bring CONFIG_FORTIFY_SOURCE back from accidental removal...

Notice that it is not working anymore.

Rename pci.c into qemu_edu.c

Organize kernel_module readmes further

kernel_module/user/README.adoc

@@ -1,25 +1,15 @@
-= user
+https://github.com/cirosantilli/linux-kernel-module-cheat#rootfs_overlay
 
-Userland C programs used to test our kernel modules.
-
-`sh` programs are simpler, and installed by copying directly with an overlay.
-
-C programs require cross compiling, but give us more control over system calls.
-
-These programs can also be compiled and used on host.
-
-. Standalone
-.. link:hello.c[]
-.. link:hello_cpp.cpp[]
-.. link:sched_getaffinity.c[]
-.. link:usermem.c[]
-... link:pagemap_dump.c[]
-.. inits
-.... link:sleep_forever.c[]
-.... link:poweroff.c[]
-.... link:init_dev_kmsg.c[]
-.. link:uio_read.c[]
-.. link:rand_check.c[]
-.. x86_64
-... link:rdtsc.c[]
-... link:ring0.c[]
+. link:hello.c[]
+. link:hello_cpp.cpp[]
+. link:sched_getaffinity.c[]
+. link:usermem.c[]
+.. link:pagemap_dump.c[]
+. inits
+... link:sleep_forever.c[]
+... link:poweroff.c[]
+... link:init_dev_kmsg.c[]
+. link:uio_read.c[]
+. link:rand_check.c[]
+. x86_64
+.. link:rdtsc.c[]

kernel_module/user/proc_events.c

@@ -1,8 +1,7 @@
-/*
-This file is licensed under the GPL v2 (http://www.gnu.org/licenses/gpl2.txt) (some parts was originally borrowed from proc events example)
-
-https://stackoverflow.com/questions/6075013/detect-launching-of-programs-on-linux-platform/8255487#8255487
-*/
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#config_proc_events
+ *
+ * Adapted from: https://stackoverflow.com/questions/6075013/detect-launching-of-programs-on-linux-platform/8255487#8255487
+ */
 
 #if defined(__aarch64__)