| From 72fc0281f9b8291a1b33fdba49e2cec4e42de9d5 Mon Sep 17 00:00:00 2001 |
| From: Dave Gerlach <d-gerlach@ti.com> |
| Date: Wed, 11 Dec 2019 22:03:14 -0600 |
| Subject: [PATCH] soc: ti: wkup_m3_ipc: Fix race condition with rproc_boot |
| |
| commit 03729cfa0d543bc996bf959e762ec999afc8f3d2 upstream. |
| |
| 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@ti.com> |
| Signed-off-by: Dave Gerlach <d-gerlach@ti.com> |
| Acked-by: Santosh Shilimkar <ssantosh@kernel.org> |
| Signed-off-by: Tony Lindgren <tony@atomide.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/soc/ti/wkup_m3_ipc.c b/drivers/soc/ti/wkup_m3_ipc.c |
| index 378369d9364a..e9ece45d7a33 100644 |
| --- a/drivers/soc/ti/wkup_m3_ipc.c |
| +++ b/drivers/soc/ti/wkup_m3_ipc.c |
| @@ -419,6 +419,8 @@ 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); |
| } |
| @@ -505,8 +507,6 @@ static int wkup_m3_ipc_probe(struct platform_device *pdev) |
| goto err_put_rproc; |
| } |
| |
| - m3_ipc_state = m3_ipc; |
| - |
| return 0; |
| |
| err_put_rproc: |
| -- |
| 2.7.4 |
| |
