On Tue, Mar 22, 2022 at 02:31:36PM +0900, Masami Hiramatsu wrote: > On Mon, 21 Mar 2022 17:48:54 +0100 > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > On Mon, Mar 21, 2022 at 02:04:05PM +0100, Peter Zijlstra wrote: > > > On Mon, Mar 21, 2022 at 01:55:49PM +0100, Peter Zijlstra wrote: > > > > On Mon, Mar 21, 2022 at 02:03:27PM +1100, Stephen Rothwell wrote: > > > > > Hi all, > > > > > > > > > > After merging the tip tree, today's linux-next build (x864 allmodconfig) > > > > > produced these new warnings: > > > > > > > > > > vmlinux.o: warning: objtool: arch_rethook_prepare()+0x55: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: arch_rethook_trampoline_callback()+0x3e: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x93e: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x5f2: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x4a7: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: __rethook_find_ret_addr()+0x81: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: __rethook_find_ret_addr()+0x90: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: rethook_trampoline_handler()+0x8c: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: rethook_trampoline_handler()+0x9b: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > > > > Hurmph, lemme go figure out where that code comes from, I've not seen > > > > those. > > > > > > Ahh, something tracing. I'll go do some patches on top of it. > > > > The below gets rid of the objtool warnings. > > Yes, I confirmed that. > > > But I still think it's fairly terrible to get a (flawed) carbon copy of > > the kretprobe code. > > Indeed. I would like to replace the trampoline code of kretprobe with > rethook, eventually. There is no reason why we keep the clone. > (But I need more arch maintainers help for that, there are too many > archs implemented kretprobes) FWIW, I'm more than happy to help on the arm64 side if you could Cc me for that; I'm aware of other things in this area I'd like to clean up for backtracing, too. Thanks, Mark.
