audit: Add generic compat syscall support

lib/audit.c provides a generic function for auditing system calls.
This patch extends it for compat syscall support on bi-architectures
(32/64-bit) by adding lib/compat_audit.c.
What is required to support this feature are:
 * add asm/unistd32.h for compat system call names
 * select CONFIG_AUDIT_ARCH_COMPAT_GENERIC

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/lib/compat_audit.c b/lib/compat_audit.c
new file mode 100644
index 000000000000..873f75b640ab
--- /dev/null
+++ b/lib/compat_audit.c
@@ -0,0 +1,50 @@
+#include <linux/init.h>
+#include <linux/types.h>
+#include <asm/unistd32.h>
+
+unsigned compat_dir_class[] = {
+#include <asm-generic/audit_dir_write.h>
+~0U
+};
+
+unsigned compat_read_class[] = {
+#include <asm-generic/audit_read.h>
+~0U
+};
+
+unsigned compat_write_class[] = {
+#include <asm-generic/audit_write.h>
+~0U
+};
+
+unsigned compat_chattr_class[] = {
+#include <asm-generic/audit_change_attr.h>
+~0U
+};
+
+unsigned compat_signal_class[] = {
+#include <asm-generic/audit_signal.h>
+~0U
+};
+
+int audit_classify_compat_syscall(int abi, unsigned syscall)
+{
+        switch (syscall) {
+#ifdef __NR_open
+        case __NR_open:
+                return 2;
+#endif
+#ifdef __NR_openat
+        case __NR_openat:
+                return 3;
+#endif
+#ifdef __NR_socketcall
+        case __NR_socketcall:
+                return 4;
+#endif
+        case __NR_execve:
+                return 5;
+        default:
+                return 1;
+        }
+}