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, 166 insertions, 0 deletions

diff --git a/lib/sys_info.c b/lib/sys_info.c
new file mode 100644
index 000000000..f32a06ec9
--- /dev/null
+++ b/lib/sys_info.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/array_size.h>
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/console.h>
+#include <linux/log2.h>
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/nmi.h>
+#include <linux/sched/debug.h>
+#include <linux/string.h>
+#include <linux/sysctl.h>
+
+#include <linux/sys_info.h>
+
+static const char * const si_names[] = {
+	[ilog2(SYS_INFO_TASKS)]			= "tasks",
+	[ilog2(SYS_INFO_MEM)]			= "mem",
+	[ilog2(SYS_INFO_TIMERS)]		= "timers",
+	[ilog2(SYS_INFO_LOCKS)]			= "locks",
+	[ilog2(SYS_INFO_FTRACE)]		= "ftrace",
+	[ilog2(SYS_INFO_PANIC_CONSOLE_REPLAY)]	= "",
+	[ilog2(SYS_INFO_ALL_BT)]		= "all_bt",
+	[ilog2(SYS_INFO_BLOCKED_TASKS)]		= "blocked_tasks",
+};
+
+/*
+ * Default kernel sys_info mask.
+ * If a kernel module calls sys_info() with "parameter == 0", then
+ * this mask will be used.
+ */
+static unsigned long kernel_si_mask;
+
+/* Expecting string like "xxx_sys_info=tasks,mem,timers,locks,ftrace,..." */
+unsigned long sys_info_parse_param(char *str)
+{
+	unsigned long si_bits = 0;
+	char *s, *name;
+	int i;
+
+	s = str;
+	while ((name = strsep(&s, ",")) && *name) {
+		i = match_string(si_names, ARRAY_SIZE(si_names), name);
+		if (i >= 0)
+			__set_bit(i, &si_bits);
+	}
+
+	return si_bits;
+}
+
+#ifdef CONFIG_SYSCTL
+
+static int sys_info_write_handler(const struct ctl_table *table,
+				  void *buffer, size_t *lenp, loff_t *ppos,
+				  unsigned long *si_bits_global)
+{
+	unsigned long si_bits;
+	int ret;
+
+	ret = proc_dostring(table, 1, buffer, lenp, ppos);
+	if (ret)
+		return ret;
+
+	si_bits = sys_info_parse_param(table->data);
+
+	/* The access to the global value is not synchronized. */
+	WRITE_ONCE(*si_bits_global, si_bits);
+
+	return 0;
+}
+
+static int sys_info_read_handler(const struct ctl_table *table,
+				 void *buffer, size_t *lenp, loff_t *ppos,
+				 unsigned long *si_bits_global)
+{
+	unsigned long si_bits;
+	unsigned int len = 0;
+	char *delim = "";
+	unsigned int i;
+
+	/* The access to the global value is not synchronized. */
+	si_bits = READ_ONCE(*si_bits_global);
+
+	for_each_set_bit(i, &si_bits, ARRAY_SIZE(si_names)) {
+		if (*si_names[i]) {
+			len += scnprintf(table->data + len, table->maxlen - len,
+					 "%s%s", delim, si_names[i]);
+			delim = ",";
+		}
+	}
+
+	return proc_dostring(table, 0, buffer, lenp, ppos);
+}
+
+int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos)
+{
+	struct ctl_table table;
+	unsigned int i;
+	size_t maxlen;
+
+	maxlen = 0;
+	for (i = 0; i < ARRAY_SIZE(si_names); i++)
+		maxlen += strlen(si_names[i]) + 1;
+
+	char *names __free(kfree) = kzalloc(maxlen, GFP_KERNEL);
+	if (!names)
+		return -ENOMEM;
+
+	table = *ro_table;
+	table.data = names;
+	table.maxlen = maxlen;
+
+	if (write)
+		return sys_info_write_handler(&table, buffer, lenp, ppos, ro_table->data);
+	else
+		return sys_info_read_handler(&table, buffer, lenp, ppos, ro_table->data);
+}
+
+static const struct ctl_table sys_info_sysctls[] = {
+	{
+		.procname	= "kernel_sys_info",
+		.data		= &kernel_si_mask,
+		.maxlen         = sizeof(kernel_si_mask),
+		.mode		= 0644,
+		.proc_handler	= sysctl_sys_info_handler,
+	},
+};
+
+static int __init sys_info_sysctl_init(void)
+{
+	register_sysctl_init("kernel", sys_info_sysctls);
+	return 0;
+}
+subsys_initcall(sys_info_sysctl_init);
+#endif
+
+static void __sys_info(unsigned long si_mask)
+{
+	if (si_mask & SYS_INFO_TASKS)
+		show_state();
+
+	if (si_mask & SYS_INFO_MEM)
+		show_mem();
+
+	if (si_mask & SYS_INFO_TIMERS)
+		sysrq_timer_list_show();
+
+	if (si_mask & SYS_INFO_LOCKS)
+		debug_show_all_locks();
+
+	if (si_mask & SYS_INFO_FTRACE)
+		ftrace_dump(DUMP_ALL);
+
+	if (si_mask & SYS_INFO_ALL_BT)
+		trigger_all_cpu_backtrace();
+
+	if (si_mask & SYS_INFO_BLOCKED_TASKS)
+		show_state_filter(TASK_UNINTERRUPTIBLE);
+}
+
+void sys_info(unsigned long si_mask)
+{
+	__sys_info(si_mask ? : kernel_si_mask);
+}