[SOLVED] Weird proton log message?

garpu · 05-09-2024, 10:19 PM

So while going through logs this past weekend, I noticed line after line of this in a steam proton log (created via PROTON_LOG=1 %command% in launch options):

Code:

"err:virtual:try_map_free_area mmap() error Operation not permitted"

I've increased vm.max_map_count, and that doesn't seem to affect it any. I'm not noticing any crashes or problems, though. I've also got at least 8GB of RAM free when playing a game. (I've been obsessively checking top when running a game after noticing that.) I got more vram free while gaming than I know what to do with now, so that's not the issue, either.

Searching through forums, it's popped up in other people's logs: https://www.linuxquestions.org/quest...ng-4175732254/

So what causes it? Is it something to fix/worry about? I was in a world event in Guild Wars 2 tonight for a solid 40 minutes with graphics absolutely cranked, and no problems.

nhattu1986 · 05-10-2024, 10:09 PM

It caused by kernel prevent application from mmap the low virtual address as method to prevent you from accidental mmap the NULL address.

from the manual of the debian mmap_min_addr:

https://wiki.debian.org/mmap_min_addr

Quote:

Allowing processes to map low values increases the security implications of a class of defects known as "kernel NULL pointer dereference" defects

also from the same page, it also note that it will interference with some application and wine is one of them

Quote:

The downside to preventing applications from mmap'ing low virtual memory addresses is that certain applications depend on this functionality. dosemu, qemu and wine

also from the kernel documentation:
https://www.kernel.org/doc/html/late...=mmap_min_addr

Quote:

By default this value is set to 0 and no protections will be enforced by the security module. Setting this value to something like 64k will allow the vast majority of applications to work correctly and provide defense in depth against future potential kernel bugs

I think in the old version of kernel that values is set to 0 and it allow wine to mmap to any address, but the recent kernel changed that to some other values that bigger than the min values that wine is using and it cause the warning, set the min mmap to 64kb will fix the issue

so you can just follow the post #2 on this thread and it should fix the warning of wine

https://www.linuxquestions.org/quest...te-4175700295/

garpu · 05-10-2024, 10:14 PM

Quote:

Originally Posted by nhattu1986

I think in the old version of kernel that values is set to 0 and it allow wine to mmap to any address, but the recent kernel changed that to some other values that bigger than the min values that wine is using and it cause the warning, set the min mmap to 64kb will fix the issue

so you can just follow the post #2 on this thread and it should fix the warning of wine

https://www.linuxquestions.org/quest...te-4175700295/

Oh cool, thanks! But isn't that the default? (65536)

nhattu1986 · 05-10-2024, 10:18 PM

Quote:

Originally Posted by garpu

Oh cool, thanks! But isn't that the default? (65536)

you can check the default of your system by using

Code:

sysctl vm.mmap_min_addr

in my system, it set to 98304

Code:

nhattu@dakstar:~$ sysctl vm.mmap_min_addr
vm.mmap_min_addr = 98304