Re: Runtime trouble with commit dbd952127d (seccomp: introduce writer locking)

[Linus Torvalds]

On Sun, Aug 10, 2014 at 1:51 PM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> That means that the broken configuration is (CONFIG_DEBUG_SPINLOCK=n,
> CONFIG_SMP=n).
> It also means that the BUG_ON checks introduced with the seccomp commit
> will cause this configuration to fail hard at least for architectures where
> CONFIG_SMP
> can be disabled, and if those architectures use
> include/linux/spinlock_types_up.h.

Yes. This is why we have "assert_spin_locked()". You can't use
BUG_ON(spin_is_locked()), and !spin_is_locked() tends to be even worse
unless you can prove that nobody else can get the lock simultaneously.

           Linus
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