KVM_DUMP(3) OpenBSD Programmer's Manual KVM_DUMP(3)NAME
kvm_dump_mkheader, kvm_dump_wrtheader, kvm_dump_inval - crash dump
support functions
SYNOPSIS
#include <kvm.h>
int
kvm_dump_mkheader(kvm_t *kd, off_t dump_off);
int
kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize);
int
kvm_dump_inval(kvm_t *kd);
DESCRIPTION
First note that the functions described here were designed to be used by
savecore(8).
The function kvm_dump_mkheader() checks if the physical memory file
associated with kd contains a valid crash dump header as generated by a
dumping kernel. When a valid header is found, kvm_dump_mkheader()
initializes the internal kvm data structures as if a crash dump generated
by the savecore(8) program was opened. This has the intentional side
effect of enabling the address translation machinery.
A call to kvm_dump_mkheader() will most likely be followed by a call to
kvm_dump_wrtheader(). This function takes care of generating the generic
header, the CORE_CPU section and the section header of the CORE_DATA
section. The data is written to the file pointed at by fp. The dumpsize
argument is only used to properly set the segment size of the CORE_DATA
section. Note that this function assumes that fp is positioned at file
location 0. This function will not seek and therefore allows fp to be a
file pointer obtained by zopen().
The kvm_dump_inval() function clears the magic number in the physical
memory file associated with kd. The address translations must be enabled
for this to work (thus assuming that kvm_dump_mkheader() was called
earlier in the sequence).
RETURN VALUES
All functions return 0 on success, -1 on failure. In the case of
failure, kvm_geterr(3) can be used to retrieve the cause of the error.
SEE ALSOkvm(3)HISTORY
These functions first appeared in NetBSD 1.1a.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
