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authorMadhusudanan Kandasamy <kmadhu@linux.vnet.ibm.com>2014-07-10 20:45:13 +0530
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-08-05 16:34:06 +1000
commiteeb03a6eaa02e9171f91e385c52a69b159fc6117 (patch)
tree8325d4ab23b055571595fb2b1434d7378201dfca /arch/powerpc/include
parentdb97efffb80652f7f879bc1d4837cbc84dc32557 (diff)
downloadop-kernel-dev-eeb03a6eaa02e9171f91e385c52a69b159fc6117.zip
op-kernel-dev-eeb03a6eaa02e9171f91e385c52a69b159fc6117.tar.gz
powerpc: Fail remap_4k_pfn() if PFN doesn't fit inside PTE
remap_4k_pfn() silently truncates upper bits of input 4K PFN if it cannot be contained in PTE. This leads invalid memory mapping and could result in a system crash when the memory is accessed. This patch fails remap_4k_pfn() and returns -EINVAL if the input 4K PFN cannot be contained in PTE. V3 : Added parentheses to protect 'pfn' and entire macro as suggested by Brian. V2 : Rewritten to avoid helper function as suggested by Stephen Rothwell. Signed-off-by: Madhusudanan Kandasamy <kmadhu@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include')
-rw-r--r--arch/powerpc/include/asm/pte-hash64-64k.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/pte-hash64-64k.h b/arch/powerpc/include/asm/pte-hash64-64k.h
index d836d94..b6d2d42 100644
--- a/arch/powerpc/include/asm/pte-hash64-64k.h
+++ b/arch/powerpc/include/asm/pte-hash64-64k.h
@@ -75,7 +75,8 @@
(((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)
#define remap_4k_pfn(vma, addr, pfn, prot) \
- remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \
- __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))
+ (WARN_ON(((pfn) >= (1UL << (64 - PTE_RPN_SHIFT)))) ? -EINVAL : \
+ remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \
+ __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN)))
#endif /* __ASSEMBLY__ */
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