• Tim Abbott's avatar
    kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms. · ca4787b7
    Tim Abbott authored
    When there are two symbols in a module with the same name, one of which is
    exported, both will be marked as exported in /proc/kallsyms.  There aren't
    any instances of this in the current kernel, but it is easy to construct a
    simple module with two compilation units that exhibits the problem.
    
    $ objdump -j .text -t testmod.ko | grep foo
    00000000 l     F .text	00000032 foo
    00000080 g     F .text	00000001 foo
    $ sudo insmod testmod.ko
    $ grep "T foo" /proc/kallsyms
    c28e8000 T foo	[testmod]
    c28e8080 T foo	[testmod]
    
    Fix this by comparing the symbol values once we've found the exported
    symbol table entry matching the symbol name.  Tested using Ksplice:
    
    $ ksplice-create --patch=this_commit.patch --id=bar .
    $ sudo ksplice-apply ksplice-bar.tar.gz
    Done!
    $ grep "T foo" /proc/kallsyms
    c28e8080 T foo	[testmod]
    Signed-off-by: default avatarTim Abbott <tabbott@mit.edu>
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
    ca4787b7
module.c 71.4 KB