diff options
Diffstat (limited to 'libartbase/base/mem_map.cc')
| -rw-r--r-- | libartbase/base/mem_map.cc | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/libartbase/base/mem_map.cc b/libartbase/base/mem_map.cc index 0ab47f2384..08d452b5ff 100644 --- a/libartbase/base/mem_map.cc +++ b/libartbase/base/mem_map.cc @@ -344,13 +344,20 @@ MemMap MemMap::MapAnonymous(const char* name, // We need to store and potentially set an error number for pretty printing of errors int saved_errno = 0; - void* actual = MapInternal(addr, - page_aligned_byte_count, - prot, - flags, - fd.get(), - 0, - low_4gb); + void* actual = nullptr; + + // New Ubuntu linux kerners seem to ignore the address hint, so make it a firm request. + // Whereas old kernels allocated at 'addr' if provided, newer kernels seem to ignore it. + // However, MAP_FIXED_NOREPLACE tells the kernel it must allocate at the address or fail. + // Do this only on host since android kernels still obey the hint without flag (for now). + if (!kIsTargetBuild && (flags & MAP_FIXED) == 0 && addr != nullptr) { + actual = MapInternal( + addr, page_aligned_byte_count, prot, flags | MAP_FIXED_NOREPLACE, fd.get(), 0, low_4gb); + // If the fixed-address allocation failed, fallback to the default path (random address). + } + if (actual == nullptr || actual == MAP_FAILED) { + actual = MapInternal(addr, page_aligned_byte_count, prot, flags, fd.get(), 0, low_4gb); + } saved_errno = errno; if (actual == MAP_FAILED) { |