| Message ID | 20210115123730.381612-4-imbrenda@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix and improve the page allocator | expand |
On 1/15/21 1:37 PM, Claudio Imbrenda wrote: > Add some asserts to make sure the state is consistent. > > Simplify and improve the readability of vm_free. > > If a NULL pointer is freed, no operation is performed. > > Fixes: 3f6fee0d4da4 ("lib/vmalloc: vmalloc support for handling allocation metadata") > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@de.ibm.com> > --- > lib/vmalloc.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > > diff --git a/lib/vmalloc.c b/lib/vmalloc.c > index 986a34c..6b52790 100644 > --- a/lib/vmalloc.c > +++ b/lib/vmalloc.c > @@ -162,13 +162,16 @@ static void *vm_memalign(size_t alignment, size_t size) > static void vm_free(void *mem) > { > struct metadata *m; > - uintptr_t ptr, end; > + uintptr_t ptr, page, i; > > + if (!mem) > + return; > /* the pointer is not page-aligned, it was a single-page allocation */ > if (!IS_ALIGNED((uintptr_t)mem, PAGE_SIZE)) { > assert(GET_MAGIC(mem) == VM_MAGIC); > - ptr = virt_to_pte_phys(page_root, mem) & PAGE_MASK; > - free_page(phys_to_virt(ptr)); > + page = virt_to_pte_phys(page_root, mem) & PAGE_MASK; > + assert(page); > + free_page(phys_to_virt(page)); > return; > } > > @@ -176,13 +179,14 @@ static void vm_free(void *mem) > m = GET_METADATA(mem); > assert(m->magic == VM_MAGIC); > assert(m->npages > 0); > + assert(m->npages < BIT_ULL(BITS_PER_LONG - PAGE_SHIFT)); > /* free all the pages including the metadata page */ > - ptr = (uintptr_t)mem - PAGE_SIZE; > - end = ptr + m->npages * PAGE_SIZE; > - for ( ; ptr < end; ptr += PAGE_SIZE) > - free_page(phys_to_virt(virt_to_pte_phys(page_root, (void *)ptr))); > - /* free the last one separately to avoid overflow issues */ > - free_page(phys_to_virt(virt_to_pte_phys(page_root, (void *)ptr))); > + ptr = (uintptr_t)m & PAGE_MASK; > + for (i = 0 ; i < m->npages + 1; i++, ptr += PAGE_SIZE) { s/i < m->npages + 1/i <= m->npages/ ? > + page = virt_to_pte_phys(page_root, (void *)ptr) & PAGE_MASK; > + assert(page); > + free_page(phys_to_virt(page)); > + } > } > > static struct alloc_ops vmalloc_ops = { >
diff --git a/lib/vmalloc.c b/lib/vmalloc.c index 986a34c..6b52790 100644 --- a/lib/vmalloc.c +++ b/lib/vmalloc.c @@ -162,13 +162,16 @@ static void *vm_memalign(size_t alignment, size_t size) static void vm_free(void *mem) { struct metadata *m; - uintptr_t ptr, end; + uintptr_t ptr, page, i; + if (!mem) + return; /* the pointer is not page-aligned, it was a single-page allocation */ if (!IS_ALIGNED((uintptr_t)mem, PAGE_SIZE)) { assert(GET_MAGIC(mem) == VM_MAGIC); - ptr = virt_to_pte_phys(page_root, mem) & PAGE_MASK; - free_page(phys_to_virt(ptr)); + page = virt_to_pte_phys(page_root, mem) & PAGE_MASK; + assert(page); + free_page(phys_to_virt(page)); return; } @@ -176,13 +179,14 @@ static void vm_free(void *mem) m = GET_METADATA(mem); assert(m->magic == VM_MAGIC); assert(m->npages > 0); + assert(m->npages < BIT_ULL(BITS_PER_LONG - PAGE_SHIFT)); /* free all the pages including the metadata page */ - ptr = (uintptr_t)mem - PAGE_SIZE; - end = ptr + m->npages * PAGE_SIZE; - for ( ; ptr < end; ptr += PAGE_SIZE) - free_page(phys_to_virt(virt_to_pte_phys(page_root, (void *)ptr))); - /* free the last one separately to avoid overflow issues */ - free_page(phys_to_virt(virt_to_pte_phys(page_root, (void *)ptr))); + ptr = (uintptr_t)m & PAGE_MASK; + for (i = 0 ; i < m->npages + 1; i++, ptr += PAGE_SIZE) { + page = virt_to_pte_phys(page_root, (void *)ptr) & PAGE_MASK; + assert(page); + free_page(phys_to_virt(page)); + } } static struct alloc_ops vmalloc_ops = {
Add some asserts to make sure the state is consistent. Simplify and improve the readability of vm_free. If a NULL pointer is freed, no operation is performed. Fixes: 3f6fee0d4da4 ("lib/vmalloc: vmalloc support for handling allocation metadata") Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> --- lib/vmalloc.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)