On Tuesday, December 31, 2013 at 11:43:48 AM, Lukasz Majewski wrote:
Hi Marek,
On Saturday, December 28, 2013 at 05:06:28 PM, Lukasz Majewski wrote:
Hi Marek,
On Thursday, December 26, 2013 at 01:01:24 AM, Marek Vasut wrote:
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,
Lukasz, can you please review this one?
No problem, I will review the patch when I come back to the office (and be able to test it on the proper HW).
Thanks, I'd love to get this fix into 2014.01 . Maybe the real fix here would be to fix the memcpy_16() instead tho.
I've tested it with eldk-5.4 toolchain on GONI device. It seems that no regression is caused by this patch.
As a side note - this problem didn't show up for GONI board. Apparently I was lucky.
I will scrutinize this code in respect of code alignment.
Applied to u-boot-onenand.
Thank you very much!
Have a happy new year, guys !
Best regards, Marek Vasut