--- zzzz-none-000/linux-3.10.107/arch/powerpc/kernel/kgdb.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/powerpc/kernel/kgdb.c	2021-02-04 17:41:59.000000000 +0000
@@ -15,7 +15,6 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/init.h>
 #include <linux/kgdb.h>
 #include <linux/smp.h>
 #include <linux/signal.h>
@@ -151,15 +150,16 @@
 	return 1;
 }
 
+static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info);
 static int kgdb_singlestep(struct pt_regs *regs)
 {
 	struct thread_info *thread_info, *exception_thread_info;
-	struct thread_info *backup_current_thread_info;
+	struct thread_info *backup_current_thread_info =
+		this_cpu_ptr(&kgdb_thread_info);
 
 	if (user_mode(regs))
 		return 0;
 
-	backup_current_thread_info = kmalloc(sizeof(struct thread_info), GFP_KERNEL);
 	/*
 	 * On Book E and perhaps other processors, singlestep is handled on
 	 * the critical exception stack.  This causes current_thread_info()
@@ -185,7 +185,6 @@
 		/* Restore current_thread_info lastly. */
 		memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
 
-	kfree(backup_current_thread_info);
 	return 1;
 }