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authorAlexey Brodkin <abrodkin@synopsys.com>2015-02-12 21:10:11 +0300
committerVineet Gupta <vgupta@synopsys.com>2015-02-13 18:01:12 +0530
commit06f34e1c28f3608b0ce5b310e41102d3fe7b65a1 (patch)
treedfe8d03ffc8a8945713174c91f7eee25e01d863d /arch/arc
parent091f56be10efe8ac7c09d6368d885f41fa7eb809 (diff)
downloadkernel-06f34e1c28f3608b0ce5b310e41102d3fe7b65a1.tar.gz
ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
We used to calculate page address differently in 2 cases: 1. In virt_to_page(x) we do --->8--- mem_map + (x - CONFIG_LINUX_LINK_BASE) >> PAGE_SHIFT --->8--- 2. In in pte_page(x) we do --->8--- mem_map + (pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT --->8--- That leads to problems in case PAGE_OFFSET != CONFIG_LINUX_LINK_BASE - different pages will be selected depending on where and how we calculate page address. In particular in the STAR 9000853582 when gdb attempted to read memory of another process it got improper page in get_user_pages() because this is exactly one of the places where we search for a page by pte_page(). The fix is trivial - we need to calculate page address similarly in both cases. Cc: <stable@vger.kernel.org> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/include/asm/pgtable.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 6b0b7f7ef783..7670f33b9ce2 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -259,7 +259,8 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0)
#define pte_page(x) (mem_map + \
- (unsigned long)(((pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT)))
+ (unsigned long)(((pte_val(x) - CONFIG_LINUX_LINK_BASE) >> \
+ PAGE_SHIFT)))
#define mk_pte(page, pgprot) \
({ \