doc/glibc-functions/explicit_bzero.texi

@node explicit_bzero
@subsection @code{explicit_bzero}
@findex explicit_bzero

Documentation:
@itemize
@item
@ifinfo
@ref{Erasing Sensitive Data,,Erasing Sensitive Data,libc},
@end ifinfo
@ifnotinfo
@url{https://www.gnu.org/software/libc/manual/html_node/Erasing-Sensitive-Data.html},
@end ifnotinfo
@item
@uref{https://www.kernel.org/doc/man-pages/online/pages/man3/explicit_bzero.3.html,,man explicit_bzero}.
@end itemize

Gnulib module: explicit_bzero
@mindex explicit_bzero

The @code{explicit_bzero} function is an approximation to what is
needed, and does not suffice in general to erase information.
Although calling @code{explicit_bzero} should clear the memory in
question, the information that was in memory may still be available
elsewhere on the machine.  Proper implementation of information
erasure requires support from levels below C code.

C23 specifies the function @code{memset_explicit}, which should be
preferred to @code{explicit_bzero} in new code.
@xref{memset_explicit}.

Portability problems fixed by Gnulib:
@itemize
@item
This function is missing on some platforms:
glibc 2.24, FreeBSD 10, NetBSD 7.1, OpenBSD 5.4, macOS 10.12, Solaris 11.4, Android 9.0,
and many other systems.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
Although the module's implementation should clear the memory on
platforms compatible with GCC and on platforms using traditional
linkers, it may not clear the memory on non-GCC platforms that use
whole-program optimization.
@end itemize