PR10750: Enforce a reasonable limit on # of varargs

If we leave the number of args unbounded, then an excessively-sized
printf could cause a kernel stack overflow.  I've arbitrarily chosen 32
as our new maximum.

* translate.cxx (c_unparser::visit_print_format): Throw if >32 args.
* testsuite/transko/varargs.stp: Assert that 33 args aren't allowed.
* testsuite/transok/varargs.stp: Assert that 32 args are ok.

1 files changed, 10 insertions, 0 deletions

diff --git a/testsuite/transko/varargs.stp b/testsuite/transko/varargs.stp
new file mode 100755
index 00000000..f38309ad
--- /dev/null
+++ b/testsuite/transko/varargs.stp
@@ -0,0 +1,10 @@
+#! stap -p3
+
+probe begin {
+    // PR10750 enforces at most 32 print args
+    println(1, 2, 3, 4, 5, 6, 7, 8,
+            9, 10, 11, 12, 13, 14, 15, 16,
+            17, 18, 19, 20, 21, 22, 23, 24,
+            25, 26, 27, 28, 29, 30, 31, 32,
+            33)
+}