Messages in this thread | | | Date | Tue, 13 Jan 2015 10:55:26 -0500 | From | Chris Metcalf <> | Subject | Re: [PATCH v2 23/40] tile: enable sparse checks for get/put_user |
| |
On 1/13/2015 4:45 AM, Michael S. Tsirkin wrote: > On Mon, Jan 12, 2015 at 07:08:36PM -0500, Chris Metcalf wrote: >> The key changes are to copy the x86 definition of __inttype(), and then to >> arrange to use an intermediate integral type that gets assigned to or from >> the actual typed value so as to expose any sparse issues. >> >> If this works for you, I'm happy to queue it in the tile tree, or I can >> provide a proper git commit for you to include in your series, whichever >> works better for you. > Please queue it up for 3.20. Extra __force is needed in a couple of > places - would you like to fix this up yourself, or do you want me to > write a patch on top?
I'll fold in your suggestions to my patch.
>> @@ -178,7 +178,7 @@ extern int fixup_exception(struct pt_regs *regs); >> "9:" \ >> : "=r" (ret), "=r" (__a), "=&r" (__b) \ >> : "r" (ptr), "i" (-EFAULT)); \ >> - (x) = (__typeof(x))(__typeof((x)-(x))) \ >> + (x) = (__typeof(x))(__inttype(x)) \ >> (((u64)__hi32(__a, __b) << 32) | \ >> __lo32(__a, __b)); \ >> }) > This cast to __typeof(x) needs to be done with __force, otherwise > there will be a warning with bitwise types.
Actually, this place no longer needs any casting at all, on reflection. I've changed the __get_user() code to do the "get" into an __inttype uniformly, so __get_user_8 will always have a u64 type for "x" here.
I'll cc you on the updated patch, so if you'd like to add your Reviewed-by tag to it, let me know.
-- Chris Metcalf, EZChip Semiconductor http://www.ezchip.com
| |