Re: segfault in stat

[Roland McGrath]

> Doesn't this trouble you?  Why is there "undefined behavior" anywhere
> in libc or the kernel?  IMNSHO, this is totally unacceptable.  

libc and the kernel are very different.  There is always undefined behavior
possible in libc, for example any time a program clobbers some random part
of its address space it might cause weird things to happen in libc.  Using
bad addresses is undefined within the context of the process.  A "bad
address" might be a valid address of some inappropriate part of memory, and
changing that memory produces unpredictable results.  A bad address that is
truly inaccessible produces a signal (SIGSEGV or SIGBUS).