iio: adc: at91_adc: Correct call to input_free_device

This error handling code can be reached before st->ts_input is initialized, so it is safer to always use the original name, input_dev.

A simplified version of the semantic match that finds this problem is:

// <smpl>
@r exists@
local idexpression struct input_dev * x;
expression ra,rr;
@@

* x = input_allocate_device(...)
... when != x = rr

      when != input_free_device(x,...)
      when != if (...) { ... input_free_device(x,...) ...}

if(...) { ... when != x = ra
when forall
* when != input_free_device(x,...)
\(return <+...x...+>; \| return...; \) }

// </smpl>

Signed-off-by Himangi Saraogi <[email protected]>

---
  drivers/iio/adc/at91_adc.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

drivers/iio/adc/at91_adc.c +1 -1

index 3b5bacd..73b2bb5 100644
@@ -1114,7 +1114,7 @@ static int at91_ts_register(struct at91_adc_state *st,
  	return ret;
 
  err:
-	input_free_device(st->ts_input);
+	input_free_device(input);
  	return ret;
  }
 

Quoted 20 lines · Himangi Saraogi

This error handling code can be reached before st->ts_input is initialized, so it is safer to always use the original name, input_dev.

A simplified version of the semantic match that finds this problem is:

// <smpl>
@r exists@
local idexpression struct input_dev * x;
expression ra,rr;
@@

* x = input_allocate_device(...)
... when != x = rr

     when != input_free_device(x,...)
     when != if (...) { ... input_free_device(x,...) ...}

if(...) { ... when != x = ra
when forall
* when != input_free_device(x,...)
\(return <+...x...+>; \| return...; \) }

Quoted 3 lines

// </smpl>

Signed-off-by Himangi Saraogi <[email protected]>

The error handling in this function has been completely rewritten so the bug is no longer there and this no longer applies.

Quoted 24 lines · Jonathan Cameron

Quoted 23 lines · Himangi Saraogi

This error handling code can be reached before st->ts_input is initialized, so it is safer to always use the original name, input_dev.

A simplified version of the semantic match that finds this problem is:

// <smpl>
@r exists@
local idexpression struct input_dev * x;
expression ra,rr;
@@

* x = input_allocate_device(...)
... when != x = rr

      when != input_free_device(x,...)
      when != if (...) { ... input_free_device(x,...) ...}

if(...) { ... when != x = ra
when forall
* when != input_free_device(x,...)
\(return <+...x...+>; \| return...; \) }

// </smpl>

Signed-off-by Himangi Saraogi <[email protected]>

Quoted 2 lines

The error handling in this function has been completely rewritten so the bug is no longer there and this no longer applies.

Hum, actually, you are wrong and I introduced that bug in 3.16. The change didn't come from your tree so it is not up to date.

So either you take it after 3.16-rc1 or we can ask Nicolas to get it through the at91 tree.

Either way:

Acked-by Alexandre Belloni <[email protected]>