kernel/module.c: compare symbol values when marking symbols as exported in /proc...
authorTim Abbott <tabbott@MIT.EDU>
Mon, 5 Jan 2009 14:40:10 +0000 (08:40 -0600)
committerRusty Russell <rusty@rustcorp.com.au>
Sun, 4 Jan 2009 22:10:11 +0000 (08:10 +1030)
commitca4787b779dd698a2a33a328aa5fa90a3e954077
tree678eddc5cfd0b366b1ef5662cf6ccdd7b7b2f135
parenta327ca2c2674c5a9a0073421df19bfc362698136
kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms.

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: Tim Abbott <tabbott@mit.edu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
kernel/module.c