Hi,
On 9/13/20 9:02 PM, trix@xxxxxxxxxx wrote:
From: Tom Rix <trix@xxxxxxxxxx>
clang static analysis flags this represenative problem
thinkpad_acpi.c:2523:7: warning: Branch condition evaluates
to a garbage value
if (!oldn->mute ||
^~~~~~~~~~~
In hotkey_kthread() mute is conditionally set by hotkey_read_nvram()
but unconditionally checked by hotkey_compare_and_issue_event().
So the tp_nvram_state variable s[2] needs to be initialized.
Fixes: 01e88f25985d ("ACPI: thinkpad-acpi: add CMOS NVRAM polling for hot keys (v9)")
Looking at the code I do not think this can actually happen,
this can only happen if the poll_mask == 0 the first time
through the loop so s[1] does never gets initialized and then
the second time to the loop poll_mask != 0, but if poll_mask
changes then we hit:
mutex_lock(&hotkey_thread_data_mutex);
if (was_frozen || hotkey_config_change != change_detector) {
/* forget old state on thaw or config change */
si = so;
t = 0;
change_detector = hotkey_config_change;
}
Where we set si = so so then this can also not happen.
I can understand the static-analyzer warning about this, and fixing
that warning is good. But I doubt that this warrants a fixes tag.
So with the Fixes tag dropped this is:
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/platform/x86/thinkpad_acpi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 47925c319d7b..24da8b6872f2 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -2573,7 +2573,7 @@ static void hotkey_compare_and_issue_event(struct tp_nvram_state *oldn,
*/
static int hotkey_kthread(void *data)
{
- struct tp_nvram_state s[2];
+ struct tp_nvram_state s[2] = { 0 };
u32 poll_mask, event_mask;
unsigned int si, so;
unsigned long t;
