From 61b101c6a150057b6d512421ed108aed16e822ea Mon Sep 17 00:00:00 2001 From: Gui-Dong Han Date: Wed, 3 Jun 2026 10:11:27 +0800 Subject: [PATCH] misc: bcm-vk: Use acquire/release for msgq_inited bcm_vk_sync_msgq() fills the message queue information and then sets msgq_inited. Readers call bcm_vk_drv_access_ok() before accessing the message queues and their cached queue information. atomic_set()/atomic_read() do not order those accesses. A reader can see msgq_inited set while still seeing stale queue information. Use release when publishing the initialized queues and acquire when checking the gate. Keep the clear in bcm_vk_blk_drv_access() as atomic_set(). It closes the gate and does not publish queue state to readers. Fixes: 111d746bb476 ("misc: bcm-vk: add VK messaging support") Signed-off-by: Gui-Dong Han Link: https://patch.msgid.link/20260603021127.3285057-1-hanguidong02@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/bcm-vk/bcm_vk_msg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c index 3916ec07ecad..2c084a6b3a92 100644 --- a/drivers/misc/bcm-vk/bcm_vk_msg.c +++ b/drivers/misc/bcm-vk/bcm_vk_msg.c @@ -108,7 +108,8 @@ u32 msgq_avail_space(const struct bcm_vk_msgq __iomem *msgq, bool bcm_vk_drv_access_ok(struct bcm_vk *vk) { - return (!!atomic_read(&vk->msgq_inited)); + /* Pair with the release store after message queue initialization. */ + return !!atomic_read_acquire(&vk->msgq_inited); } void bcm_vk_set_host_alert(struct bcm_vk *vk, u32 bit_mask) @@ -501,7 +502,8 @@ int bcm_vk_sync_msgq(struct bcm_vk *vk, bool force_sync) msgq++; } } - atomic_set(&vk->msgq_inited, 1); + /* Publish message queue info before allowing driver access. */ + atomic_set_release(&vk->msgq_inited, 1); return ret; }