Messages in this thread | | | Date | Fri, 11 Mar 2016 14:05:45 +0100 | Subject | Re: [PATCH v5 2/7] mm, kasan: SLAB support | From | Alexander Potapenko <> |
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On Fri, Mar 11, 2016 at 12:47 PM, Andrey Ryabinin <ryabinin.a.a@gmail.com> wrote: > 2016-03-09 14:05 GMT+03:00 Alexander Potapenko <glider@google.com>: > >> +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
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