[llvm] r279605 - Preserve a pointer to the newly allocated signal stack as well. That too

[Chandler Carruth via llvm-commits]

Author: chandlerc
Date: Tue Aug 23 22:42:51 2016
New Revision: 279605

URL: http://llvm.org/viewvc/llvm-project?rev=279605&view=rev
Log:
Preserve a pointer to the newly allocated signal stack as well. That too
is flagged by LSan at least among leak detectors.

Modified:
    llvm/trunk/lib/Support/Unix/Signals.inc

Modified: llvm/trunk/lib/Support/Unix/Signals.inc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Unix/Signals.inc?rev=279605&r1=279604&r2=279605&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Unix/Signals.inc (original)
+++ llvm/trunk/lib/Support/Unix/Signals.inc Tue Aug 23 22:42:51 2016
@@ -120,11 +120,12 @@ static void RegisterHandler(int Signal)
 }
 
 #if defined(HAVE_SIGALTSTACK)
-// Hold onto the old alternate signal stack so that it's not reported as a leak.
-// We don't make any attempt to remove our alt signal stack if we remove our
-// signal handlers; that can't be done reliably if someone else is also trying
-// to do the same thing.
+// Hold onto both the old and new alternate signal stack so that it's not
+// reported as a leak. We don't make any attempt to remove our alt signal
+// stack if we remove our signal handlers; that can't be done reliably if
+// someone else is also trying to do the same thing.
 static stack_t OldAltStack;
+static void* NewAltStackPointer;
 
 static void CreateSigAltStack() {
   const size_t AltStackSize = MINSIGSTKSZ + 64 * 1024;
@@ -140,6 +141,7 @@ static void CreateSigAltStack() {
 
   stack_t AltStack = {};
   AltStack.ss_sp = reinterpret_cast<char *>(malloc(AltStackSize));
+  NewAltStackPointer = AltStack.ss_sp; // Save to avoid reporting a leak.
   AltStack.ss_size = AltStackSize;
   if (sigaltstack(&AltStack, &OldAltStack) != 0)
     free(AltStack.ss_sp);