From: Oleg Drokin <gr...@linuxhacker.ru>
In debugfs it's not enough to just set file mode to read-only to
deny write access to a file, instead just don't provide
the write method unless write access is really requested.
Signed-off-by: Oleg Drokin <gr...@linuxhacker.ru>
---
I assume allowing run-time changes via /sys/module is preferrable,
opposed to forced module unload and reload to change this option,
but I can submit another patch to only depend on the module parameter
too, please let me know.
drivers/acpi/ec_sys.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c
index bea8e42..6c7dd7a 100644
--- a/drivers/acpi/ec_sys.c
+++ b/drivers/acpi/ec_sys.c
@@ -73,6 +73,9 @@ static ssize_t acpi_ec_write_io(struct file *f, const char
__user *buf,
loff_t init_off = *off;
int err = 0;
+ if (!write_support)
+ return -EINVAL;
+
if (*off >= EC_SPACE_SIZE)
return 0;
if (*off + count >= EC_SPACE_SIZE) {
--
2.1.0
