Top posts

Every blog post that took off on Hacker News, ranked by the votes of its best submission. 4,390 posts.

Systems & Performance
Any year
4232

Plan9 from?

I have been saying for years that I am seeing the same phenomonon today that I saw thirty years ago when the microprocessor was first invented. At that time I argued a lot with all the computer scientists. They insisted that microprocessors were not really computers because they did not run the same software that…

4236

X86 Register Encoding

If you've ever look at the disassembly output for C or C++ code, you'll probably notice that there are a lot of push/pop instructions. And if you pay close enough attention, you'll notice that the compiler prefers to use certain registers over others. In particular, compilers will prefer pushing "old" registers like…

4238

File Locks on Linux

You're probably reading this page because you've attempted to access some part of my blog (Wandering Thoughts) or CSpace , the wiki thing it's part of. Unfortunately you're using a browser version that my anti-crawler precautions consider suspicious, most often because it's too old (most often this applies to versions…

4245

When can glibc be built with Clang?

Updated in 2026: glibc 2.43 added experimental support for building with Clang. In September 2021, I wrote "So, dear glibc, will you be happy with my sending Clang patches?" in Build glibc with LLD 13. We have come to a turning point. In Linux Plumbers Conference 2021, at the glibc Birds of a Feather session, I asked…

4255

Reversing a MacOS Kernel Extension

In my last post I covered the basics of kernel debugging in macOS. In this post we will put some of that to use and work through the process of reversing a macOS kernel module. As I said in my last post, in macOS there is a kernel module named “Don’t Steal Mac OS X” (DSMOS) which registers a function with the Mach-O…