[smart] fixup of lwp recycling and mm varea (#8206)

Signed-off-by: shell <wangxiaoyao@rt-thread.com>
Signed-off-by: Shell <smokewood@qq.com>
Co-authored-by: xqyjlj <xqyjlj@126.com>

libcpu/aarch64/SConscript

@@ -12,9 +12,9 @@ bsp_path = Dir('#').abspath
 
 if not os.path.exists(bsp_path + "/link.lds"):
     Env['LINKFLAGS'] = Env['LINKFLAGS'].replace('link.lds', cwd + "/link.lds")
-    # fix the linker with crtx.o
     Preprocessing("link.lds.S", ".lds", CPPPATH=[bsp_path])
 
+# fix the linker with crtx.o
 Env['LINKFLAGS'] += ' -nostartfiles'
 
 # add common code files

libcpu/aarch64/common/trap.c

@@ -373,6 +373,8 @@ void rt_hw_trap_exception(struct rt_hw_exp_stack *regs)
 #endif
 
 #ifdef RT_USING_LWP
+    /* restore normal execution environment */
+    __asm__ volatile("msr daifclr, 0x3\ndmb ishst\nisb\n");
     _check_fault(regs, 0, "user fault");
 #endif