tree 2faddbd4253ce4cc0ef9f9216fce451d2f9b9c47
parent 11458e5b098319cf3e2d05c8cbaa74d58db740e3
author Rich Felker <dalias@aerifal.cx> 1345238033 -0400
committer Rich Felker <dalias@aerifal.cx> 1345238033 -0400

fix extremely rare but dangerous race condition in robust mutexes

if new shared mappings of files/devices/shared memory can be made
between the time a robust mutex is unlocked and its subsequent removal
from the pending slot in the robustlist header, the kernel can
inadvertently corrupt data in the newly-mapped pages when the process
terminates. i am fixing the bug by using the same global vm lock
mechanism that was used to fix the race condition with unmapping
barriers after pthread_barrier_wait returns.