From 3372f5a7d005dd42e754490fed6a0171c4a018c6 Mon Sep 17 00:00:00 2001 From: Alexander Stein Date: Mon, 23 Jan 2012 15:45:56 +0100 Subject: m68k: Do not set global share for non-kernel shared pages If the SG bit is set in MMUTR the page is accessible for all userspace processes (ignoring the ASID). So a process might randomly access a page from a different process which had a shared page (from shared memory) in its context. Signed-off-by: Alexander Stein Signed-off-by: Greg Ungerer --- arch/m68k/mm/mcfmmu.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'arch/m68k/mm') diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c index babd5a97cdcb..875b800ef0dd 100644 --- a/arch/m68k/mm/mcfmmu.c +++ b/arch/m68k/mm/mcfmmu.c @@ -87,7 +87,7 @@ void __init paging_init(void) int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word) { - unsigned long flags, mmuar; + unsigned long flags, mmuar, mmutr; struct mm_struct *mm; pgd_t *pgd; pmd_t *pmd; @@ -137,9 +137,10 @@ int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word) if (!pte_dirty(*pte) && !KMAPAREA(mmuar)) set_pte(pte, pte_wrprotect(*pte)); - mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | - (((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK) - >> CF_PAGE_MMUTR_SHIFT) | MMUTR_V); + mmutr = (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | MMUTR_V; + if ((mmuar < TASK_UNMAPPED_BASE) || (mmuar >= TASK_SIZE)) + mmutr |= (pte->pte & CF_PAGE_MMUTR_MASK) >> CF_PAGE_MMUTR_SHIFT; + mmu_write(MMUTR, mmutr); mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) | ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X); -- cgit v1.2.3