Messages in this thread | | | Date | Fri, 3 Nov 2023 14:30:04 +0800 | From | kernel test robot <> | Subject | Re: [PATCH v3] Fixing directly deferencing a __rcu pointer warning |
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Hello,
kernel test robot noticed "WARNING:suspicious_RCU_usage" on:
commit: 0c940f3d0d4c41567b1957a4e09ad68bdeee2111 ("[PATCH v3] Fixing directly deferencing a __rcu pointer warning") url: https://github.com/intel-lab-lkp/linux/commits/Abhinav-Singh/Fixing-directly-deferencing-a-__rcu-pointer-warning/20231029-044918 base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/all/20231028204609.426841-1-singhabhinav9051571833@gmail.com/ patch subject: [PATCH v3] Fixing directly deferencing a __rcu pointer warning
in testcase: boot
compiler: gcc-12 test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
(please refer to attached dmesg/kmsg for entire log/backtrace)
+--------------------------------------------------------+------------+------------+ | | 44c9217272 | 0c940f3d0d | +--------------------------------------------------------+------------+------------+ | WARNING:suspicious_RCU_usage | 0 | 8 | | kernel/fork.c:#suspicious_rcu_dereference_check()usage | 0 | 8 | +--------------------------------------------------------+------------+------------+
If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <oliver.sang@intel.com> | Closes: https://lore.kernel.org/oe-lkp/202311031320.c3ebc782-oliver.sang@intel.com
[ 2.386253][ T0] WARNING: suspicious RCU usage [ 2.386253][ T0] 6.6.0-rc4-00506-g0c940f3d0d4c #7 Not tainted [ 2.386253][ T0] ----------------------------- [ 2.386253][ T0] kernel/fork.c:2688 suspicious rcu_dereference_check() usage! [ 2.386253][ T0] [ 2.386253][ T0] other info that might help us debug this: [ 2.386253][ T0] [ 2.386253][ T0] rcu_scheduler_active = 2, debug_locks = 1 [ 2.386253][ T0] 3 locks held by swapper/0: [ 2.386253][ T0] #0: ffffffff84dbdc50 (cgroup_threadgroup_rwsem){.+.+}-{0:0}, at: cgroup_can_fork (kbuild/src/rand-x86_64-3/kernel/cgroup/cgroup.c:6538) [ 2.386253][ T0] #1: ffffffff8482f010 (tasklist_lock){....}-{2:2}, at: copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2624) [ 2.386253][ T0] #2: ffffffff84846178 (init_sighand.siglock){....}-{2:2}, at: copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2226 kbuild/src/rand-x86_64-3/kernel/fork.c:2643) [ 2.386253][ T0] [ 2.386253][ T0] stack backtrace: [ 2.386253][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 6.6.0-rc4-00506-g0c940f3d0d4c #7 88a30a6c68427eeed926405592f52ff30544ebdd [ 2.386253][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 2.386253][ T0] Call Trace: [ 2.386253][ T0] <TASK> [ 2.386253][ T0] copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2688 (discriminator 9)) [ 2.386253][ T0] ? pidfd_prepare (kbuild/src/rand-x86_64-3/kernel/fork.c:2245) [ 2.386253][ T0] ? acpi_hw_validate_register (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwregs.c:196) [ 2.386253][ T0] ? proc_register (kbuild/src/rand-x86_64-3/fs/proc/generic.c:383) [ 2.386253][ T0] kernel_clone (kbuild/src/rand-x86_64-3/include/linux/random.h:26 kbuild/src/rand-x86_64-3/kernel/fork.c:2903) [ 2.386253][ T0] ? acpi_hw_register_read (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwregs.c:489) [ 2.386253][ T0] ? create_io_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2862) [ 2.386253][ T0] user_mode_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2971) [ 2.386253][ T0] ? kernel_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2971) [ 2.386253][ T0] ? acpi_hw_validate_io_request (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwvalid.c:128) [ 2.386253][ T0] ? rest_init (kbuild/src/rand-x86_64-3/init/main.c:1429) [ 2.386253][ T0] rest_init (kbuild/src/rand-x86_64-3/init/main.c:691) [ 2.386253][ T0] arch_call_rest_init+0x13/0x80 [ 2.386253][ T0] start_kernel (kbuild/src/rand-x86_64-3/init/main.c:992 (discriminator 1)) [ 2.386253][ T0] x86_64_start_reservations (kbuild/src/rand-x86_64-3/arch/x86/kernel/head64.c:544) [ 2.386253][ T0] x86_64_start_kernel (??:?) [ 2.386253][ T0] secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 2.386253][ T0] </TASK> [ 2.386253][ T0] [ 2.386253][ T0] ============================= [ 2.386253][ T0] WARNING: suspicious RCU usage [ 2.386253][ T0] 6.6.0-rc4-00506-g0c940f3d0d4c #7 Not tainted [ 2.386253][ T0] ----------------------------- [ 2.386253][ T0] kernel/fork.c:2689 suspicious rcu_dereference_check() usage! [ 2.386253][ T0] [ 2.386253][ T0] other info that might help us debug this: [ 2.386253][ T0] [ 2.386253][ T0] rcu_scheduler_active = 2, debug_locks = 1 [ 2.386253][ T0] 3 locks held by swapper/0: [ 2.386253][ T0] #0: ffffffff84dbdc50 (cgroup_threadgroup_rwsem){.+.+}-{0:0}, at: cgroup_can_fork (kbuild/src/rand-x86_64-3/kernel/cgroup/cgroup.c:6538) [ 2.386253][ T0] #1: ffffffff8482f010 (tasklist_lock){....}-{2:2}, at: copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2624) [ 2.386253][ T0] #2: ffffffff84846178 (init_sighand.siglock){....}-{2:2}, at: copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2226 kbuild/src/rand-x86_64-3/kernel/fork.c:2643) [ 2.386253][ T0] [ 2.386253][ T0] stack backtrace: [ 2.386253][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 6.6.0-rc4-00506-g0c940f3d0d4c #7 88a30a6c68427eeed926405592f52ff30544ebdd [ 2.386253][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 2.386253][ T0] Call Trace: [ 2.386253][ T0] <TASK> [ 2.386253][ T0] copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2689 (discriminator 9)) [ 2.386253][ T0] ? pidfd_prepare (kbuild/src/rand-x86_64-3/kernel/fork.c:2245) [ 2.386253][ T0] ? acpi_hw_validate_register (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwregs.c:196) [ 2.386253][ T0] ? proc_register (kbuild/src/rand-x86_64-3/fs/proc/generic.c:383) [ 2.386253][ T0] kernel_clone (kbuild/src/rand-x86_64-3/include/linux/random.h:26 kbuild/src/rand-x86_64-3/kernel/fork.c:2903) [ 2.386253][ T0] ? acpi_hw_register_read (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwregs.c:489) [ 2.386253][ T0] ? create_io_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2862) [ 2.386253][ T0] user_mode_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2971) [ 2.386253][ T0] ? kernel_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2971) [ 2.386253][ T0] ? acpi_hw_validate_io_request (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwvalid.c:128) [ 2.386253][ T0] ? rest_init (kbuild/src/rand-x86_64-3/init/main.c:1429) [ 2.386253][ T0] rest_init (kbuild/src/rand-x86_64-3/init/main.c:691) [ 2.386253][ T0] arch_call_rest_init+0x13/0x80 [ 2.386253][ T0] start_kernel (kbuild/src/rand-x86_64-3/init/main.c:992 (discriminator 1)) [ 2.386253][ T0] x86_64_start_reservations (kbuild/src/rand-x86_64-3/arch/x86/kernel/head64.c:544) [ 2.386253][ T0] x86_64_start_kernel (??:?) [ 2.386253][ T0] secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 2.386253][ T0] </TASK> [ 2.386253][ T0] [ 2.386253][ T0] ============================= [ 2.386253][ T0] WARNING: suspicious RCU usage [ 2.386253][ T0] 6.6.0-rc4-00506-g0c940f3d0d4c #7 Not tainted [ 2.386253][ T0] ----------------------------- [ 2.386253][ T0] kernel/fork.c:2690 suspicious rcu_dereference_check() usage! [ 2.386253][ T0] [ 2.386253][ T0] other info that might help us debug this: [ 2.386253][ T0] [ 2.386253][ T0] rcu_scheduler_active = 2, debug_locks = 1 [ 2.386253][ T0] 3 locks held by swapper/0: [ 2.386253][ T0] #0: ffffffff84dbdc50 (cgroup_threadgroup_rwsem){.+.+}-{0:0}, at: cgroup_can_fork (kbuild/src/rand-x86_64-3/kernel/cgroup/cgroup.c:6538) [ 2.386253][ T0] #1: ffffffff8482f010 (tasklist_lock){....}-{2:2}, at: copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2624) [ 2.386253][ T0] #2: ffffffff84846178 (init_sighand.siglock){....}-{2:2}, at: copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2226 kbuild/src/rand-x86_64-3/kernel/fork.c:2643) [ 2.386253][ T0] [ 2.386253][ T0] stack backtrace: [ 2.386253][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 6.6.0-rc4-00506-g0c940f3d0d4c #7 88a30a6c68427eeed926405592f52ff30544ebdd [ 2.386253][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 2.386253][ T0] Call Trace: [ 2.386253][ T0] <TASK> [ 2.386253][ T0] copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2690 (discriminator 9)) [ 2.386253][ T0] ? pidfd_prepare (kbuild/src/rand-x86_64-3/kernel/fork.c:2245) [ 2.386253][ T0] ? acpi_hw_validate_register (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwregs.c:196) [ 2.386253][ T0] ? proc_register (kbuild/src/rand-x86_64-3/fs/proc/generic.c:383) [ 2.386253][ T0] kernel_clone (kbuild/src/rand-x86_64-3/include/linux/random.h:26 kbuild/src/rand-x86_64-3/kernel/fork.c:2903) [ 2.386253][ T0] ? acpi_hw_register_read (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwregs.c:489) [ 2.386253][ T0] ? create_io_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2862) [ 2.386253][ T0] user_mode_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2971) [ 2.386253][ T0] ? kernel_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2971) [ 2.386253][ T0] ? acpi_hw_validate_io_request (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/hwvalid.c:128) [ 2.386253][ T0] ? rest_init (kbuild/src/rand-x86_64-3/init/main.c:1429) [ 2.386253][ T0] rest_init (kbuild/src/rand-x86_64-3/init/main.c:691) [ 2.386253][ T0] arch_call_rest_init+0x13/0x80 [ 2.386253][ T0] start_kernel (kbuild/src/rand-x86_64-3/init/main.c:992 (discriminator 1)) [ 2.386253][ T0] x86_64_start_reservations (kbuild/src/rand-x86_64-3/arch/x86/kernel/head64.c:544) [ 2.386253][ T0] x86_64_start_kernel (??:?) [ 2.386253][ T0] secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 2.386253][ T0] </TASK> [ 2.387851][ T1] RCU Tasks: Setting shift to 0 and lim to 1 rcu_task_cb_adjust=1. [ 2.389031][ T1] RCU Tasks Rude: Setting shift to 0 and lim to 1 rcu_task_cb_adjust=1. [ 2.390637][ T1] RCU Tasks Trace: Setting shift to 0 and lim to 1 rcu_task_cb_adjust=1. [ 2.391901][ T1] Running RCU-tasks wait API self tests
The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20231103/202311031320.c3ebc782-oliver.sang@intel.com
-- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
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