Hi Rusty,
I thought I should report this problem to you now, as I'm
about to have to explore some code that I'm not too familiar with
(vfree) as I continue debugging it. Also note I am running a
modified kernel/module.c, so it is remotely possible that this problem
is self-inflicted, but I don't think so.
In 2.5.70-bk1[23], I get a kernel bad memory reference
when trying load a module with an undefined symbol that is not found.
The bad memory reference occurs in load_module after the call
to module_free(mod,mod->module_core), the next time that "mod" is
dereferenced. Here is a commented excerpt from load_module
in kernel/module.c:
cleanup:
module_unload_free(mod);
module_free(mod, mod->module_init);
free_core:
module_free(mod, mod->module_core);
/* The following "if" statement generates a kernel bad memory
reference. --Adam */
free_percpu:
if (mod->percpu)
percpu_modfree(mod->percpu);
For whatever reason, module->module_core (ee820000) points to
an address slightly before mod (mod = ee828780, the bad dereference
is to ee8298a4). On x86, module_free() is vfree(). I suspect that
somehow vfree() has gotten confused.
By the way, there also seems to be a bug in the
2.5.70-bk12/kernel/module.c changes where mod->percpu is left unitialized
if a module has no per-cpu data. I've verified that there really is a
junk non-zero value in mod->percpu in that case. However, fixing that
bug does not eliminate this problem.
Adam J. Richter __ ______________ 575 Oroville Road
adam@yggdrasil.com \ / Miplitas, California 95035
+1 408 309-6081 | g g d r a s i l United States of America
"Free Software For The Rest Of Us."
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This archive was generated by hypermail 2b29 : Sun Jun 15 2003 - 22:00:20 EST