On Fri, Sep 29, 2017 at 01:00:56PM -0700, Guenter Roeck wrote: > Hi Josh, > > when trying to compile an image with KCFLAGS="-frecord-gcc-switches", > I get the folllowing build warning/error. > > make allmodconfig > KCFLAGS="-frecord-gcc-switches" make arch/x86/kvm/emulate.o > ./tools/objtool/objtool check --no-unreachable "arch/x86/kvm/emulate.o" > > arch/x86/kvm/emulate.o: warning: > objtool: .GCC.command.line+0x0: special: can't find new instruction > > Building a full image aborts with: > > WARNING: arch/x86/kvm/kvm.o(__ex_table+0x4c): Section mismatch in reference > from the (unknown reference) (unknown) > to the variable .GCC.command.line:kvm_fastop_exception > FATAL: The relocation at __ex_table+0x4c references > section ".GCC.command.line" which is not executable, IOW > the kernel will fault if it ever tries to > jump to it. Something is seriously wrong > and should be fixed. > make[2]: *** [arch/x86/kvm/kvm.o] Error 1 > > Any idea what might cause this problem ? >
Here is another interesting problem, seen when building arm64 allmodconfig -CONFIG_CPU_BIG_ENDIAN +CONFIG_EFI. kallsyms failure: relative symbol value 0xffffff9008073000 out of range in relative mode This is due to symbols such as 000000000000000e n __efistub_$d in the symbol table. Those are not filtered out by kallsyms, resulting in a relative "base" address of 0x0e, and all other symbols are out of range. Those symbols are only generated in efi/libstubs. Any idea what might be going on there, and how to fix it ? An easy fix would be something like - else if (stype == 'N') + else if (toupper(stype) == 'N') in kallsyms, but that doesn't seem like a clean solution to me. Thanks, Guenter