MACH-FILE(3) MACH-FILE(3)
NAME
crackhdr, uncrackhdr, mapfile, unmapfile, mapproc,
unmapproc, detachproc, ctlproc, procnotes - machine-
independent access to exectuable files and running processes
SYNOPSIS
#include <u.h>
#include <libc.h>
#include <mach.h>
int crackhdr(int fd, Fhdr *hdr)
void uncrackhdr(Fhdr *hdr)
int mapfile(Fhdr *hdr, ulong base, Map *map, Regs **regs)
void unmapfile(Fhdr *hdr, Map *map)
int mapproc(int pid, Map *map, Regs **regs)
void unmapproc(Map *map)
int detachproc(int pid)
int ctlproc(int pid, char *msg)
int procnotes(int pid, char ***notes)
DESCRIPTION
These functions parse executable files and provide access to
those files and to running processes.
Crackhdr opens and parses the named executable file. The
returned data structure hdr is initialized with a machine-
independent description of the header information. The fol-
lowing fields are the most commonly used:
mach a pointer to the Mach structure for the target archi-
tecture
mname
the name of the target architecture
fname
a description of the kind of file (e.g., executable,
core dump)
aname
a description of the application binary interface this
file uses; typically it is the name of an operating
system If the global variable mach is nil, crackhdr
points it to the same Mach structure.
Mapfile adds the segments found in hdr to map. If hdr is an
executable file, there are typically three segments: text,
data, and a zero-backed bss. If hdr is a dynamic shared
library, its segments are relocated by base before being
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MACH-FILE(3) MACH-FILE(3)
mapping.
If hdr is a core file, there is one segment named core for
each contiguous section of memory recorded in the core file.
There are often quite a few of these, as most operating sys-
tems omit clean memory pages when writing core files (Mac OS
X is the only exception among the supported systems).
Because core files have such holes, it is typically neces-
sary to construct the core map by calling mapfile on the
executable and then calling it again on the core file.
Newly-added segments are mapped on top of existing segments,
so this arrangement will use the core file for the segments
it contains but fall back to the executable for the rest.
Unmapfile removes the mappings in map corresponding to hdr.
Mapproc attaches to a running program and adds its segments
to the given map. It adds one segment for each contiguous
section of mapped memory. On systems where this information
cannot be determined, it adds a single segment covering the
entire address space. Accessing areas of this segment that
are actually not mapped in the process address space will
cause the get/put routines to return errors.
Unmapproc removes the mappings in map corresponding to pid.
Detachproc detaches from all previously attached processes.
Ctlproc manipulates the process with id pid according to the
message msg. Valid messages include:
kill terminate the process
startstop
start the process and wait for it to stop
sysstop
arrange for the process to stop at its next system
call, start the process, and then wait for it to stop
waitstop
wait for the process to stop
start
start the process
Procnotes fills *notes with a pointer to an array of strings
representing pending notes waiting for the process. (On
Unix, these notes are textual descriptions of any pending
signals.) Procnotes returns the number of pending notes.
The memory at *notes should be freed via free (see
malloc(3)) when no longer needed.
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MACH-FILE(3) MACH-FILE(3)
SOURCE
/usr/local/plan9/src/libmach
SEE ALSO
mach(3), mach-map(3)
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