NAME

ktrace − interpret kernel stack dumps

SYNOPSIS

­ktrace [ ­-i ] ­kernel ­pc ­sp [ ­link ]

DESCRIPTION

­Ktrace translates a hexadecimal kernel stack dump into a sequence of acid(1) commands to show the points in the call trace. The ­kernel argument should be the path of the kernel being debugged, and ­pc and ­sp are the PC and SP values given in the stack dump.  For MIPS kernels, the contents of the ­link register must also be supplied. 

A stack trace consists of a ­ktrace command followed by a series of lines containing fields of the form location=contents:

ktrace /kernel/path 80105bc1 8048e174
8048e114=80105ac6 8048e120=80140bb4 8048e134=8010031c
8048e16c=80137e45 8048e170=80105bc1 8048e178=80137e62
...

The trace can be edited to provide the correct kernel path and then pasted into a shell window.  If the ­-i option is present, ­ktrace instead prompts for the contents of the memory locations in which it is interested; this is useful when the stack trace is on a screen rather than in a machine readable form. 

SOURCE

­/sys/src/cmd/ktrace.c

SEE ALSO

acid(1), rdbfs(4)

BUGS

When examining a kernel trace resulting from an interrupt on top of other interrupts, only the topmost call trace is printed. 

Plan 9  —  May 09, 2000