[PATCH liburing 0/3] Fix undefined behavior, acessing dead object

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

This series fixes undefined behavior caused by accessing local
variables that have been out of their scope.

FWIW, compile the following code with gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0:
```
#include <stdio.h>

int main(void)
{
	int *pa, *pb;

	{
		int a;
		pa = &a;
	}

	{
		int b;
		pb = &b;
	}

	*pa = 100;
	*pb = 200;

	printf("(pa == pb) = %d\n", pa == pb);
	printf("*pa == %d; *pb == %d\n", *pa, *pb);
	return 0;
}
```

produces the following output:

```
  ammarfaizi2@integral2:/tmp$ gcc q.c -o q
  ammarfaizi2@integral2:/tmp$ ./q
  (pa == pb) = 1
  *pa == 200; *pb == 200
  ammarfaizi2@integral2:/tmp$
  ammarfaizi2@integral2:/tmp$ gcc -O3 q.c -o q
  ammarfaizi2@integral2:/tmp$ ./q
  (pa == pb) = 0
  *pa == 100; *pb == 200
  ammarfaizi2@integral2:/tmp$
```

Note that the `int a` and `int b` lifetime have ended, but we still
hold the references to them dereference them.

Also the result differs for the different optimization levels.
That's to say, there is no guarantee due to UB. Compiler is free
to reuse "out of scope variable"'s storage.

The same happens with test/socket-rw{,-eagain,-offset}.c.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
Ammar Faizi (3):
  test/socket-rw-eagain: Fix UB, accessing dead object
  test/socket-rw: Fix UB, accessing dead object
  test/socket-rw-offset: Fix UB, accessing dead object

 test/socket-rw-eagain.c | 17 +++++++----------
 test/socket-rw-offset.c | 17 +++++++----------
 test/socket-rw.c        | 17 +++++++----------
 3 files changed, 21 insertions(+), 30 deletions(-)


base-commit: 918d8061ffdfdf253806a1e8e141c71644e678bd
-- 
2.32.0