Gentoo Archives: gentoo-user

From: Jorge Almeida <jjalmeida@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] memset_s
Date: Tue, 14 Nov 2017 17:36:33
Message-Id: CAKpSnpJ0NHBnzj6ggEkx4TG36oNFBk7k=UoKxHC+5Wmw7029Kg@mail.gmail.com
In Reply to: Re: [gentoo-user] memset_s by Jorge Almeida
On Fri, Nov 10, 2017 at 12:09 PM, Jorge Almeida <jjalmeida@×××××.com> wrote:

> http://www.daemonology.net/blog/2014-09-04-how-to-zero-a-buffer.html > > >>> Of course, what would really solve the optimize-into-oblivion problem >>> is a pragma that when invoked on a particular block of code (maybe >>> only a function definition) would tell the compiler to do what the >>> programmer says rather than viewing a function as a kind of black box. >>> >>
It seems a solution exists with gcc: https://stackoverflow.com/questions/2219829/how-to-prevent-gcc-optimizing-some-statements-in-c The last reply: void __attribute__((optimize("O0"))) foo(unsigned char data) { // unmodifiable compiler code } Any comments, anyone? Yes, it's gcc, but IMO this should be in the language itself. Am I right to assume this is a poorly known feature of gcc? It allows, for example, to replace sensitive data by random bytes, existing system callls like memset() or getrandom() can be used as they are, no reimplementation needed. Jorge Almeida

Replies

Subject Author
Re: [gentoo-user] memset_s R0b0t1 <r030t1@×××××.com>
[gentoo-user] Re: memset_s Nikos Chantziaras <realnc@×××××.com>