Messages in this thread | | | Date | Tue, 25 Aug 2009 12:34:21 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH] x86: Execute WP test after interrupts are enabled |
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On 08/25/09 12:16, Pekka Enberg wrote: > Commit 83b519e8b9572c319c8e0c615ee5dd7272856090 ("slab: setup allocators > earlier in the boot sequence") changed the boot sequence to call > mem_init() early. Unfortunately Xen is not prepared to handle the WP test at > that point so we need to make the test run later. > > This patch fixes the Xen boot failures reported by Arnd Hannemann. >
I don't think this is the real fix, and it seems a bit ugly. I'm OK with it as a workaround, but I think it will end up getting reverted if applied.
J
> Reported-by: Arnd Hannemann <hannemann@nets.rwth-aachen.de> > Tested-by: Arnd Hannemann <hannemann@nets.rwth-aachen.de> > Cc: Jeremy Fitzhardinge <jeremy@goop.org> > Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> > --- > arch/x86/Kconfig | 5 +++++ > arch/x86/mm/init_32.c | 10 +++++++--- > include/linux/mm.h | 8 ++++++++ > init/main.c | 1 + > 4 files changed, 21 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 13ffa5d..b6ff185 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -50,6 +50,7 @@ config X86 > select HAVE_KERNEL_BZIP2 > select HAVE_KERNEL_LZMA > select HAVE_ARCH_KMEMCHECK > + select HAVE_ARCH_MEM_INIT_LATE if X86_32 > > config OUTPUT_FORMAT > string > @@ -86,6 +87,10 @@ config STACKTRACE_SUPPORT > config HAVE_LATENCYTOP_SUPPORT > def_bool y > > +config HAVE_ARCH_MEM_INIT_LATE > + def_bool y > + depends on X86_32 > + > config FAST_CMPXCHG_LOCAL > bool > default y > diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c > index 3cd7711..488ed4b 100644 > --- a/arch/x86/mm/init_32.c > +++ b/arch/x86/mm/init_32.c > @@ -956,13 +956,17 @@ void __init mem_init(void) > BUG_ON(VMALLOC_START >= VMALLOC_END); > BUG_ON((unsigned long)high_memory > VMALLOC_START); > > - if (boot_cpu_data.wp_works_ok < 0) > - test_wp_bit(); > - > save_pg_dir(); > zap_low_mappings(true); > } > > +void __init mem_init_late(void) > +{ > + /* Interrupts are enabled at this point. */ > + if (boot_cpu_data.wp_works_ok < 0) > + test_wp_bit(); > +} > + > #ifdef CONFIG_MEMORY_HOTPLUG > int arch_add_memory(int nid, u64 start, u64 size) > { > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 9a72cc7..eefcfbe 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1052,6 +1052,14 @@ extern void si_meminfo(struct sysinfo * val); > extern void si_meminfo_node(struct sysinfo *val, int nid); > extern int after_bootmem; > > +#ifdef CONFIG_HAVE_ARCH_MEM_INIT_LATE > +extern void mem_init_late(void); > +#else > +static inline void mem_init_late(void) > +{ > +} > +#endif > + > #ifdef CONFIG_NUMA > extern void setup_per_cpu_pageset(void); > #else > diff --git a/init/main.c b/init/main.c > index 2d9d6bd..45d8dbd 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -643,6 +643,7 @@ asmlinkage void __init start_kernel(void) > set_gfp_allowed_mask(__GFP_BITS_MASK); > > kmem_cache_init_late(); > + mem_init_late(); > > /* > * HACK ALERT! This is early. We're enabling the console before >
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