From 291073a566b2094c7192872cc0f17ce73d83cb76 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 3 Oct 2021 13:34:19 -0700 Subject: [PATCH] kvm: fix objtool relocation warning The recent change to make objtool aware of more symbol relocation types (commit 24ff65257375: "objtool: Teach get_alt_entry() about more relocation types") also added another check, and resulted in this objtool warning when building kvm on x86: arch/x86/kvm/emulate.o: warning: objtool: __ex_table+0x4: don't know how to handle reloc symbol type: kvm_fastop_exception The reason seems to be that kvm_fastop_exception() is marked as a global symbol, which causes the relocation to ke kept around for objtool. And at the same time, the kvm_fastop_exception definition (which is done as an inline asm statement) doesn't actually set the type of the global, which then makes objtool unhappy. The minimal fix is to just not mark kvm_fastop_exception as being a global symbol. It's only used in that one compilation unit anyway, so it was always pointless. That's how all the other local exception table labels are done. I'm not entirely happy about the kinds of games that the kvm code plays with doing its own exception handling, and the fact that it confused objtool is most definitely a symptom of the code being a bit too subtle and ad-hoc. But at least this trivial one-liner makes objtool no longer upset about what is going on. Fixes: 24ff65257375 ("objtool: Teach get_alt_entry() about more relocation types") Link: https://lore.kernel.org/lkml/CAHk-=wiZwq-0LknKhXN4M+T8jbxn_2i9mcKpO+OaBSSq_Eh7tg@mail.gmail.com/ Cc: Borislav Petkov Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Vitaly Kuznetsov Cc: Wanpeng Li Cc: Jim Mattson Cc: Joerg Roedel Cc: Peter Zijlstra Cc: Josh Poimboeuf Cc: Nathan Chancellor Signed-off-by: Linus Torvalds --- arch/x86/kvm/emulate.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index c589ac832265..9a144ca8e146 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -435,7 +435,6 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop); __FOP_RET(#op) asm(".pushsection .fixup, \"ax\"\n" - ".global kvm_fastop_exception \n" "kvm_fastop_exception: xor %esi, %esi; ret\n" ".popsection"); -- GitLab