Add highsys to test syscall high bits

3 files changed, 20 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index 13a1dfb..c77a446 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@ evil-clock-test
 context_switch_latency
 kernel_pf
 user_visible_state
+highpid
 *~
 *_32
 *_64
diff --git a/Makefile b/Makefile
index cf97ede..0cd9eb3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 .PHONY: all clean
 
-SIMPLE_C_TARGETS := dump-vdso dump-vvar dump-vsyscall context_switch_latency kernel_pf user_visible_state null_seccomp
+SIMPLE_C_TARGETS := dump-vdso dump-vvar dump-vsyscall context_switch_latency kernel_pf user_visible_state null_seccomp highsys
 
 SIMPLE_CC_TARGETS := evil-clock-test
 
diff --git a/highsys.c b/highsys.c
new file mode 100644
index 0000000..93eb45e
--- /dev/null
+++ b/highsys.c
@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include <sys/syscall.h>
+
+static long high_getpid(void)
+{
+  long ret;
+  asm volatile ("syscall" :
+		"=a" (ret) :
+		"a" (SYS_getpid | 0xbaadf00d00000000ULL) :
+		"memory", "cc", "rcx", "r11");
+  return ret;
+}
+
+int main()
+{
+  printf("high_getpid says %ld\n", high_getpid());
+  return 0;
+}