When running applications which make large (sparsely populated) address ranges
(e.g. when using address sanitizer with LibAFL) the inability to exclude these
regions from any core dump can result in very large files which fill the disk.
A coredump is obvously very useful for performing a post-mortem when fuzzing.
Whilst the man pages state that madvise provides only a hint (and hence can be
ignored), this patch adds support to handle MADV_DONTDUMP and set a
corresponding flag in the page flags, thus allowing QEMU to exclude these
regions from the core file.
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