How does bash deal with signal?

[Peng Yu]

Hi,

I see sigaction() and signal() are not exactly the same. Does bash
code use sigaction() exclusively?

https://stackoverflow.com/questions/231912/what-is-the-difference-between-sigaction-and-signal

If so, I can expect all other signals will be blocked until the
current handler returns?

And there should be not a vulnerability like the following in bash?

"This means that the signal() handler must reinstall itself as its
first action. It also opens up a window of vulnerability ..."

-- 
Regards,
Peng