Tanel Poder personal blog
When eBPF pt_regs reads return garbage on the latest Linux kernels, blame Fred
TLDR; Starting from Linux kernel version 6.9 on x86_64, there’s a new config option CONFIG_X86_FRED enabled and it adds 16 bytes to the starting point of a task’s kernel stack area, so you’ll need to account for this extra padding in your “raw” kernel stack & pt_regs lookup code. Update: It turns out that there’s a…
- Points
- 105
- HN comments
- 11
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- 1
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Systems & PerformanceSoftware Engineering2025
On Hacker News
| Submitted | Title on HN | Points | Comments |
|---|---|---|---|
| Mar 1, 2025 | When eBPF pt_regs reads return garbage on the latest Linux kernels, blame Fred by tanelpoder | 105 | 11 |
