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 marex@denx.de Cc: Albert Aribaud albert.u.boot@aribaud.net Cc: Scott Wood scottwood@freescale.com Cc: Tom Rini trini@ti.com --- drivers/mtd/onenand/onenand_base.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
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,