From: Marek Vasut Date: Thu, 26 Dec 2013 00:01:24 +0000 (+0100) Subject: mtd: onenand: Fix unaligned access X-Git-Tag: v2014.01-rc3~26^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9b56942f7d2f67e620662cfeb4269a9a938d55da;p=platform%2Fkernel%2Fu-boot.git mtd: onenand: Fix unaligned access Fix unaligned access in OneNAND core. The problem is that the ffchars[] array is an array of "unsigned char", but in onenand_write_ops_nolock() can be passed to the memcpy_16() function. The memcpy_16() function will treat the buffer as an array of "unsigned short", thus triggering unaligned access if the compiler decided ffchars[] to be not aligned. I managed to trigger the problem with regular ELDK 5.4 GCC compiler. Signed-off-by: Marek Vasut Cc: Albert Aribaud Cc: Scott Wood Cc: Tom Rini --- diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c index 979e4af..e33e8d3 100644 --- a/drivers/mtd/onenand/onenand_base.c +++ b/drivers/mtd/onenand/onenand_base.c @@ -91,7 +91,13 @@ static struct nand_ecclayout onenand_oob_32 = { .oobfree = { {2, 3}, {14, 2}, {18, 3}, {30, 2} } }; -static const unsigned char ffchars[] = { +/* + * Warning! This array is used with the memcpy_16() function, thus + * it must be aligned to 2 bytes. GCC can make this array unaligned + * as the array is made of unsigned char, which memcpy16() doesn't + * like and will cause unaligned access. + */ +static const unsigned char __aligned(2) ffchars[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16 */ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,