On Mon, Mar 16, 2015 at 01:24:19PM -0400, Adam Jackson wrote: > On Fri, 2015-03-13 at 12:14 +0100, Florian Weimer wrote: > > On 03/12/2015 03:41 PM, Adam Jackson wrote: > > > > > We may want to revisit this, honestly. The actual proposal was just to > > > build executables as PIE, right? Forcing -z now is a bit more than > > > maybe was expected. > > > > People tell conflicting things about PIE. I have asked essentially the > > same thing, and I was told, no, PIE itself alters symbol resolution. Is > > this true or not? > > PIE does alter symbol resolution, though not in a particularly big way. > In a normal executable, taking the address of a global function takes > the address of the definition found in the executable itself, if any; in > a PIE, you take the address of the first definition found by the runtime > linker. Normally that's not a correctness issue since the executable > usually ends up as the first object searched, but it does mean an > LD_PRELOAD can override more symbols than it used to because the > (now-PIE) executable is importing more symbols than before. ??? PIE is the first object in symbol search scope, before LD_PRELOAD, identically to normal executables. Jakub -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
