iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
new file mode 100644
index 000000000..d84a879f0
--- /dev/null
+++ b/lib/kunit/try-catch.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * An API to allow a function, that may fail, to be executed, and recover in a
+ * controlled manner.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/test.h>
+#include <linux/completion.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/sched/task.h>
+
+#include "try-catch-impl.h"
+
+void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
+{
+	try_catch->try_result = -EFAULT;
+	kthread_exit(0);
+}
+EXPORT_SYMBOL_GPL(kunit_try_catch_throw);
+
+static int kunit_generic_run_threadfn_adapter(void *data)
+{
+	struct kunit_try_catch *try_catch = data;
+
+	try_catch->try_result = -EINTR;
+	try_catch->try(try_catch->context);
+	if (try_catch->try_result == -EINTR)
+		try_catch->try_result = 0;
+
+	return 0;
+}
+
+void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
+{
+	struct kunit *test = try_catch->test;
+	struct task_struct *task_struct;
+	struct completion *task_done;
+	int exit_code, time_remaining;
+
+	try_catch->context = context;
+	try_catch->try_result = 0;
+	task_struct = kthread_create(kunit_generic_run_threadfn_adapter,
+				     try_catch, "kunit_try_catch_thread");
+	if (IS_ERR(task_struct)) {
+		try_catch->try_result = PTR_ERR(task_struct);
+		try_catch->catch(try_catch->context);
+		return;
+	}
+	get_task_struct(task_struct);
+	/*
+	 * As for a vfork(2), task_struct->vfork_done (pointing to the
+	 * underlying kthread->exited) can be used to wait for the end of a
+	 * kernel thread. It is set to NULL when the thread exits, so we
+	 * keep a copy here.
+	 */
+	task_done = task_struct->vfork_done;
+	wake_up_process(task_struct);
+
+	time_remaining = wait_for_completion_timeout(
+		task_done, try_catch->timeout);
+	if (time_remaining == 0) {
+		try_catch->try_result = -ETIMEDOUT;
+		kthread_stop(task_struct);
+	}
+
+	put_task_struct(task_struct);
+	exit_code = try_catch->try_result;
+
+	if (!exit_code)
+		return;
+
+	if (exit_code == -EFAULT)
+		try_catch->try_result = 0;
+	else if (exit_code == -EINTR) {
+		if (test->last_seen.file)
+			kunit_err(test, "try faulted: last line seen %s:%d\n",
+				  test->last_seen.file, test->last_seen.line);
+		else
+			kunit_err(test, "try faulted\n");
+	} else if (exit_code == -ETIMEDOUT)
+		kunit_err(test, "try timed out\n");
+	else if (exit_code)
+		kunit_err(test, "Unknown error: %d\n", exit_code);
+
+	try_catch->catch(try_catch->context);
+}
+EXPORT_SYMBOL_GPL(kunit_try_catch_run);