Bug 996996 - Move fopen into non-sanboxed process. r=mrbkap

dom/base/Navigator.cpp

@@ -98,6 +98,11 @@
 #include "WorkerPrivate.h"
 #include "WorkerRunnable.h"
 
+#if defined(XP_LINUX)
+#include "mozilla/Hal.h"
+#endif
+#include "mozilla/dom/ContentChild.h"
+
 namespace mozilla {
 namespace dom {
 
@@ -1483,41 +1488,27 @@ Navigator::GetFeature(const nsAString& aName)
 
 #if defined(XP_LINUX)
   if (aName.EqualsLiteral("hardware.memory")) {
-    static int memLevel = 1;
-    if (memLevel == 1) {
-      FILE* f = fopen("/proc/meminfo", "r");
-      if (!f) {
-        p->MaybeReject(NS_LITERAL_STRING("CannotOpenMeminfo"));
-        return p.forget();
-      }
-
-      int memTotal;
-      int n = fscanf(f, "MemTotal: %d kB\n", &memTotal);
-      fclose(f);
-
-      if (memTotal == 0 || n != 1) {
+    // with seccomp enabled, fopen() should be in a non-sandboxed process
+    if (XRE_GetProcessType() == GeckoProcessType_Default) {
+      uint32_t memLevel = mozilla::hal::GetTotalSystemMemoryLevel();
+      if (memLevel == 0) {
         p->MaybeReject(NS_LITERAL_STRING("Abnormal"));
         return p.forget();
       }
-      // From KB to MB
-      memTotal /= 1024;
-
-      // round the value up to the next power of two
-      while (memLevel <= memTotal) {
-        memLevel *= 2;
-      }
+      p->MaybeResolve((int)memLevel);
+    } else {
+      mozilla::dom::ContentChild* cc =
+        mozilla::dom::ContentChild::GetSingleton();
+      nsRefPtr<Promise> ipcRef(p);
+      cc->SendGetSystemMemory(reinterpret_cast<uint64_t>(ipcRef.forget().take()));
     }
-    p->MaybeResolve(memLevel);
+    return p.forget();
   } // hardware.memory
-  else
 #endif
-  {
-    // resolve with <undefined> because the feature name is not supported
-    p->MaybeResolve(JS::UndefinedHandleValue);
-  }
+  // resolve with <undefined> because the feature name is not supported
+  p->MaybeResolve(JS::UndefinedHandleValue);
 
   return p.forget();
-
 }
 
 

dom/ipc/ContentChild.cpp

@@ -23,6 +23,7 @@
 #include "mozilla/dom/ExternalHelperAppChild.h"
 #include "mozilla/dom/PCrashReporterChild.h"
 #include "mozilla/dom/DOMStorageIPC.h"
+#include "mozilla/dom/Promise.h"
 #include "mozilla/hal_sandbox/PHalChild.h"
 #include "mozilla/ipc/BackgroundChild.h"
 #include "mozilla/ipc/FileDescriptorUtils.h"
@@ -1437,6 +1438,22 @@ ContentChild::AddRemoteAlertObserver(const nsString& aData,
     return NS_OK;
 }
 
+
+bool
+ContentChild::RecvSystemMemoryAvailable(const uint64_t& aGetterId,
+                                        const uint32_t& aMemoryAvailable)
+{
+  nsRefPtr<Promise> p = dont_AddRef(reinterpret_cast<Promise*>(aGetterId));
+
+  if (!aMemoryAvailable) {
+    p->MaybeReject(NS_LITERAL_STRING("Abnormal"));
+    return true;
+  }
+
+  p->MaybeResolve((int)aMemoryAvailable);
+  return true;
+}
+
 bool
 ContentChild::RecvPreferenceUpdate(const PrefSetting& aPref)
 {

dom/ipc/ContentChild.h

@@ -218,6 +218,9 @@ public:
     // auto remove when alertfinished is received.
     nsresult AddRemoteAlertObserver(const nsString& aData, nsIObserver* aObserver);
 
+    virtual bool RecvSystemMemoryAvailable(const uint64_t& aGetterId,
+                                           const uint32_t& aMemoryAvailable) MOZ_OVERRIDE;
+
     virtual bool RecvPreferenceUpdate(const PrefSetting& aPref) MOZ_OVERRIDE;
 
     virtual bool RecvNotifyAlertsObserver(const nsCString& aType,

dom/ipc/ContentParent.cpp

@@ -119,6 +119,10 @@
 #include "nsSystemInfo.h"
 #endif
 
+#if defined(XP_LINUX)
+#include "mozilla/Hal.h"
+#endif
+
 #ifdef ANDROID
 # include "gfxAndroidPlatform.h"
 #endif
@@ -3056,6 +3060,21 @@ ContentParent::RecvGetRandomValues(const uint32_t& length,
     return true;
 }
 
+bool
+ContentParent::RecvGetSystemMemory(const uint64_t& aGetterId)
+{
+  uint32_t memoryTotal = 0;
+
+#if defined(XP_LINUX)
+  memoryTotal = mozilla::hal::GetTotalSystemMemoryLevel();
+#endif
+
+  unused << SendSystemMemoryAvailable(aGetterId, memoryTotal);
+
+  return true;
+}
+
+
 bool
 ContentParent::RecvLoadURIExternal(const URIParams& uri)
 {

dom/ipc/ContentParent.h

@@ -523,7 +523,7 @@ private:
 
     virtual bool RecvAudioChannelChangeDefVolChannel(const int32_t& aChannel,
                                                      const bool& aHidden) MOZ_OVERRIDE;
-
+    virtual bool RecvGetSystemMemory(const uint64_t& getterId) MOZ_OVERRIDE;
     virtual bool RecvBroadcastVolume(const nsString& aVolumeName) MOZ_OVERRIDE;
 
     virtual bool RecvSpeakerManagerGetSpeakerStatus(bool* aValue) MOZ_OVERRIDE;

dom/ipc/PContent.ipdl

@@ -357,6 +357,8 @@ child:
 
     async NotifyVisited(URIParams uri);
 
+    async SystemMemoryAvailable(uint64_t getterId, uint32_t memoryAvailable);
+
     PreferenceUpdate(PrefSetting pref);
 
     NotifyAlertsObserver(nsCString topic, nsString data);
@@ -436,6 +438,8 @@ parent:
     sync GetRandomValues(uint32_t length)
         returns (uint8_t[] randomValues);
 
+    async GetSystemMemory(uint64_t getterId);
+
     PHal();
 
     PIndexedDB();

hal/Hal.cpp

@@ -1232,6 +1232,11 @@ GetTotalSystemMemory()
   return hal_impl::GetTotalSystemMemory();
 }
 
+uint32_t
+GetTotalSystemMemoryLevel()
+{
+  return hal_impl::GetTotalSystemMemoryLevel();
+}
 
 } // namespace hal
 } // namespace mozilla

hal/Hal.h

@@ -616,6 +616,14 @@ void StopDiskSpaceWatcher();
  */
 uint32_t GetTotalSystemMemory();
 
+/**
+ * Get the level of total system memory on device in MiB.
+ * (round the value up to the next power of two)
+ *
+ * Returns 0 if we are unable to determine this information from /proc/meminfo.
+ */
+uint32_t GetTotalSystemMemoryLevel();
+
 } // namespace MOZ_HAL_NAMESPACE
 } // namespace mozilla
 

hal/fallback/FallbackMemory.cpp

@@ -16,5 +16,11 @@ GetTotalSystemMemory()
 	return 0;
 }
 
+uint32_t
+GetTotalSystemMemoryLevel()
+{
+	return 0;
+}
+
 } // namespace hal_impl
 } // namespace mozilla

hal/linux/LinuxMemory.cpp

@@ -35,5 +35,37 @@ GetTotalSystemMemory()
   return sTotalMemory * 1024;
 }
 
+uint32_t
+GetTotalSystemMemoryLevel()
+{
+  static uint32_t sTotalMemoryLevel = 1;
+  uint32_t sTotalMemory;
+  static bool sTotalMemoryObtained = false;
+
+  if (!sTotalMemoryObtained) {
+    sTotalMemoryObtained = true;
+
+    FILE* fd = fopen("/proc/meminfo", "r");
+    if (!fd) {
+      return 0;
+    }
+
+    int rv = fscanf(fd, "MemTotal: %i kB", &sTotalMemory);
+
+    if (fclose(fd) || rv != 1) {
+      return 0;
+    }
+
+    // From KB to MiB
+    sTotalMemory /= 1024;
+
+    while (sTotalMemoryLevel <= sTotalMemory) {
+      sTotalMemoryLevel *= 2;
+    }
+  }
+
+  return sTotalMemoryLevel;
+}
+
 } // namespace hal_impl
 } // namespace mozilla