From de96ec2a77c6d06a423c2c495bb4a2f4299f3d9e Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Fri, 23 Sep 2016 16:38:27 +0100 Subject: OF: Prevent unaligned access in of_alias_scan() When allocating a struct alias_prop, of_alias_scan() only requested that it be aligned on a 4 byte boundary. The struct contains pointers which leads to us attempting 64 bit writes on 64 bit systems, and if the CPU doesn't support unaligned memory accesses then this causes problems - for example on some MIPS64r2 CPUs including the "mips64r2-generic" QEMU emulated CPU it will trigger an address error exception. Fix this by requesting alignment for the struct alias_prop allocation matching that which the compiler expects, using the __alignof__ keyword. Signed-off-by: Paul Burton Acked-by: Rob Herring Reviewed-by: Grant Likely Cc: Frank Rowand Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14306/ Signed-off-by: Ralf Baechle --- drivers/of/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/of') diff --git a/drivers/of/base.c b/drivers/of/base.c index d4bea3c797d6..84cf2f3f396c 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -2112,7 +2112,7 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) continue; /* Allocate an alias_prop with enough space for the stem */ - ap = dt_alloc(sizeof(*ap) + len + 1, 4); + ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap)); if (!ap) continue; memset(ap, 0, sizeof(*ap) + len + 1); -- cgit v1.2.3-58-ga151