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, 6 insertions, 0 deletions

diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 4315ee99b967..9af01d77dc44 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -362,6 +362,12 @@ enum {
 #define AUDIT_ARCH_SPARC64      (EM_SPARCV9|__AUDIT_ARCH_64BIT)
 #define AUDIT_ARCH_X86_64       (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 
+#ifdef CONFIG_COMPAT
+#define audit_is_compat(arch)   (!((arch) & __AUDIT_ARCH_64BIT))
+#else
+#define audit_is_compat(arch)   false
+#endif
+
 #define AUDIT_PERM_EXEC         1
 #define AUDIT_PERM_WRITE        2
 #define AUDIT_PERM_READ         4