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=head1 NAME
nbd_set_pread_initialize - control whether libnbd pre-initializes read
buffers
=head1 SYNOPSIS
#include <libnbd.h>
int nbd_set_pread_initialize (
struct nbd_handle *h, bool request
);
=head1 DESCRIPTION
By default, libnbd will pre-initialize the contents of a buffer
passed to calls such as L<nbd_pread(3)> to all zeroes prior to
checking for any other errors, so that even if a client application
passed in an uninitialized buffer but fails to check for errors, it
will not result in a potential security risk caused by an accidental
leak of prior heap contents (see CVE-2022-0485 in
L<libnbd-security(3)> for an example of a security hole in an
application built against an earlier version of libnbd that lacked
consistent pre-initialization). However, for a client application
that has audited that an uninitialized buffer is never dereferenced,
or which performs its own pre-initialization, libnbd's sanitization
efforts merely pessimize performance (although the time spent in
pre-initialization may pale in comparison to time spent waiting on
network packets).
Calling this function with C<request> set to false tells libnbd to
skip the buffer initialization step in read commands.
=head1 RETURN VALUE
If the call is successful the function returns C<0>.
=head1 ERRORS
On error C<-1> is returned.
Refer to L<libnbd(3)/ERROR HANDLING>
for how to get further details of the error.
The following parameters must not be NULL: C<h>.
For more information see L<libnbd(3)/Non-NULL parameters>.
=head1 VERSION
This function first appeared in libnbd 1.12.
If you need to test if this function is available at compile time
check if the following macro is defined:
#define LIBNBD_HAVE_NBD_SET_PREAD_INITIALIZE 1
=head1 SEE ALSO
L<nbd_aio_pread(3)>,
L<nbd_aio_pread_structured(3)>,
L<nbd_create(3)>,
L<nbd_get_pread_initialize(3)>,
L<nbd_pread(3)>,
L<nbd_pread_structured(3)>,
L<nbd_set_strict_mode(3)>,
L<libnbd(3)>.
=head1 AUTHORS
Eric Blake
Richard W.M. Jones
=head1 COPYRIGHT
Copyright Red Hat
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