Messages in this thread | | | Date | Sat, 5 May 2012 17:49:33 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] ARM: SMP: prevent use of the console when using idmap_pgd |
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On Fri, May 04, 2012 at 06:14:02PM -0700, Colin Cross wrote: > Commit 4e8ee7de227e3ab9a72040b448ad728c5428a042 (ARM: SMP: use > idmap_pgd for mapping MMU enable during secondary booting) > switched secondary boot to use idmap_pgd, which is initialized > during early_initcall, instead of a page table initialized during > __cpu_up. This causes idmap_pgd to contain the static mappings > but be missing all dynamic mappings. > > If a console is registered that creates a dynamic mapping, the > printk in secondary_start_kernel will trigger a data abort on > the missing mapping before the exception handlers have been > initialized, leading to a hang. Initial boot is not affected > because no consoles have been registered, and resume is usually > not affected because the offending console is suspended. > Onlining a cpu with hotplug triggers the problem. > > A workaround is to the printk in secondary_start_kernel until > after the page tables have been switched back to init_mm.
I think this is fine. Please put it in the patch system, thanks.
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