schulung_tools: add various demos and tools

Different tools have been used by various trainers as demos. Put
all these into master so they are available to all trainers.

ipc_pipe: ipc demo using pipes
ipc_shm: ipc demo using shared memory
libduma: source and instructions for compiling libduma
matrix: demo of good and bad cache access
mtrace: patch and infos for using mtrace with ASLR
rtex: demo of handling page faults

Signed-off-by: John Ogness <john.ogness@linutronix.de>

4 files changed, 66 insertions, 0 deletions

diff --git a/schulung_tools/mtrace/Makefile b/schulung_tools/mtrace/Makefile
new file mode 100644
index 0000000..224a9fa
--- /dev/null
+++ b/schulung_tools/mtrace/Makefile
@@ -0,0 +1,7 @@
+leak: leak.c
+	gcc -g -O0 -o$@ $<
+
+clean:
+	rm -f leak
+
+.PHONY: clean
diff --git a/schulung_tools/mtrace/README b/schulung_tools/mtrace/README
new file mode 100644
index 0000000..0c61b6d
--- /dev/null
+++ b/schulung_tools/mtrace/README
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# copy original mtrace (perl script)
+cp /usr/bin/mtrace .
+
+# patch it to support new ASLR semantics
+patch -p1 < mtrace.patch
+
+# disable randomization
+setarch `uname -m` -R /bin/bash
+
+# build leaking test program
+make
+
+# run test program and record leaks
+MALLOC_TRACE=./leak.trace ./leak
+
+# view found
+./mtrace ./leak ./leak.trace
diff --git a/schulung_tools/mtrace/leak.c b/schulung_tools/mtrace/leak.c
new file mode 100644
index 0000000..45ec7b1
--- /dev/null
+++ b/schulung_tools/mtrace/leak.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <mcheck.h>
+
+void a(void)
+{
+	malloc(1024);
+}
+
+int main(void)
+{
+	mtrace();
+	a();
+	return 0;
+}
diff --git a/schulung_tools/mtrace/mtrace.patch b/schulung_tools/mtrace/mtrace.patch
new file mode 100644
index 0000000..874388c
--- /dev/null
+++ b/schulung_tools/mtrace/mtrace.patch
@@ -0,0 +1,25 @@
+Patch mtrace to deal with new ASLR issues.
+--- a/mtrace	2017-06-15 20:17:14.000000000 +0100
++++ b/mtrace	2017-12-13 12:09:31.584089486 +0000
+@@ -75,10 +75,10 @@ if ($#ARGV == 0) {
+     } else {
+ 	$prog = "./$binary";
+     }
+-    if (open (LOCS, "env LD_TRACE_LOADED_OBJECTS=1 $prog |")) {
++    if (open (LOCS, "env LD_TRACE_PRELINKING=1 $prog |")) {
+ 	while (<LOCS>) {
+ 	    chop;
+-	    if (/^.*=> (.*) .(0x[0123456789abcdef]*).$/) {
++	    if (/^.*=> (.*) .(0x[0123456789abcdef]*),.*/) {
+ 		$locs{$1} = $2;
+ 	    }
+ 	}
+@@ -111,7 +111,7 @@ sub location {
+ 	my $searchaddr;
+ 	return $cache{$addr} if (exists $cache{$addr});
+ 	if ($locs{$prog} ne "") {
+-	    $searchaddr = sprintf "%#x", $addr - $locs{$prog};
++	    $searchaddr = sprintf "%#x", hex($addr) - hex($locs{$prog});
+ 	} else {
+ 	    $searchaddr = $addr;
+ 	    $prog = $binary;