Messages in this thread | | | Subject | Re: [RFC] kasan stack overflow warnings again: READ_ONCE(), typecheck() | From | Christian Borntraeger <> | Date | Wed, 15 Feb 2017 17:20:06 +0100 |
| |
On 02/15/2017 05:18 PM, Christian Borntraeger wrote: > On 02/15/2017 12:03 AM, Arnd Bergmann wrote: >> >> -#define WRITE_ONCE(x, val) \ >> -({ \ >> - union { typeof(x) __val; char __c[1]; } __u = \ >> - { .__val = (__force typeof(x)) (val) }; \ >> - __write_once_size(&(x), __u.__c, sizeof(x)); \ >> - __u.__val; \ >> -}) >> +#define WRITE_ONCE(x, val) \ >> +( \ >> + __builtin_choose_expr(sizeof(x) == 1, *(volatile typeof(&(x)))&(x) = (val), \ >> + __builtin_choose_expr(sizeof(x) == 2, *(volatile typeof(&(x)))&(x) = (val), \ >> + __builtin_choose_expr(sizeof(x) == 4, *(volatile typeof(&(x)))&(x) = (val), \ >> + __builtin_choose_expr(sizeof(x) == sizeof(long), *(volatile typeof(&(x)))&(x) = (val), \ > > Have you run sparse on those changes? > IIRC we had to add the __force to get rid of address space annotations > in that macro above. Cannot tell if we need something like that here. >
The original warning was fs/afs/inode.c:448:9: sparse: incorrect type in initializer (different address spaces) fs/afs/inode.c:448:9: expected struct afs_permits *__val fs/afs/inode.c:448:9: got void [noderef] <asn:4>*<noident>
| |