baremetal: build userland/ programs using baremetal path property instead of symlinks

Otherwise I'll go crazy with symlink action.

userland/c/abort.c

@@ -0,0 +1,34 @@
+/* # abort
+ *
+ * Raise a SIGABRT, an ANSI C signal which by default kills the program.
+ *
+ * ....
+ * man abort
+ * ....
+ *
+ * Bibliography:
+ *
+ * * http://stackoverflow.com/questions/397075/what-is-the-difference-between-exit-and-abort
+ * * http://stackoverflow.com/questions/3676221/when-abort-is-preferred-over-exit
+ *
+ * Differences from exit: does not run regular program teardown:
+ *
+ * * does not call `atexit` function.
+ * * does not call C++ destructors
+ *
+ * `assert()` exits the program with abort.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+void atexit_func() {
+    puts("atexit");
+}
+
+int main(void) {
+    /* Will not get called. */
+    atexit(atexit_func);
+    abort();
+    return EXIT_SUCCESS;
+}

userland/c/add.c

@@ -1 +0,0 @@
-../../lkmc/c/add.c

userland/c/add.c

@@ -0,0 +1,13 @@
+#include <assert.h>
+
+int main(void) {
+    int i, j, k;
+    i = 1;
+    /* test-gdb-op1 */
+    j = 2;
+    /* test-gdb-op2 */
+    k = i + j;
+    /* test-gdb-result */
+    if (k != 3)
+        assert(0);
+}

userland/c/add.py

@@ -1 +0,0 @@
-../../lkmc/c/add.py

userland/c/add.py

@@ -0,0 +1,9 @@
+def test(self):
+    self.sendline('tbreak main')
+    self.sendline('continue')
+    self.continue_to('op1')
+    assert self.get_int('i') == 1
+    self.continue_to('op2')
+    assert self.get_int('j') == 2
+    self.continue_to('result')
+    assert self.get_int('k') == 3

userland/c/assert_fail.c

@@ -1 +0,0 @@
-../../lkmc/c/assert_fail.c

userland/c/assert_fail.c

@@ -0,0 +1,18 @@
+/* Let's see what happens when an assert fails.
+ *
+ * Outcome on Ubuntu 19.04 shows the failure line:
+ *
+ *     assert_fail.out: /path/to/linux-kernel-module-cheat/userland/c/assert_fail.c:15: main: Assertion `0' failed.
+ *
+ * and exit status 134 == 128 + 6, which corresponds to SIGABORT (6).
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int main(void) {
+    assert(0);
+    puts("here");
+    return EXIT_SUCCESS;
+}

userland/c/exit0.c

@@ -0,0 +1,7 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#magic-failure-string */
+
+#include <stdlib.h>
+
+int main(void) {
+    exit(0);
+}

userland/c/exit1.c

@@ -0,0 +1,7 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#magic-failure-string */
+
+#include <stdlib.h>
+
+int main(void) {
+    exit(1);
+}

userland/c/exit2.c

@@ -0,0 +1,7 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#magic-failure-string */
+
+#include <stdlib.h>
+
+int main(void) {
+    exit(2);
+}

userland/c/getchar.c

@@ -1 +0,0 @@
-../../lkmc/c/getchar.c

userland/c/getchar.c

@@ -0,0 +1,21 @@
+/* Get on character from stdin, and then print it back out.
+ *
+ * Same as getc(stdin).
+ *
+ * You have to press enter for the character to go through:
+ * https://stackoverflow.com/questions/1798511/how-to-avoid-pressing-enter-with-getchar
+ *
+ * Used at:
+ * https://stackoverflow.com/questions/556405/what-do-real-user-and-sys-mean-in-the-output-of-time1/53937376#53937376
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    char c;
+    printf("enter a character: ");
+    c = getchar();
+    printf("you entered: %c\n", c);
+    return EXIT_SUCCESS;
+}

userland/c/hello.c

@@ -1 +0,0 @@
-../../lkmc/c/hello.c

userland/c/hello.c

@@ -0,0 +1,9 @@
+/* Print hello to stdout ;-) */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    puts("hello");
+    return EXIT_SUCCESS;
+}

userland/c/infinite_loop.c

@@ -1 +0,0 @@
-../../lkmc/c/infinite_loop.c

userland/c/infinite_loop.c

@@ -0,0 +1,29 @@
+/* Loop infinitely. Print an integer whenever a period is reached:
+ *
+ * ....
+ * ./infinite_loop [period]
+ * ....
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv) {
+    uintmax_t i, j, period;
+    if (argc > 1) {
+        period = strtoumax(argv[1], NULL, 10);
+    } else {
+        period = 100000000;
+    }
+    i = 0;
+    j = 0;
+    while (1) {
+        i++;
+        if (i % period == 0) {
+            printf("%ju\n", j);
+            j++;
+        }
+    }
+}

userland/c/out_of_memory.c

@@ -0,0 +1,18 @@
+/* Let's see how much memory Linux lets us allocate. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    char *ptr = NULL;
+    size_t size = 1;
+    while (1) {
+        printf("0x%zx\n", size);
+        ptr = realloc(ptr, size);
+        if (ptr == NULL) {
+            break;
+        } else {
+            size <<= 1;
+        }
+    }
+}

userland/c/return0.c

@@ -0,0 +1,6 @@
+/* false.c is a superset of this, this is mainly a sanity check for
+ * baremetal where we don't have CLI arguments yet:
+ * https://github.com/cirosantilli/linux-kernel-module-cheat/issues/67
+ */
+
+int main(void) { return 0; }

userland/c/return1.c

@@ -0,0 +1,2 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#magic-failure-string */
+int main(void) { return 1; }

userland/c/return2.c

@@ -0,0 +1,2 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#magic-failure-string */
+int main(void) { return 2; }

userland/c/stderr.c

@@ -1 +0,0 @@
-../../lkmc/c/stderr.c

userland/c/stderr.c

@@ -0,0 +1,7 @@
+/* Print hello to stderr. */
+
+#include <stdio.h>
+
+int main(void) {
+    fputs("hello\n", stderr);
+}