[FFmpeg-cvslog] configure: Support for HEASLR on mingw targets

[Alex Smith]

ffmpeg | branch: master | Alex Smith <alex.smith at warpsharp.info> | Sat Sep 26 02:43:23 2015 -0400| [a58c22d61260941fc651add73836882d5b112fdb] | committer: Hendrik Leppkes

configure: Support for HEASLR on mingw targets

The appropriate flag for HEASLR (--high-entropy-va) was added in
binutils 2.25.

Also set the image base >4GB so higher entropy gets applied to image
base randomization when used with HEASLR (8 -> 17 bits of
randomization).  Windows does this for compatibility because of "latent
pointer truncation issues".

Signed-off-by: Alex Smith <alex.smith at warpsharp.info>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a58c22d61260941fc651add73836882d5b112fdb
---

 configure |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure b/configure
index bd4f91d..b572d59 100755
--- a/configure
+++ b/configure
@@ -4400,6 +4400,10 @@ case $target_os in
             add_ldexeflags -Wl,--pic-executable,-e,_mainCRTStartup
         elif enabled x86_64; then
             add_ldexeflags -Wl,--pic-executable,-e,mainCRTStartup
+            check_ldflags -Wl,--high-entropy-va # binutils 2.25
+            # Set image base >4GB for extra entropy with HEASLR
+            add_ldexeflags -Wl,--image-base,0x140000000
+            append SHFLAGS -Wl,--image-base,0x180000000
         fi
         ;;
     win32|win64)