* tip-bot2 for Andrea Righi <tip-b...@linutronix.de> wrote:
> The following commit has been merged into the x86/entry branch of tip: > > Commit-ID: e6d92b6680371ae1aeeb6c5eb2387fdc5d9a2c89 > Gitweb: > https://git.kernel.org/tip/e6d92b6680371ae1aeeb6c5eb2387fdc5d9a2c89 > Author: Andrea Righi <andrea.ri...@canonical.com> > AuthorDate: Thu, 14 Jan 2021 12:48:35 +01:00 > Committer: Ingo Molnar <mi...@kernel.org> > CommitterDate: Thu, 21 Jan 2021 08:11:52 +01:00 > > x86/entry: Build thunk_$(BITS) only if CONFIG_PREEMPTION=y > > With CONFIG_PREEMPTION disabled, arch/x86/entry/thunk_64.o is just an > empty object file. > > With the newer binutils (tested with 2.35.90.20210113-1ubuntu1) the GNU > assembler doesn't generate a symbol table for empty object files and > objtool fails with the following error when a valid symbol table cannot > be found: > > arch/x86/entry/thunk_64.o: warning: objtool: missing symbol table > > To prevent this from happening, build thunk_$(BITS).o only if > CONFIG_PREEMPTION is enabled. > > BugLink: https://bugs.launchpad.net/bugs/1911359 > > Fixes: 320100a5ffe5 ("x86/entry: Remove the TRACE_IRQS cruft") > Signed-off-by: Andrea Righi <andrea.ri...@canonical.com> > Signed-off-by: Ingo Molnar <mi...@kernel.org> > Cc: Borislav Petkov <b...@alien8.de> > Link: https://lore.kernel.org/r/YAAvk0UQelq0Ae7+@xps-13-7390 Hm, this fails to build on UML defconfig: /home/mingo/gcc/cross/lib/gcc/x86_64-linux/9.3.1/../../../../x86_64-linux/bin/ld: arch/x86/um/../entry/thunk_64.o: in function `preempt_schedule_thunk': /home/mingo/tip.cross/arch/x86/um/../entry/thunk_64.S:34: undefined reference to `preempt_schedule' /home/mingo/gcc/cross/lib/gcc/x86_64-linux/9.3.1/../../../../x86_64-linux/bin/ld: arch/x86/um/../entry/thunk_64.o: in function `preempt_schedule_notrace_thunk': /home/mingo/tip.cross/arch/x86/um/../entry/thunk_64.S:35: undefined reference to `preempt_schedule_notrace' Thanks, Ingo