait_task_stopped(struct wait_opts *wo,
|
|
int ptrace, struct task_struct *p)
|
|
{
|
|
struct waitid_info *infop;
|
|
int exit_code, *p_code, why;
|
|
uid_t uid = 0; /* unneeded, required by compiler */
|
|
pid_t pid;
|
|
|
|
/*
|
|
* Traditionally we see ptrace'd stopped tasks regardless of options.
|
|
*/
|
|
if (!ptrace && !(wo->wo_flags & WUNTRACED))
|
|
return 0;
|
|
|
|
if (!task_stopped_code(p, ptrace))
|
|
return 0;
|
|
|
|
exit_code = 0;
|
|
spin_lock_irq(&p->sighand->siglock);
|
|
|
|
p_code = task_stopped_code(p, ptrace);
|
|
if (unlikely(!p_code))
|
|
goto unlock_sig;
|
|
|
|
exit_code = *p_code;
|
|
if (!exit_code)
|
|
goto unlock_sig;
|
|
|
|
if (!unlikely(wo->wo_flags & WNOWAIT))
|
|
*p_code = 0;
|
|
|
|
uid = from_kuid_munged(current_user_ns(), task_uid(p));
|
|
unlock_sig:
|
|
spin_unlock_irq(&p->sighand->siglock);
|
|
if (!exit_code)
|
|
return 0;
|
|
|
|
/*
|
|
* Now we are pretty sure this task is interesting.
|
|
* Make sure it doesn't get reaped out from under us while we
|
|
* give up the lock and then examine it below. We don't want to
|
|
* keep holding onto the tasklist_lock while we call getrusage and
|
|
* possibly take page faults for user memory.
|
|
*/
|
|
get_task_struct(p);
|
|
pid = task_pid_vnr(p);
|
|
why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
|
|
read_unlock(&tasklist_lock);
|
|
sched_annotate_sleep();
|
|
if (wo->wo_rusage)
|
|
getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
|
|
put_task_struct(p);
|
|
|
|
if (likely(!(wo->wo_flags & WNOWAIT)))
|
|
wo->wo_stat = (exit_code << 8) | 0x7f;
|
|
|
|
infop = wo->wo_info;
|
|
if (infop) {
|
|
infop->cause = why;
|
|
infop->status = exit_code;
|
|
infop->pid = pid;
|
|
infop->uid = uid;
|
|
}
|
|
return pid;
|
|
}
|
|
|
|
/*
|
|
* Handle do_wait work for one task in a live, non-stopped state.
|
|
* read_lock(&tasklist_lock) on entry. If we return zero, we still hold
|
|
* the lock and this task is uninteresting. If we return nonzero, we have
|
|
* released the lock and the system call should return.
|
|
*/
|
|
static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
|
|
{
|
|
struct waitid_info *infop;
|
|
pid_t pid;
|
|
uid_t uid;
|
|
|
|
if (!unlikely(wo->wo_flags & WCONTINUED))
|
|
return 0;
|
|
|
|
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
|
|
return 0;
|
|
|
|
spin_lock_irq(&p->sighand->siglock);
|
|
/* Re-check with the lock held. */
|
|
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
|
|
spin_unlock_irq(&p->sighand->siglock);
|
|
return 0;
|
|
}
|
|
if (!unlikely(wo->wo_flags & WNOWAIT))
|
|
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
|
|
uid = from_kuid_munged(current_user_ns(), task_uid(p));
|
|
spin_unlock_irq(&p->sighand->siglock);
|
|
|
|
pid = task_pid_vnr(p);
|
|
get_task_struct(p);
|
|
read_unlock(&tasklist_lock);
|
|
sched_annotate_sleep();
|
|
if (wo->wo_rusage)
|
|
getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
|
|
put_task_struct(p);
|
|
|
|
infop = wo->wo_info;
|
|
if (!infop) {
|
|
wo->wo_stat = 0xffff;
|
|
} else {
|
|
infop->cause = CLD_CONTINUED;
|
|
infop->pid = pid;
|
|
infop->uid = uid;
|
|
infop->status = SIGCONT;
|
|
}
|
|
return pid;
|
|
}
|
|
|
|
/*
|
|
* Consider @p for a wait by @parent.
|
|
*
|
|
* -ECHILD should be in ->notask_error before the first call.
|
|
* Returns nonzero for a final return, when we have unlocked tasklist_lock.
|
|
* Returns zero if the search for a child should continue;
|
|
* then ->notask_error is 0 if @p is an eligible child,
|
|
* or still -ECHILD.
|
|
*/
|
|
static int wait_consider_task(struct wait_opts *wo, int ptrace,
|
|
struct task_struct *p)
|
|
{
|
|
/*
|
|
* We can race with wait_task_zombie() from another thread.
|
|
* Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
|
|
* can't confuse the checks below.
|
|
*/
|
|
int exit_state = READ_ONCE(p->exit_state);
|
|
int ret;
|
|
|
|
if (unlikely(exit_state == EXIT_DEAD))
|
|
return 0;
|
|
|
|
ret = eligible_child(wo, ptrace, p);
|
|
if (!ret)
|
|
return ret;
|
|
|
|
if (unlikely(exit_state == EXIT_TRACE)) {
|
|
/*
|
|
* ptrace == 0 means we are the natural parent. In this case
|
|
* we should clear notask_error, debugger will notify us.
|
|
*/
|
|
if (likely(!ptrace))
|
|
wo->notask_error = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (likely(!ptrace) && unlikely(p->ptrace)) {
|
|
/*
|
|
* If it is traced by its real parent's group, just pretend
|
|
* the caller is ptrace_do_wait() and reap this child if it
|
|
* is zombie.
|
|
*
|
|
* This also hides group stop state from real parent; otherwise
|
|
* a single stop can be reported twice as group and ptrace stop.
|
|
* If a ptracer wants to distinguish these two events for its
|
|
* own children it should create a separate process which takes
|
|
* the role of real parent.
|
|
*/
|
|
if (!ptrace_reparented(p))
|
|
ptrace = 1;
|
|
}
|
|
|
|
/* slay zombie? */
|
|
if (exit_state == EXIT_ZOMBIE) {
|
|
/* we don't reap group leaders with subthreads */
|
|
if (!delay_group_leader(p)) {
|
|
/*
|
|
* A zombie ptracee is only visible to its ptracer.
|
|
* Notification and reaping will be cascaded to the
|
|
* real parent when the ptracer detaches.
|
|
*/
|
|
if (unlikely(ptrace) || likely(!p->ptrace))
|
|
return wait_task_zombie(wo, p);
|
|
}
|
|
|
|
/*
|
|
* Allow access to stopped/continued state via zombie by
|
|
* falling through. Clearing of notask_error is complex.
|
|
*
|
|
* When !@ptrace:
|
|
*
|
|
* If WEXITED is set, notask_error should naturally be
|
|
* cleared. If not, subset of WSTOPPED|WCONTINUED is set,
|
|
* so, if there are live subthreads, there are events to
|
|
* wait for. If all subthreads are dead, it's still safe
|
|
* to clear - this function will be called again in finite
|
|
* amount time once all the subthreads are released and
|
|
* will then return without clearing.
|
|
*
|
|
* When @ptrace:
|
|
*
|
|
* Stopped state is per-task and thus can't change once the
|
|
* target task dies. Only continued and exited can happen.
|
|
* Clear notask_error if WCONTINUED | WEXITED.
|
|
*/
|
|
if (likely(!ptrace) || (wo->wo_flags & (WCONTINUED | WEXITED)))
|
|
wo->notask_error = 0;
|
|
} else {
|
|
/*
|
|
* @p is alive and it's gonna stop, continue or exit, so
|
|
* there always is something to wait for.
|
|
*/
|
|
wo->notask_error = 0;
|
|
}
|
|
|
|
/*
|
|
* Wait for stopped. Depending on @ptrace, different stopped state
|
|
* is used and the two don't interact with each other.
|
|
*/
|
|
ret = wait_task_stopped(wo, ptrace, p);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Wait for continued. There's only one continued state and the
|
|
* ptracer can consume it which can confuse the real parent. Don't
|
|
* use WCONTINUED from ptracer. You don't need or want it.
|
|
*/
|
|
return wait_task_continued(wo, p);
|
|
}
|
|
|
|
/*
|
|
* Do the work of do_wait() for one thread in the group, @tsk.
|
|
*
|
|
* -ECHILD should be in ->notask_error before the first call.
|
|
* Returns nonzero for a final return, when we have unlocked tasklist_lock.
|
|
* Returns zero if the search for a child should continue; then
|
|
* ->notask_error is 0 if there were any eligible children,
|
|
* or still -ECHILD.
|
|
*/
|
|
static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
list_for_each_entry(p, &tsk->children, sibling) {
|
|
int ret = wait_consider_task(wo, 0, p);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
|
|
{
|
|
struct task_struct *p;
|
|
|
|
list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
|
|
int ret = wait_consider_task(wo, 1, p);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int child_wait_callback(wait_queue_entry_t *wait, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct wait_opts *wo = container_of(wait, struct wait_opts,
|
|
child_wait);
|
|
struct task_struct *p = key;
|
|
|
|
if (!eligible_pid(wo, p))
|
|
return 0;
|
|
|
|
if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent)
|
|
return 0;
|
|
|
|
return default_wake_function(wait, mode, sync, key);
|
|
}
|
|
|
|
void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
|
|
{
|
|
__wake_up_sync_key(&parent->signal->wait_chldexit,
|
|
TASK_INTERRUPTIBLE, p);
|
|
}
|
|
|
|
static bool is_effectively_child(struct wait_opts *wo, bool ptrace,
|
|
struct task_struct *target)
|
|
{
|
|
struct task_struct *parent =
|
|
!ptrace ? target->real_parent : target->parent;
|
|
|
|
return current == parent || (!(wo->wo_flags & __WNOTHREAD) &&
|
|
same_thread_group(current, parent));
|
|
}
|
|
|
|
/*
|
|
* Optimization for waiting on PIDTYPE_PID. No need to iterate through child
|
|
* and tracee lists to find the target task.
|
|
*/
|
|
static int do_wait_pid(struct wait_opts *wo)
|
|
{
|
|
bool ptrace;
|
|
struct task_struct *target;
|
|
int retval;
|
|
|
|
ptrace = false;
|
|
target = pid_task(wo->wo_pid, PIDTYPE_TGID);
|
|
if (target && is_effectively_child(wo, ptrace, target)) {
|
|
retval = wait_consider_task(wo, ptrace, target);
|
|
if (retval)
|
|
return retval;
|
|
}
|
|
|
|
ptrace = true;
|
|
target = pid_task(wo->wo_pid, PIDTYPE_PID);
|
|
if (target && target->ptrace &&
|
|
is_effectively_child(wo, ptrace, target)) {
|
|
retval = wait_consider_task(wo, ptrace, target);
|
|
if (retval)
|
|
return retval;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long do_wait(struct wait_opts *wo)
|
|
{
|
|
int retval;
|
|
|
|
trace_sched_process_wait(wo->wo_pid);
|
|
|
|
init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
|
|
wo->child_wait.private = current;
|
|
add_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
|
|
repeat:
|
|
/*
|
|
* If there is nothing that can match our criteria, just get out.
|
|
* We will clear ->notask_error to zero if we see any child that
|
|
* might later match our criteria, even if we are not able to reap
|
|
* it yet.
|
|
*/
|
|
wo->notask_error = -ECHILD;
|
|
if ((wo->wo_type < PIDTYPE_MAX) &&
|
|
(!wo->wo_pid || !pid_has_task(wo->wo_pid, wo->wo_type)))
|
|
goto notask;
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
read_lock(&tasklist_lock);
|
|
|
|
if (wo->wo_type == PIDTYPE_PID) {
|
|
retval = do_wait_pid(wo);
|
|
if (retval)
|
|
goto end;
|
|
} else {
|
|
struct task_struct *tsk = current;
|
|
|
|
do {
|
|
retval = do_wait_thread(wo, tsk);
|
|
if (retval)
|
|
goto end;
|
|
|
|
retval = ptrace_do_wait(wo, tsk);
|
|
if (retval)
|
|
goto end;
|
|
|
|
if (wo->wo_flags & __WNOTHREAD)
|
|
break;
|
|
} while_each_thread(current, tsk);
|
|
}
|
|
read_unlock(&tasklist_lock);
|
|
|
|
notask:
|
|
retval = wo->notask_error;
|
|
if (!retval && !(wo->wo_flags & WNOHANG)) {
|
|
retval = -ERESTARTSYS;
|
|
if (!signal_pending(current)) {
|
|
schedule();
|
|
goto repeat;
|
|
}
|
|
}
|
|
end:
|
|
__set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
|
|
return retval;
|
|
}
|
|
|
|
static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
|
|
int options, struct rusage *ru)
|
|
{
|
|
struct wait_opts wo;
|
|
struct pid *pid = NULL;
|
|
enum pid_type type;
|
|
long ret;
|
|
unsigned int f_flags = 0;
|
|
|
|
if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
|
|
__WNOTHREAD|__WCLONE|__WALL))
|
|
return -EINVAL;
|
|
if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
|
|
return -EINVAL;
|
|
|
|
switch (which) {
|
|
case P_ALL:
|
|
type = PIDTYPE_MAX;
|
|
break;
|
|
case P_PID:
|
|
type = PIDTYPE_PID;
|
|
if (upid <= 0)
|
|
return -EINVAL;
|
|
|
|
pid = find_get_pid(upid);
|
|
break;
|
|
case P_PGID:
|
|
type = PIDTYPE_PGID;
|
|
if (upid < 0)
|
|
return -EINVAL;
|
|
|
|
if (upid)
|
|
pid = find_get_pid(upid);
|
|
else
|
|
pid = get_task_pid(current, PIDTYPE_PGID);
|
|
break;
|
|
case P_PIDFD:
|
|
type = PIDTYPE_PID;
|
|
if (upid < 0)
|
|
return -EINVAL;
|
|
|
|
pid = pidfd_get_pid(upid, &f_flags);
|
|
if (IS_ERR(pid))
|
|
return PTR_ERR(pid);
|
|
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
wo.wo_type = type;
|
|
wo.wo_pid = pid;
|
|
wo.wo_flags = options;
|
|
wo.wo_info = infop;
|
|
wo.wo_rusage = ru;
|
|
if (f_flags & O_NONBLOCK)
|
|
wo.wo_flags |= WNOHANG;
|
|
|
|
ret = do_wait(&wo);
|
|
if (!ret && !(options & WNOHANG) && (f_flags & O_NONBLOCK))
|
|
ret = -EAGAIN;
|
|
|
|
put_pid(pid);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
|
|
infop, int, options, struct rusage __user *, ru)
|
|
{
|
|
struct rusage r;
|
|
struct waitid_info info = {.status = 0};
|
|
long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
|
|
int signo = 0;
|
|
|
|
if (err > 0) {
|
|
signo = SIGCHLD;
|
|
err = 0;
|
|
if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
|
|
return -EFAULT;
|
|
}
|
|
if (!infop)
|
|
return err;
|
|
|
|
if (!user_write_access_begin(infop, sizeof(*infop)))
|
|
return -EFAULT;
|
|
|
|
unsafe_put_user(signo, &infop->si_signo, Efault);
|
|
unsafe_put_user(0, &infop->si_errno, Efault);
|
|
unsafe_put_user(info.cause, &infop->si_code, Efault);
|
|
unsafe_put_user(info.pid, &infop->si_pid, Efault);
|
|
unsafe_put_user(info.uid, &infop->si_uid, Efault);
|
|
unsafe_put_user(info.status, &infop->si_status, Efault);
|
|
user_write_access_end();
|
|
return err;
|
|
Efault:
|
|
user_write_access_end();
|
|
return -EFAULT;
|
|
}
|
|
|
|
long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
|
|
struct rusage *ru)
|
|
{
|
|
struct wait_opts wo;
|
|
struct pid *pid = NULL;
|
|
enum pid_type type;
|
|
long ret;
|
|
|
|
if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
|
|
__WNOTHREAD|__WCLONE|__WALL))
|
|
return -EINVAL;
|
|
|
|
/* -INT_MIN is not defined */
|
|
if (upid == INT_MIN)
|
|
return -ESRCH;
|
|
|
|
if (upid == -1)
|
|
type = PIDTYPE_MAX;
|
|
else if (upid < 0) {
|
|
type = PIDTYPE_PGID;
|
|
pid = find_get_pid(-upid);
|
|
} else if (upid == 0) {
|
|
type = PIDTYPE_PGID;
|
|
pid = get_task_pid(current, PIDTYPE_PGID);
|
|
} else /* upid > 0 */ {
|
|
type = PIDTYPE_PID;
|
|
pid = find_get_pid(upid);
|
|
}
|
|
|
|
wo.wo_type = type;
|
|
wo.wo_pid = pid;
|
|
wo.wo_flags = options | WEXITED;
|
|
wo.wo_info = NULL;
|
|
wo.wo_stat = 0;
|
|
wo.wo_rusage = ru;
|
|
ret = do_wait(&wo);
|
|
put_pid(pid);
|
|
if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
|
|
ret = -EFAULT;
|
|
|
|
return ret;
|
|
}
|
|
|
|
int kernel_wait(pid_t pid, int *stat)
|
|
{
|
|
struct wait_opts wo = {
|
|
.wo_type = PIDTYPE_PID,
|
|
.wo_pid = find_get_pid(pid),
|
|
.wo_flags = WEXITED,
|
|
};
|
|
int ret;
|
|
|
|
ret = do_wait(&wo);
|
|
if (ret > 0 && wo.wo_stat)
|
|
*stat = wo.wo_stat;
|
|
put_pid(wo.wo_pid);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
|
|
int, options, struct rusage __user *, ru)
|
|
{
|
|
struct rusage r;
|
|
long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);
|
|
|
|
if (err > 0) {
|
|
if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
|
|
return -EFAULT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_WAITPID
|
|
|
|
/*
|
|
* sys_waitpid() remains for compatibility. waitpid() should be
|
|
* implemented by calling sys_wait4() from libc.a.
|
|
*/
|
|
SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
|
|
{
|
|
return kernel_wait4(pid, stat_addr, options, NULL);
|
|
}
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
COMPAT_SYSCALL_DEFINE4(wait4,
|
|
compat_pid_t, pid,
|
|
compat_uint_t __user *, stat_addr,
|
|
int, options,
|
|
struct compat_rusage __user *, ru)
|
|
{
|
|
struct rusage r;
|
|
long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);
|
|
if (err > 0) {
|
|
if (ru && put_compat_rusage(&r, ru))
|
|
return -EFAULT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE5(waitid,
|
|
int, which, compat_pid_t, pid,
|
|
struct compat_siginfo __user *, infop, int, options,
|
|
struct compat_rusage __user *, uru)
|
|
{
|
|
struct rusage ru;
|
|
struct waitid_info info = {.status = 0};
|
|
long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
|
|
int signo = 0;
|
|
if (err > 0) {
|
|
signo = SIGCHLD;
|
|
err = 0;
|
|
if (uru) {
|
|
/* kernel_waitid() overwrites everything in ru */
|
|
if (COMPAT_USE_64BIT_TIME)
|
|
err = copy_to_user(uru, &ru, sizeof(ru));
|
|
else
|
|
err = put_compat_rusage(&ru, uru);
|
|
if (err)
|
|
return -EFAULT;
|
|
}
|
|
}
|
|
|
|
if (!infop)
|
|
return err;
|
|
|
|
if (!user_write_access_begin(infop, sizeof(*infop)))
|
|
return -EFAULT;
|
|
|
|
unsafe_put_user(signo, &infop->si_signo, Efault);
|
|
unsafe_put_user(0, &infop->si_errno, Efault);
|
|
unsafe_put_user(info.cause, &infop->si_code, Efault);
|
|
unsafe_put_user(info.pid, &infop->si_pid, Efault);
|
|
unsafe_put_user(info.uid, &infop->si_uid, Efault);
|
|
unsafe_put_user(info.status, &infop->si_status, Efault);
|
|
user_write_access_end();
|
|
return err;
|
|
Efault:
|
|
user_write_access_end();
|
|
return -EFAULT;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* thread_group_exited - check that a thread group has exited
|
|
* @pid: tgid of thread group to be checked.
|
|
*
|
|
* Test if the thread group represented by tgid has exited (all
|
|
* threads are zombies, dead or completely gone).
|
|
*
|
|
* Return: true if the thread group has exited. false otherwise.
|
|
*/
|
|
bool thread_group_exited(struct pid *pid)
|
|
{
|
|
struct task_struct *task;
|
|
bool exited;
|
|
|
|
rcu_read_lock();
|
|
task = pid_task(pid, PIDTYPE_PID);
|
|
exited = !task ||
|
|
(READ_ONCE(task->exit_state) && thread_group_empty(task));
|
|
rcu_read_unlock();
|
|
|
|
return exited;
|
|
}
|
|
EXPORT_SYMBOL(thread_group_exited);
|
|
|
|
__weak void abort(void)
|
|
{
|
|
BUG();
|
|
|
|
/* if that doesn't kill us, halt */
|
|
panic("Oops failed to kill thread");
|
|
}
|
|
EXPORT_SYMBOL(abort);
|