misc: fastrpc: return -EPIPE to invocations on device removal

The return value is initialized as -1, or -EPERM. The completion of an
invocation implies that the return value is set appropriately, but
"Permission denied" does not accurately describe the outcome of the
invocation. Set the invocation's return value to a more appropriate
"Broken pipe", as the cleanup breaks the driver's connection with rpmsg.

Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context Invoke method")
Cc: stable <stable@kernel.org>
Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230523152550.438363-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index a654dc416480bf7bc614a025e6d13d15b871c91f..964f67dad2f9f410d9f0b097367ce275833ae524 100644 (file)
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -2349,8 +2349,10 @@ static void fastrpc_notify_users(struct fastrpc_user *user)
        struct fastrpc_invoke_ctx *ctx;
 
        spin_lock(&user->lock);
-       list_for_each_entry(ctx, &user->pending, node)
+       list_for_each_entry(ctx, &user->pending, node) {
+               ctx->retval = -EPIPE;
                complete(&ctx->work);
+       }
        spin_unlock(&user->lock);
 }