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proc: skip TID 0 when listing /proc - #15327
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IDOfThreadGroup can return 0 after deleteTask at Zombie->Dead, which made readdir(/proc) emit a /proc/0 dirent. Linux has no such directory. Test: ProcTask.ProcRootNeverListsZeroTID fails if "0" appears during reap churn and passes after the skip. Assisted-by: Cortex Code
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proc: skip TID 0 when listing /proc
Summary
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IDOfThreadGroup == 0intasksInode.IterDirentsso readdir(/proc) never emits a/proc/0dirent.IDOfThreadGroupcan return 0 afterdeleteTaskat Zombie→Dead while a directory listing is in progress. Linux has no/proc/0.Linux Fidelity
proc_pid_readdir/next_tgidnever publish tgid 0. gVisor listed the thread group after the PID mapping was already gone.Test Plan
ProcTask.ProcRootNeverListsZeroTIDraces concurrentreaddir(/proc)against reap churn.listed_zero == true; failed 3/3.waitpidand passed stock; the rewritten test is the negative control.Made with Cursor
FUTURE_COPYBARA_INTEGRATE_REVIEW=#15011 from hugelgupf:pr/procfs-iterdirents-skip-tid0 fd2e845