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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: qemu-stable@nongnu.org, Peter Maydell <peter.maydell@linaro.org>
Subject: [PULL 02/10] util/interval-tree: Use qatomic_set_mb in rb_link_node
Date: Mon, 31 Jul 2023 14:02:03 -0700	[thread overview]
Message-ID: <20230731210211.137353-3-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230731210211.137353-1-richard.henderson@linaro.org>

Ensure that the stores to rb_left and rb_right are complete before
inserting the new node into the tree.  Otherwise a concurrent reader
could see garbage in the new leaf.

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 util/interval-tree.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/util/interval-tree.c b/util/interval-tree.c
index 5a0ad21b2d..759562db7d 100644
--- a/util/interval-tree.c
+++ b/util/interval-tree.c
@@ -128,7 +128,11 @@ static inline void rb_link_node(RBNode *node, RBNode *parent, RBNode **rb_link)
     node->rb_parent_color = (uintptr_t)parent;
     node->rb_left = node->rb_right = NULL;
 
-    qatomic_set(rb_link, node);
+    /*
+     * Ensure that node is initialized before insertion,
+     * as viewed by a concurrent search.
+     */
+    qatomic_set_mb(rb_link, node);
 }
 
 static RBNode *rb_next(RBNode *node)
-- 
2.34.1



  parent reply	other threads:[~2023-07-31 21:03 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-31 21:02 [PULL 00/10] tcg patch queue for rc2 Richard Henderson
2023-07-31 21:02 ` [PULL 01/10] util/interval-tree: Use qatomic_read for left/right while searching Richard Henderson
2023-07-31 21:02 ` Richard Henderson [this message]
2023-08-04  9:02   ` [PULL 02/10] util/interval-tree: Use qatomic_set_mb in rb_link_node Michael Tokarev
2023-08-04 13:41     ` Richard Henderson
2023-08-04 16:22       ` Michael Tokarev
2023-07-31 21:02 ` [PULL 03/10] util/interval-tree: Introduce pc_parent Richard Henderson
2023-07-31 21:02 ` [PULL 04/10] util/interval-tree: Use qatomic_read/set for rb_parent_color Richard Henderson
2023-07-31 21:02 ` [PULL 05/10] accel/tcg: Clear tcg_ctx->gen_tb on buffer overflow Richard Henderson
2023-07-31 21:02 ` [PULL 06/10] bsd-user: Allocate guest virtual address space Richard Henderson
2023-07-31 21:02 ` [PULL 07/10] bsd-user: Specify host page alignment if none specified Richard Henderson
2023-07-31 21:02 ` [PULL 08/10] target/ppc: Disable goto_tb with architectural singlestep Richard Henderson
2023-08-01  6:05   ` Michael Tokarev
2023-08-01  6:08     ` Michael Tokarev
2023-07-31 21:02 ` [PULL 09/10] linux-user/armeb: Fix __kernel_cmpxchg() for armeb Richard Henderson
2023-07-31 21:02 ` [PULL 10/10] target/s390x: Move trans_exc_code update to do_program_interrupt Richard Henderson
2023-08-01  4:08 ` [PULL 00/10] tcg patch queue for rc2 Richard Henderson

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