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"The language" ? C doesn't define behaviour of a null deref, but most compilers map a -rwx page there to ensure that attempts to deref fault. In what circumst
by richo 12y ago
"The language" ?
C doesn't define behaviour of a null deref, but most compilers map a -rwx page there to ensure that attempts to deref fault.
In what circumstance do they not?
- dbaupp 12y agoThe compilers don't map pages there, the operating system does. The problem is the compiler will optimise assuming that a null deref never happens, so you can have source that looks like it should crash due to a null deref, but the compiler has "misoptimised" it to have very different behaviour. http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html http://blog.llvm.org/2011/05/what-every-c-programmer-should-...