Re: Can kfree() sleep at runtime?

From: Jia-Ju Bai
Date: Thu May 31 2018 - 21:22:26 EST




On 2018/5/31 22:30, Christopher Lameter wrote:
On Thu, 31 May 2018, Matthew Wilcox wrote:

Freeing a page in the page allocator also was traditionally not sleeping.
That has changed?
No. "Your bug" being "The bug in your static analysis tool". It probably
isn't following the data flow correctly (or deeply enough).
Well ok this is not going to trigger for kfree(), this is x86 specific and
requires CONFIG_DEBUG_PAGEALLOC and a free of a page in a huge page.

Ok that is a very contorted situation but how would a static checker deal
with that?

I admit that my tool does not follow the data flow well, and I need to improve it.
In this case of kfree(), I want know how the data flow leads to my mistake.


Best wishes,
Jia-Ju Bai