Drop prelink support.
Audit RequiredrL253280

Description

Drop prelink support.

The way prelink used to work was

  • The compiler decides if a given section only has relocations that

are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.

  • The static linker puts all of these together.
  • The prelinker program assigns addresses to each library and resolves

the local relocations.

There are many problems with this:

  • It is incompatible with address space randomization.
  • The information passed by the compiler is redundant. The linker

knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.

  • There are newer ways of speeding up DSO (gnu hash for example).
  • Even if we want to implement this again in the compiler, the previous implementation is pretty broken. It talks about relocations that are "resolved by the static linker". If they are resolved, there are none left for the prelinker. What one needs to track is if an expression will require only dynamic relocations that point to the same DSO.

At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)

This patch removes support for it. That is, it stops printing the
".local" sections.

Details

Auditors
dsanders
H39 Triggered Audit
grosbach
H23 Triggered Audit
Committed
rafaelNov 16 2015, 4:51 PM
Parents
rL253279: Assume lane masks are always precise
Branches
Unknown
Tags
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