missing symbol do_softirq in net moduels for pre-2

Hi,

Built -pre2 and noticed most of the modules in net/* are getting a missing symbol for do_softirq.

Have I messed up, or is there a real error?

Ed Tomlinson <[email protected]>

http://www.tux.org/lkml/#s8-8

Hmm, I don't think this is it--I'm seeing the same thing, and I have tried 'make mrproper'. All symbols are getting versionated except certain calls to do_softirq() in, e.g., sunrpc.o and the iptables modules.

I looked into this, and I believe the problem is due to 2.4.6-pre2's change to the i386 local_bh_enable() macro--the C version has been replaced with an assembly language version that does "call do_doftirq;". Perhaps this function call from the assembly language version does not get versionated?

Cheers, Wayne

Keith Owens:

I got the same error on -pre1, and tried the info in the link, didn't help:

root@test4:/usr/src# depmod -ae
depmod: *** Unresolved symbols in /lib/modules/2.4.6-pre1/kernel/net/ipv4/netfilter/ip_tables.o
depmod:         do_softirq
depmod: *** Unresolved symbols in /lib/modules/2.4.6-pre1/kernel/net/ipv4/netfilter/ipt_LOG.o
depmod:         do_softirq

Am I missing something in my .config, or is there something else that's wrong? Any clues to where I should look?

-Thomas

It was missing in 6-pre1. It should have been fixed in 6-pre2.

The fix to export ksyms for do_softirq is _in_ pre2... its just not working.

from ksyms in pre2:
/* software interrupts */
EXPORT_SYMBOL(tasklet_hi_vec);
EXPORT_SYMBOL(tasklet_vec);
EXPORT_SYMBOL(bh_task_vec);
EXPORT_SYMBOL(init_bh);
EXPORT_SYMBOL(remove_bh);
EXPORT_SYMBOL(tasklet_init);
EXPORT_SYMBOL(tasklet_kill);
EXPORT_SYMBOL(__run_task_queue);
EXPORT_SYMBOL(do_softirq);
EXPORT_SYMBOL(tasklet_schedule);
EXPORT_SYMBOL(tasklet_hi_schedule);

in the arch code for softirq we now have:

+#define local_bh_enable()                                              \
+do {                                                                   \
+       unsigned int *ptr = &local_bh_count(smp_processor_id());        \
+                                                                       \
+       if (!--*ptr)                                                    \
+               __asm__ __volatile__ (                                  \
+                       "cmpl $0, -8(%0);"                              \
+                       "jnz 2f;"                                       \
+                       "1:;"                                           \
+                                                                       \
+                       ".section .text.lock,\"ax\";"                   \
+                       "2: pushl %%eax; pushl %%ecx; pushl %%edx;"     \

+ "call do_softirq;"

What has to happen to get assembly code to version the symbol?

Ed Tomlinson

I have verified that the versioning of the do_softirq symbol above is the source of the problems in 2.4.6-pre2: I made two copies of the local_bh_enable macro, one with the versioning hash explicitly appended to the symbol, and chose between with #ifdef MODULE. Everything works fine now.

Of course, this is ugly, ugly, ugly, so hopefully someone will answer Ed's question as to the correct way of doing this.

Cheers, Wayne

Resend, the first patch never appeared. The problem is the call to do_softirq inside an asm string where cpp cannot convert it. The correct fix is toe xpose do_softirq so cpp can convert it then map to a string and concatenate with teh asm string. But that requires ugly helper macros, a cleaner fix is:

Against 2.4.6-pre2. Note: you must run make mrproper after applying this patch.

Index: 6-pre2.1/kernel/ksyms.c

@@ -536,7 +536,7 @@ EXPORT_SYMBOL(remove_bh);
 EXPORT_SYMBOL(tasklet_init);
 EXPORT_SYMBOL(tasklet_kill);
 EXPORT_SYMBOL(__run_task_queue);
-EXPORT_SYMBOL(do_softirq);
+EXPORT_SYMBOL_NOVERS(do_softirq);
 EXPORT_SYMBOL(tasklet_schedule);
 EXPORT_SYMBOL(tasklet_hi_schedule);
 

In my case its off a clean tree patched with lvm, ide patches, dma timeout retry patch and reiserfs fixes. Did we not have a problem a while back in ac with versioned symbols in assembly?

Ed Tomlinson