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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-08-23 16:51:47 +0300
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-11-14 21:46:08 +0300
commitb8f2ed538477d9ab803c6458f497df1b1c6cf4ce (patch)
tree60ba4899c6b8c4dc48a727209a94435c21980647 /kernel/rcu
parent1001354ca34179f3db924eb66672442a173147dc (diff)
downloadlinux-b8f2ed538477d9ab803c6458f497df1b1c6cf4ce.tar.xz
rcu: Tighten up __call_rcu() rcu_head alignment check
Commit 720abae3d68ae ("rcu: force alignment on struct callback_head/rcu_head") forced the rcu_head (AKA callback_head) structure's alignment to pointer size, that is, to 4-byte boundaries on 32-bit systems and to 8-byte boundaries on 64-bit systems. This commit therefore checks for this same alignment in __call_rcu(), which used to contain a looser check for two-byte alignment. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 69a5611a7e7c..37e4f7d2be0c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3121,7 +3121,9 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func,
unsigned long flags;
struct rcu_data *rdp;
- WARN_ON_ONCE((unsigned long)head & 0x1); /* Misaligned rcu_head! */
+ /* Misaligned rcu_head! */
+ WARN_ON_ONCE((unsigned long)head & (sizeof(void *) - 1));
+
if (debug_rcu_head_queue(head)) {
/* Probable double call_rcu(), so leak the callback. */
WRITE_ONCE(head->func, rcu_leak_callback);