diff --git a/valgrind-3.12.0-deregister-stack.patch b/valgrind-3.12.0-deregister-stack.patch
new file mode 100644
index 0000000..5fe4a11
--- /dev/null
+++ b/valgrind-3.12.0-deregister-stack.patch
@@ -0,0 +1,111 @@
+commit 2b49317b4f237ea5f648d8b958f96cd03fcabc7d
+Author: philippe <philippe@a5019735-40e9-0310-863c-91ae7b9d1cf9>
+Date: Mon Nov 28 19:34:06 2016 +0000
+
+ Fix 373046 - Stacks registered by core are never deregistered
+
+
+ git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16159 a5019735-40e9-0310-863c-91ae7b9d1cf9
+
+diff --git a/coregrind/m_scheduler/scheduler.c b/coregrind/m_scheduler/scheduler.c
+index 0363898..49f51d6 100644
+--- a/coregrind/m_scheduler/scheduler.c
++++ b/coregrind/m_scheduler/scheduler.c
+@@ -488,6 +488,7 @@ static void os_state_clear(ThreadState *tst)
+ {
+ tst->os_state.lwpid = 0;
+ tst->os_state.threadgroup = 0;
++ tst->os_state.stk_id = NULL_STK_ID;
+ # if defined(VGO_linux)
+ /* no other fields to clear */
+ # elif defined(VGO_darwin)
+@@ -504,7 +505,6 @@ static void os_state_clear(ThreadState *tst)
+ # if defined(VGP_x86_solaris)
+ tst->os_state.thrptr = 0;
+ # endif
+- tst->os_state.stk_id = (UWord)-1;
+ tst->os_state.ustack = NULL;
+ tst->os_state.in_door_return = False;
+ tst->os_state.door_return_procedure = 0;
+diff --git a/coregrind/m_syswrap/syswrap-generic.c b/coregrind/m_syswrap/syswrap-generic.c
+index 6ef6a90..28972ae 100644
+--- a/coregrind/m_syswrap/syswrap-generic.c
++++ b/coregrind/m_syswrap/syswrap-generic.c
+@@ -84,11 +84,14 @@ void ML_(guess_and_register_stack) (Addr sp, ThreadState* tst)
+ tst->client_stack_highest_byte = (Addr)VG_PGROUNDUP(sp)-1;
+ tst->client_stack_szB = tst->client_stack_highest_byte - seg->start + 1;
+
+- VG_(register_stack)(seg->start, tst->client_stack_highest_byte);
++ tst->os_state.stk_id
++ = VG_(register_stack)(seg->start, tst->client_stack_highest_byte);
+
+ if (debug)
+- VG_(printf)("tid %u: guessed client stack range [%#lx-%#lx]\n",
+- tst->tid, seg->start, tst->client_stack_highest_byte);
++ VG_(printf)("tid %u: guessed client stack range [%#lx-%#lx]"
++ " as stk_id %lu\n",
++ tst->tid, seg->start, tst->client_stack_highest_byte,
++ tst->os_state.stk_id);
+ } else {
+ VG_(message)(Vg_UserMsg,
+ "!? New thread %u starts with SP(%#lx) unmapped\n",
+diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
+index af10b92..725ad78 100644
+--- a/coregrind/m_syswrap/syswrap-linux.c
++++ b/coregrind/m_syswrap/syswrap-linux.c
+@@ -52,6 +52,7 @@
+ #include "pub_core_options.h"
+ #include "pub_core_scheduler.h"
+ #include "pub_core_signals.h"
++#include "pub_core_stacks.h"
+ #include "pub_core_syscall.h"
+ #include "pub_core_syswrap.h"
+ #include "pub_core_inner.h"
+@@ -162,6 +163,10 @@ static void run_a_thread_NORETURN ( Word tidW )
+ c = VG_(count_living_threads)();
+ vg_assert(c >= 1); /* stay sane */
+
++ /* Deregister thread's stack. */
++ if (tst->os_state.stk_id != NULL_STK_ID)
++ VG_(deregister_stack)(tst->os_state.stk_id);
++
+ // Tell the tool this thread is exiting
+ VG_TRACK( pre_thread_ll_exit, tid );
+
+diff --git a/coregrind/pub_core_threadstate.h b/coregrind/pub_core_threadstate.h
+index f3d956c..3307e75 100644
+--- a/coregrind/pub_core_threadstate.h
++++ b/coregrind/pub_core_threadstate.h
+@@ -114,6 +114,8 @@ typedef
+ ThreadArchState;
+
+
++#define NULL_STK_ID (~(UWord)0)
++
+ /* OS-specific thread state. IMPORTANT: if you add fields to this,
+ you _must_ add code to os_state_clear() to initialise those
+ fields. */
+@@ -129,6 +131,12 @@ typedef
+ Addr valgrind_stack_base; // Valgrind's stack (VgStack*)
+ Addr valgrind_stack_init_SP; // starting value for SP
+
++ /* Client stack is registered as stk_id (on linux/darwin, by
++ ML_(guess_and_register_stack)).
++ Stack id NULL_STK_ID means that the user stack is not (yet)
++ registered. */
++ UWord stk_id;
++
+ /* exit details */
+ Word exitcode; // in the case of exitgroup, set by someone else
+ Int fatalsig; // fatal signal
+@@ -281,10 +289,6 @@ typedef
+ the 64-bit offset associated with a %fs value of zero. */
+ # endif
+
+- /* Stack id (value (UWord)(-1) means that there is no stack). This
+- tracks a stack that is set in restore_stack(). */
+- UWord stk_id;
+-
+ /* Simulation of the kernel's lwp->lwp_ustack. Set in the PRE wrapper
+ of the getsetcontext syscall, for SETUSTACK. Used in
+ VG_(save_context)(), VG_(restore_context)() and
diff --git a/valgrind.spec b/valgrind.spec
index 01285b3..443b9b3 100644
--- a/valgrind.spec
+++ b/valgrind.spec
@@ -98,6 +98,9 @@ Patch10: valgrind-3.12.0-quick-fatal-sigs.patch
# KDE#372504 Hanging on exit_group
Patch11: valgrind-3.12.0-exit_group.patch
+# KDE#373046 Stacks registered by core are never deregistered
+Patch12: valgrind-3.12.0-deregister-stack.patch
+
%if %{build_multilib}
# Ensure glibc{,-devel} is installed for both multilib arches
BuildRequires: /lib/libc.so.6 /usr/lib/libc.so /lib64/libc.so.6 /usr/lib64/libc.so
@@ -218,6 +221,7 @@ Valgrind User Manual for details.
%patch9 -p1
%patch10 -p1
%patch11 -p1
+%patch12 -p1
%build
# We need to use the software collection compiler and binutils if available.
@@ -417,6 +421,7 @@ echo ===============END TESTING===============
- Add valgrind-3.12.0-clone-spawn.patch
- Add valgrind-3.12.0-quick-fatal-sigs.patch
- Add valgrind-3.12.0-exit_group.patch
+- Add valgrind-3.12.0-deregister-stack.patch
* Fri Feb 17 2017 Mark Wielaard <mjw@redhat.com> - 3.12.0-5
- Add valgrind-3.12.0-ppc64-r2.patch (#1424367)