# [SOLVED] Why is USE=cet forcefully masked by portage?

## xgivolari

Hello everyone,

Since my Tiger Lake CPU supports it, I'd like to enable control flow enforcement on my system. However, the corresponding "cet" USE-flag is apparently masked on a global level. I was unable to find any explanation on why this is the case. Are there currently any complications with using CET on Gentoo? Thanks!Last edited by xgivolari on Tue Sep 07, 2021 10:25 am; edited 1 time in total

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## Hu

What do you see that makes you think it is globally masked?  I only see it masked on a few packages:

```
# New and for Gentoo still quite experimental. You've been

# warned. (Also, works only on x86_64 and with certain CPUs

# and compiler/binutils combinations.)

sys-devel/binutils cet

sys-devel/binutils-hppa64 cet

sys-devel/gdb cet

sys-libs/binutils-libs cet

sys-libs/glibc cet
```

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## xgivolari

My bad, since these 5 packages are the only ones to have the cet USE-flag in the first place, I thought the masking was done globally. Looks like I should have checked the profiles directory more carefully. But good to know that there is no explicit problem with CET on Gentoo, thanks!

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## Hu

I found the above through a recursive grep (which only showed the masks, but not the comment justifying them).

```
$ cd "$PORTDIR" && grep -r cet --include='*use.mask'
```

I initially couldn't find it because I searched for masks on their own line, which can match global masks, but not package-specific masks.

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