Compiler is not happy about using ARRAY_SIZE() in comparison to smaller type:
CC drivers/tty/serial/serial_core.o
.../serial_core.c: In function ‘uart_try_toggle_sysrq’:
.../serial_core.c:3222:24: warning: comparison is always false due to limited range of data type [-Wtype-limits]
3222 | if (++port->sysrq_seq < (ARRAY_SIZE(sysrq_toggle_seq) - 1)) {
| ^
Looking at the code it appears that there is an additional weirdness,
i.e. use ARRAY_SIZE() against simple string literal. Yes, the idea probably
was to allow '\0' in the sequence, but it's impractical: kernel configuration
won't accept it to begin with followed by a comment about '\0' before
comparison in question.
Drop all these by switching to strlen() and convert code accordingly.
Fixes: 68af43173d3f ("serial/sysrq: Add MAGIC_SYSRQ_SERIAL_SEQUENCE")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index aec98db45406..ec3b833e9f22 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3209,7 +3209,9 @@ static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
*/
static bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
{
- if (ARRAY_SIZE(sysrq_toggle_seq) <= 1)
+ int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
+
+ if (!sysrq_toggle_seq_len)
return false;
BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
@@ -3218,8 +3220,7 @@ static bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
return false;
}
- /* Without the last \0 */
- if (++port->sysrq_seq < (ARRAY_SIZE(sysrq_toggle_seq) - 1)) {
+ if (++port->sysrq_seq < sysrq_toggle_seq_len) {
port->sysrq = jiffies + SYSRQ_TIMEOUT;
return true;
}
--
2.25.1
