[PATCH] SPARC64: Fix D-cache corruption in mremap

If we move a mapping from one virtual address to another,
and this changes the virtual color of the mapping to those
pages, we can see corrupt data due to D-cache aliasing.

Check for and deal with this by overriding the move_pte()
macro.  Set things up so that other platforms can cleanly
override the move_pte() macro too.

This long standing bug corrupts user memory, and in particular
has been notorious for corrupting Debian package database
files on sparc64 boxes.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 358e4d309ceb179776f2a7036dabce02cdfad1d2..c2059a3a06216cb936a163255501e20d464c6b21 100644 (file)
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -159,17 +159,8 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #define lazy_mmu_prot_update(pte)      do { } while (0)
 #endif
 
-#ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE
+#ifndef __HAVE_ARCH_MOVE_PTE
 #define move_pte(pte, prot, old_addr, new_addr)        (pte)
-#else
-#define move_pte(pte, prot, old_addr, new_addr)                                \
-({                                                                     \
-       pte_t newpte = (pte);                                           \
-       if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&              \
-                       pte_page(pte) == ZERO_PAGE(old_addr))           \
-               newpte = mk_pte(ZERO_PAGE(new_addr), (prot));           \
-       newpte;                                                         \
-})
 #endif
 
 /*

diff --git a/include/asm-mips/pgtable.h b/include/asm-mips/pgtable.h
index 702a28fa7a3489d01c2ff986c7dfd0adefebe0bc..69cebbd9f3e01928bc9ca64a27e3a7d98954677a 100644 (file)
--- a/include/asm-mips/pgtable.h
+++ b/include/asm-mips/pgtable.h
@@ -70,7 +70,15 @@ extern unsigned long zero_page_mask;
 #define ZERO_PAGE(vaddr) \
        (virt_to_page(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))
 
-#define __HAVE_ARCH_MULTIPLE_ZERO_PAGE
+#define __HAVE_ARCH_MOVE_PTE
+#define move_pte(pte, prot, old_addr, new_addr)                                \
+({                                                                     \
+       pte_t newpte = (pte);                                           \
+       if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&              \
+                       pte_page(pte) == ZERO_PAGE(old_addr))           \
+               newpte = mk_pte(ZERO_PAGE(new_addr), (prot));           \
+       newpte;                                                         \
+})
 
 extern void paging_init(void);
 

diff --git a/include/asm-sparc64/pgtable.h b/include/asm-sparc64/pgtable.h
index f0a9b44d3eb5068c1c70b14520d25c4f5226974b..3d6dff2ca1bfdc50b06181afdef4212b9e07587e 100644 (file)
--- a/include/asm-sparc64/pgtable.h
+++ b/include/asm-sparc64/pgtable.h
@@ -335,6 +335,23 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *p
 #define pte_clear(mm,addr,ptep)                \
        set_pte_at((mm), (addr), (ptep), __pte(0UL))
 
+#ifdef DCACHE_ALIASING_POSSIBLE
+#define __HAVE_ARCH_MOVE_PTE
+#define move_pte(pte, prot, old_addr, new_addr)                                \
+({                                                                     \
+       pte_t newpte = (pte);                                           \
+       if (pte_present(pte)) {                                         \
+               unsigned long this_pfn = pte_pfn(pte);                  \
+                                                                       \
+               if (pfn_valid(this_pfn) &&                              \
+                   (((old_addr) ^ (new_addr)) & (1 << 13)))            \
+                       flush_dcache_page_all(current->mm,              \
+                                             pfn_to_page(this_pfn));   \
+       }                                                               \
+       newpte;                                                         \
+})
+#endif
+
 extern pgd_t swapper_pg_dir[2048];
 extern pmd_t swapper_low_pmd_dir[2048];