4 Aug
2025
4 Aug
'25
6:28 p.m.
On Mon, Aug 04, 2025 at 05:34:10AM -0700, Breno Leitao wrote:
On Mon, Aug 04, 2025 at 01:08:15PM +0100, Catalin Marinas wrote:
I'm surprised we haven't seen these until recently. Has printk always allocated memory?
I can talk about netconsole, and the answer is yes!
weird enought, lockdep never picked this issue, and I have a few set of hosts running kmemleak and lockdep for a while.
This time was different because I have decided to invstiage the code, and found the deadlock. Still, no lockdep complain at all.
I guess it's because kmemleak is quiet in general, unless problems are found, and lockdep never registered this combination - printk() called with the kmemleak_lock held.
Thanks for investigating.
--
Catalin