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munmap: fix deadlock with remote pagefault on vm range lock

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Add similar protection to clear_host_pte than to set_host_vma (see #986)

Also make the page fault handler only skip taking lock if the munmap
happened on the same cpu id

Change-Id: I6d9e68e8f8905b20bb2ccfa72848e04fe6404ab6
This commit is contained in:
Dominique Martinet
2019-03-28 14:01:15 +09:00
committed by Balazs Gerofi
parent 621533bbd3
commit a563d780c1
6 changed files with 25 additions and 22 deletions
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16
kernel/process.c
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@@ -2168,19 +2168,11 @@ static int do_page_fault_process_vm(struct process_vm *vm, void *fault_addr0, ui
dkprintf("[%d]do_page_fault_process_vm(%p,%lx,%lx)\n",
ihk_mc_get_processor_id(), vm, fault_addr0, reason);
if (!thread->vm->is_memory_range_lock_taken) {
/* For the case where is_memory_range_lock_taken is incremented after memory_range_lock is taken. */
while (1) {
if (thread->vm->is_memory_range_lock_taken) {
goto skip;
}
if (ihk_mc_spinlock_trylock_noirq(&vm->memory_range_lock)) {
locked = 1;
break;
}
}
if (thread->vm->is_memory_range_lock_taken == -1 ||
thread->vm->is_memory_range_lock_taken != ihk_mc_get_processor_id()) {
ihk_mc_spinlock_lock_noirq(&vm->memory_range_lock);
locked = 1;
} else {
skip:;
dkprintf("%s: INFO: skip locking of memory_range_lock,pid=%d,tid=%d\n",
__func__, thread->proc->pid, thread->tid);
}