Messages in this thread | | | Date | Wed, 24 Apr 2013 16:49:33 +0300 | Subject | Re: [PATCH] x86_32: Fix module version table mismatch. | From | Andy Shevchenko <> |
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It works Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
On Wed, Apr 24, 2013 at 1:13 PM, James Hogan <james.hogan@imgtec.com> wrote: > On 24/04/13 02:00, H. Peter Anvin wrote: >> On 04/23/2013 05:52 PM, H. Peter Anvin wrote: >>> On 04/23/2013 05:40 AM, Tetsuo Handa wrote: >>>> Commit a4b6a77b "module: fix symbol versioning with symbol prefixes" broke >>>> loading of net/ipv6/ipv6.ko built with CONFIG_MODVERSIONS=y for x86_32. >>> >>> This really does seem to be the offending commit, although I'm still >>> confused how the heck that is possible. >>> >> >> OK, now I grok. >> >> The bug is the use of VMLINUX_SYMBOL_STR(%s) which expands at the time >> the output of modpost is compiled. However, VMLINUX_SYMBOL_STR() unlike >> __VMLINUX_SYMBOL_STR() does macro expansion on its argument, which is >> actively wrong here. > > Yes, nasty bug there (sorry!) > >> I think the choice is either to change this to __VMLINUX_SYMBOL_STR() or >> re-introduce CONFIG_SYMBOL_PREFIX (or its equivalent) so that modprobe >> can emit it at compile time > > Using __VMLINUX_SYMBOL_STR looks like the correct solution to me. > >> (assuming there even should *be* a prefix on >> the symbol here, i.e. that the compiler won't add it.) > > [__]VMLINUX_SYMBOL_STR expands to a string (e.g. "_" "memcmp" or just > "memcmp") so the compiler won't touch it. > >> >> Either way -- James, Rusty, this is in your court. > > How does the patch below look? I presume this is preferred over > making VMLINUX_SYMBOL_STR non-argument-expanding? > > Thanks > James > > Subject: [PATCH 1/1] modpost: fix unwanted VMLINUX_SYMBOL_STR expansion > > Commit a4b6a77b77ba4f526392612c2365797fab956014 ("module: fix symbol > versioning with symbol prefixes") broke the MODVERSIONS loading of any > module using memcmp (e.g. ipv6) on x86_32, as it's defined to > __builtin_memcmp which is expanded by VMLINUX_SYMBOL_STR. Use > __VMLINUX_SYMBOL_STR instead which doesn't expand the argument. > > Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Signed-off-by: James Hogan <james.hogan@imgtec.com> > Cc: Rusty Russell <rusty@rustcorp.com.au> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Cc: H. Peter Anvin <hpa@zytor.com> > --- > 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 1f90961..a4be8e1 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -1957,7 +1957,7 @@ static int add_versions(struct buffer *b, struct module *mod) > s->name, mod->name); > continue; > } > - buf_printf(b, "\t{ %#8x, VMLINUX_SYMBOL_STR(%s) },\n", > + buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n", > s->crc, s->name); > } > > -- > 1.8.1.2 >
-- With Best Regards, Andy Shevchenko
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