--- title: Redefining Go Functions | daily.dev description: Go functions can be redefined at runtime by manipulating memory directly, despite lacking language-level support for monkey patching. The technique involves... canonical: https://daily.dev/posts/redefining-go-functions-xw2qyqen0 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Redefining Go Functions | daily.dev og:description: Go functions can be redefined at runtime by manipulating memory directly, despite lacking language-level support for monkey patching. The technique involves... og:url: https://daily.dev/posts/redefining-go-functions-xw2qyqen0 og:image: https://api.daily.dev/og/posts/XW2QYQEn0.png og:image:alt: Redefining Go Functions og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Redefining Go Functions **[Lobsters](https://daily.dev/sources/lobsters)** · 8 min read · 2 upvotes · 1 comments ## Summary Go functions can be redefined at runtime by manipulating memory directly, despite lacking language-level support for monkey patching. The technique involves using reflection to get function addresses, modifying memory page permissions with mprotect, and writing JMP instructions to redirect execution. The article provides working x86 and ARM64 implementations, explains how to handle instruction encoding and cache invalidation, and warns about serious limitations including inline functions, generics, and struct layout mismatches that can cause crashes or memory corruption. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@pkraszewski** · 0 upvotes > For heaven's sake, just **don't**. The _W^X_ paradigm is here for a reason. ## Similar posts on daily.dev - [macOS code injection for fun and no profit](https://daily.dev/posts/macos-code-injection-for-fun-and-no-profit-0c9d9lwbb) · Hacker News · 0 upvotes · 0 comments - [A Basic Just-In-Time Compiler](https://daily.dev/posts/a-basic-just-in-time-compiler-mrdvhvck5) · Hacker News · 1 upvotes · 0 comments - [cloud security, system engineering and compilers](https://daily.dev/posts/cloud-security-system-engineering-and-compilers-sxfl15jgp) · Lobsters · 1 upvotes · 0 comments --- Tags: [#golang](https://daily.dev/tags/golang), [#assembly](https://daily.dev/tags/assembly) [View this post on daily.dev](https://daily.dev/posts/redefining-go-functions-xw2qyqen0) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Redefining Go Functions","url":"https://daily.dev/posts/redefining-go-functions-xw2qyqen0","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/redefining-go-functions-xw2qyqen0"},"datePublished":"2026-02-11T12:06:32.735Z","dateModified":"2026-02-11T12:06:55.629Z","description":"Go functions can be redefined at runtime by manipulating memory directly, despite lacking language-level support for monkey patching. 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The W^X paradigm is here for a reason.","datePublished":"2026-02-11T15:40:07.818Z","dateModified":"2026-02-11T15:40:18.597Z","url":"https://daily.dev/posts/XW2QYQEn0#c-kFCymgRY1","author":{"@type":"Person","name":"Paweł Kraszewski","url":"https://daily.dev/pkraszewski","image":"https://avatars.githubusercontent.com/u/1206223?v=4"}}]} ```