Re: RNG (was: Re: SSD drives)
On Sun, Jan 6, 2013 at 1:34 AM, Amos Shapira amos.shap...@gmail.com wrote: If someone is really concerned about NSA knowing their random seed through Intel's hardware implementation - can't these few people add hardware RNG's to their sources? (one ref: http://en.wikipedia.org/wiki/Comparison_of_hardware_random_number_generators ) To make it clear: I, for one, am not concerned that NSA will know the seed of an RNG at any given time. Nor do I think this is an attack vector they normally consider. I am concerned that someone (possibly less well equipped than NSA) may exploit the lack of randomness in an RNG and wouldn't need to know the seed at all. Why would anyone be interested? In your personal laptop, quite possibly no one (depends on how naughty you are and whom did you piss off). In your work laptop - depends on what you do for a living. In a bank's server that you may administer or run your software on - maybe quite a few resourceful people. And so on. As as Nadav quite properly mentioned other uses of RNGs (e.g., Monte Carlo and other simulations), do you really want the investment house that manages your savings to systematically misprice securities? Just as an example... -- Oleg Goldshmidt | p...@goldshmidt.org ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [HAIFUX LECTURE] Introduction to Flash Memory -- Leon Romanovsky
Hi all, Is anyone going by car from Jerusalem to this lecture tomorrow? And do you have room? Thanks, Eliyahu - אליהו 2013/1/5 Eli Billauer e...@billauer.co.il: On Monday, January 7th at 18:30, Haifux will gather to hear a talk by Leon Romanovsky: Introduction to Flash Memory Abstract In this lecture we will discuss flash memory. We will go through history, different types and physics. We will talk about current limitations of flash. This lecture will help us to understand, WHY we need new flash friendly file system. = We meet in Taub building, room 6. For instructions see: http://www.haifux.org/where.html Attendance is free, and you are all invited! == Future lectures: 21/01/13 Flash Friendly File System (F2FS): Leon Romanovsky 04/02/13 Bitcoin: Meni Rosenfeld == We are always interested in hearing your talks and ideas. If you wish to give a talk, hold a discussion, or just plan some event haifux might be interested in, please contact us at webmas...@haifux.org -- Web: http://www.billauer.co.il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
The New Coolest Hack: emscripten - an LLVM bitcode to JavaScript Compiler
Hi all, [Note to Muli: prepare the groggers]. The executive summary is that you should probably check out https://github.com/kripken/emscripten which is an LLVM bitcode to JavaScript compiler, which allows one to compile any language that has a front-end to compile to LLVM bitcode (including C, C++, Objective C, etc. via clang or llvm-gcc) into JavaScript code that can run on the browser. It's great and incredibly useful. - Here's the longer story from my POV. As you probably now I am the creator and maintainer of Freecell Solver ( http://fc-solve.shlomifish.org/ ), which is a C library (-std=gnu99) and some command line programs to solve Freecell and similar solitaire games. Now, as well as the source (which is open source under the MIT/X11 licence), I provide some Win32 binaries, and there are also some GUI frontends that can make use of it to display the cards and moved in an animated manner (see for instance http://www.youtube.com/watch?v=hYdqNuX4WJc ). The Freecell Solver download page contains a huge note with a stop sign at the top saying that you probably want one of these interfaces, and the Win32 binary also emits a message to STDERR to avoid people asking about an empty dos box which does nothing (but in fact waits for standard input.). The problem is that for some users it was not enough, and they asked me at least two times by E-mail to provide them with a solution to a Freecell layout with which they had difficulties. I complied with this request, but having read http://www.joelonsoftware.com/articles/customerservice.html , I knew that I should also find a way to fix such questions permanently, and the natural way was to provide a web-interface for the solver. So how to do that? One way would have been to write a server-side CGI (or FastCGI or whatever) program that runs on the server and emits solution. However, keeping a CGI program online, updated and secure requires some effort, especially when large parts of it are written in C, and quite a clever one and very optimised to speed at that. So I've contemplated somehow creating a version in JavaScript that will run entirely, or almost entirely, on the client-side. But how? I thought that maybe somehow have written a C-JavaScript compiler by now and so searched the web for it and the first hit was indeed https://github.com/kripken/emscripten . I cloned the repository and tried out several demos and they worked nicely. However, I then ran into this bug - https://github.com/kripken/emscripten/issues/766 - and reported it. The maintainer tried to help, but he was unable to follow my instructions at first, so I had to fix them and make my code's build system more idiot-proof. Eventually after he was able to try everything, it worked there, and then it worked for me after I did git pull to update the code, and so the bug was fixed independently of my bug report. So I was able to proceed. Since I'm a lazy bottom-up learner, who does not always take the time to read all the documentation right at first, it took me some time and trial and error to get everything right, and in the process discovered what seems to be another bug - https://github.com/kripken/emscripten/issues/774 (which was not fixed yet) - but I eventually got the code to work. The generated JavaScript is large: * 2,326,040 bytes originally. * 1,271,024 after minification by jsmin (though there may be better minifiers) * 250,897 after being minified and compressed with gzip -9 (I could not serve it this way on HostGator, but it may be possible). This is in comparison to libfreecell-solver.so.0.5.0 which is 376,122 bytes with debugging symbols and 163,976 bytes after being stripped (and it's an x86-64 system and I didn't use -Os). Nevertheless, it was easier than writing an entirely new code in JavaScript and maintaining it, and you can see the beta demo in its temporary location here: * http://www.shlomifish.org/Files/files/code/fc-solve/js-port/web_fc_solve.html Emscripten has many more, much cooler, demos here: https://github.com/kripken/emscripten/wiki including ports of Python, Ruby and Lua and some graphical games. You can also read this announcement about the fc-solve demo on fc-solve-discuss: http://tech.groups.yahoo.com/group/fc-solve-discuss/message/1331 -- So if you're looking to convert C, C++, etc. code to JavaScript so people can run it in the convenience of their browsers, then look no further than Emscripten. Another compiler with a JS backend is https://github.com/fglock/Perlito which compiles a subset of Perl 5 and Perl 6 to JavaScript (and to themselves), but is still work under progress. Here is the Perl 5 compiler demo - http://perlcabal.org/~fglock/perlito5.html . You can use this makefile as a reference or skeleton for using emscripten: https://bitbucket.org/shlomif/fc-solve/src/42ee84534876f728edd30b845c8799440a25af88/fc-solve/source/Makefile.to-javascript.mak?at=master (short URL - http://is.gd/JmPCKe ). - Regards,
Re: The New Coolest Hack: emscripten - an LLVM bitcode to JavaScript Compiler
Hi all, On Sun, 6 Jan 2013 12:59:43 +0200 Shlomi Fish shlo...@shlomifish.org wrote: Nevertheless, it was easier than writing an entirely new code in JavaScript and maintaining it, and you can see the beta demo in its temporary location here: * http://www.shlomifish.org/Files/files/code/fc-solve/js-port/web_fc_solve.html Just a note that after applying some finishing touches, I have placed it online on the Freecell Solver site here: * http://fc-solve.shlomifish.org/js-fc-solve/text/ There's still some work left to do on the web user interface, and I also want to create a rich web UI, but it should still be quite usable. It also seems to take a while to load. Maybe I can find some way to load it after the page loads. Regards, Shlomi Fish Emscripten has many more, much cooler, demos here: https://github.com/kripken/emscripten/wiki including ports of Python, Ruby and Lua and some graphical games. You can also read this announcement about the fc-solve demo on fc-solve-discuss: http://tech.groups.yahoo.com/group/fc-solve-discuss/message/1331 -- - Shlomi Fish http://www.shlomifish.org/ Why I Love Perl - http://shlom.in/joy-of-perl Tcl is Lisp on drugs. Using strings instead of S‐expressions for closures is Evil with one of those gigantic E’s you can find at the beginning of chapters. Please reply to list if it's a mailing list post - http://shlom.in/reply . ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: The New Coolest Hack: emscripten - an LLVM bitcode to JavaScript Compiler
On Sun, Jan 06, 2013 at 06:55:22PM +0200, Shlomi Fish wrote: Emscripten has many more, much cooler, demos here: https://github.com/kripken/emscripten/wiki including ports of Python, Ruby and Lua and some graphical games. On a semi-related note, see this, if you haven't already: http://bellard.org/jslinux/ It's a Javascript emulator of a PC, booting linux right inside your browser. In case you do not recognize the name, this is the guy that wrote and maintained for a long time qemu, ffmpeg, and other, lesser known but not less amazing stuff. Have a look at his homepage. -- Didi ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: The New Coolest Hack: emscripten - an LLVM bitcode to JavaScript Compiler
Hi Yedidyah, On Sun, 6 Jan 2013 19:47:58 +0200 Yedidyah Bar-David linux...@didi.bardavid.org wrote: On Sun, Jan 06, 2013 at 06:55:22PM +0200, Shlomi Fish wrote: Emscripten has many more, much cooler, demos here: https://github.com/kripken/emscripten/wiki including ports of Python, Ruby and Lua and some graphical games. On a semi-related note, see this, if you haven't already: http://bellard.org/jslinux/ It's a Javascript emulator of a PC, booting linux right inside your browser. I am well aware of it having been pointed to it by a friend of mine. There's also http://en.wikipedia.org/wiki/JPC_%28emulator%29 which is written in Java. I tried jslinux and as cool as it is, it seemed very slow, even on my Core i3 machine. Emscripten seems to generate faster code, and since I hope the bug getting -O2 (or even -O3 which is not always guaranteed to work properly, but might work in my case) to work properly will be fixed, it may be even faster than it currently is without any optimisations. I wonder how usable will QEmu be after being compiled to JavaScript using emscripten ... evil-grin /. In case you do not recognize the name, this is the guy that wrote and maintained for a long time qemu, ffmpeg, and other, lesser known but not less amazing stuff. Have a look at his homepage. Impressive. Regards, Shlomi Fish -- - Shlomi Fish http://www.shlomifish.org/ List of Portability Libraries - http://shlom.in/port-libs The best thing about a UDP joke is that I don’t care if you get it or not. — http://gregsowell.com/?p=2742 Please reply to list if it's a mailing list post - http://shlom.in/reply . ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: SSD drives
On Tue, Jan 1, 2013 at 11:41 PM, E.S. Rosenberg esr+linux...@g.jct.ac.il wrote: If it's encrypted with a good strength cypher and keylength then what are you worried about, they just have to return the encrypted blob to you? I'm using luks for encryption with a fairly long key. Never the less, for 500nis it simply doesn't worth the risk. - Gilboa ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: SSD drives
On Wed, Jan 2, 2013 at 8:38 AM, Steve Litt sl...@troubleshooters.com wrote: On Mon, 31 Dec 2012 09:27:44 +0200 Gilboa Davara gilb...@gmail.com wrote: It's a 180Gb Intel 520 Series SSD with firmware version 400i. ... I have an ext4 filesystem on it. Semi-OT: A word of friendly warning: I recently bricked a 120GB Intel 520 w/ the latest firmware (not sure if it was 400i) w/ ext4 on Fedora 17/x86_64. (Second bricked SSD in 12 months) A *very* short power shortage crept under my APC UPS and bricked the SSD. Amazingly enough, the power shortage didn't crash the machine - which continued working off the main HDD software RAID array. Then how can you be certain that the power shortage was the cause? SteveT ... I was sitting in front of the machine when it happened. Lights flickered, UPS made clicked (when it went on-line) and boom, dmesg errors. - Gilboa ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
