Merge r229669 - Improve error message when Gigacage cannot allocate v…

…irtual memory

https://bugs.webkit.org/show_bug.cgi?id=183329

Reviewed by Filip Pizlo.

We've discovered that Deja Dup monitor sets a virtual memory limit, breaking Gigacage. Since
it runs in the background on a fresh out-of-the-box install of Ubuntu, this is not good.
That will have to be fixed by Deja Dup, but there is concern that other applications might
try this, or that users will set a virtual memory limit for the entire desktop session. Of
particular concern is the possibility that users might have copypasted a ulimit line into
a session startup script without understanding it. Let's try to make it slightly easier to
understand what's going wrong.

* bmalloc/Gigacage.cpp:
(Gigacage::ensureGigacage):

Source/bmalloc/ChangeLog

@@ -1,3 +1,21 @@
+2018-03-16  Michael Catanzaro  <mcatanzaro@igalia.com>
+
+        Improve error message when Gigacage cannot allocate virtual memory
+        https://bugs.webkit.org/show_bug.cgi?id=183329
+
+        Reviewed by Filip Pizlo.
+
+        We've discovered that Deja Dup monitor sets a virtual memory limit, breaking Gigacage. Since
+        it runs in the background on a fresh out-of-the-box install of Ubuntu, this is not good.
+        That will have to be fixed by Deja Dup, but there is concern that other applications might
+        try this, or that users will set a virtual memory limit for the entire desktop session. Of
+        particular concern is the possibility that users might have copypasted a ulimit line into
+        a session startup script without understanding it. Let's try to make it slightly easier to
+        understand what's going wrong.
+
+        * bmalloc/Gigacage.cpp:
+        (Gigacage::ensureGigacage):
+
 2018-02-05  JF Bastien  <jfbastien@apple.com>
 
         Gigacage: enable only for WebContent process and token executables

Source/bmalloc/bmalloc/Gigacage.cpp

@@ -151,6 +151,7 @@ void ensureGigacage()
                 if (GIGACAGE_ALLOCATION_CAN_FAIL)
                     return;
                 fprintf(stderr, "FATAL: Could not allocate gigacage memory with maxAlignment = %lu, totalSize = %lu.\n", maxAlignment, totalSize);
+                fprintf(stderr, "(Make sure you have not set a virtual memory limit.)\n");
                 BCRASH();
             }