On 09/21/2016 12:34 PM, zijun_hu wrote:
> From: zijun_hu <zijun_hu@xxxxxxx>
>
> fix the following bug:
> - endless loop maybe happen when v[un]mapping improper ranges
> whose either boundary is not aligned to page
>
> Signed-off-by: zijun_hu <zijun_hu@xxxxxxx>
> ---
> mm/vmalloc.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 5eeecc3..16fe957 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -67,7 +67,7 @@ static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
> do {
> pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
> WARN_ON(!pte_none(ptent) && !pte_present(ptent));
> - } while (pte++, addr += PAGE_SIZE, addr != end);
> + } while (pte++, addr += PAGE_SIZE, addr < end && addr >= PAGE_SIZE);
> }
>
> static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
> @@ -108,6 +108,9 @@ static void vunmap_page_range(unsigned long addr, unsigned long end)
> unsigned long next;
>
> BUG_ON(addr >= end);
> + WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
> +
> + addr = round_down(addr, PAGE_SIZE);
> pgd = pgd_offset_k(addr);
> do {
> next = pgd_addr_end(addr, end);
> @@ -139,7 +142,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
> return -ENOMEM;
> set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
> (*nr)++;
> - } while (pte++, addr += PAGE_SIZE, addr != end);
> + } while (pte++, addr += PAGE_SIZE, addr < end);
> return 0;
> }
>
> @@ -193,6 +196,8 @@ static int vmap_page_range_noflush(unsigned long start, unsigned long end,
> int nr = 0;
>
> BUG_ON(addr >= end);
> + BUG_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
> +
> pgd = pgd_offset_k(addr);
> do {
> next = pgd_addr_end(addr, end);
>
From: zijun_hu <zijun_hu@xxxxxxx>
s/WARN_ON()/WARN_ON_ONCE()/ to reduce warning messages
Signed-off-by: zijun_hu <zijun_hu@xxxxxxx>
---
mm/vmalloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 16fe957..e34031e 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -108,7 +108,7 @@ static void vunmap_page_range(unsigned long addr, unsigned long end)
unsigned long next;
BUG_ON(addr >= end);
- WARN_ON(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
+ WARN_ON_ONCE(!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(end));
addr = round_down(addr, PAGE_SIZE);
pgd = pgd_offset_k(addr);
--
1.9.1
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