userland: disable PIE explicitly on command line for all executables

path_properties.py

@@ -17,6 +17,15 @@ class PathProperties:
             '-Wno-unused-function', LF,
             '-fopenmp', LF,
             '-ggdb3', LF,
+            # PIE causes the following problems:
+            # * QEMU GDB step debug does not find breakpoints:
+            #   https://stackoverflow.com/questions/51310756/how-to-gdb-step-debug-a-dynamically-linked-executable-in-qemu-user-mode/51343326#51343326
+            # * when writing assembly code, we have to constantly think about it:
+            #   https://stackoverflow.com/questions/2463150/what-is-the-fpie-option-for-position-independent-executables-in-gcc-and-ld/51308031#51308031
+            # As of 91986fb2955f96e06d1c5ffcc5536ba9f0af1fd9, our Buildroot toolchain
+            # does not have it enabled by default, but the Ubuntu 18.04 host toolchain does.
+            '-fno-pie', LF,
+            '-no-pie', LF,
         ],
         'cc_flags_after': [],
         'cc_pedantic': True,
@@ -266,10 +275,6 @@ path_properties_tuples = (
             {
                 'arch': (
                     {
-                        'cc_flags': [
-                            '-fno-pie', LF,
-                            '-no-pie', LF,
-                        ],
                         'extra_objs_userland_asm': True,
                     },
                     {