Re: untrusted string optimization
On Mon, 2005-05-16 at 16:36 -0400, Steve Grubb wrote:
I was looking at some ascii charts trying to interpret an untrusted
string and
realized something. We have this test in audit_log_untrustedstring() in
audit.c:
if (*p == '"' || *p == ' ' || *p < 0x20 || *p > 0x7f) {
It turns out that space is hex 20. So we could have:
if (*p == '"' || *p < 0x21 || *p > 0x7f) {
and have one less compare in that loop.
Look at the assembly code. If that change actually does give us one
fewer compare, then file a GCC bug.
Given that it's already upstream, we might as well leave it the way it
is. As it is, it clearly documents the fact that a space is going to
cause the string to be quoted.
--
dwmw2