diff options
| author | Colin Cross <ccross@android.com> | 2012-05-05 20:58:13 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-05-11 13:14:59 +0100 |
| commit | 2f03a6bb3e9dc3a1b5fb10c7885033809896c4f9 (patch) | |
| tree | 1aea72851343a3f44c8fd76ecc52a768f5a86d31 | |
| parent | 3e9221a04341a2e8380ad7f391c4c61cd4126387 (diff) | |
ARM: 7414/1: SMP: prevent use of the console when using idmap_pgd
commit fde165b2a29673aabf18ceff14dea1f1cfb0daad upstream.
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.
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/arm/kernel/smp.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index ef5640b9e21..e10e59a4dc1 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -297,8 +297,6 @@ asmlinkage void __cpuinit secondary_start_kernel(void) struct mm_struct *mm = &init_mm; unsigned int cpu = smp_processor_id(); - printk("CPU%u: Booted secondary processor\n", cpu); - /* * All kernel threads share the same mm context; grab a * reference and switch to it. @@ -310,6 +308,8 @@ asmlinkage void __cpuinit secondary_start_kernel(void) enter_lazy_tlb(mm, current); local_flush_tlb_all(); + printk("CPU%u: Booted secondary processor\n", cpu); + cpu_init(); preempt_disable(); trace_hardirqs_off(); |