Add dump-vdso for real

2 files changed, 25 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 575630d..d68d939 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 .PHONY: all
-all: timing_test evil-clock-test test_vsyscall
+all: timing_test evil-clock-test test_vsyscall dump-vdso
 
 timing_test: timing_test.cc
 	g++ -o $@ -lrt -ldl -O2 -Wall -g $^
@@ -9,3 +9,6 @@ evil-clock-test: evil-clock-test.cc
 
 test_vsyscall: test_vsyscall.cc
 	g++ -o $@ -std=gnu++0x -lrt -ldl -O2 -Wall -g $^
+
+dump-vdso: dump-vdso.c
+	gcc -o $@ -ldl -O2 $^
diff --git a/dump-vdso.c b/dump-vdso.c
new file mode 100644
index 0000000..937c00c
--- /dev/null
+++ b/dump-vdso.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <string.h>
+
+int
+main()
+{
+	FILE *maps;
+	void *vdso_begin, *vdso_end;
+
+	maps = fopen("/proc/self/maps", "r");
+	char buf[1024];
+	while (fgets(buf, 1024, maps)) {
+		if (strstr(buf, "[vdso]")) break;
+	}
+	fclose(maps);
+
+	sscanf(buf, "%p-%p", &vdso_begin, &vdso_end);
+	write(1, vdso_begin, vdso_end - vdso_begin);
+
+	return 0;
+}