Revert 51371 - Catch OOMs in purgeable memory.

BUG=http://crbug.com/47980
TEST=unit tested

Review URL: http://codereview.chromium.org/2859036

TBR=avi@chromium.org
Review URL: http://codereview.chromium.org/2883014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@51373 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 120 deletions

diff --git a/base/process_util_mac.mm b/base/process_util_mac.mm
index c9543db..457e69b 100644
--- a/base/process_util_mac.mm
+++ b/base/process_util_mac.mm
@@ -7,7 +7,6 @@
 
 #import <Cocoa/Cocoa.h>
 #include <crt_externs.h>
-#include <dlfcn.h>
 #include <mach/mach.h>
 #include <mach/mach_init.h>
 #include <mach/task.h>
@@ -406,12 +405,6 @@ valloc_type g_old_valloc;
 realloc_type g_old_realloc;
 memalign_type g_old_memalign;
 
-malloc_type g_old_malloc_purgeable;
-calloc_type g_old_calloc_purgeable;
-valloc_type g_old_valloc_purgeable;
-realloc_type g_old_realloc_purgeable;
-memalign_type g_old_memalign_purgeable;
-
 void* oom_killer_malloc(struct _malloc_zone_t* zone,
                         size_t size) {
   void* result = g_old_malloc(zone, size);
@@ -460,54 +453,6 @@ void* oom_killer_memalign(struct _malloc_zone_t* zone,
   return result;
 }
 
-void* oom_killer_malloc_purgeable(struct _malloc_zone_t* zone,
-                                  size_t size) {
-  void* result = g_old_malloc_purgeable(zone, size);
-  if (!result && size)
-    DebugUtil::BreakDebugger();
-  return result;
-}
-
-void* oom_killer_calloc_purgeable(struct _malloc_zone_t* zone,
-                                  size_t num_items,
-                                  size_t size) {
-  void* result = g_old_calloc_purgeable(zone, num_items, size);
-  if (!result && num_items && size)
-    DebugUtil::BreakDebugger();
-  return result;
-}
-
-void* oom_killer_valloc_purgeable(struct _malloc_zone_t* zone,
-                                  size_t size) {
-  void* result = g_old_valloc_purgeable(zone, size);
-  if (!result && size)
-    DebugUtil::BreakDebugger();
-  return result;
-}
-
-void* oom_killer_realloc_purgeable(struct _malloc_zone_t* zone,
-                                   void* ptr,
-                                   size_t size) {
-  void* result = g_old_realloc_purgeable(zone, ptr, size);
-  if (!result && size)
-    DebugUtil::BreakDebugger();
-  return result;
-}
-
-void* oom_killer_memalign_purgeable(struct _malloc_zone_t* zone,
-                                    size_t alignment,
-                                    size_t size) {
-  void* result = g_old_memalign_purgeable(zone, alignment, size);
-  // Only die if posix_memalign would have returned ENOMEM, since there are
-  // other reasons why NULL might be returned (see
-  // http://opensource.apple.com/source/Libc/Libc-583/gen/malloc.c ).
-  if (!result && size && alignment >= sizeof(void*)
-      && (alignment & (alignment - 1)) == 0) {
-    DebugUtil::BreakDebugger();
-  }
-  return result;
-}
-
 // === C++ operator new ===
 
 void oom_killer_new() {
@@ -595,16 +540,6 @@ id oom_killer_allocWithZone(id self, SEL _cmd, NSZone* zone)
 
 }  // namespace
 
-malloc_zone_t* GetPurgeableZone() {
-  // malloc_default_purgeable_zone only exists on >= 10.6. Use dlsym to grab it
-  // at runtime because it may not be present in the SDK used for compilation.
-  typedef malloc_zone_t* (*malloc_default_purgeable_zone_t)(void);
-  malloc_default_purgeable_zone_t malloc_purgeable_zone =
-      reinterpret_cast<malloc_default_purgeable_zone_t>(
-          dlsym(RTLD_DEFAULT, "malloc_default_purgeable_zone"));
-  return malloc_purgeable_zone();
-}
-
 void EnableTerminationOnOutOfMemory() {
   if (g_oom_killer_enabled)
     return;
@@ -628,43 +563,23 @@ void EnableTerminationOnOutOfMemory() {
   CHECK(!g_old_malloc && !g_old_calloc && !g_old_valloc && !g_old_realloc &&
         !g_old_memalign) << "Old allocators unexpectedly non-null";
 
-  CHECK(!g_old_malloc_purgeable && !g_old_calloc_purgeable &&
-        !g_old_valloc_purgeable && !g_old_realloc_purgeable &&
-        !g_old_memalign_purgeable) << "Old allocators unexpectedly non-null";
-
   // See http://trac.webkit.org/changeset/53362/trunk/WebKitTools/DumpRenderTree/mac
   bool zone_allocators_protected =
       ((os_major == 10 && os_minor > 6) || os_major > 10);
 
   ChromeMallocZone* default_zone =
       reinterpret_cast<ChromeMallocZone*>(malloc_default_zone());
-  ChromeMallocZone* purgeable_zone =
-      reinterpret_cast<ChromeMallocZone*>(GetPurgeableZone());
 
-  vm_address_t page_start_default = NULL;
-  vm_address_t page_start_purgeable = NULL;
-  vm_size_t len_default = 0;
-  vm_size_t len_purgeable = 0;
+  vm_address_t page_start = NULL;
+  vm_size_t len = 0;
   if (zone_allocators_protected) {
-    page_start_default = reinterpret_cast<vm_address_t>(default_zone) &
+    page_start = reinterpret_cast<vm_address_t>(default_zone) &
         static_cast<vm_size_t>(~(getpagesize() - 1));
-    len_default = reinterpret_cast<vm_address_t>(default_zone) -
-        page_start_default + sizeof(ChromeMallocZone);
-    mprotect(reinterpret_cast<void*>(page_start_default), len_default,
-             PROT_READ | PROT_WRITE);
-
-    if (purgeable_zone) {
-      page_start_purgeable = reinterpret_cast<vm_address_t>(purgeable_zone) &
-          static_cast<vm_size_t>(~(getpagesize() - 1));
-      len_purgeable = reinterpret_cast<vm_address_t>(purgeable_zone) -
-          page_start_purgeable + sizeof(ChromeMallocZone);
-      mprotect(reinterpret_cast<void*>(page_start_purgeable), len_purgeable,
-               PROT_READ | PROT_WRITE);
-    }
+    len = reinterpret_cast<vm_address_t>(default_zone) -
+        page_start + sizeof(malloc_zone_t);
+    mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ | PROT_WRITE);
   }
 
-  // Default zone
-
   g_old_malloc = default_zone->malloc;
   g_old_calloc = default_zone->calloc;
   g_old_valloc = default_zone->valloc;
@@ -683,36 +598,8 @@ void EnableTerminationOnOutOfMemory() {
       default_zone->memalign = oom_killer_memalign;
   }
 
-  // Purgeable zone (if it exists)
-
-  if (purgeable_zone) {
-    g_old_malloc_purgeable = purgeable_zone->malloc;
-    g_old_calloc_purgeable = purgeable_zone->calloc;
-    g_old_valloc_purgeable = purgeable_zone->valloc;
-    g_old_realloc_purgeable = purgeable_zone->realloc;
-    CHECK(g_old_malloc_purgeable && g_old_calloc_purgeable &&
-          g_old_valloc_purgeable && g_old_realloc_purgeable)
-        << "Failed to get system allocation functions.";
-
-    purgeable_zone->malloc = oom_killer_malloc_purgeable;
-    purgeable_zone->calloc = oom_killer_calloc_purgeable;
-    purgeable_zone->valloc = oom_killer_valloc_purgeable;
-    purgeable_zone->realloc = oom_killer_realloc_purgeable;
-
-    if (purgeable_zone->version >= 5) {
-      g_old_memalign_purgeable = purgeable_zone->memalign;
-      if (g_old_memalign_purgeable)
-        purgeable_zone->memalign = oom_killer_memalign_purgeable;
-    }
-  }
-
   if (zone_allocators_protected) {
-    mprotect(reinterpret_cast<void*>(page_start_default), len_default,
-             PROT_READ);
-    if (purgeable_zone) {
-      mprotect(reinterpret_cast<void*>(page_start_purgeable), len_purgeable,
-               PROT_READ);
-    }
+    mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ);
   }
 
   // === C malloc_zone_batch_malloc ===