From 010060741ad35eacb504414bc6fb9bb575b15f62 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 29 Jan 2009 16:02:12 +0100
Subject: [PATCH] x86: add might_sleep() to do_page_fault()
Impact: widen debug checks
VirtualBox calls do_page_fault() from an atomic context but runs into a
might_sleep() way pas this point, cure that.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/mm/fault.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8f4b859a04b3f..eb4d7fe05938e 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -888,6 +888,12 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
return;
}
down_read(&mm->mmap_sem);
+ } else {
+ /*
+ * The above down_read_trylock() might have succeeded in which
+ * case we'll have missed the might_sleep() from down_read().
+ */
+ might_sleep();
}
vma = find_vma(mm, address);
--
2.30.2