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2022-02-01net: sched: fix use-after-free in tc_new_tfilter()Eric Dumazet1-4/+7
Whenever tc_new_tfilter() jumps back to replay: label, we need to make sure @q and @chain local variables are cleared again, or risk use-after-free as in [1] For consistency, apply the same fix in tc_ctl_chain() BUG: KASAN: use-after-free in mini_qdisc_pair_swap+0x1b9/0x1f0 net/sched/sch_generic.c:1581 Write of size 8 at addr ffff8880985c4b08 by task syz-executor.4/1945 CPU: 0 PID: 1945 Comm: syz-executor.4 Not tainted 5.17.0-rc1-syzkaller-00495-gff58831fa02d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 mini_qdisc_pair_swap+0x1b9/0x1f0 net/sched/sch_generic.c:1581 tcf_chain_head_change_item net/sched/cls_api.c:372 [inline] tcf_chain0_head_change.isra.0+0xb9/0x120 net/sched/cls_api.c:386 tcf_chain_tp_insert net/sched/cls_api.c:1657 [inline] tcf_chain_tp_insert_unique net/sched/cls_api.c:1707 [inline] tc_new_tfilter+0x1e67/0x2350 net/sched/cls_api.c:2086 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:5583 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x331/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmmsg+0x195/0x470 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f2647172059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2645aa5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f2647285100 RCX: 00007f2647172059 RDX: 040000000000009f RSI: 00000000200002c0 RDI: 0000000000000006 RBP: 00007f26471cc08d R08: 0000000000000000 R09: 0000000000000000 R10: 9e00000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffb3f7f02f R14: 00007f2645aa5300 R15: 0000000000022000 </TASK> Allocated by task 1944: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc_node include/linux/slab.h:604 [inline] kzalloc_node include/linux/slab.h:726 [inline] qdisc_alloc+0xac/0xa10 net/sched/sch_generic.c:941 qdisc_create.constprop.0+0xce/0x10f0 net/sched/sch_api.c:1211 tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5592 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x331/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmmsg+0x195/0x470 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 3609: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x130/0x160 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kfree+0xcb/0x280 mm/slub.c:4562 rcu_do_batch kernel/rcu/tree.c:2527 [inline] rcu_core+0x7b8/0x1540 kernel/rcu/tree.c:2778 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3026 [inline] call_rcu+0xb1/0x740 kernel/rcu/tree.c:3106 qdisc_put_unlocked+0x6f/0x90 net/sched/sch_generic.c:1109 tcf_block_release+0x86/0x90 net/sched/cls_api.c:1238 tc_new_tfilter+0xc0d/0x2350 net/sched/cls_api.c:2148 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:5583 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x331/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmmsg+0x195/0x470 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff8880985c4800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 776 bytes inside of 1024-byte region [ffff8880985c4800, ffff8880985c4c00) The buggy address belongs to the page: page:ffffea0002617000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x985c0 head:ffffea0002617000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010c41dc0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 1941, ts 1038999441284, free_ts 1033444432829 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0x28a/0x3b0 mm/slub.c:2004 ___slab_alloc+0x87c/0xe90 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] slab_alloc mm/slub.c:3238 [inline] __kmalloc+0x2fb/0x340 mm/slub.c:4420 kmalloc include/linux/slab.h:586 [inline] kzalloc include/linux/slab.h:715 [inline] __register_sysctl_table+0x112/0x1090 fs/proc/proc_sysctl.c:1335 neigh_sysctl_register+0x2c8/0x5e0 net/core/neighbour.c:3787 devinet_sysctl_register+0xb1/0x230 net/ipv4/devinet.c:2618 inetdev_init+0x286/0x580 net/ipv4/devinet.c:278 inetdev_event+0xa8a/0x15d0 net/ipv4/devinet.c:1532 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919 call_netdevice_notifiers_extack net/core/dev.c:1931 [inline] call_netdevice_notifiers net/core/dev.c:1945 [inline] register_netdevice+0x1073/0x1500 net/core/dev.c:9698 veth_newlink+0x59c/0xa90 drivers/net/veth.c:1722 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 release_pages+0x748/0x1220 mm/swap.c:956 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline] tlb_flush_mmu_free mm/mmu_gather.c:243 [inline] tlb_flush_mmu+0xe9/0x6b0 mm/mmu_gather.c:250 zap_pte_range mm/memory.c:1441 [inline] zap_pmd_range mm/memory.c:1490 [inline] zap_pud_range mm/memory.c:1519 [inline] zap_p4d_range mm/memory.c:1540 [inline] unmap_page_range+0x1d1d/0x2a30 mm/memory.c:1561 unmap_single_vma+0x198/0x310 mm/memory.c:1606 unmap_vmas+0x16b/0x2f0 mm/memory.c:1638 exit_mmap+0x201/0x670 mm/mmap.c:3178 __mmput+0x122/0x4b0 kernel/fork.c:1114 mmput+0x56/0x60 kernel/fork.c:1135 exit_mm kernel/exit.c:507 [inline] do_exit+0xa3c/0x2a30 kernel/exit.c:793 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 __do_sys_exit_group kernel/exit.c:946 [inline] __se_sys_exit_group kernel/exit.c:944 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff8880985c4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880985c4a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880985c4b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880985c4b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880985c4c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc Fixes: 470502de5bdb ("net: sched: unlock rules update API") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Vlad Buslov <vladbu@mellanox.com> Cc: Jiri Pirko <jiri@mellanox.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20220131172018.3704490-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-01net: allow SO_MARK with CAP_NET_RAW via cmsgJakub Kicinski1-1/+2
There's not reason SO_MARK would be allowed via setsockopt() and not via cmsg, let's keep the two consistent. See commit 079925cce1d0 ("net: allow SO_MARK with CAP_NET_RAW") for justification why NET_RAW -> SO_MARK is safe. Reviewed-by: Maciej Żenczykowski <maze@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220131233357.52964-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-01ethernet: smc911x: fix indentation in get/set EEPROMJakub Kicinski1-4/+4
Build bot produced a smatch indentation warning, the code looks correct but it mixes spaces and tabs. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/20220131211730.3940875-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-01clocksource: Add a Kconfig option for WATCHDOG_MAX_SKEWWaiman Long2-1/+16
A watchdog maximum skew of 100us may still be too small for some systems or archs. It may also be too small when some kernel debug config options are enabled. So add a new Kconfig option CLOCKSOURCE_WATCHDOG_MAX_SKEW_US to allow kernel builders to have more control on the threshold for marking clocksource as unstable. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01tools/memory-model: Explain syntactic and semantic dependenciesAlan Stern1-0/+51
Paul Heidekrüger pointed out that the Linux Kernel Memory Model documentation doesn't mention the distinction between syntactic and semantic dependencies. This is an important difference, because the compiler can easily break dependencies that are only syntactic, not semantic. This patch adds a few paragraphs to the LKMM documentation explaining these issues and illustrating how they can matter. Suggested-by: Paul Heidekrüger <paul.heidekrueger@in.tum.de> Reviewed-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Change KVM environment variable to RCUTORTUREPaul E. McKenney6-19/+19
The torture-test scripting's long-standing use of KVM as the environment variable tracking the pathname of the rcutorture directory now conflicts with allmodconfig builds due to the virt/kvm/Makefile.kvm file's use of this as a makefile variable. This commit therefore changes the torture-test scripting from KVM to RCUTORTURE, avoiding the name conflict. Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Tested-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Make kvm-find-errors.sh notice missing vmlinux filePaul E. McKenney1-0/+6
Currently, an obtuse compiler diagnostic can fool kvm-find-errors.sh into believing that the build was successful. This commit therefore adds a check for a missing vmlinux file. Note that in the case of repeated torture-test scenarios ("--configs '2*TREE01'"), the vmlinux file will only be present in the first directory, that is, in TREE01 but not TREE01.2. Link: https://lore.kernel.org/lkml/36bd91e4-8eda-5677-7fde-40295932a640@molgen.mpg.de/ Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Print only one summary line per runPaul E. McKenney1-1/+1
The torture.sh scripts currently duplicates the summary lines, getting one during the run phase and one during the summary phase of each run. This commit therefore removes the run phase from consideration so as to get only one summary line per run. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Make kvm-remote.sh try multiple times to download tarballPaul E. McKenney1-6/+11
This commit ups the retries for downloading the build-product tarball to a given remote system from once to five times, the better to handle transient network failures. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Compress KCSAN as well as KASAN vmlinux filesPaul E. McKenney1-9/+9
Compressing KASAN vmlinux files reduces torture.sh res file size from about 100G to about 50G, which is good, but the KCSAN vmlinux files are also large. Compressing them reduces their size from about 700M to about 100M (but of course your mileage may vary). This commit therefore compresses both KASAN and KCSAN vmlinux files. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Indicate which torture.sh runs' bugs are all KCSAN reportsPaul E. McKenney1-1/+11
This commit further improves torture.sh run summaries by indicating which runs' "Bugs:" counts are all KCSAN reports, and further printing an additional end-of-run summary line when all errors reported in all runs were KCSAN reports. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Make kvm.sh summaries note runs having only KCSAN reportsPaul E. McKenney2-1/+11
Runs having only KCSAN reports will normally print a summary line containing only a "Bugs:" entry. However, these bugs might or might not be KCSAN reports. This commit therefore flags runs in which all the "Bugs:" entries are KCSAN reports. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Output per-failed-run summary lines from torture.shPaul E. McKenney1-1/+1
Currently, torture.sh lists the failed runs, but it is up to the user to work out what failed. This is especially annoying for KCSAN runs, where RCU's tighter definitions result in failures being reported for other parts of the kernel. This commit therefore outputs "Summary:" lines for each failed run, allowing the user to more quickly identify which failed runs need focused attention. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Allow four-digit repetition numbers for --configs parameterPaul E. McKenney1-1/+1
In a clear-cut case of "not thinking big enough", kvm.sh limits the multipliers for torture-test scenarios to three digits. Although this is large enough for any single system that I have ever run rcutorture on, it does become a problem when you want to use kvm-remote.sh to run as many instances of TREE09 as fit on a set of 20 systems with 80 CPUs each. Yes, one could simply say "--configs '800*TREE09 800*TREE09'", but this commit removes the need for that sort of hacky workaround by permitting four-digit repetition numbers, thus allowing "--configs '1600*TREE09'". Five-digit repetition numbers remain off the menu. Should they ever really be needed, they can easily be added! Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Drop trailing ^M from console outputPaul E. McKenney1-1/+1
Console logs can sometimes have trailing control-M characters, which the forward-progress evaluation code in kvm-recheck-rcu.sh passes through to the user output. Which does not cause a technical problem, but which can look ugly. This commit therefore strips the control-M characters. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Enable limited callback-flooding tests of SRCUPaul E. McKenney1-0/+2
This commit allows up to 50,000 callbacks worth of callback-flooding tests of SRCU. The goal of this change is to exercise Tree SRCU's ability to transition from SRCU_SIZE_SMALL to SRCU_SIZE_BIG triggered by callback-queue-time lock contention. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Wake up kthreads after storing task_struct pointerPaul E. McKenney1-1/+3
Currently, _torture_create_kthread() uses kthread_run() to create torture-test kthreads, which means that the resulting task_struct pointer is stored after the newly created kthread has been marked runnable. This in turn can cause spurious failure of checks for code being run by a particular kthread. This commit therefore changes _torture_create_kthread() to use kthread_create(), then to do an explicit wake_up_process() after the task_struct pointer has been stored. Reported-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Fix rcu_fwd_mutex deadlockPaul E. McKenney1-2/+2
The rcu_torture_fwd_cb_hist() function acquires rcu_fwd_mutex, but is invoked from rcutorture_oom_notify() function, which hold this same mutex across this call. This commit fixes the resulting deadlock. Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Oliver Sang <oliver.sang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Add end-of-test check to rcu_torture_fwd_prog() loopPaul E. McKenney1-1/+1
The second and subsequent forward-progress kthreads loop waiting for the first forward-progress kthread to start the next test interval. Unfortunately, if the test ends while one of those kthreads is waiting, the test will hang. This hang occurs because that wait loop fails to check for the end of the test. This commit therefore adds an end-of-test check to that wait loop. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Make rcu_fwd_cb_nodelay be a counterPaul E. McKenney1-7/+7
Back when only one rcutorture kthread could do forward-progress testing, it was just fine for rcu_fwd_cb_nodelay to be a non-atomic bool. It was set at the start of forward-progress testing and cleared at the end. But now that there are multiple threads, the value can be cleared while one of the threads is still doing forward-progress testing. This commit therefore makes rcu_fwd_cb_nodelay be an atomic counter, replacing the WRITE_ONCE() operations with atomic_inc() and atomic_dec(). Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Increase visibility of forward-progress hangsPaul E. McKenney1-0/+4
This commit adds a few pr_alert() calls to rcutorture's forward-progress testing in order to better diagnose shutdown-time hangs. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01torture: Distinguish kthread stopping and being asked to stopPaul E. McKenney1-1/+1
Right now, if a given kthread (call it "kthread") realizes that it needs to stop, "Stopping kthread" is written to the console. When the cleanup code decides that it is time to stop that kthread, "Stopping kthread tasks" is written to the console. These two events might happen in either order, especially in the case of time-based torture-test shutdown. But it is hard to distinguish these, especially for those unfamiliar with the torture tests. This commit therefore changes the first case from "Stopping kthread" to "kthread is stopping" to make things more clear. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcutorture: Print message before invoking ->cb_barrier()Paul E. McKenney1-2/+6
The various ->cb_barrier() functions, for example, rcu_barrier(), sometimes cause rcutorture hangs. But currently, the last console message is the unenlightening "Stopping rcu_torture_stats". This commit therefore prints a message of the form "rcu_torture_cleanup: Invoking rcu_barrier+0x0/0x1e0()" to help point people in the right direction. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Add per-CPU rcuc task dumps to RCU CPU stall warningsZqiang4-0/+42
When the rcutree.use_softirq kernel boot parameter is set to zero, all RCU_SOFTIRQ processing is carried out by the per-CPU rcuc kthreads. If these kthreads are being starved, quiescent states will not be reported, which in turn means that the grace period will not end, which can in turn trigger RCU CPU stall warnings. This commit therefore dumps stack traces of stalled CPUs' rcuc kthreads, which can help identify what is preventing those kthreads from running. Suggested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Zqiang <qiang1.zhang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Don't deboost before reporting expedited quiescent statePaul E. McKenney1-4/+4
Currently rcu_preempt_deferred_qs_irqrestore() releases rnp->boost_mtx before reporting the expedited quiescent state. Under heavy real-time load, this can result in this function being preempted before the quiescent state is reported, which can in turn prevent the expedited grace period from completing. Tim Murray reports that the resulting expedited grace periods can take hundreds of milliseconds and even more than one second, when they should normally complete in less than a millisecond. This was fine given that there were no particular response-time constraints for synchronize_rcu_expedited(), as it was designed for throughput rather than latency. However, some users now need sub-100-millisecond response-time constratints. This patch therefore follows Neeraj's suggestion (seconded by Tim and by Uladzislau Rezki) of simply reversing the two operations. Reported-by: Tim Murray <timmurray@google.com> Reported-by: Joel Fernandes <joelaf@google.com> Reported-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Tested-by: Tim Murray <timmurray@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Sandeep Patil <sspatil@google.com> Cc: <stable@vger.kernel.org> # 5.4.x Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Update documentation regarding kthread_prio cmdline parameterAlison Chaiken1-0/+2
Inform readers that the priority of RCU no-callback threads will also be boosted. Signed-off-by: Alison Chaiken <achaiken@aurora.tech> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Elevate priority of offloaded callback threadsAlison Chaiken2-1/+4
When CONFIG_PREEMPT_RT=y, the rcutree.kthread_prio command-line parameter signals initialization code to boost the priority of rcuc callbacks to the designated value. With the additional CONFIG_RCU_NOCB_CPU=y configuration and an additional rcu_nocbs command-line parameter, the callbacks on the listed cores are offloaded to new rcuop kthreads that are not pinned to the cores whose post-grace-period work is performed. While the rcuop kthreads perform the same function as the rcuc kthreads they offload, the kthread_prio parameter only boosts the priority of the rcuc kthreads. Fix this inconsistency by elevating rcuop kthreads to the same priority as the rcuc kthreads. Signed-off-by: Alison Chaiken <achaiken@aurora.tech> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Make priority of grace-period thread consistentAlison Chaiken1-0/+4
The priority of RCU grace period threads is set to kthread_prio when they are launched from rcu_spawn_gp_kthread(). The same is not true of rcu_spawn_one_nocb_kthread(). Accordingly, add priority elevation to rcu_spawn_one_nocb_kthread(). Signed-off-by: Alison Chaiken <achaiken@aurora.tech> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Move kthread_prio bounds-check to a separate functionAlison Chaiken1-16/+23
Move the bounds-check of the kthread_prio cmdline parameter to a new function in order to faciliate a different callsite. Signed-off-by: Alison Chaiken <achaiken@aurora.tech> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Create per-cpu rcuc kthreads only when rcutree.use_softirq=0Zqiang1-1/+1
The per-CPU "rcuc" kthreads are used only by kernels booted with rcutree.use_softirq=0, but they are nevertheless unconditionally created by kernels built with CONFIG_RCU_BOOST=y. This results in "rcuc" kthreads being created that are never actually used. This commit therefore refrains from creating these kthreads unless the kernel is actually booted with rcutree.use_softirq=0. Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Zqiang <qiang1.zhang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Remove unused rcu_state.boostNeeraj Upadhyay2-5/+2
Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu/nocb: Handle concurrent nocb kthreads creationNeeraj Upadhyay2-1/+8
When multiple CPUs in the same nocb gp/cb group concurrently come online, they might try to concurrently create the same rcuog kthread. Fix this by using nocb gp CPU's spawn mutex to provide mutual exclusion for the rcuog kthread creation code. [ paulmck: Whitespace fixes per kernel test robot feedback. ] Acked-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Mark accesses to boost_starttimePaul E. McKenney1-3/+4
The boost_starttime shared variable has conflicting unmarked C-language accesses, which are dangerous at best. This commit therefore adds appropriate marking. This was found by KCSAN. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu: Mark ->expmask access in synchronize_rcu_expedited_wait()Paul E. McKenney1-1/+2
This commit adds a READ_ONCE() to an access to the rcu_node structure's ->expmask field to prevent compiler mischief. Detected by KCSAN. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01rcu/exp: Fix check for idle context in rcu_exp_handlerNeeraj Upadhyay1-1/+1
For PREEMPT_RCU, the rcu_exp_handler() function checks whether the current CPU is in idle, by calling rcu_dynticks_curr_cpu_in_eqs(). However, rcu_exp_handler() is called in IPI handler context. So, it should be checking the idle context using rcu_is_cpu_rrupt_from_idle(). Fix this by using rcu_is_cpu_rrupt_from_idle() instead of rcu_dynticks_curr_cpu_in_eqs(). Non-preempt configuration already uses the correct check. Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-02-01selinux: various sparse fixesPaul Moore4-7/+8
When running the SELinux code through sparse, there are a handful of warnings. This patch resolves some of these warnings caused by "__rcu" mismatches. % make W=1 C=1 security/selinux/ Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-02-01docs: scheduler: Fix outdated parameter of rebalance_domainsTang Yizhou1-4/+4
According to the function prototype of rebalance_domains(), its first parameter is *rq* and the document need to be updated. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Link: https://lore.kernel.org/r/20211221031818.23186-1-tangyizhou@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-02-01docs/zh_CN: Add rbtree Chinese translationTang Yizhou2-1/+392
Translate core-api/rbtree.rst into Chinese. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/20211225015146.1535-1-tangyizhou@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-02-01Merge branch 'bpf-drop-libbpf-from-preload'Daniel Borkmann7-452/+527
Alexei Starovoitov says: ==================== CO-RE in the kernel support allows bpf preload to switch to light skeleton and remove libbpf dependency. This reduces the size of bpf_preload_umd from 300kbyte to 19kbyte and eventually will make "kernel skeleton" possible. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2022-02-01bpf: Drop libbpf, libelf, libz dependency from bpf preload.Alexei Starovoitov1-26/+2
Drop libbpf, libelf, libz dependency from bpf preload. This reduces bpf_preload_umd binary size from 1.7M to 30k unstripped with debug info and from 300k to 19k stripped. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-8-alexei.starovoitov@gmail.com
2022-02-01bpf: Open code obj_get_info_by_fd in bpf preload.Alexei Starovoitov1-1/+17
Open code obj_get_info_by_fd in bpf preload. It's the last part of libbpf that preload/iterators were using. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-7-alexei.starovoitov@gmail.com
2022-02-01bpf: Convert bpf preload to light skeleton.Alexei Starovoitov4-420/+436
Convert bpffs preload iterators to light skeleton. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-6-alexei.starovoitov@gmail.com
2022-02-01bpf: Remove unnecessary setrlimit from bpf preload.Alexei Starovoitov1-2/+0
BPF programs and maps are memcg accounted. setrlimit is obsolete. Remove its use from bpf preload. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-5-alexei.starovoitov@gmail.com
2022-02-01libbpf: Open code raw_tp_open and link_create commands.Alexei Starovoitov2-3/+29
Open code raw_tracepoint_open and link_create used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com
2022-02-01libbpf: Open code low level bpf commands.Alexei Starovoitov1-2/+42
Open code low level bpf commands used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-3-alexei.starovoitov@gmail.com
2022-02-01libbpf: Add support for bpf iter in light skeleton.Alexei Starovoitov1-1/+4
bpf iterator programs should use bpf_link_create to attach instead of bpf_raw_tracepoint_open like other tracing programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-2-alexei.starovoitov@gmail.com
2022-02-01xfs: ensure log flush at the end of a synchronous fallocate callDave Chinner1-16/+16
Since we've started treating fallocate more like a file write, we should flush the log to disk if the user has asked for synchronous writes either by setting it via fcntl flags, or inode flags, or with the sync mount option. We've already got a helper for this, so use it. [The original patch by Darrick was massaged by Dave to fit this patchset] Signed-off-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-02-01xfs: move xfs_update_prealloc_flags() to xfs_pnfs.cDave Chinner3-42/+36
The operations that xfs_update_prealloc_flags() perform are now unique to xfs_fs_map_blocks(), so move xfs_update_prealloc_flags() to be a static function in xfs_pnfs.c and cut out all the other functionality that is doesn't use anymore. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-02-01xfs: set prealloc flag in xfs_alloc_file_space()Dave Chinner2-14/+3
Now that we only call xfs_update_prealloc_flags() from xfs_file_fallocate() in the case where we need to set the preallocation flag, do this in xfs_alloc_file_space() where we already have the inode joined into a transaction and get rid of the call to xfs_update_prealloc_flags() from the fallocate code. This also means that we now correctly avoid setting the XFS_DIFLAG_PREALLOC flag when xfs_is_always_cow_inode() is true, as these inodes will never have preallocated extents. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-02-01xfs: fallocate() should call file_modified()Dave Chinner1-4/+9
In XFS, we always update the inode change and modification time when any fallocate() operation succeeds. Furthermore, as various fallocate modes can change the file contents (extending EOF, punching holes, zeroing things, shifting extents), we should drop file privileges like suid just like we do for a regular write(). There's already a VFS helper that figures all this out for us, so use that. The net effect of this is that we no longer drop suid/sgid if the caller is root, but we also now drop file capabilities. We also move the xfs_update_prealloc_flags() function so that it now is only called by the scope that needs to set the the prealloc flag. Based on a patch from Darrick Wong. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>