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>

1 files changed, 41 insertions, 0 deletions

diff --git a/schulung_tools/ipc_shm/send.c b/schulung_tools/ipc_shm/send.c
new file mode 100644
index 0000000..028610f
--- /dev/null
+++ b/schulung_tools/ipc_shm/send.c
@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include "shm.h"
+
+int main(void)
+{
+	struct share_data *data;
+	int rv;
+
+	data = get_share();
+	if (!data)
+		return 1;
+
+	rv = pthread_mutex_lock(&data->m);
+	if (rv != 0) {
+		if (rv == EOWNERDEAD) {
+			printf("send (%d): recover mutex\n", getpid());
+			data->msg[0] = 0;
+			pthread_mutex_consistent(&data->m);
+		} else {
+			/* maybe rv == ENOTRECOVERABLE */
+			return 1;
+		}
+	}
+
+	printf("send (%d): type message and hit RETURN to send signal\n",
+	       getpid());
+	fgets(data->msg, sizeof(data->msg), stdin);
+
+	/* set "sending" uprobe here */
+
+	pthread_cond_signal(&data->c);
+	pthread_mutex_unlock(&data->m);
+
+	sleep(1);
+
+	return 0;
+}