Hi, On 2021-11-22 20:13:28 -0500, Bruce Momjian wrote: > On Mon, Nov 22, 2021 at 03:57:45PM -0800, Andres Freund wrote: > > It does however change symbol binding, basically making all symbols bound > > eagerly. Which I guess theoretically could be considered an ABI change, > > because it removes the ability to intercept symbols referenced in a > > previously > > loaded shared library, with a subsequently loaded library (e.g. loaded with > > RTLD_DEEPBIND) function before the symbol is used. But that seems like a > > stretch. And I think most ELF platforms/linux distributions have/are moving > > towards using -Wl,-z,now -Wl,-z,relro also makes symbols bound eagerly. > > I found this really interesting, and I am surprised how things got so > suboptimal.
It's always been this way on ELF afaict (*). I don't think anybody would design ELF the same way today. I think it's pretty clear that defaulting to making symbols interceptable was a bad idea. But it's where we are... > Has it always been this way? Is it the use of C++ that is causing this by > default? Nope, this is with plain C. Greetings, Andres Freund (*) I guess you can argue it got a tad worse with the increasing use of position independent executables, but that's a relatively small difference in the scope of the issue.
