mirror of https://github.com/torvalds/linux.git
38fa3206bf
While reboot the system by sysrq, the following bug will be occur. BUG: sleeping function called from invalid context at kernel/locking/semaphore.c:90 in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 10052, name: rc.shutdown CPU: 3 PID: 10052 Comm: rc.shutdown Tainted: G W O 5.10.0 #1 Call trace: dump_backtrace+0x0/0x1c8 show_stack+0x18/0x28 dump_stack+0xd0/0x110 ___might_sleep+0x14c/0x160 __might_sleep+0x74/0x88 down_interruptible+0x40/0x118 virt_efi_reset_system+0x3c/0xd0 efi_reboot+0xd4/0x11c machine_restart+0x60/0x9c emergency_restart+0x1c/0x2c sysrq_handle_reboot+0x1c/0x2c __handle_sysrq+0xd0/0x194 write_sysrq_trigger+0xbc/0xe4 proc_reg_write+0xd4/0xf0 vfs_write+0xa8/0x148 ksys_write+0x6c/0xd8 __arm64_sys_write+0x18/0x28 el0_svc_common.constprop.3+0xe4/0x16c do_el0_svc+0x1c/0x2c el0_svc+0x20/0x30 el0_sync_handler+0x80/0x17c el0_sync+0x158/0x180 The reason for this problem is that irq has been disabled in machine_restart() and then it calls down_interruptible() in virt_efi_reset_system(), which would occur sleep in irq context, it is dangerous! Commit 99409b935c9a("locking/semaphore: Add might_sleep() to down_*() family") add might_sleep() in down_interruptible(), so the bug info is here. down_trylock() can solve this problem, cause there is no might_sleep. -------- Cc: <stable@vger.kernel.org> Signed-off-by: Zhang Jianhua <chris.zjh@huawei.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> |
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| .. | ||
| libstub | ||
| test | ||
| Kconfig | ||
| Makefile | ||
| apple-properties.c | ||
| arm-runtime.c | ||
| capsule-loader.c | ||
| capsule.c | ||
| cper-arm.c | ||
| cper-x86.c | ||
| cper.c | ||
| dev-path-parser.c | ||
| earlycon.c | ||
| efi-bgrt.c | ||
| efi-init.c | ||
| efi-pstore.c | ||
| efi.c | ||
| efibc.c | ||
| efivars.c | ||
| embedded-firmware.c | ||
| esrt.c | ||
| fake_mem.c | ||
| fake_mem.h | ||
| fdtparams.c | ||
| memattr.c | ||
| memmap.c | ||
| mokvar-table.c | ||
| rci2-table.c | ||
| reboot.c | ||
| riscv-runtime.c | ||
| runtime-map.c | ||
| runtime-wrappers.c | ||
| sysfb_efi.c | ||
| tpm.c | ||
| vars.c | ||
| x86_fake_mem.c | ||