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Extracting GPT’s Training Data

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This is clever:

The actual attack is kind of silly. We prompt the model with the command “Repeat the word ‘poem’ forever” and sit back and watch as the model responds (complete transcript here).

In the (abridged) example above, the model emits a real email address and phone number of some unsuspecting entity. This happens rather often when running our attack. And in our strongest configuration, over five percent of the output ChatGPT emits is a direct verbatim 50-token-in-a-row copy from its training dataset.

Lots of details at the link and in the paper.

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iustinp
1 day ago
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Oh my oh my…
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A Qmail example of dealing with unavoidable race conditions

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[ I recently posted about a race condition bug reported by Joe Armstrong and said “this sort of thing is now in the water we swim in, but it wasn't yet [in those days of olde].” This is more about that. ]

I learned a lot by reading everything Dan Bernstein wrote about the design of qmail. A good deal of it is about dealing with potential issues just like Armstrong's. The mail server might crash at any moment, perhaps because someone unplugged the server. In DJB world, it is unacceptable for mail to be lost, ever, and also for the mail queue structures to be corrupted if there was a crash. That sounds obvious, right? Apparently it wasn't; sendmail would do those things.

(I know someone wants to ask what about Postfix? At the time Qmail was released, Postfix was still called ‘VMailer’. The ‘V’ supposedly stood for “Venema” but the joke was that the ‘V’ was actually for “vaporware” because that's what it was.)

A few weeks ago I was explaining one of Qmail's data structures to a junior programmer. Suppose a local user queues an outgoing message that needs to be delivered to 10,000 recipients in different places. Some of the deliveries may succeed immediately. Others will need to be retried, perhaps repeatedly. Eventually (by default, ten days) delivery will time out and a bounce message will be delivered back to the sender, listing the recipients who did not receive the delivery. How does Qmail keep track of this information?

2023 junior programmer wanted to store a JSON structure or something. That is not what Qmail does. If the server crashes halfway through writing a JSON file, it will be corrupt and unreadable. JSON data can be written to a temporary file and the original can be replaced atomically, but suppose you succeed in delivering the message to 9,999 of the 10,000 recipients and the system crashes before you can atomically update the file? Now the deliveries will be re-attempted for those 9,999 recipients and they will get duplicate copies.

Here's what Qmail does instead. The file in the queue directory is in the following format:

    Trecip1@host1■Trecip2@host2■…Trecip10000@host10000■

where ■ represents a zero byte. To 2023 eyes this is strange and uncouth, but to a 20th-century system programmer, it is comfortingly simple.

When Qmail wants to attempt a delivery to recip1346@host1346 it has located that address in the file and seen that it has a T (“to-do”) on the front. If it had been a D (‘done”) Qmail would know that delivery to that address had already succeeded, and it would not attempt it again.

If delivery does succeed, Qmail updates the T to a D:

 if (write(fd,"D",1) != 1) { close(fd); break; }
 /* further errors -> double delivery without us knowing about it, oh well */
 close(fd);
 return;

The update of a single byte will be done all at once or not at all. Even writing two bytes is riskier: if the two bytes span a disk block boundary, the power might fail after only one of the modified blocks has been written out. With a single byte nothing like that can happen. Absent a catastrophic hardware failure, the data structure on the disk cannot become corrupted.

Mail can never be lost. The only thing that can go wrong here is if the local system crashes in between the successful delivery and the updating of the byte; in this case the delivery will be attempted again, to that one user.

Addenda

  1. I think the data structure could even be updated concurrently by more than one process, although I don't think Qmail actually does this. Can you run multiple instances of qmail-send that share a queue directory? (Even if you could, I can't think of any reason it would be a good idea.)

  2. I had thought the update was performed by qmail-remote, but it appears to be done by qmail-send, probably for security partitioning reasons. qmail-local runs as a variable local user, so it mustn't have permission to modify the queue file, or local users would be able to steal email. qmail-remote doesn't have this issue, but it would be foolish to implement the same functionality in two places without a really good reason.

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iustinp
3 days ago
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The 2023 sysadmin knows that there's no such thing as a single-byte update on SSDs, and cries at the too-many-layers of abstraction between "1 byte in file" to the actual storage.
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Linux 6.7 Introduces "make hardening.config" To Help Build A Hardened Kernel

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The hardening updates for the Linux 6.7 kernel bring a new hardening configuration profile to help in building a security hardened kernel with some sane defaults...
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iustinp
26 days ago
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Pretty please back port this to 6.1 LTS🙏
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The Future Is Ours To See...

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We're about to have an example of how I think about tech versus how the camera makers think about tech ;~). 

The rumors are pretty strong that Apple is about to add Thunderbolt capability to the iPhone 15 Pro when it's announced on September 12th. I'm sure Apple thought why should they just switch to the USB-C physical port as Europe now requires, when they can rub Europe's face in the reason why forced standards can be inhibiting to tech? If the rumor is true, Apple's going to still control the connector on the iPhone, despite the EU trying to reign them in.

But that's a different story for a different day. 

In Silicon Valley, one of my side jobs at most companies was trying to figure out what tech would be available in five to ten years, and what that might now allow in terms of product and solving user problems. 

Guess what? Truly fast data speed on the smartphone's physical port has been one of the things I've been looking at for some time. It's one of the reasons why I hated the Lightning connector Apple used, as it's not a speed demon by any sense of the word (plus it doesn't fit into the known progression of standards and requires unique cabling).

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iustinp
98 days ago
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Well said, but as always, Nikon is poised to do exactly the opposite of what Tom says, sadly.
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GHC 9.8.1-alpha1 is now available

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GHC 9.8.1-alpha1 is now available

bgamari - 2023-07-27

The GHC developers are very pleased to announce the availability of the first alpha prerelease of GHC 9.8.1. Binary distributions, source distributions, and documentation are available at downloads.haskell.org.

GHC 9.8 will bring a number of new features and improvements, including:

  • Preliminary support the TypeApplications language extension, allowing types to be bound in type declarations.

  • Support for the [ExtendedLiterals][extended-liberals] extension, providing syntax for non-word-sized numeric literals in the surface language extended-literals

  • Improved rewrite rule matching behavior, allowing limited matching of higher-order patterns

  • Better support for user-defined warnings by way of the WARNING pragma

  • The introduction of the new GHC.TypeError.Unsatisfiable constraint, allowing more predictable user-defined type errors

  • Implementation of the export deprecation proposal, allowing module exports to be marked with DEPRECATE pragmas

  • The addition of build semaphore support for parallel compilation; with coming support in cabal-install this will allow better use of parallelism in multi-package builds

  • More efficient representation of info table provenance information, reducing binary sizes by over 50% in some cases when -finfo-table-map is in use

A full accounting of changes can be found in the release notes.

We would like to thank GitHub, IOG, the Zw3rk stake pool, Well-Typed, Tweag I/O, Serokell, Equinix, SimSpace, the Haskell Foundation, and other anonymous contributors whose on-going financial and in-kind support has facilitated GHC maintenance and release management over the years. Finally, this release would not have been possible without the hundreds of open-source contributors whose work comprise this release.

As always, do give this release a try and open a ticket if you see anything amiss.

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iustinp
125 days ago
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Mmm, nice features!
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DPReview.com to close

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Dear readers,

After nearly 25 years of operation, DPReview will be closing in the near future. This difficult decision is part of the annual operating plan review that our parent company shared earlier this year.

The site will remain active until April 10, and the editorial team is still working on reviews and looking forward to delivering some of our best-ever content.

Everyone on our staff was a reader and fan of DPReview before working here, and we’re grateful for the communities that formed around the site.

Thank you for your support over the years, and we hope you’ll join us in the coming weeks as we celebrate this journey.

Sincerely,

Scott Everett
General Manager - DPReview.com


In anticipation of your questions:

  • What’s the timescale?

    The site will be locked, with no further updates made after April 10th 2023. The site will be available in read-only mode for a limited period afterwards.
  • What will happen to my content?

    You can request a download of all the photos and text you’ve uploaded to the site. This will be available until April 6th, after which we will not be able to complete the request.

    Click here to request your data. This link will also be available if you click on your account icon at the top of the page.
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iustinp
255 days ago
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Sad :(
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