CRASHME(9)

CRASHME(9) | Kernel Developer's Manual | CRASHME(9)

# NAME

`crashme`, `crashme_add`, `crashme_remove` —
in-kernel testing of crash handling

# SYNOPSIS

`#include <sys/crashme.h>`

int
`crashme_add`(crashme_node *cn);

int
`crashme_remove`(crashme_node *cn);

# DESCRIPTION

The `crashme` functions provide access to dynamically add and remove crashme nodes. These nodes are simply named callbacks that are expected to cause the system to crash.

The crashme functionality is only available in kernels with the options(4) `DEBUG` option set.

Each crashme node is maintained in a crashme_node structure which has the following public members:

    typedef int (*crashme_fn)(int);

    typedef struct crashme_node {
    	const char	*cn_name;
    	const char	*cn_longname;
    	crashme_fn	 cn_fn;
    } crashme_node;

The caller must fill in the cn_name, cn_longname, and cn_fn members.

The flags parameter is passed from sysctl. The return value is 0 upon success or non zero for failure.

# SYSCTL SUPPORT

The following sysctl(8) variables are provided by the `crashme` subsystem:

`debug.crashme_enable`
  Must be set to 1 for any `crashme` node to be executed.

The following sysctl(8) nodes trigger crashes in different ways when written:

`debug.crashme.panic`
  Call panic(9).
`debug.crashme.null_deref`
  Dereference a null pointer.
`debug.crashme.null_jump`
  Call a null function pointer, i.e., jump to the instruction address zero.
`debug.crashme.ddb`
  Enter ddb(9) directly by calling Debugger(9). Requires options(4) `DDB`.

# SEE ALSO

options(4), panic(9)

# HISTORY

The `crashme` driver appeared in NetBSD 9.0.

# AUTHORS

Matthew R. Green

January 7, 2019 | NetBSD 10.1