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KVM_DUMP_MKHEADER(3) Library Functions Manual KVM_DUMP_MKHEADER(3)

kvm_dump_mkheader, kvm_dump_wrtheader, kvm_dump_invalcrash dump support functions

#include <kvm.h>

kvm_dump_mkheader(kvm_t *kd, off_t dump_off);

kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize);

kvm_dump_inval(kvm_t *kd);

First note that the functions described here were designed to be used by savecore(8).

The function () 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 () will most likely be followed by a call to (). 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 ().

The () 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).

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.


These functions first appeared in NetBSD 1.1A.

January 4, 2023 OpenBSD-current