Commit Graph

5 Commits

Author SHA1 Message Date
Rafael Espindola 82d6725c3a Add a test showing that nocopyreloc is only about copy relocs.
For functions the linker uses a related hack: creating a plt in the
main executable that preempts the function.

Like bfd and gold, we don't disable it with nocopyreloc.

llvm-svn: 295976
2017-02-23 14:41:24 +00:00
Peter Collingbourne 628ec9f193 ELF: Place relro sections after non-relro sections in r/w segment.
This is in preparation for my next change, which will introduce a relro
nobits section. That requires that relro sections appear at the end of the
progbits part of the r/w segment so that the relro nobits section can appear
contiguously.

Because of the amount of churn required in the test suite, I'm making this
change separately.

llvm-svn: 291523
2017-01-10 01:21:30 +00:00
Ed Maste 8fd0196c6f lld: Default image base address to 0x200000 on x86-64
Align to the large page size (known as a superpage or huge page).
FreeBSD automatically promotes large, superpage-aligned allocations.

Differential Revision:	https://reviews.llvm.org/D27042

llvm-svn: 287782
2016-11-23 17:44:02 +00:00
Rafael Espindola a85efd985c Don't create dynamic relocations to ro segments.
These would just crash at runtime.

If we ever decide to support rw text segments this should make it easier
to implement as there is now a single point where we notice the problem.

I have tested this with a freebsd buildworld. It found a non pic
assembly file being linked into a .so,. With that fixed, buildworld
finished.

llvm-svn: 268149
2016-04-30 01:15:17 +00:00
Rafael Espindola a0a65f973a Use the plt entry as the address of some symbols.
This is the function equivalent of a copy relocation.

Since functions are expected to change sizes, we cannot use copy
relocations. In situations where one would be needed, what is done
instead is:
* Create a plt entry
* Output an undefined symbol whose addr is the plt entry.

The dynamic linker makes sure any shared library uses the plt entry as
the function address.

llvm-svn: 260224
2016-02-09 15:11:01 +00:00