u64_stats,lockdep: Fix u64_stats_init() vs lockdep
Jakub reported that: static struct net_device *rtl8139_init_board(struct pci_dev *pdev) { ... u64_stats_init(&tp->rx_stats.syncp); u64_stats_init(&tp->tx_stats.syncp); ... } results in lockdep getting confused between the RX and TX stats lock. This is because u64_stats_init() is an inline calling seqcount_init(), which is a macro using a static variable to generate a lockdep class. By wrapping that in an inline, we negate the effect of the macro and fold the static key variable, hence the confusion. Fix by also making u64_stats_init() a macro for the case where it matters, leaving the other case an inline for argument validation etc. Reported-by:Jakub Kicinski <kuba@kernel.org> Debugged-by:
"Ahmed S. Darwish" <a.darwish@linutronix.de> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by:
"Erhard F." <erhard_f@mailbox.org> Link: https://lkml.kernel.org/r/YEXicy6+9MksdLZh@hirez.programming.kicks-ass.net
parent
50bf8080