• Alexander Lobakin's avatar
    modpost: fix removing numeric suffixes · b5beffa2
    Alexander Lobakin authored
    With the `-z unique-symbol` linker flag or any similar mechanism,
    it is possible to trigger the following:
    
    ERROR: modpost: "param_set_uint.0" [vmlinux] is a static EXPORT_SYMBOL
    
    The reason is that for now the condition from remove_dot():
    
    if (m && (s[n + m] == '.' || s[n + m] == 0))
    
    which was designed to test if it's a dot or a '\0' after the suffix
    is never satisfied.
    This is due to that `s[n + m]` always points to the last digit of a
    numeric suffix, not on the symbol next to it (from a custom debug
    print added to modpost):
    
    param_set_uint.0, s[n + m] is '0', s[n + m + 1] is '\0'
    
    So it's off-by-one and was like that since 2014.
    
    Fix this for the sake of any potential upcoming features, but don't
    bother stable-backporting, as it's well hidden -- apart from that
    LD flag, it can be triggered only with GCC LTO which never landed
    upstream.
    
    Fixes: fcd38ed0 ("scripts: modpost: fix compilation warning")
    Signed-off-by: default avatarAlexander Lobakin <alexandr.lobakin@intel.com>
    Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
    Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
    b5beffa2
modpost.c 68.2 KB