On Mon, Oct 12, 2026 at 02:04:26AM -0700, Kees Cook wrote: > With MITIGATION_RETPOLINE=y, GCC lowers the computed goto in > ___bpf_prog_run() to a jump through __x86_indirect_thunk_rdx. objtool > puts that jump on the retpoline call list along with the indirect calls, > so with CONFIG_CFI=y the kCFI check wants a UD2 before it: > > vmlinux.o: warning: objtool: ___bpf_prog_run+0x1e: no-cfi indirect call! > > The jump goes through the "jumptable" array, which objtool already reads > from .data.rel.ro.c_jump_table, so its targets stay inside the function > and need no kCFI check. Skip jump table jumps in the check. Clang does > not emit this jump: with retpolines, it lowers the computed goto without > an indirect jump.
I am confused.. I don't see a computed goto in __bpf_prog_run(), and we build with -fno-jump-tables.
