On Fri, Mar 11, 2016 at 12:47 PM, Andrey Ryabinin
<[email protected]> wrote:
> 2016-03-09 14:05 GMT+03:00 Alexander Potapenko <[email protected]>:
>
>> +struct kasan_track {
>> + u64 cpu : 6; /* for NR_CPUS = 64 */
>
> What about NR_CPUS > 64 ?
After a discussion with Dmitry we've decided to drop |cpu| and |when|
at all, as they do not actually help debugging.
This way we'll make kasan_track only 8 bytes (4 bytes for PID, 4 bytes
for stack handle).
Then the meta structures will be smaller and have nice alignment:
struct kasan_track {
u32 pid;
depot_stack_handle_t stack;
};
struct kasan_alloc_meta {
struct kasan_track track;
u32 state : 2; /* enum kasan_state */
u32 alloc_size : 30;
u32 reserved; /* we can use it to store an additional stack
handle, e.g. for debugging RCU */
};
struct kasan_free_meta {
/* This field is used while the object is in the quarantine.
* Otherwise it might be used for the allocator freelist.
*/
void **quarantine_link;
struct kasan_track track;
};
>> + u64 pid : 16; /* 65536 processes */
>> + u64 when : 42; /* ~140 years */
>> +};
>> +
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
