MmapFixedNoReserve does not terminate process on failure.
Failure to check its result and die will always lead to harder
to debug crashes later in execution. This was observed in Go
processes due to some address space conflicts.
Consistently check result of MmapFixedNoReserve.
While we are here also add warn_unused_result attribute
to prevent such bugs in future and change return type to bool
as that's what all callers want.
Reviewed in https://reviews.llvm.org/D49367
llvm-svn: 337531
Summary:
On PPC64 if you disable ASLR (or run under gdb) you're likely to see
mmap returning a mapping right at the end of the application address
space region. This caused SetShadow to call MEM_TO_SHADOW() on the
last+1 address in the region, which seems wrong to me; how can
MEM_TO_SHADOW() distinguish this from the first address in the following
region?
Fixed by only calling MEM_TO_SHADOW() once, on the start address.
Reviewers: samsonov, wschmidt, eugenis
Reviewed By: eugenis
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10735
llvm-svn: 240690
Dmitry Vyukov