On 08/05/2015 05:23 PM, Leonid Yegoshin wrote:
On 08/05/2015 05:14 PM, David Daney wrote:
On 08/05/2015 05:06 PM, Leonid Yegoshin wrote:
On 08/05/2015 04:55 PM, Paul Burton wrote:
As was pointed out last time you posted this, it breaks backwards
compatibility with userland & thus cannot be applied.
Never observed since first version.
In other side, the problem with apps like ssh_keygen is observed in
absence of executable stack protection.
You cannot change the default.
If your ssh_keygen is broken, get a working version.
It is actually any application which requests non-executable stack
protection and needs some emulation BEFORE GLIBC cancels that
non-executable stack protection due to libraries.
If you build all libraries with PT_GNU_STACK 'non-executable' and use
application with the same protection then you can't emulate even a
single instruction - it crashes immediately. So, it is not a bad
application, it is a bad choice for emulation space in past.
This just means that your userspace is broken.
If GLibC cannot do the right thing then it should be fixed.
The very first thing that is executed is ld.so, you need to make your
ld.so do the right thing before transferring control to your program's
entry point.
You cannot change the default setting for executable stack just because
you have created a broken userspace.
The ability of legacy userspace to continue functioning cannot be
sacrificed.
David Daney
