map bss to addr zero

Srinivas Ramanan [off-list ref] wrote:

Hi all,
This is an interview question.
"What is the implication of mapping BSS to the Virtual Memory Segment
0?"

I was not able to find the answer from web. So posting here.
thanks,
srinivas

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As a guess,

Linux kernel developers leverage the fact that low address values are illegal, thus a pointer handling error that generates a low address value triggers a trap which allows the programmer to know he screwed up.

Using virtual memory segment zero makes those valid addresses and thus programming errors are more likely to slip through un-noticed.

HTH
Greg
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.