[PATCH] Wrong page aligned size calculation in ioremapping code

From: Florian Zumbiehl
Date: Tue Jun 15 2010 - 13:17:26 EST


Hi,

over the years since when I last reported this (and then lost track of it)
this has been fixed in most places/architectures - but two instances still
remain (or have appeared newly?), so here is the fix, and this time
I'm gonna make sure it gets applied ;-)

The patch is untested, but I guess it's simple enough ...

Florian
---------------------------------------------------------------------------
parisc __ioremap()/x86 early_iounmap(): fix off-by-one error in page
alignment of allocation size for sizes where size%PAGE_SIZE==1.

Signed-off-by: Florian Zumbiehl <florz@xxxxxxxx>

diff --git a/arch/parisc/mm/ioremap.c b/arch/parisc/mm/ioremap.c
index 92d496a..838d025 100644
--- a/arch/parisc/mm/ioremap.c
+++ b/arch/parisc/mm/ioremap.c
@@ -71,7 +71,7 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
- size = PAGE_ALIGN(last_addr) - phys_addr;
+ size = PAGE_ALIGN(last_addr + 1) - phys_addr;

/*
* Ok, go for it..
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 12e4d2d..a4643e5 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -613,7 +613,7 @@ void __init early_iounmap(void __iomem *addr, unsigned long size)
return;
}
offset = virt_addr & ~PAGE_MASK;
- nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
+ nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;

idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
while (nrpages > 0) {
--
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