启用内核内存泄漏检测器后无法触发扫描的问题求助

Hey there, let's work through this kmemleak issue you're facing. First off, that "Device or resource busy" error almost never boils down to root permissions—root has full access to /sys/kernel/debug nodes once debugfs is mounted correctly. The problem is usually that kmemleak is already in a busy state. Here's how to fix it:

• Check if kmemleak is already running a scan
  Run cat /sys/kernel/debug/kmemleak first. If the output mentions an ongoing scan (like "Scanning..."), that's why your manual scan is being blocked. Kmemleak can only handle one scan operation at a time.

• Disable automatic scanning temporarily
  Kmemleak might be running periodic auto-scans by default. Check its configuration with:

  cat /sys/kernel/debug/kmemleak/parameters
  

  If you see autoscan = on, turn it off before trying your manual scan:

  echo off > /sys/kernel/debug/kmemleak/autoscan
  

  Then trigger your scan again:

  echo scan > /sys/kernel/debug/kmemleak
  

• Double-check the debugfs mount
  Even though you said debugfs is mounted, verify there are no oddities:

  mount | grep debugfs
  

  Make sure the mount point is /sys/kernel/debug and it's not mounted as read-only (look for rw in the mount options). If it's read-only, remount it with write access:

  mount -o remount,rw /sys/kernel/debug
  

• Check kernel logs for kmemleak errors
  Run dmesg | grep kmemleak to see if there are initialization issues or unexpected behavior. Look for messages like "kmemleak: Initialization failed" which could point to deeper kernel-side problems.

• Force stop and restart kmemleak
  If none of the above works, try stopping kmemleak completely before scanning:

  echo stop > /sys/kernel/debug/kmemleak
  echo scan > /sys/kernel/debug/kmemleak
  

  If you need auto-scanning later, re-enable it with echo on > /sys/kernel/debug/kmemleak/autoscan.

内容的提问来源于stack exchange，提问作者Boooooo