From: Matt Mullins <mmullins@mmlx.us>
Date: Sat, 21 Sep 2013 04:37:50 +0000 (-0700)
Subject: Read random memory out of the address space.
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=a0c58e5bd1bb00220020ae9ab26d5effd5783c3b;p=mmap_everything.git

Read random memory out of the address space.
---

diff --git a/mmap_everything.c b/mmap_everything.c
index 2e9c7c3..8cd4646 100644
--- a/mmap_everything.c
+++ b/mmap_everything.c
@@ -1,7 +1,10 @@
 #include <limits.h>
 #include <sys/mman.h>
 #include <sys/types.h>
+#include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
 #include <unistd.h>
 
 #define MAX_BITS (sizeof(size_t) * CHAR_BIT - 1)
@@ -41,5 +44,18 @@ int main() {
 		}
 	}
 
-	getchar();
+	srand48(time(NULL));
+	while (1) {
+		printf("Press enter to read a random byte of memory. (pid %d) >", pid);
+		while (getchar() != '\n');
+		uint32_t lower = lrand48();
+		uint32_t upper = lrand48();
+
+		long pvalue = ((long)lower << 32) | ((long)upper);
+		// align to integer, keep in "userspace" address space
+		pvalue &= 0x00007FFFFFFFFFF0;
+
+		int *pi = (void*)(pvalue);
+		printf("*%p = %x\n", (void*)pi, *pi);
+	}
 }