diff options
| author | Dave Hansen <dave@linux.vnet.ibm.com> | 2013-01-22 13:24:30 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-01-25 16:33:22 -0800 |
| commit | a25b9316841c5afa226f8f70a457861b35276a92 (patch) | |
| tree | e1fb6722bcb783329de3c09d7a9df1a6b0f25d58 /arch/x86/mm/pat.c | |
| parent | 7b5c4a65cc27f017c170b025f8d6d75dabb11c6f (diff) | |
x86, mm: Make DEBUG_VIRTUAL work earlier in boot
The KVM code has some repeated bugs in it around use of __pa() on
per-cpu data. Those data are not in an area on which using
__pa() is valid. However, they are also called early enough in
boot that __vmalloc_start_set is not set, and thus the
CONFIG_DEBUG_VIRTUAL debugging does not catch them.
This adds a check to also verify __pa() calls against max_low_pfn,
which we can use earler in boot than is_vmalloc_addr(). However,
if we are super-early in boot, max_low_pfn=0 and this will trip
on every call, so also make sure that max_low_pfn is set before
we try to use it.
With this patch applied, CONFIG_DEBUG_VIRTUAL will actually
catch the bug I was chasing (and fix later in this series).
I'd love to find a generic way so that any __pa() call on percpu
areas could do a BUG_ON(), but there don't appear to be any nice
and easy ways to check if an address is a percpu one. Anybody
have ideas on a way to do this?
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130122212430.F46F8159@kernel.stglabs.ibm.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 0eb572eda406..2610bd93c896 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -560,10 +560,10 @@ int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags) { unsigned long id_sz; - if (base >= __pa(high_memory)) + if (base > __pa(high_memory-1)) return 0; - id_sz = (__pa(high_memory) < base + size) ? + id_sz = (__pa(high_memory-1) <= base + size) ? __pa(high_memory) - base : size; |