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The CONFIG_CSD_LOCK_WAIT_DEBUG option enables debugging of hung smp_call_function*() calls (e.g. when the target CPU gets stuck within the callback function). Testing this option requires triggering such hangs. This patch adds an lkdtm test with a hung smp_call_function_single() callback, which can be used to test CONFIG_CSD_LOCK_WAIT_DEBUG and NMI backtraces (as CONFIG_CSD_LOCK_WAIT_DEBUG will attempt an NMI backtrace of the hung target CPU). On arm64 using pseudo-NMI, this looks like: | # mount -t debugfs none /sys/kernel/debug/ | # echo SMP_CALL_LOCKUP > /sys/kernel/debug/provoke-crash/DIRECT | lkdtm: Performing direct entry SMP_CALL_LOCKUP | smp: csd: Detected non-responsive CSD lock (#1) on CPU#1, waiting 5000000176 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0). | smp: csd: CSD lock (#1) handling this request. | Sending NMI from CPU 1 to CPUs 0: | NMI backtrace for cpu 0 | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.9.0-rc4-00001-gfdfd281212ec #1 | Hardware name: linux,dummy-virt (DT) | pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--) | pc : __lkdtm_SMP_CALL_LOCKUP+0x0/0x8 | lr : __flush_smp_call_function_queue+0x1b0/0x290 | sp : ffff800080003f30 | pmr_save: 00000060 | x29: ffff800080003f30 x28: ffffa4ce961a4900 x27: 0000000000000000 | x26: fff000003fcfa0c0 x25: ffffa4ce961a4900 x24: ffffa4ce959aa140 | x23: ffffa4ce959aa140 x22: 0000000000000000 x21: ffff800080523c40 | x20: 0000000000000000 x19: 0000000000000000 x18: fff05b31aa323000 | x17: fff05b31aa323000 x16: ffff800080000000 x15: 0000330fc3fe6b2c | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000279 | x11: 0000000000000040 x10: fff000000302d0a8 x9 : fff000000302d0a0 | x8 : fff0000003400270 x7 : 0000000000000000 x6 : ffffa4ce9451b810 | x5 : 0000000000000000 x4 : fff05b31aa323000 x3 : ffff800080003f30 | x2 : fff05b31aa323000 x1 : ffffa4ce959aa140 x0 : 0000000000000000 | Call trace: | __lkdtm_SMP_CALL_LOCKUP+0x0/0x8 | generic_smp_call_function_single_interrupt+0x14/0x20 | ipi_handler+0xb8/0x178 | handle_percpu_devid_irq+0x84/0x130 | generic_handle_domain_irq+0x2c/0x44 | gic_handle_irq+0x118/0x240 | call_on_irq_stack+0x24/0x4c | do_interrupt_handler+0x80/0x84 | el1_interrupt+0x44/0xc0 | el1h_64_irq_handler+0x18/0x24 | el1h_64_irq+0x78/0x7c | default_idle_call+0x40/0x60 | do_idle+0x23c/0x2d0 | cpu_startup_entry+0x38/0x3c | kernel_init+0x0/0x1d8 | start_kernel+0x51c/0x608 | __primary_switched+0x80/0x88 | CPU: 1 PID: 128 Comm: sh Not tainted 6.9.0-rc4-00001-gfdfd281212ec #1 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0x90/0xe8 | show_stack+0x18/0x24 | dump_stack_lvl+0xac/0xe8 | dump_stack+0x18/0x24 | csd_lock_wait_toolong+0x268/0x338 | smp_call_function_single+0x1dc/0x2f0 | lkdtm_SMP_CALL_LOCKUP+0xcc/0xfc | lkdtm_do_action+0x1c/0x38 | direct_entry+0xbc/0x14c | full_proxy_write+0x60/0xb4 | vfs_write+0xd0/0x35c | ksys_write+0x70/0x104 | __arm64_sys_write+0x1c/0x28 | invoke_syscall+0x48/0x114 | el0_svc_common.constprop.0+0x40/0xe0 | do_el0_svc+0x1c/0x28 | el0_svc+0x38/0x108 | el0t_64_sync_handler+0x120/0x12c | el0t_64_sync+0x1a4/0x1a8 | smp: csd: Continued non-responsive CSD lock (#1) on CPU#1, waiting 10000064272 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0). | smp: csd: CSD lock (#1) handling this request. | smp: csd: Continued non-responsive CSD lock (#1) on CPU#1, waiting 15000064384 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0). | smp: csd: CSD lock (#1) handling this request. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Cc: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20240515120828.375585-1-mark.rutland@arm.com Signed-off-by: Kees Cook <kees@kernel.org> |
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| altera-stapl | ||
| bcm-vk | ||
| c2port | ||
| cardreader | ||
| cb710 | ||
| cxl | ||
| echo | ||
| eeprom | ||
| genwqe | ||
| ibmasm | ||
| lis3lv02d | ||
| lkdtm | ||
| mchp_pci1xxxx | ||
| mei | ||
| ocxl | ||
| pvpanic | ||
| sgi-gru | ||
| sgi-xp | ||
| ti-st | ||
| uacce | ||
| vmw_vmci | ||
| ad525x_dpot-i2c.c | ||
| ad525x_dpot-spi.c | ||
| ad525x_dpot.c | ||
| ad525x_dpot.h | ||
| apds990x.c | ||
| apds9802als.c | ||
| atmel-ssc.c | ||
| bh1770glc.c | ||
| cs5535-mfgpt.c | ||
| ds1682.c | ||
| dummy-irq.c | ||
| dw-xdata-pcie.c | ||
| enclosure.c | ||
| fastrpc.c | ||
| gehc-achc.c | ||
| hi6421v600-irq.c | ||
| hisi_hikey_usb.c | ||
| hmc6352.c | ||
| hpilo.c | ||
| hpilo.h | ||
| ibmvmc.c | ||
| ibmvmc.h | ||
| ics932s401.c | ||
| isl29003.c | ||
| isl29020.c | ||
| Kconfig | ||
| kgdbts.c | ||
| lattice-ecp3-config.c | ||
| Makefile | ||
| nsm.c | ||
| ntsync.c | ||
| open-dice.c | ||
| pch_phub.c | ||
| pci_endpoint_test.c | ||
| phantom.c | ||
| qcom-coincell.c | ||
| smpro-errmon.c | ||
| smpro-misc.c | ||
| sram-exec.c | ||
| sram.c | ||
| sram.h | ||
| tifm_7xx1.c | ||
| tifm_core.c | ||
| tps6594-esm.c | ||
| tps6594-pfsm.c | ||
| tsl2550.c | ||
| vcpu_stall_detector.c | ||
| vmw_balloon.c | ||
| xilinx_sdfec.c | ||
| xilinx_tmr_inject.c | ||
| xilinx_tmr_manager.c | ||