Commit 3047e99e authored Jul 03, 2006 by Ingo Molnar Committed by Linus Torvalds Jul 03, 2006

[PATCH] lockdep: x86 smp alternatives workaround



Disable SMP alternatives fixups (the patching in of NOPs on 1-CPU systems) if
the lock validator is enabled: there is a binutils section handling bug that
causes corrupted instructions when UP instructions are patched in.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 2148270c

arch/i386/kernel/alternative.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -303,6 +303,16 @@ void alternatives_smp_switch(int smp)
		struct smp_alt_module *mod;
		unsigned long flags;

		#ifdef CONFIG_LOCKDEP
		/*
		* A not yet fixed binutils section handling bug prevents
		* alternatives-replacement from working reliably, so turn
		* it off:
		*/
		printk("lockdep: not fixing up alternatives.\n");
		return;
		#endif

		if (no_replacement \|\| smp_alt_once)
		return;
		BUG_ON(!smp && (num_online_cpus() > 1));