Messages in this thread | | | Date | Fri, 18 Aug 2023 16:31:43 +0200 | Subject | Re: [BUG] KCSAN: data-race in _find_next_bit+0x42/0xf0 | From | Mirsad Todorovac <> |
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On 8/17/23 22:29, Mirsad Todorovac wrote: > Hi, > > This is your friendly bug reporter :-) > > This is probably the last one for today from the KCSAN series. > > The setup is vanilla torvalds kernel, Ubuntu 22.04 LTS and a Ryzen 7950X box. > > NOTE: There are no proprietary modules to my knowledge, the Canonical Livepatch did not work for this > kernel, but I suspect the taint was turned on by the previous instances of bugs. > > Please find complete dmesg output and lshw output attached. > > dmesg output except: > > [10026.864497] ================================================================== > [10026.864516] BUG: KCSAN: data-race in _find_next_bit+0x42/0xf0 > > [10026.864544] race at unknown origin, with read to 0xffff9b7440075408 of 8 bytes by interrupt on cpu 0: > [10026.864562] _find_next_bit+0x42/0xf0 > [10026.864577] _nohz_idle_balance.isra.0+0x1ff/0x3f0 > [10026.864594] run_rebalance_domains+0x75/0x90 > [10026.864610] __do_softirq+0xda/0x330 > [10026.864626] __irq_exit_rcu+0x75/0xa0 > [10026.864640] irq_exit_rcu+0xe/0x20 > [10026.864654] sysvec_call_function_single+0x96/0xb0 > [10026.864671] asm_sysvec_call_function_single+0x1b/0x20 > [10026.864690] cpuidle_enter_state+0x1df/0x520 > [10026.864709] cpuidle_enter+0x41/0x70 > [10026.864725] call_cpuidle+0x23/0x60 > [10026.864742] do_idle+0x1f1/0x250 > [10026.864754] cpu_startup_entry+0x20/0x30 > [10026.864767] rest_init+0x121/0x140 > [10026.864786] arch_call_rest_init+0xe/0x30 > [10026.864803] start_kernel+0x8e3/0xd70 > [10026.864819] x86_64_start_reservations+0x18/0x30 > [10026.864835] x86_64_start_kernel+0xc0/0x110 > [10026.864848] secondary_startup_64_no_verify+0x17e/0x18b > > [10026.864876] value changed: 0x00000000ffffffcf -> 0x00000000ffffffff > > [10026.864897] Reported by Kernel Concurrency Sanitizer on: > [10026.864908] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G L 6.5.0-rc6-net-cfg-kcsan-00038-g16931859a650 #35 > [10026.864926] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 > [10026.864936] ==================================================================
P.S.
By Mr. Heo's instructions, I am adding the decoded stacktrace to this bug report, which ought to have been done in the first place.
Apology for the inconvenience.
[ 1092.112020] ================================================================== [ 1092.112039] BUG: KCSAN: data-race in _find_next_bit (lib/find_bit.c:133 (discriminator 2))
[ 1092.112068] race at unknown origin, with read to 0xffff963d80075a38 of 8 bytes by interrupt on cpu 0: [ 1092.112086] _find_next_bit (lib/find_bit.c:133 (discriminator 2)) [ 1092.112102] _nohz_idle_balance.isra.0 (./include/linux/find.h:430 kernel/sched/fair.c:11676) [ 1092.112119] run_rebalance_domains (kernel/sched/fair.c:11969) [ 1092.112136] __do_softirq (kernel/softirq.c:553) [ 1092.112152] __irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632) [ 1092.112167] irq_exit_rcu (kernel/softirq.c:647) [ 1092.112181] sysvec_call_function_single (arch/x86/kernel/smp.c:287 (discriminator 14)) [ 1092.112198] asm_sysvec_call_function_single (./arch/x86/include/asm/idtentry.h:653) [ 1092.112218] cpuidle_enter_state (drivers/cpuidle/cpuidle.c:291) [ 1092.112238] cpuidle_enter (drivers/cpuidle/cpuidle.c:390) [ 1092.112254] call_cpuidle (kernel/sched/idle.c:135) [ 1092.112271] do_idle (kernel/sched/idle.c:219 kernel/sched/idle.c:282) [ 1092.112284] cpu_startup_entry (kernel/sched/idle.c:378 (discriminator 1)) [ 1092.112298] rest_init (./include/linux/cpumask.h:1058 init/main.c:700) [ 1092.112311] arch_call_rest_init+0xe/0x30 [ 1092.112326] start_kernel (init/main.c:833 init/main.c:909) [ 1092.112340] x86_64_start_reservations (arch/x86/kernel/head64.c:544) [ 1092.112356] x86_64_start_kernel (arch/x86/kernel/head64.c:486 (discriminator 17)) [ 1092.112368] secondary_startup_64_no_verify (arch/x86/kernel/head_64.S:441)
[ 1092.112388] value changed: 0x00000000fbffffff -> 0x00000000fbfffffd
[ 1092.112402] Reported by Kernel Concurrency Sanitizer on: [ 1092.112410] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G L 6.5.0-rc6+ #44 [ 1092.112422] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 [ 1092.112429] ==================================================================
I should probably take a break while this is being investigated.
Best regards, Mirsad Todorovac
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