Bug 7034

Please attach your .config
(In particular, I need to know whether CONFIG_MODPROBE_SMALL is selected).

Ah, you are talking about modules.dep.bb, it means you are using
CONFIG_MODPROBE_SMALL=y

I am trying to reproduce this bug.
This is on Fedora 18 machine:
I built current git with CONFIG_MODPROBE_SMALL=y.
Ran "busybox depmod", it generated /lib/modules/3.10.11/modules.dep.bb
and I do have an entry there for pata_via:

kernel/drivers/ata/pata_via.ko pci:v00001106d00009001sv*sd*bc*sc*i* pci:v00001106d0000C409sv*sd*bc*sc*i* pci:v00001106d00005324sv*sd*bc*sc*i* pci:v00001106d00003164sv*sd*bc*sc*i* pci:v00001106d00001571sv*sd*bc*sc*i* pci:v00001106d00000581sv*sd*bc*sc*i* pci:v00001106d00000571sv*sd*bc*sc*i* pci:v00001106d00000415sv*sd*bc*sc*i*     

Now I enable debugging in modprobe_small.c:

#if 0   <============ HERE changed to 0
# define dbg1_error_msg(...) ((void)0)
# define dbg2_error_msg(...) ((void)0)
#else
# define dbg1_error_msg(...) bb_error_msg(__VA_ARGS__)
# define dbg2_error_msg(...) bb_error_msg(__VA_ARGS__)
#endif

and I try to modprobe the alias which doesn't work for you:

# ./busybox modprobe pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a
modprobe: loading modules.dep.bb
modprobe: process_module('pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a','(null)')
modprobe: already_loaded:0 is_rmmod:0
modprobe: process_module('pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a'): options:'(null)'
modprobe: find_alias('pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a')
modprobe: found alias 'pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a' in module 'kernel/drivers/ata/pata_via.ko'
modprobe: load_module('kernel/drivers/ata/pata_via.ko','(null)')
modprobe: load_module:0

As you see, it works for me.
In particular, the match triggered here:

                /* Does matching substring exist? */
                for (s = desc; *s; s += strlen(s) + 1) {
                        /* Aliases in module bodies can be defined with
                         * shell patterns. Example:
                         * "pci:v000010DEd000000D9sv*sd*bc*sc*i*".
                         * Plain strcmp() won't catch that */
                        if (fnmatch(s, alias, 0) == 0) {
                                dbg1_error_msg("found alias '%s' in module '%s'",
                                                alias, modinfo[i].pathname);
                                result = &modinfo[i];
                                break;
                        }
                }

Please enable debugging in modprobe_small.c, run modprobe and tell me what it says.
Please try current git.
Please attach your modules.dep.bb.

Created attachment 5342 [details]
busybox .config via "busybox bbconfig"

Yes, CONFIG_MODPROBE_SMALL is selected.  I did not think this would matter since the strings involved are the same whether this is selected or not.  

I provided the relevant line from modules.dep.bb which AFAIK is only created when CONFIG_MODPROBE_SMALL is set.

(In reply to comment #3)
> Created attachment 5342 [details]
> busybox .config via "busybox bbconfig"
> 
> Yes, CONFIG_MODPROBE_SMALL is selected.  I did not think this would matter
> since the strings involved are the same whether this is selected or not.  
> 
> I provided the relevant line from modules.dep.bb which AFAIK is only created
> when CONFIG_MODPROBE_SMALL is set.

It works for me with your .config and with modules.dep.bb containing just one line:

kernel/drivers/ata/pata_via.ko pci:v00001106d00009001sv*sd*bc*sc*i* pci:v00001106d0000C409sv*sd*bc*sc*i* pci:v00001106d00005324sv*sd*bc*sc*i* pci:v00001106d00
003164sv*sd*bc*sc*i* pci:v00001106d00001571sv*sd*bc*sc*i* pci:v00001106d00000581sv*sd*bc*sc*i* pci:v00001106d00000571sv*sd*bc*sc*i* pci:v00001106d00000415sv*s
d*bc*sc*i*

(all on one line)

Please enable debugging in modprobe_small.c, run modprobe and tell me what it
says.
Please try current git.
Please attach your modules.dep.bb. Not one line. Entire file.

I will do those things but I can't do them instantly.  I had already moved on to kmod.  I compile busybox on a different system, etc.

Created attachment 5348 [details]
Debug output from modprobe command

The alias matches ata_generic.ko and the search seems to end there.  Should we not be using this module?

I will also attach modules.dep.bb.

Created attachment 5354 [details]
modules.dep.bb created by busybox

I believe this was with a recent Debian kernel.  

$ file vmlinuz
vmlinuz: Linux kernel x86 boot executable bzImage, version 3.12-0.bpo.1-686-pae (debian-kernel@lists.debian.org) #1 SMP De, RO-rootFS, swap_dev 0x2, Normal VGA

We did not maintain the directory structure under /lib/modules/*/.   Could this be contributing to the problem?

The problem still exits when I use the current git sources.  The debug messages look the same but I didn't diff them.  It stops after matching ata_generic.ko.

Aha, it's a dup of 627.
I think I have a fix for that.

Please try current git, it has this commit:

commit 07e5555a8f7469f6f45cacd7fc188816ae644f74
Author: Denys Vlasenko <vda.linux@googlemail.com>
Date:   Mon Apr 21 16:59:36 2014 +0200

    modprobe-small: (un)load all modules which match the alias, not only first one

    Closes 627 and 7034.

    Commonly seen case is (un)loading of an alias
    which matches ata_generic and a more specific ata module.

    For example:

    modprobe [-r] pci:v00008086d00007010sv00000000sd00000000bc01sc01i80
    (ata_generic and pata_acpi)

    modprobe [-r] pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a
    (ata_generic and pata_via)

I will try it.  BTW: I did not see bug 627 when I did a search for "modprobe".