[PATCH 2/3] lib/ioremap.c: avoid endless loop under ioremapping improper ranges

From: zijun_hu
Date: Tue Sep 20 2016 - 01:50:55 EST


From: zijun_hu <zijun_hu@xxxxxxx>

for ioremap_page_range(), endless loop maybe happen if either of parameter
addr and end is not page aligned, in order to fix this issue and hint range
parameter requirements BUG_ON() checkup are performed firstly

for ioremap_pte_range(), loop end condition is optimized due to lack of
relevant macro pte_addr_end()

Signed-off-by: zijun_hu <zijun_hu@xxxxxxx>
---
lib/ioremap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/ioremap.c b/lib/ioremap.c
index 86c8911..0058cc8 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -64,7 +64,7 @@ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
BUG_ON(!pte_none(*pte));
set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
pfn++;
- } while (pte++, addr += PAGE_SIZE, addr != end);
+ } while (pte++, addr += PAGE_SIZE, addr < end);
return 0;
}

@@ -129,6 +129,7 @@ int ioremap_page_range(unsigned long addr,
int err;

BUG_ON(addr >= end);
+ BUG_ON(!PAGE_ALIGNED(addr | end));

start = addr;
phys_addr -= addr;
--
1.9.1