Hi Steven and Josh- This test recursively faulted in is_ftrace_trampoline. It's not immediately obvious to me what went wrong -- is_ftrace_trampoline doesn't seem to be dereferencing the provided address.
On Fri, Aug 5, 2016 at 7:07 AM, kernel test robot <[email protected]> wrote: > > FYI, we noticed the following commit: > > https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/vmap_stack > commit 4bc0303affaa75add8c5c2fbfd6d27d9b644fa0d ("x86/mm/64: Enable vmapped > stacks") > > in testcase: boot > > on test machine: 1 threads qemu-system-x86_64 -enable-kvm -cpu Westmere with > 512M memory > > caused below changes: > > > +-------------------------------------------------------+------------+------------+ > | | ee12d3b8b1 | > 4bc0303aff | > +-------------------------------------------------------+------------+------------+ > | boot_successes | 388 | 398 > | > | boot_failures | 32 | 39 > | > | WARNING:at_kernel/trace/ftrace.c:#ftrace_bug | 32 | 39 > | > | general_protection_fault:#[##]SMP | 32 | 37 > | > | RIP:is_ftrace_trampoline | 32 | 37 > | > | Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 18 | 8 > | > | backtrace:perf_ftrace_event_register | 32 | 39 > | > | backtrace:perf_trace_init | 32 | 39 > | > | backtrace:perf_tp_event_init | 32 | 39 > | > | backtrace:perf_try_init_event | 32 | 39 > | > | backtrace:SYSC_perf_event_open | 31 | 38 > | > | backtrace:SyS_perf_event_open | 32 | 39 > | > | Kernel_panic-not_syncing:Fatal_exception | 12 | 13 > | > | WARNING:at_include/linux/uaccess.h:#pagefault_enable | 4 | > | > | RIP:#d:[<#>][<#>]is_ftrace_trampoline | 1 | > | > | BUG:kernel_test_hang | 1 | 16 > | > | BUG:unable_to_handle_kernel | 1 | > | > | Oops | 1 | > | > | RIP:task_curr | 1 | > | > | BUG:stack_guard_page_was_hit_at#(stack_is#..#) | 0 | 17 > | > | RIP:fb_get_color_depth | 0 | 3 > | > | RIP:cfb_imageblit | 0 | 8 > | > | RIP:fb_get_buffer_offset | 0 | 4 > | > | RIP:get_attribute | 0 | 1 > | > | RIP:number | 0 | 1 > | > +-------------------------------------------------------+------------+------------+ > > [ 68.243445] Call Trace: > [ 68.244310] general protection fault: 0000 [#18] SMP > [ 68.249171] BUG: stack guard page was hit at ffffc900001bbff8 (stack is > ffffc900001bc000..ffffc900001bffff) > [ 68.249174] kernel stack overflow (double-fault): 0000 [#19] SMP > [ 68.249175] Modules linked in: > [ 68.249178] CPU: 0 PID: 6 Comm: kworker/u2:0 Tainted: G W > 4.7.0-06443-g4bc0303 #82 > [ 68.249179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > Debian-1.8.2-1 04/01/2014 > [ 68.249185] Workqueue: netns cleanup_net > [ 68.249187] task: ffff8800314ec180 task.stack: ffffc900001bc000 > [ 68.249192] RIP: 0010:[<ffffffff817f31f0>] [<ffffffff817f31f0>] > fb_get_buffer_offset+0x18/0x8c > [ 68.249193] RSP: 0000:ffffc900001bc000 EFLAGS: 00010002 > [ 68.249194] RAX: 0000000000000001 RBX: ffff88002deab000 RCX: > 0000000000000001 > [ 68.249195] RDX: 0000000000000001 RSI: ffff88002deab320 RDI: > ffff88002deab000 > [ 68.249197] RBP: ffffc900001bc018 R08: 0000000000000000 R09: > 0000000000000048 > [ 68.249198] R10: 0000000000000000 R11: ffffffff83174d50 R12: > ffff88002cb68000 > [ 68.249199] R13: 00000000ffffffff R14: 0000000000000010 R15: > ffff880031c0d800 > [ 68.249202] FS: 0000000000000000(0000) GS:ffff880033200000(0000) > knlGS:0000000000000000 > [ 68.249203] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 68.249204] CR2: ffffc900001bbff8 CR3: 0000000004021000 CR4: > 00000000000006f0 > [ 68.249208] DR0: 0000000008c45968 DR1: 0000000000000000 DR2: > 0000000000000000 > [ 68.249210] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: > 0000000000000600 > [ 68.249210] Stack: > [ 68.249211] > > > FYI, raw QEMU command line is: > > qemu-system-x86_64 -enable-kvm -cpu Westmere -kernel > /pkg/linux/x86_64-allyesdebian/gcc-6/4bc0303affaa75add8c5c2fbfd6d27d9b644fa0d/vmlinuz-4.7.0-06443-g4bc0303 > -append 'ip=::::vm-kbuild-yocto-ia32-29::dhcp root=/dev/ram0 user=lkp > job=/lkp/scheduled/vm-kbuild-yocto-ia32-29/boot-1-yocto-minimal-i386.cgz-4bc0303affaa75add8c5c2fbfd6d27d9b644fa0d-20160801-54711-lk1j2k-228.yaml > ARCH=x86_64 kconfig=x86_64-allyesdebian > branch=linux-devel/devel-catchup-201607300515 > commit=4bc0303affaa75add8c5c2fbfd6d27d9b644fa0d > BOOT_IMAGE=/pkg/linux/x86_64-allyesdebian/gcc-6/4bc0303affaa75add8c5c2fbfd6d27d9b644fa0d/vmlinuz-4.7.0-06443-g4bc0303 > max_uptime=600 > RESULT_ROOT=/result/boot/1/vm-kbuild-yocto-ia32/yocto-minimal-i386.cgz/x86_64-allyesdebian/gcc-6/4bc0303affaa75add8c5c2fbfd6d27d9b644fa0d/227 > LKP_SERVER=inn debug apic=debug sysrq_always_enabled > rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 > nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 > systemd.log_level=err ignore_loglevel earlyprintk=ttyS0,115200 > console=ttyS0,115200 console=tty0 vga=normal rw drbd.minor_count=8' -initrd > /fs/sdh1/initrd-vm-kbuild-yocto-ia32-29 -m 832 -smp 1 -device > e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog > i6300esb -watchdog-action debug -rtc base=localtime -drive > file=/fs/sdh1/disk0-vm-kbuild-yocto-ia32-29,media=disk,if=virtio -pidfile > /dev/shm/kboot/pid-vm-kbuild-yocto-ia32-29 -serial > file:/dev/shm/kboot/serial-vm-kbuild-yocto-ia32-29 -daemonize -display none > -monitor null > > > > > > Thanks, > Xiaolong -- Andy Lutomirski AMA Capital Management, LLC
dmesg.xz
Description: application/xz
dmesg.xz
Description: application/xz
