Julien Grall
2013-Nov-18 13:08 UTC
[PATCH v2] xen/arm: ioremap_attr: return NULL is __vmap failed
Most of ioremap_* caller check if ioremap returns NULL. Actually, if the
physical address is non-aligned, Xen will return the pointer given by
__vmap plus the offset in the page. So if ioremap_* fails, the caller
will retrieve an non-NULL address and continue as if there was no error.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
Changes in v2:
- remove brackets for return
- don''t split declaration and initialisation of ptr
---
xen/arch/arm/mm.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 26c6768..d5b22a4 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -742,8 +742,12 @@ void *ioremap_attr(paddr_t pa, size_t len, unsigned int
attributes)
unsigned long pfn = PFN_DOWN(pa);
unsigned int offs = pa & (PAGE_SIZE - 1);
unsigned int nr = PFN_UP(offs + len);
+ void *ptr = __vmap(&pfn, nr, 1, 1, attributes);
- return (__vmap(&pfn, nr, 1, 1, attributes) + offs);
+ if ( ptr == NULL )
+ return NULL;
+
+ return ptr + offs;
}
void *ioremap(paddr_t pa, size_t len)
--
1.8.3.1
Ian Campbell
2013-Nov-19 14:45 UTC
Re: [PATCH v2] xen/arm: ioremap_attr: return NULL is __vmap failed
On Mon, 2013-11-18 at 13:08 +0000, Julien Grall wrote:> Most of ioremap_* caller check if ioremap returns NULL. Actually, if the > physical address is non-aligned, Xen will return the pointer given by > __vmap plus the offset in the page. So if ioremap_* fails, the caller > will retrieve an non-NULL address and continue as if there was no error. > > Signed-off-by: Julien Grall <julien.grall@linaro.org> > Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>Acked-by: Ian Campbell <ian.campbell@citrix.com>
Ian Campbell
2013-Nov-19 16:42 UTC
Re: [PATCH v2] xen/arm: ioremap_attr: return NULL is __vmap failed
On Tue, 2013-11-19 at 14:45 +0000, Ian Campbell wrote:> On Mon, 2013-11-18 at 13:08 +0000, Julien Grall wrote: > > Most of ioremap_* caller check if ioremap returns NULL. Actually, if the > > physical address is non-aligned, Xen will return the pointer given by > > __vmap plus the offset in the page. So if ioremap_* fails, the caller > > will retrieve an non-NULL address and continue as if there was no error. > > > > Signed-off-by: Julien Grall <julien.grall@linaro.org> > > Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > Acked-by: Ian Campbell <ian.campbell@citrix.com>Applied this + xen/arm: Panic if platform initialization failed xen/arm: Panic if we are unable to initialize platform timer from the first posting.