By: gpd (gpderetta.delete@this.gmail.com), September 24, 2021 2:59 am
Room: Moderated Discussions
Linus Torvalds (torvalds.delete@this.linux-foundation.org) on September 23, 2021 12:01 pm wrote:
> The fact is, the whole notion of passing magic pointers and trying to associate random state with
> them between two random untrusted but somehow cooperative entities is pure BS. And I claim that
> no amount of segmentation - whatever you call it - will make it anything else.
They seem useful in a post-spectre world to run potentially hostile (but otherwise memory safe) code in process, for example a web browser that wants to isolate different JS VMs. Software boundary checking doesn't cut it anymore and separate processes (the current solution) has overhead. This assumes that segments handling does not have meltdown-like vulnerabilities (which is not a given, but it seems possible to implement correctly).
The kernel could use it to isolate BPF programs for example.
> The fact is, the whole notion of passing magic pointers and trying to associate random state with
> them between two random untrusted but somehow cooperative entities is pure BS. And I claim that
> no amount of segmentation - whatever you call it - will make it anything else.
They seem useful in a post-spectre world to run potentially hostile (but otherwise memory safe) code in process, for example a web browser that wants to isolate different JS VMs. Software boundary checking doesn't cut it anymore and separate processes (the current solution) has overhead. This assumes that segments handling does not have meltdown-like vulnerabilities (which is not a given, but it seems possible to implement correctly).
The kernel could use it to isolate BPF programs for example.
| Topic | Posted By | Date |
|---|---|---|
| POWER10 SAP SD benchmark | anon2 | 2021/09/06 02:36 PM |
| POWER10 SAP SD benchmark | Daniel B | 2021/09/07 01:31 AM |
| "Cores" (and SPEC) | Rayla | 2021/09/07 06:51 AM |
| "Cores" (and SPEC) | anon | 2021/09/07 02:56 PM |
| POWER10 SAP SD benchmark | Anon | 2021/09/07 02:24 PM |
| POWER10 SAP SD benchmark | Anon | 2021/09/07 02:27 PM |
| Virtually tagged L1-caches | sr | 2021/09/08 04:49 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/08 07:22 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 07:56 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/08 07:58 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 09:09 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/08 09:46 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 10:35 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/08 11:23 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 11:40 AM |
| Virtually tagged L1-caches | anon | 2021/09/09 02:16 AM |
| Virtually tagged L1-caches | Konrad Schwarz | 2021/09/10 04:19 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/10 05:59 AM |
| Virtually tagged L1-caches | anon | 2021/09/14 02:17 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/14 08:34 AM |
| Or use a PLB (NT) | Paul A. Clayton | 2021/09/14 08:45 AM |
| Or use a PLB | Linus Torvalds | 2021/09/14 02:27 PM |
| Or use a PLB | anon | 2021/09/14 11:15 PM |
| Or use a PLB | Michael S | 2021/09/15 02:21 AM |
| Or use a PLB | dmcq | 2021/09/15 02:42 PM |
| Or use a PLB | Konrad Schwarz | 2021/09/16 03:24 AM |
| Or use a PLB | Michael S | 2021/09/16 09:13 AM |
| Or use a PLB | --- | 2021/09/16 12:02 PM |
| PLB reference | Paul A. Clayton | 2021/09/18 01:35 PM |
| PLB reference | Michael S | 2021/09/18 03:14 PM |
| Demand paging/translation orthogonal | Paul A. Clayton | 2021/09/19 06:33 AM |
| Demand paging/translation orthogonal | Michael S | 2021/09/19 08:10 AM |
| PLB reference | Carson | 2021/09/20 09:19 PM |
| PLB reference | sr | 2021/09/20 05:02 AM |
| PLB reference | Michael S | 2021/09/20 06:03 AM |
| PLB reference | Linus Torvalds | 2021/09/20 11:10 AM |
| Or use a PLB | sr | 2021/09/20 03:32 AM |
| Or use a PLB | sr | 2021/09/21 08:36 AM |
| Or use a PLB | Linus Torvalds | 2021/09/21 09:04 AM |
| Or use a PLB | sr | 2021/09/21 09:48 AM |
| Or use a PLB | Linus Torvalds | 2021/09/21 12:55 PM |
| Or use a PLB | sr | 2021/09/22 05:55 AM |
| Or use a PLB | rwessel | 2021/09/22 06:09 AM |
| Or use a PLB | Linus Torvalds | 2021/09/22 10:50 AM |
| Or use a PLB | sr | 2021/09/22 12:00 PM |
| Or use a PLB | dmcq | 2021/09/22 03:07 PM |
| Or use a PLB | Etienne Lorrain | 2021/09/23 07:50 AM |
| Or use a PLB | anon2 | 2021/09/22 03:09 PM |
| Or use a PLB | dmcq | 2021/09/23 01:35 AM |
| Or use a PLB | ⚛ | 2021/09/23 08:37 AM |
| Or use a PLB | Linus Torvalds | 2021/09/23 11:01 AM |
| Or use a PLB | gpd | 2021/09/24 02:59 AM |
| Or use a PLB | Linus Torvalds | 2021/09/24 09:45 AM |
| Or use a PLB | dmcq | 2021/09/24 11:43 AM |
| Or use a PLB | sr | 2021/09/25 09:19 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 09:44 AM |
| Or use a PLB | sr | 2021/09/25 10:11 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 10:31 AM |
| Or use a PLB | sr | 2021/09/25 10:52 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 11:05 AM |
| Or use a PLB | sr | 2021/09/25 11:23 AM |
| Or use a PLB | rwessel | 2021/09/25 02:29 PM |
| Or use a PLB | sr | 2021/09/30 11:22 PM |
| Or use a PLB | rwessel | 2021/10/01 05:19 AM |
| Or use a PLB | David Hess | 2021/10/01 09:35 AM |
| Or use a PLB | rwessel | 2021/10/02 03:47 AM |
| Or use a PLB | sr | 2021/10/02 10:16 AM |
| Or use a PLB | rwessel | 2021/10/02 10:53 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 10:57 AM |
| Or use a PLB | sr | 2021/09/25 11:07 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 11:21 AM |
| Or use a PLB | sr | 2021/09/25 11:40 AM |
| Or use a PLB | nksingh | 2021/09/27 08:07 AM |
| Or use a PLB | ⚛ | 2021/09/27 08:02 AM |
| Or use a PLB | Linus Torvalds | 2021/09/27 09:20 AM |
| Or use a PLB | Linus Torvalds | 2021/09/27 11:58 AM |
| Or use a PLB | dmcq | 2021/09/28 09:59 AM |
| Or use a PLB | sr | 2021/09/25 09:34 AM |
| Or use a PLB | rwessel | 2021/09/25 02:44 PM |
| Or use a PLB | sr | 2021/10/01 12:04 AM |
| Or use a PLB | rwessel | 2021/10/01 05:33 AM |
| I386 segmentation highlights | sr | 2021/10/04 06:53 AM |
| I386 segmentation highlights | Adrian | 2021/10/04 08:53 AM |
| I386 segmentation highlights | sr | 2021/10/04 09:19 AM |
| I386 segmentation highlights | rwessel | 2021/10/04 03:57 PM |
| I386 segmentation highlights | sr | 2021/10/05 10:16 AM |
| I386 segmentation highlights | Michael S | 2021/10/05 11:27 AM |
| I386 segmentation highlights | rwessel | 2021/10/05 03:20 PM |
| Or use a PLB | JohnG | 2021/09/25 09:18 PM |
| Or use a PLB | ⚛ | 2021/09/27 06:37 AM |
| Or use a PLB | Heikki Kultala | 2021/09/28 02:53 AM |
| Or use a PLB | rwessel | 2021/09/28 06:29 AM |
| Or use a PLB | David Hess | 2021/09/23 05:00 PM |
| Or use a PLB | Adrian | 2021/09/24 12:21 AM |
| Or use a PLB | dmcq | 2021/09/25 11:41 AM |
| Or use a PLB | blaine | 2021/09/26 10:19 PM |
| Or use a PLB | David Hess | 2021/09/27 10:35 AM |
| Or use a PLB | blaine | 2021/09/27 04:19 PM |
| Or use a PLB | Adrian | 2021/09/27 09:40 PM |
| Or use a PLB | Adrian | 2021/09/27 09:59 PM |
| Or use a PLB | dmcq | 2021/09/28 06:45 AM |
| Or use a PLB | rwessel | 2021/09/28 06:45 AM |
| Or use a PLB | David Hess | 2021/09/28 11:50 AM |
| Or use a PLB | Etienne Lorrain | 2021/09/30 12:25 AM |
| Or use a PLB | David Hess | 2021/10/01 09:40 AM |
| MMU privileges | sr | 2021/09/21 10:07 AM |
| MMU privileges | Linus Torvalds | 2021/09/21 12:49 PM |
| Virtually tagged L1-caches | Konrad Schwarz | 2021/09/16 03:18 AM |
| Virtually tagged L1-caches | Carson | 2021/09/16 12:12 PM |
| Virtually tagged L1-caches | anon2 | 2021/09/16 04:16 PM |
| Virtually tagged L1-caches | rwessel | 2021/09/16 05:29 PM |
| Virtually tagged L1-caches | sr | 2021/09/20 03:20 AM |
| Virtually tagged L1-caches | --- | 2021/09/08 01:28 PM |
| Virtually tagged L1-caches | anonymou5 | 2021/09/08 07:28 PM |
| Virtually tagged L1-caches | anonymou5 | 2021/09/08 07:34 PM |
| Virtually tagged L1-caches | --- | 2021/09/09 09:14 AM |
| Virtually tagged L1-caches | anonymou5 | 2021/09/09 09:44 PM |
| Multi-threading? | David Kanter | 2021/09/09 08:32 PM |
| Multi-threading? | --- | 2021/09/10 08:19 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 12:19 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 12:36 AM |
| Virtually tagged L1-caches | --- | 2021/09/11 08:53 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 11:43 PM |
| Virtually tagged L1-caches | Linus Torvalds | 2021/09/12 10:10 AM |
| Virtually tagged L1-caches | sr | 2021/09/12 10:57 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/13 07:31 AM |
| Virtually tagged L1-caches | sr | 2021/09/20 03:11 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 01:49 AM |
| Virtually tagged L1-caches | Linus Torvalds | 2021/09/08 11:34 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/09 01:46 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/09 01:58 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 12:29 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/11 07:59 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 11:57 PM |
| Virtually tagged L1-caches | dmcq | 2021/09/12 07:44 AM |
| Virtually tagged L1-caches | sr | 2021/09/12 08:48 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/12 12:22 PM |
| Virtually tagged L1-caches | sr | 2021/09/20 03:40 AM |
| Where do you see this information? (NT) | anon2 | 2021/09/09 01:45 AM |
| Where do you see this information? | sr | 2021/09/11 12:40 AM |
| Where do you see this information? | anon2 | 2021/09/11 12:53 AM |
| Where do you see this information? | sr | 2021/09/11 01:08 AM |
| Thank you (NT) | anon2 | 2021/09/11 03:31 PM |