On Fri, Mar 18, 2016 at 11:56:37AM +0100, Hendrik Leppkes wrote: > On Sat, Mar 12, 2016 at 3:09 AM, Michael Niedermayer > <mich...@niedermayer.cc> wrote: > > On Thu, Mar 10, 2016 at 07:57:53PM +0100, Hendrik Leppkes wrote: > >> On Mon, Sep 21, 2015 at 6:41 AM, Alex Smith <alex.sm...@warpsharp.info> > >> wrote: > >> > From: Alex Smith <alex.sm...@warpsharp.info> > >> > > >> > Binutils will always strip the relocation information from executable > >> > files even if it needs it (dynamicbase/ASLR). We can work around this > >> > by using the pic-executable flag combined with setting the correct entry > >> > point since apparently ld forgets what that should be. This problem > >> > affects both 32 and 64-bit mingw-w64. > >> > > >> > We can combine the nxcompat/dynamicbase check because they were added to > >> > binutils at the same time. > >> > > >> > Signed-off-by: Alex Smith <alex.sm...@warpsharp.info> > >> > > >> > Conflicts: > >> > configure > >> > --- > >> > configure | 13 +++++++++++-- > >> > 1 file changed, 11 insertions(+), 2 deletions(-) > >> > > >> > diff --git a/configure b/configure > >> > index d2a25bb..d6ab35a 100755 > >> > --- a/configure > >> > +++ b/configure > >> > @@ -4367,8 +4367,6 @@ case $target_os in > >> > LIBTARGET=arm-wince > >> > fi > >> > enabled shared && ! enabled small && check_cmd $windres > >> > --version && enable gnu_windres > >> > - check_ldflags -Wl,--nxcompat > >> > - check_ldflags -Wl,--dynamicbase > >> > enabled x86_32 && check_ldflags -Wl,--large-address-aware > >> > shlibdir_default="$bindir_default" > >> > SLIBPREF="" > >> > @@ -4392,6 +4390,17 @@ case $target_os in > >> > objformat="win32" > >> > ranlib=: > >> > enable dos_paths > >> > + check_ldflags -Wl,--nxcompat,--dynamicbase > >> > + # Lets work around some stupidity in binutils. > >> > + # ld will strip relocations from executables even though we > >> > need them > >> > + # for dynamicbase (ASLR). Using -pie does retain the reloc > >> > section > >> > + # however ld then forgets what the entry point should be (oops) > >> > so we > >> > + # have to manually (re)set it. > >> > + if enabled x86_32; then > >> > + add_ldexeflags -Wl,--pic-executable,-e,_mainCRTStartup > >> > + elif enabled x86_64; then > >> > + add_ldexeflags -Wl,--pic-executable,-e,mainCRTStartup > >> > + fi > >> > ;; > >> > win32|win64) > >> > disable symver > >> > >> This patch (the relocations part) broke debugging mingw-w64 ffmpeg > >> builds with gdb, you can't set breakpoints anymore when its applied. > >> It should either be reverted or made dependent on > >> --enable/disable-debug (I would favor the first, honestly, since its a > >> rather ugly hack in itself). > > > > as i was the one applying it IIRC, i should probably comment ... > > iam not against this being partially or fully revered/mode conditional > > if it causes more problems than it does good. > > > > > > I was hoping Alex would comment, but not being able to debug using GDB > is a serious issue which people have reported ever since it was > commited, we just never knew the cause of it.
CCing alex (again) [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB You can kill me, but you cannot change the truth.
signature.asc
Description: Digital signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
