1 files changed, 47 insertions, 0 deletions
diff --git a/src/tests/filst/sc-bad-exit.c b/src/tests/filst/sc-bad-exit.c
new file mode 100644
index 0000000..19945fc
--- /dev/null
+++ b/src/tests/filst/sc-bad-exit.c
@@ -0,0 +1,47 @@
+#include <syscall-nr.h>
+#include <stdio.h>
+#include "tests/lib.h"
+#include "tests/main.h"
+
+/**
+ * From threads/vaddr.h:
+ */
+#define BITMASK(SHIFT, CNT) (((1ul << (CNT)) - 1) << (SHIFT))
+
+#define PGSHIFT 0                          /* Index of first offset bit. */
+#define PGBITS  12                         /* Number of offset bits. */
+#define PGSIZE  (1 << PGBITS)              /* Bytes in a page. */
+#define PGMASK  BITMASK(PGSHIFT, PGBITS)   /* Page offset bits (0:12). */
+
+static inline void *pg_round_up (const void *va) {
+    return (void *) (((uintptr_t) va + PGSIZE - 1) & ~PGMASK);
+}
+
+/**
+ * External symbol which address is the first address after all data in the BSS segment.
+ */
+extern int _end_bss;
+
+void test_main(void)
+{
+    // Get the address of the first unmapped page in the process.
+    unsigned page = (unsigned)pg_round_up(&_end_bss);
+
+    // Reserve space for the syscall number and a part of the exit code (1 out of 4 bytes).
+    unsigned base = page - sizeof(int) - 1;
+
+    // Call a syscall.
+    asm volatile (
+        "movl %%esp, %%edi;" // Save the stack pointer in case we survive.
+        "movl %0, %%esp;"    // Set stack pointer.
+        "movl %1, (%%esp);"  // Try to call SYS_EXIT
+        "movb $1, 4(%%esp);" // Set the first byte of the syscall number to zero.
+        "int $0x30;"         // Trigger syscall.
+        "movl %%edi, %%esp;" // Restore the old stack if we survivied.
+        :
+        : "r" (base),
+          "i" (SYS_EXIT)
+        : "%esp", "%eax", "%edi");
+
+    fail("should have died.");
+}