On Tue, Dec 31, 2024 at 03:16:25PM +0800, Z qiang wrote:
> >
> >
> >
> > Hello,
> >
> > kernel test robot noticed "BUG:unable_to_handle_page_fault_for_address" on:
> >
> > commit: 9216c28c6a927fd20f116feed55bba025f18f401 ("srcu: Make SRCU readers use ->srcu_ctrs for counter selection")
> > https://github.com/paulmckrcu/linux dev.2024.12.24a
> >
> > in testcase: rcutorture
> > version:
> > with following parameters:
> >
> > runtime: 300s
> > test: default
> > torture_type: srcu
> >
> >
> >
> > config: i386-randconfig-005-20241230
> > 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)
> >
> >
> > +------------------------------------------------+------------+------------+
> > | | 2add2e88ea | 9216c28c6a |
> > +------------------------------------------------+------------+------------+
> > | BUG:unable_to_handle_page_fault_for_address | 0 | 6 |
> > | Oops | 0 | 6 |
> > | EIP:__srcu_read_lock | 0 | 6 |
> > | Kernel_panic-not_syncing:Fatal_exception | 0 | 6 |
> > +------------------------------------------------+------------+------------+
> >
> >
> > 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@xxxxxxxxx>
> > | Closes: https://lore.kernel.org/oe-lkp/202412311203.ca7bddba-lkp@xxxxxxxxx
> >
>
> Please try the following modifications:
>
> diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
> index e85db7d5b364..7c7304dee645 100644
> --- a/kernel/rcu/srcutree.c
> +++ b/kernel/rcu/srcutree.c
> @@ -1999,6 +1999,7 @@ static int srcu_module_coming(struct module *mod)
> for (i = 0; i < mod->num_srcu_structs; i++) {
> ssp = *(sspp++);
> ssp->sda = alloc_percpu(struct srcu_data);
> + ssp->srcu_ctrp = &ssp->sda->srcu_ctrs[0];
This does look quite promising, so thank you for digging into this!!!
Looking forward to seeing if it fixes the problem. ;-)
Thanx, Paul
> if (WARN_ON_ONCE(!ssp->sda))
> return -ENOMEM;
> }
>
>
>
> Thanks
> Zqiang
>
> >
> > [ 168.973150][ T628] BUG: unable to handle page fault for address: 2367a000
> > [ 168.973700][ T628] #PF: supervisor write access in kernel mode
> > [ 168.974809][ T628] #PF: error_code(0x0002) - not-present page
> > [ 168.975761][ T628] *pde = 00000000
> > [ 168.976236][ T628] Oops: Oops: 0002 [#1] PREEMPT SMP
> > [ 168.977052][ T628] CPU: 0 UID: 0 PID: 628 Comm: rcu_torture_wri Tainted: G T 6.13.0-rc2-00067-g9216c28c6a92 #1
> > [ 168.978867][ T628] Tainted: [T]=RANDSTRUCT
> > [ 168.979429][ T628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 168.980862][ T628] EIP: __srcu_read_lock (kernel/rcu/srcutree.c:749)
> > [ 168.981213][ T628] Code: 85 ff 74 0c e8 45 59 00 00 83 3b 00 74 02 0f 0b 5b 5e 5f 5d c3 8b 00 f0 83 44 24 fc 00 83 c0 07 83 e0 fc c3 55 89 e5 8b 50 04 <64> ff 02 f0 83 44 24 fc 00 2b 50 08 5d 89 d0 c1 f8 03 c3 55 89 e5
> > All code
> > ========
> > 0: 85 ff test %edi,%edi
> > 2: 74 0c je 0x10
> > 4: e8 45 59 00 00 call 0x594e
> > 9: 83 3b 00 cmpl $0x0,(%rbx)
> > c: 74 02 je 0x10
> > e: 0f 0b ud2
> > 10: 5b pop %rbx
> > 11: 5e pop %rsi
> > 12: 5f pop %rdi
> > 13: 5d pop %rbp
> > 14: c3 ret
> > 15: 8b 00 mov (%rax),%eax
> > 17: f0 83 44 24 fc 00 lock addl $0x0,-0x4(%rsp)
> > 1d: 83 c0 07 add $0x7,%eax
> > 20: 83 e0 fc and $0xfffffffc,%eax
> > 23: c3 ret
> > 24: 55 push %rbp
> > 25: 89 e5 mov %esp,%ebp
> > 27: 8b 50 04 mov 0x4(%rax),%edx
> > 2a:* 64 ff 02 incl %fs:(%rdx) <-- trapping instruction
> > 2d: f0 83 44 24 fc 00 lock addl $0x0,-0x4(%rsp)
> > 33: 2b 50 08 sub 0x8(%rax),%edx
> > 36: 5d pop %rbp
> > 37: 89 d0 mov %edx,%eax
> > 39: c1 f8 03 sar $0x3,%eax
> > 3c: c3 ret
> > 3d: 55 push %rbp
> > 3e: 89 e5 mov %esp,%ebp
> >
> > Code starting with the faulting instruction
> > ===========================================
> > 0: 64 ff 02 incl %fs:(%rdx)
> > 3: f0 83 44 24 fc 00 lock addl $0x0,-0x4(%rsp)
> > 9: 2b 50 08 sub 0x8(%rax),%edx
> > c: 5d pop %rbp
> > d: 89 d0 mov %edx,%eax
> > f: c1 f8 03 sar $0x3,%eax
> > 12: c3 ret
> > 13: 55 push %rbp
> > 14: 89 e5 mov %esp,%ebp
> > [ 168.982540][ T628] EAX: ef0c8420 EBX: ef0c8420 ECX: e5e1e840 EDX: 00000000
> > [ 168.983022][ T628] ESI: ef0c919c EDI: 00000000 EBP: c75e9ee8 ESP: c75e9ee8
> > [ 168.983503][ T628] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010246
> > [ 168.984024][ T628] CR0: 80050033 CR2: 2367a000 CR3: 075f5000 CR4: 00040690
> > [ 168.984518][ T628] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
> > [ 168.985008][ T628] DR6: fffe0ff0 DR7: 00000400
> > [ 168.985329][ T628] Call Trace:
> > [ 168.985571][ T628] ? show_regs (arch/x86/kernel/dumpstack.c:479 arch/x86/kernel/dumpstack.c:465)
> > [ 168.985877][ T628] ? __die_body (arch/x86/kernel/dumpstack.c:421)
> > [ 168.986185][ T628] ? __die (arch/x86/kernel/dumpstack.c:435)
> > [ 168.986466][ T628] ? page_fault_oops (arch/x86/mm/fault.c:715)
> > [ 168.986811][ T628] ? kernelmode_fixup_or_oops+0x50/0x58
> > [ 168.987273][ T628] ? __bad_area_nosemaphore+0x37/0x1d5
> > [ 168.987726][ T628] ? validate_chain (kernel/locking/lockdep.c:3819 kernel/locking/lockdep.c:3872)
> > [ 168.988058][ T628] ? bad_area_nosemaphore (arch/x86/mm/fault.c:835)
> > [ 168.988406][ T628] ? do_user_addr_fault (arch/x86/mm/fault.c:1280 (discriminator 1))
> > [ 168.988763][ T628] ? exc_page_fault (arch/x86/include/asm/irqflags.h:26 arch/x86/include/asm/irqflags.h:87 arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539)
> > [ 168.989110][ T628] ? pvclock_clocksource_read_nowd (arch/x86/mm/fault.c:1494)
> > [ 168.989472][ T628] ? handle_exception (arch/x86/entry/entry_32.S:1048)
> > [ 168.989800][ T628] ? siphash_4u64 (lib/siphash.c:203)
> > [ 168.990123][ T628] ? pvclock_clocksource_read_nowd (arch/x86/mm/fault.c:1494)
> > [ 168.990539][ T628] ? __srcu_read_lock (kernel/rcu/srcutree.c:749)
> > [ 168.990858][ T628] ? rcu_torture_barrier_init (kernel/rcu/rcutorture.c:3381) rcutorture
> > [ 168.991319][ T628] ? siphash_4u64 (lib/siphash.c:203)
> > [ 168.991618][ T628] ? pvclock_clocksource_read_nowd (arch/x86/mm/fault.c:1494)
> > [ 168.992021][ T628] ? __srcu_read_lock (kernel/rcu/srcutree.c:749)
> > [ 168.992340][ T628] srcu_read_lock (include/linux/srcu.h:165 include/linux/srcu.h:257) rcutorture
> > [ 168.992735][ T628] srcu_torture_read_lock (kernel/rcu/rcutorture.c:693) rcutorture
> > [ 168.993184][ T628] rcu_torture_writer (kernel/rcu/rcutorture.c:1528) rcutorture
> > [ 168.993615][ T628] ? _raw_spin_unlock_irqrestore (arch/x86/include/asm/irqflags.h:26 arch/x86/include/asm/irqflags.h:87 arch/x86/include/asm/irqflags.h:147 include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194)
> > [ 168.994020][ T628] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:80 (discriminator 13))
> > [ 168.994369][ T628] kthread (kernel/kthread.c:391)
> > [ 168.994647][ T628] ? rcu_torture_pipe_update (kernel/rcu/rcutorture.c:1447) rcutorture
> > [ 168.995108][ T628] ? list_del_init (include/linux/lockdep.h:248)
> > [ 168.995428][ T628] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 168.995735][ T628] ? list_del_init (include/linux/lockdep.h:248)
> > [ 168.996053][ T628] ret_from_fork_asm (arch/x86/entry/entry_32.S:737)
> > [ 168.996380][ T628] entry_INT80_32 (arch/x86/entry/entry_32.S:942)
> > [ 168.996692][ T628] Modules linked in: rcutorture(+) torture intel_rapl_msr intel_rapl_common iosf_mbi crc32c_intel aesni_intel input_leds led_class fuse
> > [ 168.997654][ T628] CR2: 000000002367a000
> > [ 168.997945][ T628] ---[ end trace 0000000000000000 ]---
> >
> >
> > The kernel config and materials to reproduce are available at:
> > https://download.01.org/0day-ci/archive/20241231/202412311203.ca7bddba-lkp@xxxxxxxxx
> >
> >
> >
> > --
> > 0-DAY CI Kernel Test Service
> > https://github.com/intel/lkp-tests/wiki
> >
> >
