Re: C aggregate passing (Rust kernel policy)

[Steven Rostedt]

On Wed, 26 Feb 2025 13:42:29 -0800
Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Wed, 26 Feb 2025 at 13:26, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> >
> > As a bystander here, I just want to ask, do you mean basically to treat all
> > reads as READ_ONCE() and all writes as WRITE_ONCE()?  
> 
> Absolutely not.
> 
> I thought I made that clear:

Sorry, I didn't make myself clear. I shouldn't have said "all reads". What
I meant was the the "initial read".

Basically:

	r = READ_ONCE(*p);

and use what 'r' is from then on.

Where the compiler reads the source once and works with what it got.

To keep it from changing:

	r = *p;
	if (r > 1000)
		goto out;
	x = r;

to:

	if (*p > 1000)
		goto out;
	x = *p;


-- Steve