This is the mail archive of the gcc-help@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: is -fPIC safe for executable programs, or must -fPIE be used?

From: Jeff Law <law at redhat dot com>
To: noloader at gmail dot com, Britton Kerin <britton dot kerin at gmail dot com>
Cc: "gcc-help at gcc dot gnu dot org" <gcc-help at gcc dot gnu dot org>
Date: Thu, 24 Mar 2016 13:43:06 -0600
Subject: Re: is -fPIC safe for executable programs, or must -fPIE be used?
Authentication-results: sourceware.org; auth=none
References: <CAC4O8c-FrGrpKUQptyYzZpu8Zr9afmyWaRHTFLRLDMyA9QZtaw at mail dot gmail dot com> <CAH8yC8kqVP-hwtWm4TXcg9b0brm4UvH8Wq4xBGZyAoEb2E11-w at mail dot gmail dot com>

On 03/24/2016 01:21 PM, Jeffrey Walton wrote:

One of the GCC devs explained why its OK a few years ago, but I can't
find the bug report with the explanation. I just use -fPIC all the
time unless its i686 because the GOT pointer basically reserves EBX.
On i686 it becomes a tradeoff because you lose a register, so you may
not want -fPIC/-fPIE at all.

Actually EBX is no longer reserved on i686 when generating PIC code. Ibelieve that code went into gcc-5.



jeff

Follow-Ups:
- Re: is -fPIC safe for executable programs, or must -fPIE be used?
  - From: Jeffrey Walton

References:
- is -fPIC safe for executable programs, or must -fPIE be used?
  - From: Britton Kerin
- Re: is -fPIC safe for executable programs, or must -fPIE be used?
  - From: Jeffrey Walton

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]