March 2011 - Pharo-dev - lists.pharo.org

Re: [Pharo-project] Issue 3806 in pharo: Duration>>hours is broken

by pharo＠googlecode.com

Updates: Status: Started Labels: -Milestone-1.3 Comment #12 on issue 3806 by marcus.d...(a)gmail.com: Duration>>hours is broken http://code.google.com/p/pharo/issues/detail?id=3806 The consensus reached (taking the discussion on the mailinglist into account) needs to be sumarized into a peace of loadable code (changeset or Slice)

March 22, 2011

Re: [Pharo-project] test crashing the cog vm

by Alexandre Bergel

> But why we could not have a byecode validator at the image level that first make sure that byte code are in sync with the format of the objects. > Why this has to be done in the vm. I agree with Stef. It is not obvious for me why it has to be done at the VM. Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

March 22, 2011

Re: [Pharo-project] Issue 3714 in pharo: ChangeSet removeSelector does not dirty packages

by pharo＠googlecode.com

Updates: Status: Invalid Comment #3 on issue 3714 by marcus.d...(a)gmail.com: ChangeSet removeSelector does not dirty packages http://code.google.com/p/pharo/issues/detail?id=3714 The reason is that there is no method embeddedInMorphicWindowLabeled: in Workspace. If you remove another one, it gets dirty as expected.

March 22, 2011

Re: [Pharo-project] Issue 3753 in pharo: SimpleMorphic Layout Code missing

by pharo＠googlecode.com

Updates: Status: FixProposed Comment #5 on issue 3753 by marcus.d...(a)gmail.com: SimpleMorphic Layout Code missing http://code.google.com/p/pharo/issues/detail?id=3753 in inbox: SimpleMorphic-KenDickey.11.mcz

March 22, 2011

Re: [Pharo-project] Issue 3339 in pharo: WeakOrderedCollection

by pharo＠googlecode.com

Updates: Status: Closed Comment #1 on issue 3339 by marcus.d...(a)gmail.com: WeakOrderedCollection http://code.google.com/p/pharo/issues/detail?id=3339 We added it

March 22, 2011

Re: [Pharo-project] test crashing the cog vm

by Toon Verwaest

Construct me any scenario just based on the image, and I can show you how I can avoid it and segfault your system anyway. Construct me any piece of code that can segfault my approach. I doubt that you'll find any. I can't really say more, since I don't know what you are unconvinced about :) cheers, Toon On 03/22/2011 03:19 PM, Alexandre Bergel wrote: > Hi Toon, > > Thanks for having taken the time to reply. > I understand your and Eliot's email but I am left unconvinced. > > Alexandre > > > > On 22 Mar 2011, at 09:02, Toon Verwaest wrote: > >> The problem is exactly what you had at hand. Your bytecode WAS valid, but it was used in combination with an incompatible class layout. So validation here wouldn't solve anything. You always need to validate in a closed world to ensure you don't accidentally break everything. Whenever you change something, you need to ensure that you revalidate the relevant parts. In this case you could for example just have validated that your new class is a valid subclass of its superclass; which it was not. >> >> To make the system more secure obviously you would have to check those things, but if you add part of the API that circumvents these checks, like you were doing by calling "Class new" rather than using the ClassBuilder which does do the checks, everything breaks. The only authority that can actually ensure that you don't circumvent these checks is the VM. >> >> Obviously you can make sure already in your image that you have enough checks everywhere. You just don't have a crashproof mechanism that will chain your users down avoiding that they shoot themselves in the foot with segfaults. If you put it inside of the VM you -can- provide such a mechanism, because you don't execute anything unless you know it's safe. And as I said, this piece of code could be a piece of prevalidated Smalltalk code that's immutable from the rest of the image. >> >> cheers, >> Toon >> >> On 03/22/2011 02:37 PM, Alexandre Bergel wrote: >>>> But why we could not have a byecode validator at the image level that first make sure that byte code are in sync with the format of the objects. >>>> Why this has to be done in the vm. >>> I agree with Stef. It is not obvious for me why it has to be done at the VM. >>> >>> Alexandre >>

March 22, 2011

[Pharo-project] [update 1.3] #13102

by StÃ©phane Ducasse

13102 ----- - Cleaning Polymorph overrides. Part two. Stef

March 22, 2011

Re: [Pharo-project] test crashing the cog vm

by Toon Verwaest

It is much simpler than that! You just need a separate Smalltalk root object to which only the VM has access. It has its own set of classes which are unique pointers. This means that the user-level image never has any pointer to any of the objects inside of this core image. This means that it can never GET access to it either! So they can't tamper with the code in the first place, since they can't see it. The VM just passes code from the user-part of the memory to the verification part of the memory, since the VM has access to both. As simple as that. cheers, Toon On 03/22/2011 02:17 PM, Igor Stasenko wrote: > On 22 March 2011 14:02, Toon Verwaest<toon.verwaest(a)gmail.com> wrote: >> The problem is exactly what you had at hand. Your bytecode WAS valid, but it >> was used in combination with an incompatible class layout. So validation >> here wouldn't solve anything. You always need to validate in a closed world >> to ensure you don't accidentally break everything. Whenever you change >> something, you need to ensure that you revalidate the relevant parts. In >> this case you could for example just have validated that your new class is a >> valid subclass of its superclass; which it was not. >> >> To make the system more secure obviously you would have to check those >> things, but if you add part of the API that circumvents these checks, like >> you were doing by calling "Class new" rather than using the ClassBuilder >> which does do the checks, everything breaks. The only authority that can >> actually ensure that you don't circumvent these checks is the VM. >> >> Obviously you can make sure already in your image that you have enough >> checks everywhere. You just don't have a crashproof mechanism that will >> chain your users down avoiding that they shoot themselves in the foot with >> segfaults. If you put it inside of the VM you -can- provide such a >> mechanism, because you don't execute anything unless you know it's safe. And >> as I said, this piece of code could be a piece of prevalidated Smalltalk >> code that's immutable from the rest of the image. >> > Yep.. and that is possible only after you introduce irreversible > immutability mechanism into VM, > which marking object(s) to be immutable for the rest of their existence. > >> cheers, >> Toon >> >> On 03/22/2011 02:37 PM, Alexandre Bergel wrote: >>>> But why we could not have a byecode validator at the image level that >>>> first make sure that byte code are in sync with the format of the objects. >>>> Why this has to be done in the vm. >>> I agree with Stef. It is not obvious for me why it has to be done at the >>> VM. >>> >>> Alexandre >> >> > >

March 22, 2011

Re: [Pharo-project] [ANN] SqueakNOS update released!

by Javier PimÃ¡s

No, we use them for much low level stuff: to directly access memory regions, which is needed in some cases, and to use callbacks, in the case of handling page faults to reenter the interpreter. You can use any plugin as long as: a) you compile it as internal and b) the plugin doesn't make any syscall or use code from other libraries that make syscalls. I don't know if this is the case of openssl and curl. Regards, Javier. On Tue, Mar 22, 2011 at 3:42 AM, Denis Kudriashov <dionisiydk(a)gmail.com>wrote: > Hello, Javier. > > Very impressive work. > > What you mean by support for Alien and FFI? > What libraries I can call from SqueakNOS? And how I can build that > libraries? > > Can I use curl plugin or openssl from SqueakNOS somehow? > > Best regards, > Denis > > > 2011/3/21 Javier PimÃ¡s <elpochodelagente(a)gmail.com> > >> For all those who may be intrested, we are glad to announce that we have >> just uploaded an updated version of SqueakNOS to our site. You can find the >> updated download links here<http://squeaknos.blogspot.com/p/download.html> >> . >> >> This release adds the following items to the previous version: (99.9% >> modeled with objects) >> >> - Improved support for ATA devices access >> - Implementation of a model of files and directories >> - Implementation of FAT32 filesystem >> - Support for reading sources from the hard disk >> - Support for X86 paging setup and handling of page faults >> - Implementation of a model of free and used memory >> - Implementation of image snapshotting (based on the paging mechanism) >> - Based on Pharo, but also supporting Squeak and Cuis >> - Added some primitives for communicating between VM and image >> - Support for Alien and FFI >> - Added basic support for writing to serial via VM so that it's possiblo >> to out debug info to the outside world. >> - Added pretty basic ATA benchmarks >> - Added some scripts to automatize work done from the outside world >> - Many code cleanups >> >> Future directions are: >> >> - Support for Cog VM >> - Investigate replacing SqueakNOS plugin with NativeBoost so that we do >> more on the image >> - Offloading memory pages to disk >> - More tests >> - Benchmarks >> >> For the brave ones, remember that you can always generate a SqueakNOS >> image by using the ConfigurationOfSqueakNOS (which is a bit outdated now), >> or by manually loading the packages from monticello. Also to generate a >> SqueakNOS VM download its code from GIT (hosted on sourceforge.net) >> >> Don't forget to visit squeaknos.blogspot.com for news and instructions. >> We hope to be able to write more soon. >> >> Many thank's t all the people who made it possible to understand the code >> and to develop all this. >> >> SqueakNOS' Team >> >> -- >> Javier PimÃ¡s >> Ciudad de Buenos Aires >> > > -- Javier PimÃ¡s Ciudad de Buenos Aires

March 22, 2011

Re: [Pharo-project] test crashing the cog vm

by Igor Stasenko

On 22 March 2011 14:02, Toon Verwaest <toon.verwaest(a)gmail.com> wrote: > The problem is exactly what you had at hand. Your bytecode WAS valid, but it > was used in combination with an incompatible class layout. So validation > here wouldn't solve anything. You always need to validate in a closed world > to ensure you don't accidentally break everything. Whenever you change > something, you need to ensure that you revalidate the relevant parts. In > this case you could for example just have validated that your new class is a > valid subclass of its superclass; which it was not. > > To make the system more secure obviously you would have to check those > things, but if you add part of the API that circumvents these checks, like > you were doing by calling "Class new" rather than using the ClassBuilder > which does do the checks, everything breaks. The only authority that can > actually ensure that you don't circumvent these checks is the VM. > > Obviously you can make sure already in your image that you have enough > checks everywhere. You just don't have a crashproof mechanism that will > chain your users down avoiding that they shoot themselves in the foot with > segfaults. If you put it inside of the VM you -can- provide such a > mechanism, because you don't execute anything unless you know it's safe. And > as I said, this piece of code could be a piece of prevalidated Smalltalk > code that's immutable from the rest of the image. > Yep.. and that is possible only after you introduce irreversible immutability mechanism into VM, which marking object(s) to be immutable for the rest of their existence. > cheers, > Toon > > On 03/22/2011 02:37 PM, Alexandre Bergel wrote: >>> >>> But why we could not have a byecode validator at the image level that >>> first make sure that byte code are in sync with the format of the objects. >>> Why this has to be done in the vm. >> >> I agree with Stef. It is not obvious for me why it has to be done at the >> VM. >> >> Alexandre > > > -- Best regards, Igor Stasenko AKA sig.

March 22, 2011