Re: [lock validator] net/ipv4/fib_hash.c: illegal {enabled-softirqs} -> {used-in-softirq} usage?

[Herbert Xu <herbert@gondor.apana.org.au>]

Ingo Molnar <mingo@elte.hu> wrote:
> the lock validator i'm working on found another item:
> 
>  ============================
>  [ BUG: illegal lock usage! ]
>  ----------------------------
>  illegal {enabled-softirqs} -> {used-in-softirq} usage.
>  hackbench/8407 [HC0[0]:SC1[2]:HE1:SE0] takes:
>   {&state[i].lock} [<c0bf7d08>] wrandom_flush+0x2a/0xb3
>  {enabled-softirqs} state was registered at:
>   [<c0befc33>] fn_hash_insert+0x565/0x5c3
>  hardirqs last enabled at: [<c0d29a36>] _spin_unlock_irq+0xd/0x10
>  softirqs last enabled at: [<c012d0a0>] irq_exit+0x36/0x38
>  
>  other info that might help us debug this:
>  locks held by hackbench/8407: <none>
>  
>  stack backtrace:
>   [<c0103e86>] show_trace+0xd/0xf
>   [<c0103e9d>] dump_stack+0x15/0x17
>   [<c013eb40>] print_usage_bug+0x16d/0x177
>   [<c013f130>] mark_lock+0xe3/0x248
>   [<c013f65d>] debug_lock_chain+0x3c8/0xb1d
>   [<c013fde3>] debug_lock_chain_spin+0x31/0x48
>   [<c0410c4e>] _raw_spin_lock+0x34/0x7f
>   [<c0d298fd>] _spin_lock+0x8/0xa
>   [<c0bf7d08>] wrandom_flush+0x2a/0xb3

Good catch.  In fact the other spin lock operation in the same file needs
BH protection as well since it is invoked by the output route path which
can be in user-context for local packets.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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