mprotect.2: Improve the description of prot

[brooks]

Summary

The new wording is based on the POSIX description.

Sponsored by: DARPA

[brooks]

As requested in D30442, this improves the wording of the description of the prot argument.

[imp]

The wording is much better, and I don't think changes the intended meaning...

[markj]

lib/libc/sys/mprotect.2

59–60

Technically, the argument should be the bitwise OR of some subset of {READ, WRITE, EXEC} or PROT_NONE. ORing PROT_NONE with other flags does nothing.

[brooks]

• Separate PROT_NONE from other arguments

[markj]

lib/libc/sys/mprotect.2

54

[alc]

lib/libc/sys/mprotect.2

75–76

While we're here, I would suggest adding the word "later" here, i.e., saying, "... from later upgrading ..." Also, wouldn't "adding" be clearer than "upgrading"?

78

Add the word "bitwise" here, like above?

[mckusick]

I agree with mark and alc comments.

[brooks]

• Adopt reviewer suggestions
• Render "or" consistently