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authorLars Persson <lars.persson@axis.com>2014-08-08 15:47:48 +0200
committerRalf Baechle <ralf@linux-mips.org>2014-08-19 13:31:09 +0200
commit2a4a8b1e5d9d343e13ff22e19af7b353f7b52d6f (patch)
treec15d58946f772c098eb990dbeabda410b245c5dd /arch/mips/include/asm/pgtable.h
parent64615682658373516863b5b5971ff1d922d0ae7b (diff)
downloadlinux-stericsson-2a4a8b1e5d9d343e13ff22e19af7b353f7b52d6f.tar.gz
MIPS: Remove race window in page fault handling
Multicore MIPSes without I/D hardware coherency suffered from a race condition in the page fault handler. The page table entry was published before any pending lazy D-cache flush was committed, hence it allowed execution of stale page cache data by other VPEs in the system. To make the cache handling safe we need to perform flushing already in the set_pte_at function. MIPSes without coherent I-caches can get a small increase in flushes due to the unavailability of the execute flag in set_pte_at. [ralf@linux-mips.org: outlining set_pte_at() saves a good k in a test build, so I moved its definition from pgtable.h to cache.c.] Signed-off-by: Lars Persson <larper@axis.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7511/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/include/asm/pgtable.h')
-rw-r--r--arch/mips/include/asm/pgtable.h8
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 027c74db13f9..df49a308085c 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -122,6 +122,9 @@ do { \
} \
} while(0)
+extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+ pte_t pteval);
+
#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
#define pte_none(pte) (!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
@@ -145,7 +148,6 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
}
}
}
-#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
@@ -183,7 +185,6 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
}
#endif
}
-#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
@@ -390,15 +391,12 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
pte_t pte);
-extern void __update_cache(struct vm_area_struct *vma, unsigned long address,
- pte_t pte);
static inline void update_mmu_cache(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
pte_t pte = *ptep;
__update_tlb(vma, address, pte);
- __update_cache(vma, address, pte);
}
static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,