Stateless and I stumbled upon this issue while discussing the
semantics of read, accepting a size_t but only being able to return
ssize_t, effectively lacking the ability to report successful
reads > SSIZE_MAX.
The discussion went along and we came to the topic of input-based
memory allocations. Basically, it was possible for the argument
to a memory-allocation-function to overflow, leading to a segfault
later.
The OpenBSD-guys came up with the ingenious reallocarray-function,
and I implemented it as ereallocarray, which automatically returns
on error.
Read more about it here[0].
A simple testcase is this (courtesy to stateless):
$ sbase-strings -n (2^(32|64) / 4)
This will segfault before this patch and properly return an OOM-
situation afterwards (thanks to the overflow-check in reallocarray).
[0]: http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man3/calloc.3
Interface and function as proposed by cls.
The reasoning behind this function is that cls expressed his
interest to keep memory allocation out of libutf, which is a
very good motive.
This simplifies the function a lot and should also increase the
speed a bit, but the most important factor here is that there's
no malloc anywhere in libutf, making it a lot smaller and more
robust with a smaller attack-surface.
Look at the paste(1) and tr(1) changes for an idiomatic way to
allocate the right amount of space for the Rune-array.
Interface as proposed by cls, but internally rewritten after a few
considerations.
The code is much shorter and to the point, aligning itself with other
standard functions. It should also be much faster, which is not bad.
It actually makes the binaries smaller, the code easier to read
(gems like "val == true", "val == false" are gone) and actually
predictable in the sense of that we actually know what we're
working with (one bitwise operator was quite adventurous and
should now be fixed).
This is also more consistent with the other suckless projects
around which don't use boolean types.
This commit adds a simple implementation of the POSIX
standard paste(1) command, and its man page.
TODO and Makefile have been updated accordingly.
Signed-off-by: Christoph Lohmann <20h@r-36.net>
FRIGN
sin
Hiltjo Posthuma
stateless
Christoph Lohmann
Lorenzo Cogotti