lkml.org 
[lkml]   [2022]   [Jun]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.18 097/339] modpost: fix removing numeric suffixes
    Date
    From: Alexander Lobakin <alexandr.lobakin@intel.com>

    [ Upstream commit b5beffa20d83c4e15306c991ffd00de0d8628338 ]

    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: fcd38ed0ff26 ("scripts: modpost: fix compilation warning")
    Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
    Reviewed-by: Petr Mladek <pmladek@suse.com>
    Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    scripts/mod/modpost.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
    index ed9d056d2108..d81019db9da4 100644
    --- a/scripts/mod/modpost.c
    +++ b/scripts/mod/modpost.c
    @@ -1993,7 +1993,7 @@ static char *remove_dot(char *s)

    if (n && s[n]) {
    size_t m = strspn(s + n + 1, "0123456789");
    - if (m && (s[n + m] == '.' || s[n + m] == 0))
    + if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
    s[n] = 0;

    /* strip trailing .prelink */
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-06-13 15:42    [W:4.029 / U:0.172 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site