ripple/minitrace: configure stack rlimits

Removing the RLIMIT_STACK soft limit changes address space layout
markedly.

Change-Id: I64d1a1fc1b397200245d5f790ce126c99d4b4797

1 files changed, 16 insertions, 0 deletions

diff --git a/ripple/minitrace/src/main.rs b/ripple/minitrace/src/main.rs
index 847fb24..c7fb369 100644
--- a/ripple/minitrace/src/main.rs
+++ b/ripple/minitrace/src/main.rs
@@ -10,6 +10,7 @@ use {
 		sys::{
 			personality::{self, Persona},
 			ptrace,
+			resource::{self, Resource as HostResource},
 			signal::Signal as HostSignal,
 			wait::{waitpid, WaitPidFlag, WaitStatus},
 		},
@@ -64,6 +65,21 @@ impl Process {
 				persona.insert(Persona::ADDR_NO_RANDOMIZE);
 				personality::set(persona)?;
 
+				// set stack limit (to guarantee top-down address space layout)
+				resource::setrlimit(
+					HostResource::RLIMIT_STACK,
+					Some(
+						// not a particularly meaningful number,
+						// just plucked from the author's system
+						8 * 1024 * 1024,
+					),
+					Some(
+						128 * 1024 * 1024
+						// guard page
+						- 4096,
+					),
+				)?;
+
 				ptrace::traceme()?;
 				Ok(())
 			});