On Mon, May 11, 2020 at 11:13:00PM +0200, Ard Biesheuvel wrote: > On Mon, 11 May 2020 at 20:36, Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote: > > > > On Mon, May 11, 2020 at 06:01:49PM +0100, Mike Lothian wrote: > > > Hi > > > > > > This patch has been causing issues for me since switching to GCC 10.1: > > > > > > CALL scripts/checksyscalls.sh > > > CALL scripts/atomic/check-atomics.sh > > > DESCEND objtool > > > CHK include/generated/compile.h > > > HOSTCC arch/x86/boot/tools/build > > > /usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/../../../../x86_64-pc-linux-gnu/bin/ld: error: linker defined: multiple definition of '_end' > > > /usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/../../../../x86_64-pc-linux-gnu/bin/ld: /tmp/ccEkW0jM.o: previous definition here > > > collect2: error: ld returned 1 exit status > > > make[1]: *** [scripts/Makefile.host:103: arch/x86/boot/tools/build] Error 1 > > > make: *** [arch/x86/Makefile:303: bzImage] Error 2 > > > > > > Cheers > > > > > > Mike > > > > I'm not getting an error even with gcc 10 for some reason, but I can see > > that it is busted. It's using the linker-defined _end symbol which is > > just pass the end of the .bss. > > > > Does adding "static" to the declaration of _end fix your error? > > This is in a host tool, so it depends on the builtin linker script the > toolchain decides to use. This is risky, though, as it may be using > PROVIDE() for _end, which means that in cases where it doesn't break, > other references to _end that may exist will be linked to the wrong > symbol. I don't think 'build' should be expected to do anything > interesting with its own representation in memory, but better fix it > nonetheless. Right, _end _is_ getting redefined in my system linker script too: I can see with objdump that the final _end symbol in my version of build is actually pointing beyond the .bss. But my toolchain doesn't report an error for some reason. > > Arvind: mind sending a fix for this, please? Yeah, I have one ready -- was just waiting to hear back if "static" did fix it, but I can send it out now.
