TODO: Needs checks to limit where it can be used, e.g. only
anonymous memory, & can't be shared between processes.
Sponsored by: Arm Ltd
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Event Timeline
| sys/vm/vm_mmap.c | ||
|---|---|---|
| 283–287 | Is this enough to stop creating shared mappings? I would like to not allow this until we understand how it will work with vMTE where tags are in the processes virtual address space. | |
| sys/vm/vm_mmap.c | ||
|---|---|---|
| 283–287 | Are you sure you want to invest time going down the vMTE road?.. | |
| sys/vm/vm_mmap.c | ||
|---|---|---|
| 283–287 | No yet, but don't want to create an ABI we can't easily support with vMTE. | |
| sys/arm64/arm64/pmap.c | ||
|---|---|---|
| 5447 | Even though it turns into a memattr, I think you're going to want a VM_PROT_MTE that is equal to PROT_MTE. | |
| sys/sys/mman.h | ||
| 60–64 | I think _PROT_ARCH isn't going to be all that generic when you combing it with CHERI. I think it's better to have per-feature defines that get ORed into _PROT_ALL or used to compose _PROT_ARCH. | |
| sys/vm/vm_mmap.c | ||
| 283–287 | For vMTE I think you'd need to prevent minherit(INHERIT_SHARE) as well. | |
| sys/arm64/arm64/pmap.c | ||
|---|---|---|
| 5447 | This block should assert that (m->oflags & VPO_UNMANAGED) == 0, otherwise it's unclear how the updates to the page's pv_flags are being synchronized. Even then, I'm not sure the object busy in vm_fault_soft_fast() is sufficient. | |
| 5450 | What if we are entering a 2MB or 64KB page, i.e., psind > 0? | |
| 5450 | What happens if an MTE page is mapped by other means, e.g., via pmap_enter_quick(), and tags aren't synced? | |