Dan Carpenter <dan.carpenter@xxxxxxxxxx> 於 2022年10月26日 週三 下午4:51寫道： > > On Wed, Oct 26, 2022 at 03:24:48PM +0800, ChiYuan Huang wrote: > > 2) normal register access with negative length > > Unable to handle kernel paging request at virtual address ffffffc009cefff2 > > pc : __memcpy+0x1dc/0x260 > > lr : _regmap_raw_write_impl+0x6d4/0x828 > > Call trace: > > __memcpy+0x1dc/0x260 > > _regmap_raw_write+0xb4/0x130a > > regmap_raw_write+0x74/0xb0 > > > > > > After applying the patch, the first case is cleared. > > But for the case 2, the root cause is not the mt6370_regmap_write() size > > check. It's in __memcpy() before mt6370_regmap_write(). > > > > I'm wondering 'is it reasonable to give the negative value as the size?' > > > > Thanks for testing! > > I'm not sure I understand exactly which code you're talking about. > Could you just create a diff with the check for negative just so I can > understand where the issue is? We can re-work it into a proper patch > from there. > Here. https://elixir.bootlin.com/linux/v6.1-rc2/source/drivers/base/regmap/regmap.c#L1860 >From my experiment, I try to access 0x00 reg for size (-1). Testing code is like as below regmap_raw_write(regmap, 0, &val, -1); That's why I think if the size check is needed, it may put into regmap_raw_write() like as regmap_raw_read(). > regards, > dan carpenter >
