diff --git a/coregrind/m_stacks.c b/coregrind/m_stacks.c
index a2ff17da4..ee3a869e7 100644
--- a/coregrind/m_stacks.c
+++ b/coregrind/m_stacks.c
@@ -277,49 +277,72 @@ void VG_(stack_limits)(Addr SP, Addr *start, Addr *end )
       *end = stack->end;
    }
 
-   /* SP is assumed to be in a RW segment.
+   /* SP is assumed to be in a RW segment or in the SkResvn segment of an
+      extensible stack (normally, only the main thread has an extensible
+      stack segment).
       If no such segment is found, assume we have no valid
       stack for SP, and set *start and *end to 0.
-      Otherwise, possibly reduce the stack limits to the boundaries of the
-      RW segment containing SP. */
+      Otherwise, possibly reduce the stack limits using the boundaries of
+      the RW segment/SkResvn segments containing SP. */
    if (stackseg == NULL) {
       VG_(debugLog)(2, "stacks", 
                     "no addressable segment for SP %p\n", 
                     (void*)SP);
       *start = 0;
       *end = 0;
-   } else if (!stackseg->hasR || !stackseg->hasW) {
+      return;
+   } 
+
+   if ((!stackseg->hasR || !stackseg->hasW)
+       && (stackseg->kind != SkResvn || stackseg->smode != SmUpper)) {
       VG_(debugLog)(2, "stacks", 
-                    "segment for SP %p is not Readable and/or not Writable\n",
+                    "segment for SP %p is not RW or not a SmUpper Resvn\n",
                     (void*)SP);
       *start = 0;
       *end = 0;
-   } else {
-      if (*start < stackseg->start) {
-         VG_(debugLog)(2, "stacks", 
-                       "segment for SP %p changed stack start limit"
-                       " from %p to %p\n",
-                       (void*)SP, (void*)*start, (void*)stackseg->start);
-         *start = stackseg->start;
-      }
-      if (*end > stackseg->end) {
-         VG_(debugLog)(2, "stacks", 
-                       "segment for SP %p changed stack end limit"
-                       " from %p to %p\n",
-                       (void*)SP, (void*)*end, (void*)stackseg->end);
-         *end = stackseg->end;
-      }
+      return;
+   } 
 
-      /* If reducing start and/or end to the SP segment gives an
-         empty range, return 'empty' limits */
-      if (*start > *end) {
+   // SP is in a RW segment, or in the SkResvn of an extensible stack.
+   if (*start < stackseg->start) {
+      VG_(debugLog)(2, "stacks", 
+                    "segment for SP %p changed stack start limit"
+                    " from %p to %p\n",
+                    (void*)SP, (void*)*start, (void*)stackseg->start);
+      *start = stackseg->start;
+   }
+
+   if (stackseg->kind == SkResvn) {
+      stackseg = VG_(am_next_nsegment)(stackseg, /*forward*/ True);
+      if (!stackseg || !stackseg->hasR || !stackseg->hasW
+          || stackseg->kind != SkAnonC) {
          VG_(debugLog)(2, "stacks", 
-                       "stack for SP %p start %p after end %p\n",
-                       (void*)SP, (void*)*start, (void*)end);
+                       "Next forward segment for SP %p Resvn segment"
+                       " is not RW or not AnonC\n",
+                       (void*)SP);
          *start = 0;
          *end = 0;
+         return;
       }
    }
+
+   if (*end > stackseg->end) {
+      VG_(debugLog)(2, "stacks", 
+                    "segment for SP %p changed stack end limit"
+                    " from %p to %p\n",
+                    (void*)SP, (void*)*end, (void*)stackseg->end);
+      *end = stackseg->end;
+   }
+
+   /* If reducing start and/or end to the SP segment gives an
+      empty range, return 'empty' limits */
+   if (*start > *end) {
+      VG_(debugLog)(2, "stacks", 
+                    "stack for SP %p start %p after end %p\n",
+                    (void*)SP, (void*)*start, (void*)end);
+      *start = 0;
+      *end = 0;
+   }
 }
 
 /* complaints_stack_switch reports that SP has changed by more than some
diff --git a/memcheck/tests/Makefile.am b/memcheck/tests/Makefile.am
index baadeb2f9..6d6b3ebf0 100644
--- a/memcheck/tests/Makefile.am
+++ b/memcheck/tests/Makefile.am
@@ -214,6 +214,7 @@ EXTRA_DIST = \
 	realloc2.stderr.exp realloc2.vgtest \
 	realloc3.stderr.exp realloc3.vgtest \
 	recursive-merge.stderr.exp recursive-merge.vgtest \
+	resvn_stack.stderr.exp resvn_stack.vgtest \
 	sbfragment.stdout.exp sbfragment.stderr.exp sbfragment.vgtest \
 	sem.stderr.exp sem.vgtest \
 	sendmsg.stderr.exp sendmsg.vgtest \
@@ -340,6 +341,7 @@ check_PROGRAMS = \
 	post-syscall \
 	realloc1 realloc2 realloc3 \
 	recursive-merge \
+	resvn_stack \
 	sbfragment \
 	sendmsg \
 	sh-mem sh-mem-random \
diff --git a/memcheck/tests/resvn_stack.c b/memcheck/tests/resvn_stack.c
new file mode 100644
index 000000000..aa1fc2af8
--- /dev/null
+++ b/memcheck/tests/resvn_stack.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+__attribute__((noinline)) void big(void)
+{
+   /* The below ensures the stack grows a lot. However, we hope the stack
+      extension is not done yet, as no memory has been read/written. */
+   volatile char c[200000];
+
+   /* Access only the higher part of the stack, to avoid mapping SP */
+   /* The below 2 printfs should produce deterministic output, whatever
+      the random value of c[]. */
+   if (c[200000 - 1])
+      fprintf(stderr, "Accessing fresh %s\n", "stack");
+   else
+      fprintf(stderr, "Accessing %s stack\n", "fresh");
+
+}
+
+int main(void )
+{
+   big();
+   return 0;
+}
diff --git a/memcheck/tests/resvn_stack.stderr.exp b/memcheck/tests/resvn_stack.stderr.exp
new file mode 100644
index 000000000..ad75467ae
--- /dev/null
+++ b/memcheck/tests/resvn_stack.stderr.exp
@@ -0,0 +1,5 @@
+Conditional jump or move depends on uninitialised value(s)
+   at 0x........: big (resvn_stack.c:12)
+   by 0x........: main (resvn_stack.c:21)
+
+Accessing fresh stack
diff --git a/memcheck/tests/resvn_stack.vgtest b/memcheck/tests/resvn_stack.vgtest
new file mode 100644
index 000000000..7b1385297
--- /dev/null
+++ b/memcheck/tests/resvn_stack.vgtest
@@ -0,0 +1,2 @@
+prog: resvn_stack
+vgopts: -q