Introduce generic hooks in remap_pfn_range and vm_insert_pfn and corresponding copy and free routines with reserve and free tracking. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha --- include/linux/mm.h | 6 +++++ mm/memory.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 59 insertions(+), 1 deletion(-) Index: tip/mm/memory.c =================================================================== --- tip.orig/mm/memory.c 2008-11-11 10:10:11.000000000 -0800 +++ tip/mm/memory.c 2008-11-11 12:10:18.000000000 -0800 @@ -99,6 +99,28 @@ int randomize_va_space __read_mostly = 2; #endif +#ifndef track_pfn_vma_new +int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot, + unsigned long pfn, unsigned long size) +{ + return 0; +} +#endif + +#ifndef track_pfn_vma_copy +int track_pfn_vma_copy(struct vm_area_struct *vma) +{ + return 0; +} +#endif + +#ifndef untrack_pfn_vma +void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, + unsigned long size) +{ +} +#endif + static int __init disable_randmaps(char *s) { randomize_va_space = 0; @@ -669,6 +691,16 @@ int copy_page_range(struct mm_struct *ds if (is_vm_hugetlb_page(vma)) return copy_hugetlb_page_range(dst_mm, src_mm, vma); + if (is_pfn_mapping(vma)) { + /* + * We do not free on error cases below as remove_vma + * gets called on error from higher level routine + */ + ret = track_pfn_vma_copy(vma); + if (ret) + return ret; + } + /* * We need to invalidate the secondary MMU mappings only when * there could be a permission downgrade on the ptes of the @@ -915,6 +947,9 @@ unsigned long unmap_vmas(struct mmu_gath if (vma->vm_flags & VM_ACCOUNT) *nr_accounted += (end - start) >> PAGE_SHIFT; + if (is_pfn_mapping(vma)) + untrack_pfn_vma(vma, 0, 0); + while (start != end) { if (!tlb_start_valid) { tlb_start = start; @@ -1473,6 +1508,7 @@ out: int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn) { + int ret; /* * Technically, architectures with pte_special can avoid all these * restrictions (same for remap_pfn_range). However we would like @@ -1489,7 +1525,15 @@ int vm_insert_pfn(struct vm_area_struct return -EFAULT; vma->vm_flags |= VM_PFNMAP; - return insert_pfn(vma, addr, pfn, vma->vm_page_prot); + if (track_pfn_vma_new(vma, vma->vm_page_prot, pfn, PAGE_SIZE)) + return -EINVAL; + + ret = insert_pfn(vma, addr, pfn, vma->vm_page_prot); + + if (ret) + untrack_pfn_vma(vma, pfn, PAGE_SIZE); + + return ret; } EXPORT_SYMBOL(vm_insert_pfn); @@ -1627,6 +1671,10 @@ int remap_pfn_range(struct vm_area_struc vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; + err = track_pfn_vma_new(vma, prot, pfn, PAGE_ALIGN(size)); + if (err) + return -EINVAL; + BUG_ON(addr >= end); pfn -= addr >> PAGE_SHIFT; pgd = pgd_offset(mm, addr); @@ -1638,6 +1686,10 @@ int remap_pfn_range(struct vm_area_struc if (err) break; } while (pgd++, addr = next, addr != end); + + if (err) + untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size)); + return err; } EXPORT_SYMBOL(remap_pfn_range); Index: tip/include/linux/mm.h =================================================================== --- tip.orig/include/linux/mm.h 2008-11-11 10:10:11.000000000 -0800 +++ tip/include/linux/mm.h 2008-11-11 10:10:12.000000000 -0800 @@ -155,6 +155,12 @@ static inline int is_pfn_mapping(struct return (vma->vm_flags & VM_PFNMAP); } +extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot, + unsigned long pfn, unsigned long size); +extern int track_pfn_vma_copy(struct vm_area_struct *vma); +extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, + unsigned long size); + /* * vm_fault is filled by the the pagefault handler and passed to the vma's * ->fault function. The vma's ->fault is responsible for returning a bitmask -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/