April 2023 - Linux-kselftest-mirror

by Naresh Kamboju

Following kernel warnings and crash notices on arm64 Rpi4 device while running selftests: gpio on Linux mainline 6.3.0-rc1 kernel and Linux next. Reported-by: Linux Kernel Functional Testing <lkft(a)linaro.org> Please refer to test log links for detailed test plan and kernel crash logs. It is reproducible on arm64 juno-r2, Rpi4 and Qualcomm dragonboard 410c and qemu-arm64. Test log: ----------- kselftest: Running tests in gpio TAP version 13 1..2 # selftests: gpio: gpio-mockup.sh # 1. Module load tests [ 61.176149] ============================================================================= [ 61.176802] [ 61.176807] ====================================================== [ 61.176809] WARNING: possible circular locking dependency detected [ 61.176811] 6.3.0-rc1-next-20230307 #1 Not tainted [ 61.176814] ------------------------------------------------------ [ 61.176816] modprobe/510 is trying to acquire lock: [ 61.176818] ffff80000b2284e8 (console_owner){..-.}-{0:0}, at: console_flush_all (kernel/printk/printk.c:2879 kernel/printk/printk.c:2942) [ 61.176846] [ 61.176846] but task is already holding lock: [ 61.176848] ffff000040000698 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node.part.0 (mm/slub.c:2271) [ 61.176861] [ 61.176861] which lock already depends on the new lock. [ 61.176861] [ 61.176863] [ 61.176863] the existing dependency chain (in reverse order) is: [ 61.176864] [ 61.176864] -> #2 (&n->list_lock){-.-.}-{2:2}: [ 61.176871] lock_acquire (kernel/locking/lockdep.c:5673) [ 61.176879] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162) [ 61.176885] get_partial_node.part.0 (mm/slub.c:2271) [ 61.176890] ___slab_alloc (mm/slub.c:2268 mm/slub.c:2386 mm/slub.c:3188) [ 61.176894] __slab_alloc.constprop.0 (mm/slub.c:3292) [ 61.176899] __kmem_cache_alloc_node (mm/slub.c:3345 mm/slub.c:3442 mm/slub.c:3491) [ 61.176903] __kmalloc (mm/slab_common.c:968 mm/slab_common.c:980) [ 61.176908] tty_buffer_alloc (drivers/tty/tty_buffer.c:182) [ 61.176914] __tty_buffer_request_room (drivers/tty/tty_buffer.c:279) [ 61.176919] __tty_insert_flip_char (drivers/tty/tty_buffer.c:398) [ 61.176924] uart_insert_char (drivers/tty/serial/serial_core.c:3341) [ 61.176929] pl011_fifo_to_tty.isra.0 (drivers/tty/serial/amba-pl011.c:314) [ 61.176934] pl011_int (include/linux/spinlock.h:390 drivers/tty/serial/amba-pl011.c:1396 drivers/tty/serial/amba-pl011.c:1571) [ 61.176937] __handle_irq_event_percpu (kernel/irq/handle.c:158) [ 61.176941] handle_irq_event (kernel/irq/handle.c:193 kernel/irq/handle.c:210) [ 61.176944] handle_fasteoi_irq (kernel/irq/chip.c:716) [ 61.176950] generic_handle_domain_irq (kernel/irq/irqdesc.c:652 kernel/irq/irqdesc.c:707) [ 61.176953] gic_handle_irq (arch/arm64/include/asm/io.h:75 include/asm-generic/io.h:335 drivers/irqchip/irq-gic.c:344) [ 61.176958] call_on_irq_stack (arch/arm64/kernel/entry.S:905) [ 61.176962] do_interrupt_handler (arch/arm64/kernel/entry-common.c:274) [ 61.176968] el1_interrupt (arch/arm64/kernel/entry-common.c:472 arch/arm64/kernel/entry-common.c:486) [ 61.176971] el1h_64_irq_handler (arch/arm64/kernel/entry-common.c:492) [ 61.176975] el1h_64_irq (arch/arm64/kernel/entry.S:587) [ 61.176978] __kmem_cache_alloc_node (mm/slub.c:3490) [ 61.176983] kmalloc_trace (mm/slab_common.c:1064 (discriminator 4)) [ 61.176986] inet6_dump_fib (net/ipv6/ip6_fib.c:657) [ 61.176991] rtnl_dump_all (net/core/rtnetlink.c:3964) [ 61.176997] netlink_dump (net/netlink/af_netlink.c:2296) [ 61.177004] netlink_recvmsg (net/netlink/af_netlink.c:2024) [ 61.177009] ____sys_recvmsg (net/socket.c:1015 net/socket.c:1036 net/socket.c:2723) [ 61.177014] ___sys_recvmsg (net/socket.c:2765) [ 61.177019] __sys_recvmsg (include/linux/file.h:31 net/socket.c:2797) [ 61.177025] __arm64_sys_recvmsg (net/socket.c:2802) [ 61.177030] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:57) [ 61.177037] el0_svc_common.constprop.0 (arch/arm64/kernel/syscall.c:149) [ 61.177043] do_el0_svc (arch/arm64/kernel/syscall.c:194) [ 61.177049] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:638) [ 61.177052] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:656) [ 61.177055] el0t_64_sync (arch/arm64/kernel/entry.S:591) [ 61.177058] [ 61.177058] -> #1 (&port_lock_key){-.-.}-{2:2}: [ 61.177065] lock_acquire (kernel/locking/lockdep.c:5673) [ 61.177071] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162) [ 61.177074] serial8250_console_write (drivers/tty/serial/8250/8250_port.c:3394) [ 61.177082] univ8250_console_write (drivers/tty/serial/8250/8250_core.c:585) [ 61.177087] console_flush_all (kernel/printk/printk.c:2888 kernel/printk/printk.c:2942) [ 61.177093] console_unlock.part.0 (kernel/printk/printk.c:3017) [ 61.177098] vprintk_emit (kernel/printk/printk.c:2317) [ 61.177104] vprintk_default (kernel/printk/printk.c:2328) [ 61.177110] vprintk (kernel/printk/printk_safe.c:50) [ 61.177116] _printk (kernel/printk/printk.c:2341) [ 61.177121] register_console (kernel/printk/printk.c:3468) [ 61.177126] uart_add_one_port (drivers/tty/serial/serial_core.c:2579 drivers/tty/serial/serial_core.c:3100) [ 61.177130] serial8250_register_8250_port (drivers/tty/serial/8250/8250_core.c:1093) [ 61.177135] bcm2835aux_serial_probe (drivers/tty/serial/8250/8250_bcm2835aux.c:184) [ 61.177141] platform_probe (drivers/base/platform.c:1405) [ 61.177148] really_probe (drivers/base/dd.c:552 drivers/base/dd.c:631) [ 61.177152] __driver_probe_device (drivers/base/dd.c:768) [ 61.177157] driver_probe_device (drivers/base/dd.c:798) [ 61.177161] __driver_attach (drivers/base/dd.c:1185) [ 61.177166] bus_for_each_dev (drivers/base/bus.c:368) [ 61.177170] driver_attach (drivers/base/dd.c:1202) [ 61.177173] bus_add_driver (drivers/base/bus.c:673) [ 61.177177] driver_register (drivers/base/driver.c:246) [ 61.177182] __platform_driver_register (drivers/base/platform.c:868) [ 61.177188] bcm2835aux_serial_driver_init (drivers/tty/serial/8250/8250_bcm2835aux.c:233) [ 61.177195] do_one_initcall (init/main.c:1306) [ 61.177199] kernel_init_freeable (init/main.c:1378 init/main.c:1395 init/main.c:1414 init/main.c:1634) [ 61.177207] kernel_init (init/main.c:1524) [ 61.177212] ret_from_fork (arch/arm64/kernel/entry.S:871) [ 61.177216] [ 61.177216] -> #0 (console_owner){..-.}-{0:0}: [ 61.177222] __lock_acquire (kernel/locking/lockdep.c:3099 kernel/locking/lockdep.c:3217 kernel/locking/lockdep.c:3832 kernel/locking/lockdep.c:5056) [ 61.177228] lock_acquire.part.0 (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5671) [ 61.177233] lock_acquire (kernel/locking/lockdep.c:5673) [ 61.177238] console_flush_all (kernel/printk/printk.c:2883 kernel/printk/printk.c:2942) [ 61.177244] console_unlock.part.0 (kernel/printk/printk.c:3017) [ 61.177250] vprintk_emit (kernel/printk/printk.c:2317) [ 61.177255] vprintk_default (kernel/printk/printk.c:2328) [ 61.177261] vprintk (kernel/printk/printk_safe.c:50) [ 61.177267] _printk (kernel/printk/printk.c:2341) [ 61.177271] slab_bug (mm/slub.c:892) [ 61.177274] check_bytes_and_report (mm/slub.c:1054) [ 61.177279] check_object (mm/slub.c:1196 (discriminator 2)) [ 61.177283] alloc_debug_processing (mm/slub.c:1415 mm/slub.c:1425) [ 61.177287] get_partial_node.part.0 (mm/slub.c:2146 mm/slub.c:2279) [ 61.177291] ___slab_alloc (mm/slub.c:2268 mm/slub.c:2386 mm/slub.c:3188) [ 61.177295] __slab_alloc.constprop.0 (mm/slub.c:3292) [ 61.177300] __kmem_cache_alloc_node (mm/slub.c:3345 mm/slub.c:3442 mm/slub.c:3491) [ 61.177304] kmalloc_trace (mm/slab_common.c:1064 (discriminator 4)) [ 61.177308] device_add (drivers/base/core.c:3436 drivers/base/core.c:3486) [ 61.177311] platform_device_add (drivers/base/platform.c:717) [ 61.177317] platform_device_register_full (drivers/base/platform.c:844) [ 61.177323] gpio_mockup_register_chip+0x1ec/0x2b8 gpio_mockup [ 61.177342] gpio_mockup_init+0xf0/0xd40 gpio_mockup [ 61.177352] do_one_initcall (init/main.c:1306) [ 61.177356] do_init_module (kernel/module/main.c:2457) [ 61.177363] load_module (kernel/module/main.c:2859) [ 61.177369] __do_sys_finit_module (kernel/module/main.c:2961) [ 61.177375] __arm64_sys_finit_module (kernel/module/main.c:2928) [ 61.177381] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:57) [ 61.177387] el0_svc_common.constprop.0 (arch/arm64/kernel/syscall.c:149) [ 61.177393] do_el0_svc (arch/arm64/kernel/syscall.c:194) [ 61.177398] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:638) [ 61.177402] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:656) [ 61.177405] el0t_64_sync (arch/arm64/kernel/entry.S:591) [ 61.177408] [ 61.177408] other info that might help us debug this: [ 61.177408] [ 61.177410] Chain exists of: [ 61.177410] console_owner --> &port_lock_key --> &n->list_lock [ 61.177410] [ 61.177417] Possible unsafe locking scenario: [ 61.177417] [ 61.177418] CPU0 CPU1 [ 61.177419] ---- ---- [ 61.177420] lock(&n->list_lock); [ 61.177423] lock(&port_lock_key); [ 61.177426] lock(&n->list_lock); [ 61.177429] lock(console_owner); [ 61.177432] [ 61.177432] *** DEADLOCK *** [ 61.177432] [ 61.177434] 3 locks held by modprobe/510: [ 61.177436] #0: ffff000040000698 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node.part.0 (mm/slub.c:2271) [ 61.177448] #1: ffff80000b227f18 (console_lock){+.+.}-{0:0}, at: vprintk_emit (kernel/printk/printk.c:1936 kernel/printk/printk.c:2315) [ 61.177460] #2: ffff80000b228388 (console_srcu){....}-{0:0}, at: console_flush_all (include/linux/srcu.h:200 kernel/printk/printk.c:290 kernel/printk/printk.c:2934) [ 61.177471] [ 61.177471] stack backtrace: [ 61.177474] CPU: 3 PID: 510 Comm: modprobe Not tainted 6.3.0-rc1-next-20230307 #1 [ 61.177479] Hardware name: Raspberry Pi 4 Model B (DT) [ 61.177482] Call trace: [ 61.177483] dump_backtrace (arch/arm64/kernel/stacktrace.c:160) [ 61.177487] show_stack (arch/arm64/kernel/stacktrace.c:167) [ 61.177490] dump_stack_lvl (lib/dump_stack.c:107) [ 61.177498] dump_stack (lib/dump_stack.c:114) [ 61.177504] print_circular_bug (kernel/locking/lockdep.c:2057) [ 61.177509] check_noncircular (kernel/locking/lockdep.c:2181) [ 61.177514] __lock_acquire (kernel/locking/lockdep.c:3099 kernel/locking/lockdep.c:3217 kernel/locking/lockdep.c:3832 kernel/locking/lockdep.c:5056) [ 61.177520] lock_acquire.part.0 (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5671) [ 61.177525] lock_acquire (kernel/locking/lockdep.c:5673) [ 61.177530] console_flush_all (kernel/printk/printk.c:2883 kernel/printk/printk.c:2942) [ 61.177536] console_unlock.part.0 (kernel/printk/printk.c:3017) [ 61.177542] vprintk_emit (kernel/printk/printk.c:2317) [ 61.177547] vprintk_default (kernel/printk/printk.c:2328) [ 61.177553] vprintk (kernel/printk/printk_safe.c:50) [ 61.177559] _printk (kernel/printk/printk.c:2341) [ 61.177564] slab_bug (mm/slub.c:892) [ 61.177567] check_bytes_and_report (mm/slub.c:1054) [ 61.177571] check_object (mm/slub.c:1196 (discriminator 2)) [ 61.177575] alloc_debug_processing (mm/slub.c:1415 mm/slub.c:1425) [ 61.177579] get_partial_node.part.0 (mm/slub.c:2146 mm/slub.c:2279) [ 61.177583] ___slab_alloc (mm/slub.c:2268 mm/slub.c:2386 mm/slub.c:3188) [ 61.177587] __slab_alloc.constprop.0 (mm/slub.c:3292) [ 61.177592] __kmem_cache_alloc_node (mm/slub.c:3345 mm/slub.c:3442 mm/slub.c:3491) [ 61.177596] kmalloc_trace (mm/slab_common.c:1064 (discriminator 4)) [ 61.177600] device_add (drivers/base/core.c:3436 drivers/base/core.c:3486) [ 61.177603] platform_device_add (drivers/base/platform.c:717) [ 61.177609] platform_device_register_full (drivers/base/platform.c:844) [ 61.177615] gpio_mockup_register_chip+0x1ec/0x2b8 gpio_mockup [ 61.177625] gpio_mockup_init+0xf0/0xd40 gpio_mockup [ 61.177634] do_one_initcall (init/main.c:1306) [ 61.177638] do_init_module (kernel/module/main.c:2457) [ 61.177644] load_module (kernel/module/main.c:2859) [ 61.177650] __do_sys_finit_module (kernel/module/main.c:2961) [ 61.177656] __arm64_sys_finit_module (kernel/module/main.c:2928) [ 61.177662] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:57) [ 61.177668] el0_svc_common.constprop.0 (arch/arm64/kernel/syscall.c:149) [ 61.177674] do_el0_svc (arch/arm64/kernel/syscall.c:194) [ 61.177680] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:638) [ 61.177683] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:656) [ 61.177686] el0t_64_sync (arch/arm64/kernel/entry.S:591) [ 62.011685] BUG kmalloc-512 (Not tainted): Poison overwritten [ 62.017513] ----------------------------------------------------------------------------- [ 62.017513] [ 62.027300] 0xffff00004ecb7a38-0xffff00004ecb7a47 @offset=31288. First byte 0x6a instead of 0x6b [ 62.036210] Allocated in swnode_register+0x40/0x218 age=808 cpu=3 pid=386 [ 62.043101] __kmem_cache_alloc_node (mm/slub.c:3345 mm/slub.c:3442 mm/slub.c:3491) [ 62.047784] kmalloc_trace (mm/slab_common.c:1064 (discriminator 4)) [ 62.051406] swnode_register (drivers/base/swnode.c:776) [ 62.055293] fwnode_create_software_node (drivers/base/swnode.c:934 (discriminator 4)) [ 62.060238] gpio_mockup_register_chip+0x1c4/0x2b8 gpio_mockup [ 62.066337] gpio_mockup_init+0xf0/0xd40 gpio_mockup [ 62.071551] do_one_initcall (init/main.c:1306) [ 62.075437] do_init_module (kernel/module/main.c:2457) [ 62.079238] load_module (kernel/module/main.c:2859) [ 62.083037] __do_sys_finit_module (kernel/module/main.c:2961) [ 62.087455] __arm64_sys_finit_module (kernel/module/main.c:2928) [ 62.092048] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:57) [ 62.095848] el0_svc_common.constprop.0 (arch/arm64/kernel/syscall.c:149) [ 62.100793] do_el0_svc (arch/arm64/kernel/syscall.c:194) [ 62.104151] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:638) [ 62.107244] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:656) [ 62.111570] Freed in software_node_release+0xdc/0x108 age=632 cpu=0 pid=428 [ 62.118633] __kmem_cache_free (mm/slub.c:3732 mm/slub.c:3788 mm/slub.c:3800) [ 62.122784] kfree (mm/slab_common.c:1020) [ 62.125788] software_node_release (drivers/base/swnode.c:761) [ 62.130204] kobject_put (lib/kobject.c:685 lib/kobject.c:712 include/linux/kref.h:65 lib/kobject.c:729) [ 62.133739] software_node_notify_remove (drivers/base/swnode.c:1093) [ 62.138597] device_del (drivers/base/core.c:2265 drivers/base/core.c:3778) [ 62.142134] platform_device_del.part.0 (drivers/base/platform.c:753) [ 62.146903] platform_device_unregister (drivers/base/platform.c:551 drivers/base/platform.c:794) [ 62.151672] gpio_mockup_exit+0x54/0x280 gpio_mockup [ 62.156888] __arm64_sys_delete_module (kernel/module/main.c:756 kernel/module/main.c:698 kernel/module/main.c:698) [ 62.161745] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:57) [ 62.165545] el0_svc_common.constprop.0 (arch/arm64/kernel/syscall.c:149) [ 62.170490] do_el0_svc (arch/arm64/kernel/syscall.c:194) [ 62.173850] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:638) [ 62.176941] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:656) [ 62.181267] el0t_64_sync (arch/arm64/kernel/entry.S:591) [ 62.184975] Slab 0xfffffc00013b2c00 objects=21 used=7 fp=0xffff00004ecb7400 flags=0x7fffc0000010200(slab|head|node=0|zone=1|lastcpupid=0xffff) [ 62.197943] Object 0xffff00004ecb7a00 @offset=31232 fp=0xffff00004ecb7400 [ 62.197943] [ 62.206325] Redzone ffff00004ecb7800: ... [ 63.089597] CPU: 3 PID: 510 Comm: modprobe Not tainted 6.3.0-rc1-next-20230307 #1 [ 63.097186] Hardware name: Raspberry Pi 4 Model B (DT) [ 63.102392] Call trace: [ 63.104865] dump_backtrace (arch/arm64/kernel/stacktrace.c:160) [ 63.108665] show_stack (arch/arm64/kernel/stacktrace.c:167) [ 63.112021] dump_stack_lvl (lib/dump_stack.c:107) [ 63.115734] dump_stack (lib/dump_stack.c:114) [ 63.119093] print_trailer (mm/slub.c:953) [ 63.122892] check_bytes_and_report (mm/slub.c:1058) [ 63.127395] check_object (mm/slub.c:1196 (discriminator 2)) [ 63.131104] alloc_debug_processing (mm/slub.c:1415 mm/slub.c:1425) [ 63.135606] get_partial_node.part.0 (mm/slub.c:2146 mm/slub.c:2279) [ 63.140286] ___slab_alloc (mm/slub.c:2268 mm/slub.c:2386 mm/slub.c:3188) [ 63.144084] __slab_alloc.constprop.0 (mm/slub.c:3292) [ 63.148674] __kmem_cache_alloc_node (mm/slub.c:3345 mm/slub.c:3442 mm/slub.c:3491) [ 63.153354] kmalloc_trace (mm/slab_common.c:1064 (discriminator 4)) [ 63.156974] device_add (drivers/base/core.c:3436 drivers/base/core.c:3486) [ 63.160508] platform_device_add (drivers/base/platform.c:717) [ 63.164837] platform_device_register_full (drivers/base/platform.c:844) [ 63.169959] gpio_mockup_register_chip+0x1ec/0x2b8 gpio_mockup [ 63.176057] gpio_mockup_init+0xf0/0xd40 gpio_mockup [ 63.181269] do_one_initcall (init/main.c:1306) [ 63.185155] do_init_module (kernel/module/main.c:2457) [ 63.188956] load_module (kernel/module/main.c:2859) [ 63.192755] __do_sys_finit_module (kernel/module/main.c:2961) [ 63.197171] __arm64_sys_finit_module (kernel/module/main.c:2928) [ 63.201765] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:57) [ 63.205565] el0_svc_common.constprop.0 (arch/arm64/kernel/syscall.c:149) [ 63.210510] do_el0_svc (arch/arm64/kernel/syscall.c:194) [ 63.213869] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:142 arch/arm64/kernel/entry-common.c:638) [ 63.216961] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:656) [ 63.221287] el0t_64_sync (arch/arm64/kernel/entry.S:591) [ 63.224998] FIX kmalloc-512: Restoring Poison 0xffff00004ecb7a38-0xffff00004ecb7a47=0x6b [ 63.233202] FIX kmalloc-512: Marking all objects used [ 63.399213] ============================================================================= links to the crash: - https://lkft.validation.linaro.org/scheduler/job/6224830#L1291 - https://lkft.validation.linaro.org/scheduler/job/6224742#L1202 - https://lkft.validation.linaro.org/scheduler/job/6224784#L3415 - https://lkft.validation.linaro.org/scheduler/job/6224810#L2029 metadata: git_ref: master git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next git_sha: 709c6adf19dc558e44ab5c01659b09a16a2d3c82 git_describe: next-20230307 kernel_version: 6.3.0-rc1 kernel-config: https://storage.tuxsuite.com/public/linaro/lkft/builds/2MfXESbRAbSUj9oic6d8… build-url: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next/-/pipelines/798095907 artifact-location: https://storage.tuxsuite.com/public/linaro/lkft/builds/2MfXESbRAbSUj9oic6d8… toolchain: gcc-11 -- Linaro LKFT https://lkft.linaro.org

3 months, 1 week

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[PATCH v1 1/2] selftests: gpio: gpio-sim: Fix BUG: test FAILED due to recent change

by Andy Shevchenko

From: Mirsad Todorovac <mirsad.todorovac(a)alu.unizg.hr> According to Mirsad the gpio-sim.sh test appears to FAIL in a wrong way due to missing initialisation of shell variables: 4.2. Bias settings work correctly cat: /sys/devices/platform/gpio-sim.0/gpiochip18/sim_gpio0/value: No such file or directory ./gpio-sim.sh: line 393: test: =: unary operator expected bias setting does not work GPIO gpio-sim test FAIL After this change the test passed: 4.2. Bias settings work correctly GPIO gpio-sim test PASS His testing environment is AlmaLinux 8.7 on Lenovo desktop box with the latest Linux kernel based on v6.2: Linux 6.2.0-mglru-kmlk-andy-09238-gd2980d8d8265 x86_64 Suggested-by: Mirsad Todorovac <mirsad.todorovac(a)alu.unizg.hr> Signed-off-by: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> --- tools/testing/selftests/gpio/gpio-sim.sh | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/testing/selftests/gpio/gpio-sim.sh b/tools/testing/selftests/gpio/gpio-sim.sh index 9f539d454ee4..fa2ce2b9dd5f 100755 --- a/tools/testing/selftests/gpio/gpio-sim.sh +++ b/tools/testing/selftests/gpio/gpio-sim.sh @@ -389,6 +389,9 @@ create_chip chip create_bank chip bank set_num_lines chip bank 8 enable_chip chip +DEVNAME=`configfs_dev_name chip` +CHIPNAME=`configfs_chip_name chip bank` +SYSFS_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio0/value" $BASE_DIR/gpio-mockup-cdev -b pull-up /dev/`configfs_chip_name chip bank` 0 test `cat $SYSFS_PATH` = "1" || fail "bias setting does not work" remove_chip chip -- 2.40.0.1.gaa8946217a0b

3 months, 2 weeks

3
6
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[PATCH] kselftest/alsa: Increase kselftest timeout

by Nícolas F. R. A. Prado

The default timeout for kselftests is 45 seconds, but pcm-test can take longer than that to run depending on the number of PCMs present on a device. As a data point, running pcm-test on mt8192-asurada-spherion takes about 1m15s. Set the timeout to 10 minutes, which should give enough slack to run the test even on devices with many PCMs. Signed-off-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com> --- tools/testing/selftests/alsa/settings | 1 + 1 file changed, 1 insertion(+) create mode 100644 tools/testing/selftests/alsa/settings diff --git a/tools/testing/selftests/alsa/settings b/tools/testing/selftests/alsa/settings new file mode 100644 index 000000000000..a62d2fa1275c --- /dev/null +++ b/tools/testing/selftests/alsa/settings @@ -0,0 +1 @@ +timeout=600 -- 2.39.0

3 months, 2 weeks

4
5
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[PATCH v2 00/24] selftests/resctrl: Fixes, cleanups, and rewritten CAT test

by Ilpo Järvinen

Here is a series with some fixes and cleanups to resctrl selftests and rewrite of CAT test into something that really tests CAT working or not condition. v2: - Rebased on top of next to solve the conflicts - Added 2 patches related to resctrl FS mount/umount (fix + cleanup) - Consistently use "alloc" in cache_alloc_size() - CAT test error handling tweaked - Remove a spurious newline change from the CAT patch - Small improvements to changelogs Ilpo Järvinen (24): selftests/resctrl: Add resctrl.h into build deps selftests/resctrl: Check also too low values for CBM bits selftests/resctrl: Move resctrl FS mount/umount to higher level selftests/resctrl: Remove mum_resctrlfs selftests/resctrl: Make span unsigned long everywhere selftests/resctrl: Express span in bytes selftests/resctrl: Remove duplicated preparation for span arg selftests/resctrl: Don't use variable argument list for ->setup() selftests/resctrl: Remove "malloc_and_init_memory" param from run_fill_buf() selftests/resctrl: Split run_fill_buf() to alloc, work, and dealloc helpers selftests/resctrl: Remove start_buf local variable from buffer alloc func selftests/resctrl: Don't pass test name to fill_buf selftests/resctrl: Add flush_buffer() to fill_buf selftests/resctrl: Remove test type checks from cat_val() selftests/resctrl: Refactor get_cbm_mask() selftests/resctrl: Create cache_alloc_size() helper selftests/resctrl: Replace count_bits with count_consecutive_bits() selftests/resctrl: Exclude shareable bits from schemata in CAT test selftests/resctrl: Pass the real number of tests to show_cache_info() selftests/resctrl: Move CAT/CMT test global vars to func they are used selftests/resctrl: Read in less obvious order to defeat prefetch optimizations selftests/resctrl: Split measure_cache_vals() function selftests/resctrl: Split show_cache_info() to test specific and generic parts selftests/resctrl: Rewrite Cache Allocation Technology (CAT) test tools/testing/selftests/resctrl/Makefile | 2 +- tools/testing/selftests/resctrl/cache.c | 154 ++++++------ tools/testing/selftests/resctrl/cat_test.c | 235 ++++++++---------- tools/testing/selftests/resctrl/cmt_test.c | 65 +++-- tools/testing/selftests/resctrl/fill_buf.c | 105 ++++---- tools/testing/selftests/resctrl/mba_test.c | 9 +- tools/testing/selftests/resctrl/mbm_test.c | 17 +- tools/testing/selftests/resctrl/resctrl.h | 32 +-- .../testing/selftests/resctrl/resctrl_tests.c | 82 ++++-- tools/testing/selftests/resctrl/resctrl_val.c | 9 +- tools/testing/selftests/resctrl/resctrlfs.c | 187 ++++++++++---- 11 files changed, 499 insertions(+), 398 deletions(-) -- 2.30.2

3 months, 2 weeks

3
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[PATCH v12 0/5] Implement IOCTL to get and optionally clear info about PTEs

by Muhammad Usama Anjum

*Changes in v12* - Update and other memory types to UFFD_FEATURE_WP_ASYNC - Rebaase on top of next-20230406 - Review updates *Changes in v11* - Rebase on top of next-20230307 - Base patches on UFFD_FEATURE_WP_UNPOPULATED - Do a lot of cosmetic changes and review updates - Remove ENGAGE_WP + !GET operation as it can be performed with UFFDIO_WRITEPROTECT *Changes in v10* - Add specific condition to return error if hugetlb is used with wp async - Move changes in tools/include/uapi/linux/fs.h to separate patch - Add documentation *Changes in v9:* - Correct fault resolution for userfaultfd wp async - Fix build warnings and errors which were happening on some configs - Simplify pagemap ioctl's code *Changes in v8:* - Update uffd async wp implementation - Improve PAGEMAP_IOCTL implementation *Changes in v7:* - Add uffd wp async - Update the IOCTL to use uffd under the hood instead of soft-dirty flags *Motivation* The real motivation for adding PAGEMAP_SCAN IOCTL is to emulate Windows GetWriteWatch() syscall [1]. The GetWriteWatch{} retrieves the addresses of the pages that are written to in a region of virtual memory. This syscall is used in Windows applications and games etc. This syscall is being emulated in pretty slow manner in userspace. Our purpose is to enhance the kernel such that we translate it efficiently in a better way. Currently some out of tree hack patches are being used to efficiently emulate it in some kernels. We intend to replace those with these patches. So the whole gaming on Linux can effectively get benefit from this. It means there would be tons of users of this code. CRIU use case [2] was mentioned by Andrei and Danylo: > Use cases for migrating sparse VMAs are binaries sanitized with ASAN, > MSAN or TSAN [3]. All of these sanitizers produce sparse mappings of > shadow memory [4]. Being able to migrate such binaries allows to highly > reduce the amount of work needed to identify and fix post-migration > crashes, which happen constantly. Andrei's defines the following uses of this code: * it is more granular and allows us to track changed pages more effectively. The current interface can clear dirty bits for the entire process only. In addition, reading info about pages is a separate operation. It means we must freeze the process to read information about all its pages, reset dirty bits, only then we can start dumping pages. The information about pages becomes more and more outdated, while we are processing pages. The new interface solves both these downsides. First, it allows us to read pte bits and clear the soft-dirty bit atomically. It means that CRIU will not need to freeze processes to pre-dump their memory. Second, it clears soft-dirty bits for a specified region of memory. It means CRIU will have actual info about pages to the moment of dumping them. * The new interface has to be much faster because basic page filtering is happening in the kernel. With the old interface, we have to read pagemap for each page. *Implementation Evolution (Short Summary)* From the definition of GetWriteWatch(), we feel like kernel's soft-dirty feature can be used under the hood with some additions like: * reset soft-dirty flag for only a specific region of memory instead of clearing the flag for the entire process * get and clear soft-dirty flag for a specific region atomically So we decided to use ioctl on pagemap file to read or/and reset soft-dirty flag. But using soft-dirty flag, sometimes we get extra pages which weren't even written. They had become soft-dirty because of VMA merging and VM_SOFTDIRTY flag. This breaks the definition of GetWriteWatch(). We were able to by-pass this short coming by ignoring VM_SOFTDIRTY until David reported that mprotect etc messes up the soft-dirty flag while ignoring VM_SOFTDIRTY [5]. This wasn't happening until [6] got introduced. We discussed if we can revert these patches. But we could not reach to any conclusion. So at this point, I made couple of tries to solve this whole VM_SOFTDIRTY issue by correcting the soft-dirty implementation: * [7] Correct the bug fixed wrongly back in 2014. It had potential to cause regression. We left it behind. * [8] Keep a list of soft-dirty part of a VMA across splits and merges. I got the reply don't increase the size of the VMA by 8 bytes. At this point, we left soft-dirty considering it is too much delicate and userfaultfd [9] seemed like the only way forward. From there onward, we have been basing soft-dirty emulation on userfaultfd wp feature where kernel resolves the faults itself when WP_ASYNC feature is used. It was straight forward to add WP_ASYNC feature in userfautlfd. Now we get only those pages dirty or written-to which are really written in reality. (PS There is another WP_UNPOPULATED userfautfd feature is required which is needed to avoid pre-faulting memory before write-protecting [9].) All the different masks were added on the request of CRIU devs to create interface more generic and better. [1] https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-… [2] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com [3] https://github.com/google/sanitizers [4] https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm#64-bit [5] https://lore.kernel.org/all/bfcae708-db21-04b4-0bbe-712badd03071@redhat.com [6] https://lore.kernel.org/all/20220725142048.30450-1-peterx@redhat.com/ [7] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.… [8] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.… [9] https://lore.kernel.org/all/20230306213925.617814-1-peterx@redhat.com [10] https://lore.kernel.org/all/20230125144529.1630917-1-mdanylo@google.com * Original Cover letter from v8* Hello, Note: Soft-dirty pages and pages which have been written-to are synonyms. As kernel already has soft-dirty feature inside which we have given up to use, we are using written-to terminology while using UFFD async WP under the hood. This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear the info about page table entries. The following operations are supported in this ioctl: - Get the information if the pages have been written-to (PAGE_IS_WRITTEN), file mapped (PAGE_IS_FILE), present (PAGE_IS_PRESENT) or swapped (PAGE_IS_SWAPPED). - Write-protect the pages (PAGEMAP_WP_ENGAGE) to start finding which pages have been written-to. - Find pages which have been written-to and write protect the pages (atomic PAGE_IS_WRITTEN + PAGEMAP_WP_ENGAGE) It is possible to find and clear soft-dirty pages entirely in userspace. But it isn't efficient: - The mprotect and SIGSEGV handler for bookkeeping - The userfaultfd wp (synchronous) with the handler for bookkeeping Some benchmarks can be seen here[1]. This series adds features that weren't present earlier: - There is no atomic get soft-dirty/Written-to status and clear present in the kernel. - The pages which have been written-to can not be found in accurate way. (Kernel's soft-dirty PTE bit + sof_dirty VMA bit shows more soft-dirty pages than there actually are.) Historically, soft-dirty PTE bit tracking has been used in the CRIU project. The procfs interface is enough for finding the soft-dirty bit status and clearing the soft-dirty bit of all the pages of a process. We have the use case where we need to track the soft-dirty PTE bit for only specific pages on-demand. We need this tracking and clear mechanism of a region of memory while the process is running to emulate the getWriteWatch() syscall of Windows. *(Moved to using UFFD instead of soft-dirtyi feature to find pages which have been written-to from v7 patch series)*: Stop using the soft-dirty flags for finding which pages have been written to. It is too delicate and wrong as it shows more soft-dirty pages than the actual soft-dirty pages. There is no interest in correcting it [2][3] as this is how the feature was written years ago. It shouldn't be updated to changed behaviour. Peter Xu has suggested using the async version of the UFFD WP [4] as it is based inherently on the PTEs. So in this patch series, I've added a new mode to the UFFD which is asynchronous version of the write protect. When this variant of the UFFD WP is used, the page faults are resolved automatically by the kernel. The pages which have been written-to can be found by reading pagemap file (!PM_UFFD_WP). This feature can be used successfully to find which pages have been written to from the time the pages were write protected. This works just like the soft-dirty flag without showing any extra pages which aren't soft-dirty in reality. The information related to pages if the page is file mapped, present and swapped is required for the CRIU project [5][6]. The addition of the required mask, any mask, excluded mask and return masks are also required for the CRIU project [5]. The IOCTL returns the addresses of the pages which match the specific masks. The page addresses are returned in struct page_region in a compact form. The max_pages is needed to support a use case where user only wants to get a specific number of pages. So there is no need to find all the pages of interest in the range when max_pages is specified. The IOCTL returns when the maximum number of the pages are found. The max_pages is optional. If max_pages is specified, it must be equal or greater than the vec_size. This restriction is needed to handle worse case when one page_region only contains info of one page and it cannot be compacted. This is needed to emulate the Windows getWriteWatch() syscall. The patch series include the detailed selftest which can be used as an example for the uffd async wp test and PAGEMAP_IOCTL. It shows the interface usages as well. [1] https://lore.kernel.org/lkml/54d4c322-cd6e-eefd-b161-2af2b56aae24@collabora… [2] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.… [3] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.… [4] https://lore.kernel.org/all/Y6Hc2d+7eTKs7AiH@x1n [5] https://lore.kernel.org/all/YyiDg79flhWoMDZB@gmail.com/ [6] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com/ Regards, Muhammad Usama Anjum Muhammad Usama Anjum (4): fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs tools headers UAPI: Update linux/fs.h with the kernel sources mm/pagemap: add documentation of PAGEMAP_SCAN IOCTL selftests: mm: add pagemap ioctl tests Peter Xu (1): userfaultfd: UFFD_FEATURE_WP_ASYNC Documentation/admin-guide/mm/pagemap.rst | 56 + Documentation/admin-guide/mm/userfaultfd.rst | 35 + fs/proc/task_mmu.c | 426 ++++++ fs/userfaultfd.c | 26 +- include/linux/userfaultfd_k.h | 29 +- include/uapi/linux/fs.h | 53 + include/uapi/linux/userfaultfd.h | 9 +- mm/hugetlb.c | 32 +- mm/memory.c | 27 +- tools/include/uapi/linux/fs.h | 53 + tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 4 +- tools/testing/selftests/mm/config | 1 + tools/testing/selftests/mm/pagemap_ioctl.c | 1301 ++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 4 + 15 files changed, 2034 insertions(+), 23 deletions(-) create mode 100644 tools/testing/selftests/mm/pagemap_ioctl.c mode change 100644 => 100755 tools/testing/selftests/mm/run_vmtests.sh -- 2.39.2

3 months, 3 weeks

3
28
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[PATCHv2] selftests: damon: add config file

by Anders Roxell

Building and running the subsuite 'damon' of kselftest, shows the following issues: selftests: damon: debugfs_attrs.sh /sys/kernel/debug/damon not found By creating a config file enabling DAMON fragments in the selftests/damon/ directory the tests pass. Fixes: b348eb7abd09 ("mm/damon: add user space selftests") Reported-by: Naresh Kamboju <naresh.kamboju(a)linaro.org> Signed-off-by: Anders Roxell <anders.roxell(a)linaro.org> --- tools/testing/selftests/damon/config | 7 +++++++ 1 file changed, 7 insertions(+) create mode 100644 tools/testing/selftests/damon/config diff --git a/tools/testing/selftests/damon/config b/tools/testing/selftests/damon/config new file mode 100644 index 000000000000..0daf38974eb0 --- /dev/null +++ b/tools/testing/selftests/damon/config @@ -0,0 +1,7 @@ +CONFIG_DAMON=y +CONFIG_DAMON_SYSFS=y +CONFIG_DAMON_DBGFS=y +CONFIG_DAMON_PADDR=y +CONFIG_DAMON_VADDR=y +CONFIG_DAMON_RECLAIM=y +CONFIG_DAMON_LRU_SORT=y -- 2.39.2

3 months, 3 weeks

3
3
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[PATCH v1 0/5] Landlock support for UML

by Mickaël Salaün

Hi, Commit cb2c7d1a1776 ("landlock: Support filesystem access-control") introduced a new ARCH_EPHEMERAL_INODES configuration, only enabled for User-Mode Linux. The reason was that UML's hostfs managed inodes in an ephemeral way: from the kernel point of view, the same inode struct could be created several times while being used by user space because the kernel didn't hold references to inodes. Because Landlock (and probably other subsystems) ties properties (i.e. access rights) to inode objects, it wasn't possible to create rules that match inodes and then allow specific accesses. This patch series fixes the way UML manages inodes according to the underlying filesystem. They are now properly handles as for other filesystems, which enables to support Landlock (and probably other features). Backporting these patches requires some selftest harness patches backports too. Regards, Mickaël Salaün (5): hostfs: Fix ephemeral inodes selftests/landlock: Don't create useless file layouts selftests/landlock: Add supports_filesystem() helper selftests/landlock: Make mounts configurable selftests/landlock: Add tests for pseudo filesystems arch/Kconfig | 7 - arch/um/Kconfig | 1 - fs/hostfs/hostfs.h | 1 + fs/hostfs/hostfs_kern.c | 213 ++++++------ fs/hostfs/hostfs_user.c | 1 + security/landlock/Kconfig | 2 +- tools/testing/selftests/landlock/config | 8 +- tools/testing/selftests/landlock/fs_test.c | 381 +++++++++++++++++++-- 8 files changed, 472 insertions(+), 142 deletions(-) base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6 -- 2.39.2

3 months, 3 weeks

3
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[PATCH v2 tracing 0/6] tracing: additional filter predicates

by Alan Maguire

For cases like IPv6 addresses, having a means to supply tracing predicates for fields with more than 8 bytes would be convenient. This series provides a simple way to support this by allowing simple ==, != memory comparison with the predicate supplied when the size of the field exceeds 8 bytes. For example, to trace ::1, the predicate "dst == 0x00000000000000000000000000000001" ..could be used. Patch 1 implements this. As a convenience, support for IPv4, IPv6 and MAC addresses are also included; patches 2-4 cover these and allow simpler comparisons which do not require getting the exact number of bytes right; for exmaple "dst == ::1" "src != 127.0.0.1" "mac_addr == ab:cd:ef:01:23:45" Patch 5 adds tests for existing and new filter predicates, and patch 6 documents the fact that for the various addresses supported and the >8 byte memory comparison. only == and != are supported. Changes since v1 [1]: - added support for IPv4, IPv6 and MAC addresses (patches 2-4) (Masami and Steven) - added selftests for IPv4, IPv6 and MAC addresses and updated docs accordingly (patches 5,6) Changes since RFC [2]: - originally a fix was intermixed with the new functionality as patch 1 in series [2]; the fix landed separately - small tweaks to how filter predicates are defined via fn_num as opposed to via fn directly [1] https://lore.kernel.org/linux-trace-kernel/1682414197-13173-1-git-send-emai… [22] https://lore.kernel.org/lkml/1659910883-18223-1-git-send-email-alan.maguire… Alan Maguire (6): tracing: support > 8 byte array filter predicates tracing: support IPv4 address filter predicate tracing: support IPv6 filter predicates tracing: support MAC address filter predicates selftests/ftrace: add test coverage for filter predicates tracing: document IPv4, IPv6, MAC address and > 8 byte numeric filtering support Documentation/trace/events.rst | 21 +++ kernel/trace/trace_events_filter.c | 164 +++++++++++++++++- .../selftests/ftrace/test.d/event/filter.tc | 91 ++++++++++ 3 files changed, 275 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/ftrace/test.d/event/filter.tc -- 2.31.1

3 months, 3 weeks

2
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[PATCH 1/2] tty: tty_io: update timestamps on all device nodes

by Michal Sekletar

User space applications watch for timestamp changes on character device files in order to determine idle time of a given terminal session. For example, "w" program uses this information to populate the IDLE column of its output [1]. Similarly, systemd-logind has optional feature where it uses atime of the tty character device to determine if there was activity on the terminal associated with the logind's session object. If there was no activity for a configured period of time then logind will terminate such session [2]. Now, usually (e.g. bash running on the terminal) the use of the terminal will update timestamps (atime and mtime) on the corresponding terminal character device. However, if access to the terminal, e.g. /dev/pts/0, is performed through magic character device /dev/tty then such access obviously changes the state of the terminal, however timestamps on the device that correspond to the terminal (/dev/pts/0) are not updated. This patch makes sure that we update timestamps on *all* character devices that correspond to the given tty, because outside observers (w, systemd-logind) are maybe checking these timestamps. Obviously, they can not check timestamps on /dev/tty as that has per-process meaning. [1] https://gitlab.com/procps-ng/procps/-/blob/v4.0.0/w.c#L286 [2] https://github.com/systemd/systemd/blob/v252/NEWS#L477 Signed-off-by: Michal Sekletar <msekleta(a)redhat.com> --- drivers/tty/tty_io.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 36fb945fdad4..48e0148b0f3e 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -101,6 +101,7 @@ #include <linux/compat.h> #include <linux/uaccess.h> #include <linux/termios_internal.h> +#include <linux/fs.h> #include <linux/kbd_kern.h> #include <linux/vt_kern.h> @@ -811,18 +812,27 @@ void start_tty(struct tty_struct *tty) } EXPORT_SYMBOL(start_tty); -static void tty_update_time(struct timespec64 *time) +static void tty_update_time(struct tty_struct *tty, int tstamp) { + struct tty_file_private *priv; time64_t sec = ktime_get_real_seconds(); - /* - * We only care if the two values differ in anything other than the - * lower three bits (i.e every 8 seconds). If so, then we can update - * the time of the tty device, otherwise it could be construded as a - * security leak to let userspace know the exact timing of the tty. - */ - if ((sec ^ time->tv_sec) & ~7) - time->tv_sec = sec; + spin_lock(&tty->files_lock); + list_for_each_entry(priv, &tty->tty_files, list) { + struct file *filp = priv->file; + struct inode *inode = file_inode(filp); + struct timespec64 *time = tstamp == S_MTIME ? &inode->i_mtime : &inode->i_atime; + + /* + * We only care if the two values differ in anything other than the + * lower three bits (i.e every 8 seconds). If so, then we can update + * the time of the tty device, otherwise it could be construded as a + * security leak to let userspace know the exact timing of the tty. + */ + if ((sec ^ time->tv_sec) & ~7) + time->tv_sec = sec; + } + spin_unlock(&tty->files_lock); } /* @@ -928,7 +938,7 @@ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) tty_ldisc_deref(ld); if (i > 0) - tty_update_time(&inode->i_atime); + tty_update_time(tty, S_ATIME); return i; } @@ -1036,7 +1046,7 @@ static inline ssize_t do_tty_write( cond_resched(); } if (written) { - tty_update_time(&file_inode(file)->i_mtime); + tty_update_time(tty, S_MTIME); ret = written; } out: -- 2.39.2

3 months, 3 weeks

3
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Re: [RFC PATCH 0/5] cgroup/cpuset: A new "isolcpus" paritition

by Tejun Heo

Hello, Waiman. On Wed, Apr 12, 2023 at 03:52:36PM -0400, Waiman Long wrote: > There is still a distribution hierarchy as the list of isolation CPUs have > to be distributed down to the target cgroup through the hierarchy. For > example, > > cgroup root > +- isolcpus (cpus 8,9; isolcpus) > +- user.slice (cpus 1-9; ecpus 1-7; member) > +- user-x.slice (cpus 8,9; ecpus 8,9; isolated) > +- user-y.slice (cpus 1,2; ecpus 1,2; member) > > OTOH, I do agree that this can be somewhat hacky. That is why I post it as a > RFC to solicit feedback. Wouldn't it be possible to make it hierarchical by adding another cpumask to cpuset which lists the cpus which are allowed in the hierarchy but not used unless claimed by an isolated domain? Thanks. -- tejun

3 months, 3 weeks

3
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