Index: lib/Target/ARM/ARMAsmPrinter.cpp
===================================================================
--- lib/Target/ARM/ARMAsmPrinter.cpp
+++ lib/Target/ARM/ARMAsmPrinter.cpp
@@ -1111,6 +1111,12 @@
         // temporary to workaround PR11902.
         if (MO.isImplicit())
           continue;
+        // Registers, pushed as a part of folding an SP update into the push
+        // instruction are marked as undef and should not be restored when
+        // unwinding, because the function can modify the corresponding stack
+        // slots.
+        if (MO.isUndef())
+          continue;
         RegList.push_back(MO.getReg());
       }
       break;
Index: lib/Target/ARM/ARMBaseInstrInfo.cpp
===================================================================
--- lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -2277,9 +2277,9 @@
        --CurRegEnc) {
     unsigned CurReg = RegClass->getRegister(CurRegEnc);
     if (!IsPop) {
-      // Pushing any register is completely harmless, mark the
-      // register involved as undef since we don't care about it in
-      // the slightest.
+      // Pushing any register is completely harmless, mark the register involved
+      // as undef since we don't care about its value and must not restore it
+      // during stack unwinding.
       RegList.push_back(MachineOperand::CreateReg(CurReg, false, false,
                                                   false, false, true));
       --RegsNeeded;
Index: test/CodeGen/ARM/PR35379.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/PR35379.ll
@@ -0,0 +1,24 @@
+; RUN: llc -mtriple=armv7a-eabi < %s | FileCheck %s --check-prefix=CHECK-ARM
+; RUN: llc -mtriple=armv6m-eabi < %s | FileCheck %s --check-prefix=CHECK-THM
+
+; Function Attrs: minsize optsize
+define void @work() local_unnamed_addr #0 {
+entry:
+  %i = alloca i32, align 4
+  %0 = bitcast i32* %i to i8*
+  store i32 1, i32* %i, align 4
+  call void @impl(i32* nonnull %i)
+  ret void
+}
+; CHECK-ARM:      .save {r11, lr}
+; CHECK-ARM-NEXT: push {r9, r10, r11, lr}
+; CHECK-ARM:      pop {r2, r3, r11, pc}
+
+; CHECK-THM:      .save {r7, lr}
+; CHECK-THM-NEXT: push {r5, r6, r7, lr}
+; CHECK-THM:      pop {r2, r3, r7, pc}
+
+; Function Attrs: minsize optsize
+declare void @impl(i32*) local_unnamed_addr #0
+
+attributes #0 = { minsize optsize }