Nice sleuthing, nonsense explanation. An extra TLB flush is never an error. (The CPU is free to flush whenever it feels like doing so.) The error seems to be that somehow a zero-page PTE was present when it shouldn’t have been.
This sounds to me like either (a) a complex race involving a CPU migration at an awkward time or (b) a bug in the zap path transiently exposing wrong PTEs.
Also, I don’t think the zero page has pfn zero.
If I had to throw a dart, I would guess that direct page table zapping is allowing a CPU to read through a higher-level-paging-structure cached entry to a table that has been freed and reused. Yuck. I’ve debugged one of these before.
What will you do when the prompt was "Figure out the bug and write a report for me". Not saying it was in this particular case, but I think at least in other cases, it will be.
Why is it unreadable? I actually find LLM bug reports/breakdowns to be far more detailed and concise that classical human written ones. If you read the linked repo it clearly goes it depth where the bug was found, how to reproduce it (and in depth). Most disclosures that are human written don't do this at all, they barely even tell you _how_ to reproduce the bug. Just look at the "3.3 The self-store tear", the LLM clearly describes exactly what went wrong, so you can verify it by hand.
Because any writing needs a core intent they need to convey, which you can summarize down to according to the audience and why it should be important to them. Kinda like the same idea of elevator pitches, “explain like I’m five” and tactical reports when there’s a time constraints.
You got none of that here. It’s just realms of text.
Maybe the person writing the report isn't an expert in this domain or doesn't have the time to commit to it? From my point of view as long as the information is accurate and reproducible, it's valuable.
The analysis of the kernel bug may be a better thing to link to: https://github.com/dfoxfranke/ripgrep-3494-analysis.
Nice sleuthing, nonsense explanation. An extra TLB flush is never an error. (The CPU is free to flush whenever it feels like doing so.) The error seems to be that somehow a zero-page PTE was present when it shouldn’t have been.
This sounds to me like either (a) a complex race involving a CPU migration at an awkward time or (b) a bug in the zap path transiently exposing wrong PTEs.
Also, I don’t think the zero page has pfn zero.
If I had to throw a dart, I would guess that direct page table zapping is allowing a CPU to read through a higher-level-paging-structure cached entry to a table that has been freed and reused. Yuck. I’ve debugged one of these before.
The explanation is obviously written by an AI agent.
soulless unreadable AI slop
I can read it but not sure if worth spending energy on it.
It doesn't make sense for the reader to spend more energy than the writer spent on creating it.
> It doesn't make sense for the reader to spend more energy than the writer spent on creating it.
Great way to summarize cultural "economics"
Couldn't put the words on this pattern but sometimes all I care about is that someone cared about.
energy might be the wrong metric, plenty of energy was wasted spinning up that LLM.
PoC||GTFO, if it reproduces, it's valuable
Then post whatever notes were fed into the AI instead. The verbosity and self-congratulating add negative value.
That I agree with (not instead, in addition)
What will you do when the prompt was "Figure out the bug and write a report for me". Not saying it was in this particular case, but I think at least in other cases, it will be.
They have a PoC, we're arguing about the LLM-generated slop explanation of the PoC.
https://github.com/dfoxfranke/ripgrep-3494-analysis#6-cross-...
Heisenbug? User environment factors? This is slop-and-dash, Brandolini's law (bullshit asymmetry).Why is it unreadable? I actually find LLM bug reports/breakdowns to be far more detailed and concise that classical human written ones. If you read the linked repo it clearly goes it depth where the bug was found, how to reproduce it (and in depth). Most disclosures that are human written don't do this at all, they barely even tell you _how_ to reproduce the bug. Just look at the "3.3 The self-store tear", the LLM clearly describes exactly what went wrong, so you can verify it by hand.
Because any writing needs a core intent they need to convey, which you can summarize down to according to the audience and why it should be important to them. Kinda like the same idea of elevator pitches, “explain like I’m five” and tactical reports when there’s a time constraints.
You got none of that here. It’s just realms of text.
Maybe the person writing the report isn't an expert in this domain or doesn't have the time to commit to it? From my point of view as long as the information is accurate and reproducible, it's valuable.
Then where’s the lie in “soulless AI slop”?
I had the opposite reaction. Clear, detailed, well-organized. Pretty close to the ideal writeup.
So, why the bug triggers only with muslc and not other libc ?
wow, everything is broken lol