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Message-Id: <20200203161924.069841377@linuxfoundation.org>
Date: Mon, 3 Feb 2020 16:19:40 +0000
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Suman Anna <s-anna@...com>,
Dave Gerlach <d-gerlach@...com>,
Santosh Shilimkar <ssantosh@...nel.org>,
Tony Lindgren <tony@...mide.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.14 55/89] soc: ti: wkup_m3_ipc: Fix race condition with rproc_boot
From: Dave Gerlach <d-gerlach@...com>
[ Upstream commit 03729cfa0d543bc996bf959e762ec999afc8f3d2 ]
Any user of wkup_m3_ipc calls wkup_m3_ipc_get to get a handle and this
checks the value of the static variable m3_ipc_state to see if the
wkup_m3 is ready. Currently this is populated during probe before
rproc_boot has been called, meaning there is a window of time that
wkup_m3_ipc_get can return a valid handle but the wkup_m3 itself is not
ready, leading to invalid IPC calls to the wkup_m3 and system
instability.
To avoid this, move the population of the m3_ipc_state variable until
after rproc_boot has succeeded to guarantee a valid and usable handle
is always returned.
Reported-by: Suman Anna <s-anna@...com>
Signed-off-by: Dave Gerlach <d-gerlach@...com>
Acked-by: Santosh Shilimkar <ssantosh@...nel.org>
Signed-off-by: Tony Lindgren <tony@...mide.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/soc/ti/wkup_m3_ipc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/ti/wkup_m3_ipc.c b/drivers/soc/ti/wkup_m3_ipc.c
index 369aef5e7228e..651827c6ee6f9 100644
--- a/drivers/soc/ti/wkup_m3_ipc.c
+++ b/drivers/soc/ti/wkup_m3_ipc.c
@@ -375,6 +375,8 @@ static void wkup_m3_rproc_boot_thread(struct wkup_m3_ipc *m3_ipc)
ret = rproc_boot(m3_ipc->rproc);
if (ret)
dev_err(dev, "rproc_boot failed\n");
+ else
+ m3_ipc_state = m3_ipc;
do_exit(0);
}
@@ -461,8 +463,6 @@ static int wkup_m3_ipc_probe(struct platform_device *pdev)
goto err_put_rproc;
}
- m3_ipc_state = m3_ipc;
-
return 0;
err_put_rproc:
--
2.20.1
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