• Will Deacon's avatar
    arm64: errata: add module build workaround for erratum #843419 · df057cc7
    Will Deacon authored
    Cortex-A53 processors <= r0p4 are affected by erratum #843419 which can
    lead to a memory access using an incorrect address in certain sequences
    headed by an ADRP instruction.
    
    There is a linker fix to generate veneers for ADRP instructions, but
    this doesn't work for kernel modules which are built as unlinked ELF
    objects.
    
    This patch adds a new config option for the erratum which, when enabled,
    builds kernel modules with the mcmodel=large flag. This uses absolute
    addressing for all kernel symbols, thereby removing the use of ADRP as
    a PC-relative form of addressing. The ADRP relocs are removed from the
    module loader so that we fail to load any potentially affected modules.
    
    Cc: <stable@vger.kernel.org>
    Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    df057cc7
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