svn commit: r361740 - head/contrib/llvm-project/lld/ELF

[Ed Maste]

Author: emaste
Date: Tue Jun  2 22:57:13 2020
New Revision: 361740
URL: https://svnweb.freebsd.org/changeset/base/361740

Log:
  lld: Set DF_1_PIE for -pie
  
  DF_1_PIE originated from Solaris[1].
  
  GNU ld[2] sets the flag on non-Solaris platforms.
  
  It can help distinguish PIE from ET_DYN.
  eu-classify from elfutils uses this to recognize PIE[3].
  
  glibc uses this flag to reject dlopen'ing a PIE[4]
  
  [1] https://docs.oracle.com/cd/E36784_01/html/E36857/chapter6-42444.html
  [2] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=5fe2850dd96483f176858fd75c098313d5b20bc2
  [3] https://sourceware.org/git/?p=elfutils.git;a=commit;h=3f489b5c7c78df6d52f8982f79c36e9a220e8951
  [4] https://sourceware.org/bugzilla/show_bug.cgi?id=24323
  
  Discussed with:	dim
  Obtained from:	LLVM ee9a251caf1d
  MFC after:	1 week
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/contrib/llvm-project/lld/ELF/SyntheticSections.cpp

Modified: head/contrib/llvm-project/lld/ELF/SyntheticSections.cpp
==============================================================================
--- head/contrib/llvm-project/lld/ELF/SyntheticSections.cpp	Tue Jun  2 22:55:51 2020	(r361739)
+++ head/contrib/llvm-project/lld/ELF/SyntheticSections.cpp	Tue Jun  2 22:57:13 2020	(r361740)
@@ -1315,6 +1315,8 @@ template <class ELFT> void DynamicSection<ELFT>::final
     dtFlags1 |= DF_1_NODELETE;
   if (config->zNodlopen)
     dtFlags1 |= DF_1_NOOPEN;
+  if (config->pie)
+    dtFlags1 |= DF_1_PIE;
   if (config->zNow) {
     dtFlags |= DF_BIND_NOW;
     dtFlags1 |= DF_1_NOW;