hi
For the cortex M interrupt handling the ARM info centre gives the best information and is part of their documentation. The interrupt handling for all Cortex M series is under ARM control.
More info on the interrupts check this link:
ARM Information Center
There are two important concepts in interrupt handling of cortex M - tail chaining and later arrival concept
This you can check at link
ARM Information Center
You need to right click on these links to open the right link under the name shown.
The above should help with all the questions that you have asked.