From ff93dc55431517ed29c70dbff6721c6b0803acf9 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 31 Oct 2017 17:07:41 +0000 Subject: [PATCH] common/multicall: Increase debugability for bad hypercalls While investigating an issue (in a new codepath I'd introduced, as it turns out), leaving interrupts disabled manifested as a subsequent op in the multicall failing a check_lock() test. The codepath would have hit the ASSERT_NOT_IN_ATOMIC on the return-to-guest path, had it not hit the check_lock() first. Call ASSERT_NOT_IN_ATOMIC() after each operation in the multicall, to make failures more obvious. Signed-off-by: Andrew Cooper Reviewed-by: George Dunlap Reviewed-by: Wei Liu Release-acked-by: Julien Grall --- xen/common/multicall.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/xen/common/multicall.c b/xen/common/multicall.c index c7af4e0156..5a199ebf8f 100644 --- a/xen/common/multicall.c +++ b/xen/common/multicall.c @@ -66,6 +66,13 @@ do_multicall( disp = arch_do_multicall_call(mcs); + /* + * In the unlikely event that a hypercall has left interrupts, + * spinlocks, or other things in a bad way, continuing the multicall + * will typically lead to far more subtle issues to debug. + */ + ASSERT_NOT_IN_ATOMIC(); + #ifndef NDEBUG { /* -- 2.30.2