PROC_RWMEM(9) FreeBSD Kernel Developer's Manual PROC_RWMEM(9)
NAME
proc_rwmem, proc_readmem, proc_writemem - read from or write to a process
address space
SYNOPSIS
#include <sys/types.h>
#include <sys/ptrace.h>
int
proc_rwmem(struct proc *p, struct uio *uio);
ssize_t
proc_readmem(struct thread *td, struct proc *p, vm_offset_t va,
void *buf, size_t len);
ssize_t
proc_writemem(struct thread *td, struct proc *p, vm_offset_t va,
void *buf, size_t len);
DESCRIPTION
These functions are used to read to or write from the address space of
the process p. The proc_rwmem() function requires the caller to specify
the I/O parameters using a struct uio, described in uio(9). The
proc_readmem() and proc_writemem() functions provide a simpler, less
general interface which allows the caller to read into or write the
kernel buffer buf of size len from or to the memory at offset va in the
address space of p. The operation is performed on behalf of thread td,
which will most often be the current thread.
These functions may sleep and thus may not be called with any non-
sleepable locks held. The process p must be held by the caller using
PHOLD(9).
RETURN VALUES
The proc_rwmem() function returns 0 on success. EFAULT is returned if
the specified user address is invalid, and ENOMEM is returned if the
target pages could not be faulted in due to a resource shortage.
The proc_readmem() and proc_writemem() functions return the number of
bytes read or written, respectively. This may be smaller than the number
of bytes requested, for example if the request spans multiple pages in
the process address space and one of them after the first is not mapped.
Otherwise, -1 is returned.
SEE ALSO
copyin(9), locking(9), PHOLD(9), uio(9)
AUTHORS
This manual page was written by Mark Johnston <
[email protected]>.
FreeBSD 14.1-RELEASE-p8 December 7, 2015 FreeBSD 14.1-RELEASE-p8