When we use 'help bt' command, the instruction of 'bt' is printed as below. crash> help bt NAME bt - backtrace ... crash> bf -FF ... #4 [ffff810072b47f10] vfs_write at ffffffff800789d8 ffff810072b47f18: [ffff81007e020380:files_cache] [ffff81007e2c2880:filp] ffff810072b47f28: 0000000000000002 fffffffffffffff7 ffff810072b47f38: 00002b141825d000 sys_write+69 #5 [ffff810072b47f40] sys_write at ffffffff80078f75 But it seems that 'bf -FF' shows misleading information because invalid output is displayed using 'bf -FF' command as below. crash> bf -FF 1 crash: command not found: bf But 'bt -FF 1' shows valid output. crash> bt -FF 1 PID: 1 TASK: cf932d40 CPU: 0 COMMAND: "systemd" #0 [<c0c1609c>] (__schedule) from [<c0c162c0>] [PC: c0c1609c LR: c0c162c0 SP: cf92fe18 SIZE: 72] cf92fe18: 40060093 _end+238341700 _end+239562316 trace_buffer_unlock_commit_regs+280 cf92fe28: 001c754b schedule+132 schedule+124 00000004 cf92fe38: 001c754b 00000000 __stack_chk_guard 00000000 cf92fe48: 00000000 80060013 _end+239554564 00000000 cf92fe58: _end+239562340 schedule+132 #1 [<c0c162c0>] (schedule) from [<c0c1ab5c>] [PC: c0c162c0 LR: c0c1ab5c SP: cf92fe60 SIZE: 8] cf92fe60: _end+239562452 schedule_hrtimeout_range_clock+300 So fix typo for 'bf -FF' command as below to avoid confusion. Signed-off-by: Austin Kim <austindh.kim(a)gmail.com&gt; --- help.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/help.c b/help.c index 2b2285b..934d8bc 100644 --- a/help.c +++ b/help.c @@ -2133,7 +2133,7 @@ char *help_bt[] = { " ffff810072b47f38: 00002b141825d000 sys_write+69 ", " #5 [ffff810072b47f40] sys_write at ffffffff80078f75", " ...", -" %s> bf -FF", +" %s> bt -FF", " ...", " #4 [ffff810072b47f10] vfs_write at ffffffff800789d8", " ffff810072b47f18: [ffff81007e020380:files_cache] [ffff81007e2c2880:filp]", -- 2.6.2