evie/android_kernel_oneplus_msm8998
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[PATCH] Fix kunmap_atomic's use of kpte_clear_flush()

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kunmap_atomic() will call kpte_clear_flush with vaddr/ptep arguments which
don't correspond if the vaddr is just a normal lowmem address (ie, not in
the KMAP area).  This patch makes sure that the pte is only cleared if kmap
area was actually used for the mapping.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Jeremy Fitzhardinge 2006-12-06 20:32:22 -08:00 • committed by Linus Torvalds
parent ad76fb6b5a
commit 3b17979bda
1 changed files with 8 additions and 10 deletions
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18
arch/i386/mm/highmem.c
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@ -50,22 +50,20 @@ void kunmap_atomic(void *kvaddr, enum km_type type)
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
#ifdef CONFIG_DEBUG_HIGHMEM
if (vaddr >= PAGE_OFFSET && vaddr < (unsigned long)high_memory) {
pagefault_enable();
return;
}
if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx))
BUG();
#endif
/* /*
* Force other mappings to Oops if they'll try to access this pte * Force other mappings to Oops if they'll try to access this pte
* without first remap it. Keeping stale mappings around is a bad idea * without first remap it. Keeping stale mappings around is a bad idea
* also, in case the page changes cacheability attributes or becomes * also, in case the page changes cacheability attributes or becomes
* a protected page in a hypervisor. * a protected page in a hypervisor.
*/ */
kpte_clear_flush(kmap_pte-idx, vaddr); if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
kpte_clear_flush(kmap_pte-idx, vaddr);
else {
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr < PAGE_OFFSET);
BUG_ON(vaddr >= (unsigned long)high_memory);
#endif
}
pagefault_enable(); pagefault_enable();
} }