[HN Gopher] Debugging a rustc segfault on Illumos
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       Debugging a rustc segfault on Illumos
        
       Author : steveklabnik
       Score  : 31 points
       Date   : 2024-08-05 19:54 UTC (3 hours ago)
        
 (HTM) web link (sunshowers.io)
 (TXT) w3m dump (sunshowers.io)
        
       | jrpelkonen wrote:
       | This is a very interesting and thorough investigation. Highly
       | recommended!
        
       | bcantrill wrote:
       | I am (obviously?) biased, but this is a great read by Rain, as it
       | takes the reader through not just some of the illumos tooling,
       | but also how compilers need to bootstrap themselves -- and why
       | heterogeneous platforms are important. (As Rain elaborates in the
       | piece, this issue was seen on illumos, but is in fact lurking on
       | other platforms.)
        
         | sunshowers wrote:
         | Thanks for the kind words, Bryan! The illumos debugging tools
         | continue to blow my mind.
        
           | neerajsi wrote:
           | It makes me wonder though if illumos is worth it for a
           | relatively small company to maintain. This bug came out of
           | the larger ecosystem not knowing what to do for a niche OS.
        
             | steveklabnik wrote:
             | What we're doing inherently requires deep integration up
             | and down the stack. We'd still have to be doing OS-level
             | work even if we used another operating system. But then
             | we'd be at the mercy of upstream of accepting patches, or
             | keeping our own fork, and at that point, you're basically
             | at the same spot we are now, but with less overall control.
             | 
             | RFD 26 talked about the context around this choice:
             | https://rfd.shared.oxide.computer/rfd/0026
             | 
             | There's a lot more to it than just this one thing I
             | mentioned :)
        
             | sunshowers wrote:
             | On top of what Steve said, illumos does support all of the
             | required APIs here, but the Rust libc crate was just
             | missing definitions for them. It's not a tremendously
             | exotic platform the way something like Haiku is.
             | 
             | Edit: also worth pointing out (again) that the bug actually
             | exists everywhere -- it was just being masked on the other
             | platforms.
        
         | sctb wrote:
         | These are easily one of my favourite types of posts (and this
         | one was particularly gratifying). I wish I could go down these
         | rabbit holes every day!
         | 
         | > [...] and why heterogeneous platforms are important
         | 
         | This prompts me to wonder vaguely whether there's any untapped
         | juice in fuzzing approaches that might be relevant here. As in,
         | how much of the platform (including configuration and
         | heuristics, and so on) could be fuzzed as program input?
        
       | shrubble wrote:
       | Curious if truss , which was used, or Dtrace would give you the
       | syscalls in a nicer format for this application?
        
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       (page generated 2024-08-05 23:00 UTC)