Initial commit

10/.nfs00000000000d5f6800004597

+gdb -q -x get_backtrace.py $1 | grep "^#" | grep -v "#0" | sed -e "s/ in.*//" | sed -e "s/^#[0-9]*  //" | head -n -1

10/Makefile

+CC = gcc
+CFLAGS = -g -fno-omit-frame-pointer
+
+all: test
+
+test: bt-test
+	bash -c "diff <(./answer ./bt-test) <(./run ./bt-test)"
+
+bt-test: test.c bt.c
+	$(CC) $(CFLAGS) $^ -o $@
+
+clean:
+	rm -f bt-test

10/answer

+gdb -q -nx -x get_backtrace.py $1 | grep "^#" | grep -v "#0" | sed -e "s/ in.*//" | sed -e "s/^#[0-9]*  //"

10/bt.c

+#include <stdlib.h>
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "bt.h"
+
+bool is_stack_address(void *addr) {
+    return ((long)addr >> 40) == 0x7f;
+}
+
+void backtrace() {
+    char arr[0];
+    // TODO (student): FIXME...this does not look right.
+    void *rsp = NULL; 
+    while (is_stack_address(rsp)) {
+        // TODO (student): Figure out what %rip is and print it out in a loop
+        void *rip = NULL;
+        printf("0x%016lx\n", (long)rip);
+        return;
+    }
+}

10/bt.h

+#ifndef __BT_H
+
+void backtrace();
+
+#endif /* __BT_H */

10/get_backtrace.py

+gdb.execute("set confirm off")
+gdb.execute("set pagination off")
+gdb.execute("b backtrace")
+gdb.execute("r")
+gdb.execute("bt")
+gdb.execute("c")
+gdb.execute("q")

10/run

+$1 | grep "^0x" | head -n -1

10/test.c

+#include <stdlib.h>
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "bt.h"
+
+int maybe(int a) {
+    int arr[5];
+    (void)arr;
+    backtrace();
+    return a + 5;
+}
+
+int call_me(int a) {
+    int arr[100];
+    return maybe(a + arr[0]);
+}
+
+int main() {
+    call_me(1);
+}

q1.md

+a.
+b.
+c.
+d.
+e.

q2.md

+2.
+
+
+| Thread 1 | Thread 2|
+| -------- | ------- |
+|          |         |
+|          |         |
+|          |         |
+|          |         |
+|          |         |
+|          |         |
+|          |         |
+|          |         |

q3.md

+3.

q4.md

+4.

q5.md

+a.
+b.
+c.
+d.
+e.

q6.md

+6.

q7.md

+7.

q8.md

+8.

q9.md

+9.