3 files changed, 26 insertions, 2 deletions

diff --git a/arch/tile/include/asm/ptrace.h b/arch/tile/include/asm/ptrace.h
index ac6d343129d3..6be2246e015c 100644
--- a/arch/tile/include/asm/ptrace.h
+++ b/arch/tile/include/asm/ptrace.h
@@ -141,6 +141,9 @@ struct single_step_state {
 /* Single-step the instruction at regs->pc */
 extern void single_step_once(struct pt_regs *regs);
 
+/* Clean up after execve(). */
+extern void single_step_execve(void);
+
 struct task_struct;
 
 extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index e90eb53173b0..5db8b5b63cea 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -574,6 +574,8 @@ SYSCALL_DEFINE4(execve, const char __user *, path,
                 goto out;
         error = do_execve(filename, argv, envp, regs);
         putname(filename);
+        if (error == 0)
+                single_step_execve();
 out:
         return error;
 }
@@ -593,6 +595,8 @@ long compat_sys_execve(const char __user *path,
                 goto out;
         error = compat_do_execve(filename, argv, envp, regs);
         putname(filename);
+        if (error == 0)
+                single_step_execve();
 out:
         return error;
 }
diff --git a/arch/tile/kernel/single_step.c b/arch/tile/kernel/single_step.c
index 1eb3b39e36c7..84a729e06ec4 100644
--- a/arch/tile/kernel/single_step.c
+++ b/arch/tile/kernel/single_step.c
@@ -56,7 +56,7 @@ enum mem_op {
         MEMOP_STORE_POSTINCR
 };
 
-static inline tile_bundle_bits set_BrOff_X1(tile_bundle_bits n, int32_t offset)
+static inline tile_bundle_bits set_BrOff_X1(tile_bundle_bits n, s32 offset)
 {
         tile_bundle_bits result;
 
@@ -254,6 +254,18 @@ P("\n");
         return bundle;
 }
 
+/*
+ * Called after execve() has started the new image.  This allows us
+ * to reset the info state.  Note that the the mmap'ed memory, if there
+ * was any, has already been unmapped by the exec.
+ */
+void single_step_execve(void)
+{
+        struct thread_info *ti = current_thread_info();
+        kfree(ti->step_state);
+        ti->step_state = NULL;
+}
+
 /**
  * single_step_once() - entry point when single stepping has been triggered.
  * @regs: The machine register state
@@ -373,7 +385,7 @@ void single_step_once(struct pt_regs *regs)
                 /* branches */
                 case BRANCH_OPCODE_X1:
                 {
-                        int32_t offset = signExtend17(get_BrOff_X1(bundle));
+                        s32 offset = signExtend17(get_BrOff_X1(bundle));
 
                         /*
                          * For branches, we use a rewriting trick to let the
@@ -731,4 +743,9 @@ void single_step_once(struct pt_regs *regs)
         __insn_mtspr(SPR_SINGLE_STEP_EN_K_K, 1 << USER_PL);
 }
 
+void single_step_execve(void)
+{
+        /* Nothing */
+}
+
 #endif /* !__tilegx__ */