• Sven Schnelle's avatar
    s390/vdso: add minimal compat vdso · 779df224
    Sven Schnelle authored
    Add a small vdso for 31 bit compat application that provides
    trampolines for calls to sigreturn,rt_sigreturn,syscall_restart.
    This is requird for moving these syscalls away from the signal
    frame to the vdso. Note that this patch effectively disables
    CONFIG_COMPAT when using clang to compile the kernel. clang
    doesn't support 31 bit mode.
    
    We want to redirect sigreturn and restart_syscall to the vdso. However,
    the kernel cannot parse the ELF vdso file, so we need to generate header
    files which contain the offsets of the syscall instructions in the vdso
    page.
    Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
    Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
    Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
    779df224
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