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A flaky test exposed a Redis client use-after-free

buildkite.engineering

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Re: A flaky test exposed a Redis client use-after-free

#6

Post by Retr0id »

VerifiedReports wrote: post #5
Retr0id wrote: post #3

Earlier quoted context omitted.

Works on my machine. (Even though HN's filters removed the leading "How")

I don't think you're replying to the right comment, since I didn't mention anything working.

The "machine" in question is my brain (or at least, the part of it that parses grammar).

Re: A flaky test exposed a Redis client use-after-free

#7

Post by serious_angel »

Thank you very much! This is great read! Though, no actual steps mentioned, including the:

> From this, he ascertained that the exception was triggered by a call to the C function memmove. While the source and destination addresses for this call looked sane, the size field was set to...

I do get the most of these stated, but it would be awesome to know more about how he did actually find it, and with what toolset. Was is gdb, Valgrind, JetBrains, IDA Pro, or some another general/complex dump viewer/toolset?

And, the interactive miracle, at the top of the website is freaking marvelous... It reminded me of the articles of the fluid simulation algorithms of Yusuke Endoh! Heartfelt gratitude to the developer, the artist who implemented it!

Apparently, behind the scene, the fluid colors are contained in an array where every single color has a defined meaning!

     // categories in STACK order: index 0 at the floor → 4 at the surface
     const CATS = [
       { key: "Code", rgb: [133, 232, 157] },
       { key: "Craft", rgb: [179, 146, 240] },
       { key: "Lessons", rgb: [249, 117, 131] },
       { key: "Story", rgb: [255, 171, 112] },
       { key: "Opinion", rgb: [158, 203, 255] },
     ];

Re: A flaky test exposed a Redis client use-after-free

#8

Post by pinzonjulian »

serious_angel wrote: post #7

Thank you very much! This is great read! Though, no actual steps mentioned, including the: > From this, he ascertained that the exception was triggered by a call to the C function memmove. While the source and destination addresses for this call looked sane, the size field was set to... I do get the most of these stated, but it would be awesome to know more about how he did actually find it, and with what toolset. Wa…

> And, the interactive miracle, at the top of the website is freaking marvelous

That's the work of https://x.com/CoreyGinnivan.

Re: A flaky test exposed a Redis client use-after-free

#9

Post by serious_angel »

pinzonjulian wrote: post #8
serious_angel wrote: post #7

Thank you very much! This is great read! Though, no actual steps mentioned, including the: > From this, he ascertained that the exception was triggered by a call to the C function memmove. While the source and destination addresses for this call looked sane, the size field was set to... I do get the most of these stated, but it would be awesome to know more about how he did actually find it, and with what toolset. Wa…

> And, the interactive miracle, at the top of the website is freaking marvelous That's the work of https://x.com/CoreyGinnivan .

Roger that! Thank you for the reference to the Artist!

Re: A flaky test exposed a Redis client use-after-free

#10

Post by DrNemski »

serious_angel wrote: post #7

Thank you very much! This is great read! Though, no actual steps mentioned, including the: > From this, he ascertained that the exception was triggered by a call to the C function memmove. While the source and destination addresses for this call looked sane, the size field was set to... I do get the most of these stated, but it would be awesome to know more about how he did actually find it, and with what toolset. Wa…

Thanks! This happened two years ago and it took me quite some time to piece together all the information of when it happened. I will see if I can get the original gdb output and add it to the blog post.
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