Messages in this thread | | | Date | Mon, 23 Apr 2012 14:54:31 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 2/2] spinlock_debug: Print kallsyms name for lock |
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On Mon, 23 Apr 2012 14:45:25 -0700 Stephen Boyd <sboyd@codeaurora.org> wrote:
> When a spinlock warning is printed we usually get > > BUG: spinlock bad magic on CPU#0, modprobe/111 > lock: 0xdff09f38, .magic: 00000000, .owner: /0, .owner_cpu: 0 > > but it's nicer to print the symbol for the lock if we have it so > that we can avoid 'grep dff09f38 /proc/kallsyms' to find out > which lock it was. Use kallsyms to print the symbol name so we > get something a bit easier to read > > BUG: spinlock bad magic on CPU#0, modprobe/112 > lock: test_lock, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 > > If the lock is not in kallsyms %ps will fall back to printing the address > directly.
hm. Is this true? From my reading of kallsyms_lookup(), it will fall into module_address_lookup() whcih is a no-op if !CONFIG_MODULES.
> --- a/lib/spinlock_debug.c > +++ b/lib/spinlock_debug.c > @@ -58,7 +58,7 @@ static void spin_dump(raw_spinlock_t *lock, const char *msg) > printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", > msg, raw_smp_processor_id(), > current->comm, task_pid_nr(current)); > - printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " > + printk(KERN_EMERG " lock: %ps, .magic: %08x, .owner: %s/%d, " > ".owner_cpu: %d\n", > lock, lock->magic, > owner ? owner->comm : "<none>",
Maybe. It will only do useful things for statically-allocated locks which are rare and which we are unlikely to screw up as easily as locks which lie in dynamically allocated memory.
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