Kernel Examination Tools

Use crash, adb, and kadb(1M) to examine the kernel.

crash Command

crash examines kernel structures interactively. It can be used on a system dump and on an active system.

The following crash functions are related to STREAMS:

• dbfree — Print data block header free list.

• dblock — Print allocated STREAMS data block headers.

• linkblk — Print the linkblk(9S) table.

• mbfree — Print free STREAMS message block headers.

• mblock — Print allocated STREAMS message block headers.

• pty — Print pseudo-TTYs now configured. The l option gives information on the line discipline module. ldterm(7M), the h option provides information on the pseudo-TTY emulation module ptem(7M). The s option gives information on the packet module pckt(7M).

• qrun — Print a list of scheduled queues.

• queue — Print the STREAMS queues.

• stream — Print the stdata table.

• strstat — Print STREAMS statistics.

• tty — Print the tty table. The l option prints details about the line-discipline module.

  The crash functions dblock, linkblk, mblock, queue, and stream take an optional table entry argument or address that is the address of the data structure. The strstat command gives information about STREAMS event cells and linkblks in addition to message blocks, data blocks, queues, and streams. On the output report, the CONFIG column represents the number of structures currently configured. It may change because resources are allocated as needed.

adb Command

adb is an interactive general-purpose debugger. It can be used to examine files and provides a controlled environment for the execution of programs. It has no support built in for any STREAMS functionality.

kadb Command

kadb(1M) is an interactive debugger with a user interface similar to adb(1), but it runs in the same virtual address space as the program begin debugged. It also has no specific STREAMS support.