• Tejun Heo's avatar
    x86, relocs: ignore R_386_NONE in kernel relocation entries · 46176b4f
    Tejun Heo authored
    For relocatable 32bit kernels, boot/compressed/relocs.c processes
    relocation entries in the kernel image and appends it to the kernel
    image such that boot/compressed/head_32.S can relocate the kernel.
    The kernel image is one statically linked object and only uses two
    relocation types - R_386_PC32 and R_386_32, of the two only the latter
    needs massaging during kernel relocation and thus handled by relocs.
    R_386_PC32 is ignored and all other relocation types are considered
    error.
    
    When the target of a relocation resides in a discarded section,
    binutils doesn't throw away the relocation record but nullifies it by
    changing it to R_386_NONE, which unfortunately makes relocs fail.
    
    The problem was triggered by yet out-of-tree x86 stack unwind patches
    but given the binutils behavior, ignoring R_386_NONE is the right
    thing to do.
    
    The problem has been tracked down to binutils behavior by Jan Beulich.
    
    [ Impact: fix build with certain binutils by ignoring R_386_NONE ]
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Cc: Jan Beulich <JBeulich@novell.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    LKML-Reference: <4A1B8150.40702@kernel.org>
    Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
    46176b4f
relocs.c 15.5 KB