commit 474f2f5c8b5dbc23ee7b5542ac6df47016efe1c3
author Evgenii Stepanov <eugenis@google.com> Mon Jul 06 19:25:43 2020 +0000
committer Evgenii Stepanov <eugenis@google.com> Mon Jul 06 19:27:55 2020 +0000
tree ddb2bac208a330c9f8f9427577f2960dbd3e528c
parent a8cf3fef2aa2201014c35c3487da222ccfedfc1c

Revert "Add randomized padding around shared library mappings."

This reverts commit a8cf3fef2aa2201014c35c3487da222ccfedfc1c.

Reason for revert: memory regression due to the fragmentation of the page tables
Bug: 159810641
Bug: 158113540

Change-Id: I6212c623ff440c7f6889f0a1e82cf7a96200a411

linker/linker.cpp

diff --git a/linker/linker.cpp b/linker/linker.cpp
index 9301f8c..edf0329 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -301,14 +301,13 @@
     return;
   }
 
-  void* start = reinterpret_cast<void*>(si->has_min_version(6) ? si->get_map_start() : si->base);
-  size_t size = si->has_min_version(6) ? si->get_map_size() : si->size;
-  if (start != nullptr && size != 0) {
+  if (si->base != 0 && si->size != 0) {
     if (!si->is_mapped_by_caller()) {
-      munmap(start, size);
+      munmap(reinterpret_cast<void*>(si->base), si->size);
     } else {
       // remap the region as PROT_NONE, MAP_ANONYMOUS | MAP_NORESERVE
-      mmap(start, size, PROT_NONE, MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
+      mmap(reinterpret_cast<void*>(si->base), si->size, PROT_NONE,
+           MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
     }
   }
 
@@ -600,8 +599,6 @@
     si_->load_bias = elf_reader.load_bias();
     si_->phnum = elf_reader.phdr_count();
     si_->phdr = elf_reader.loaded_phdr();
-    si_->set_map_start(elf_reader.map_start());
-    si_->set_map_size(elf_reader.map_size());
 
     return true;
   }