From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- .../litmus-tests/MP+onceassign+derefonce.litmus | 33 ++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus (limited to 'tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus') diff --git a/tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus b/tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus new file mode 100644 index 000000000..d84160b9c --- /dev/null +++ b/tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus @@ -0,0 +1,33 @@ +C MP+onceassign+derefonce + +(* + * Result: Never + * + * This litmus test demonstrates that rcu_assign_pointer() and + * rcu_dereference() suffice to ensure that an RCU reader will not see + * pre-initialization garbage when it traverses an RCU-protected data + * structure containing a newly inserted element. + *) + +{ +p=y; +} + +P0(int *x, int **p) // Producer +{ + WRITE_ONCE(*x, 1); + rcu_assign_pointer(*p, x); +} + +P1(int *x, int **p) // Consumer +{ + int *r0; + int r1; + + rcu_read_lock(); + r0 = rcu_dereference(*p); + r1 = READ_ONCE(*r0); + rcu_read_unlock(); +} + +exists (1:r0=x /\ 1:r1=0) (* Bad outcome. *) -- cgit v1.2.3