Messages in this thread | | | Date | Thu, 15 May 2014 13:28:28 -0400 (EDT) | From | Nicolas Pitre <> | Subject | Re: [PATCHv2] ARM: ioremap: Fix static vm area boundary checking. |
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On Thu, 15 May 2014, Richard Lee wrote:
> Static vm area boundary check: > > paddr1 --->| | > | | > |-------| <-\--- svm->vm->addr(is page aligned) > paddr2 --->| | | > | --| <--|-- svm->vm->phys_addr > | | | > paddr3 --->| | | > | | | > |-------| <--|-- next page boundary > | | | > paddr4 --->| | | <----- svm->vm->size(including guard page) > | | | > | | | > max paddr_end -->|-------| <--|-- svm->vm's phys_addr_end > | ///// | | > paddr5 --->| guard | | > | page | | > | ///// | | > ------- <-/--- svm->vm->addr + svm->vm_size > > <1> If the paddr == paddr1, then continue; > <2> If the paddr == paddr2~paddr4 and paddr_end > phys_addr_end, > then continue; > <3> if the paddr >= paddr5 then continue; > > Signed-off-by: Richard Lee <superlibj8301@gmail.com>
instead of doing this repeatedly, why not simply ensure the recorded static vm information is already page aligned in the first place?
> --- > > > Change in V2: > - PAGE_SIZE --> PAGE_MASK > - remove the 'size' page size align operation. > > > > > > > arch/arm/mm/ioremap.c | 40 ++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 38 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c > index be69333..f235ab7 100644 > --- a/arch/arm/mm/ioremap.c > +++ b/arch/arm/mm/ioremap.c > @@ -47,16 +47,52 @@ static struct static_vm *find_static_vm_paddr(phys_addr_t paddr, > { > struct static_vm *svm; > struct vm_struct *vm; > + size_t offset; > + > + offset = paddr & ~PAGE_MASK; > > list_for_each_entry(svm, &static_vmlist, list) { > + phys_addr_t paddr_end, phys_addr_end; > + size_t vmoff; > + > vm = &svm->vm; > if (!(vm->flags & VM_ARM_STATIC_MAPPING)) > continue; > if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype)) > continue; > > - if (vm->phys_addr > paddr || > - paddr + size - 1 > vm->phys_addr + vm->size - 1) > + /* Static vm area boundary check: > + * > + * paddr1 --->| | > + * | | > + * |-------| <-\--- svm->vm->addr(page aligned) > + * paddr2 --->| | | > + * | --| <--|-- svm->vm->phys_addr > + * | | | > + * paddr3 --->| | | > + * | | | > + * |-------| <--|-- next page boundary > + * | | | > + * paddr4 --->| | | <----- svm->vm->size, > + * | | | including guard page > + * | | | > + * max paddr_end -->|-------| <--|-- svm->vm's phys_addr_end > + * | ///// | | > + * paddr5 --->| guard | | > + * | page | | > + * | ///// | | > + * ------- <-/-- svm->vm->addr + svm->vm_size > + * > + * <1> If paddr == paddr1, then continue; > + * <2> If paddr == paddr2~paddr4 and paddr_end > phys_addr_end, > + * then continue; > + * <3> if paddr >= paddr5 then continue; > + */ > + vmoff = vm->phys_addr & ~PAGE_MASK; > + phys_addr_end = vm->phys_addr + vm->size - PAGE_SIZE - vmoff; > + paddr_end = paddr + size - offset; > + if (__phys_to_pfn(vm->phys_addr) > __phys_to_pfn(paddr) || > + paddr_end - 1 > phys_addr_end - 1) > continue; > > return svm; > -- > 1.8.4 >
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