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| author | Andreas Gampe <agampe@google.com> | 2014-05-19 17:01:13 -0700 |
|---|---|---|
| committer | Andreas Gampe <agampe@google.com> | 2014-05-20 11:18:01 -0700 |
| commit | d8f26dbebe72c1cbdfa85bdeeb003283c7435db3 (patch) | |
| tree | d752729ef80ed46877681874ac69b3e846f34078 /runtime/mem_map.h | |
| parent | fd1264475562006c93b651d33e0a6266e8093ebe (diff) | |
| download | android_art-d8f26dbebe72c1cbdfa85bdeeb003283c7435db3.tar.gz android_art-d8f26dbebe72c1cbdfa85bdeeb003283c7435db3.tar.bz2 android_art-d8f26dbebe72c1cbdfa85bdeeb003283c7435db3.zip | |
ART: Randomize mem_map start address for linear scan search
When using linear scan for mem_map, randomize the start of the
search with getauxval(AT_RANDOM).
Change-Id: Id1e4c86b928147d74b9b0b73ff704de5d87b4500
Diffstat (limited to 'runtime/mem_map.h')
| -rw-r--r-- | runtime/mem_map.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/runtime/mem_map.h b/runtime/mem_map.h index 4255d17f27..141185663b 100644 --- a/runtime/mem_map.h +++ b/runtime/mem_map.h @@ -28,6 +28,12 @@ namespace art { // Used to keep track of mmap segments. +// +// On 64b systems not supporting MAP_32BIT, the implementation of MemMap will do a linear scan +// for free pages. For security, the start of this scan should be randomized. This requires a +// dynamic initializer. +// For this to work, it is paramount that there are no other static initializers that access MemMap. +// Otherwise, calls might see uninitialized values. class MemMap { public: // Request an anonymous region of length 'byte_count' and a requested base address. |