12:55 a.m.
lib/audit.c provides a generic definition 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
* enable CONFIG_AUDIT_COMPAT_GENERIC
Signed-off-by: AKASHI Takahiro <takahiro.akashi(a)linaro.org>
---
include/linux/audit.h | 8 +++++++
include/uapi/linux/audit.h | 6 ++++++
lib/Kconfig | 5 +++++
lib/Makefile | 1 +
lib/audit.c | 15 ++++++++++++-
lib/compat_audit.c | 50 ++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 84 insertions(+), 1 deletion(-)
create mode 100644 lib/compat_audit.c
diff --git a/include/linux/audit.h b/include/linux/audit.h
index bf1ef22..b5d5cca 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -78,6 +78,14 @@ extern int is_audit_feature_set(int which);
extern int __init audit_register_class(int class, unsigned *list);
extern int audit_classify_syscall(int abi, unsigned syscall);
extern int audit_classify_arch(int arch);
+/* only for compat system calls */
+extern unsigned compat_write_class[];
+extern unsigned compat_read_class[];
+extern unsigned compat_dir_class[];
+extern unsigned compat_chattr_class[];
+extern unsigned compat_signal_class[];
+
+extern int __weak audit_classify_compat_syscall(int abi, unsigned syscall);
/* audit_names->type values */
#define AUDIT_TYPE_UNKNOWN 0 /* we don't know yet */
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 44b05a0..0a73cf3 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -355,6 +355,12 @@ 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
diff --git a/lib/Kconfig b/lib/Kconfig
index 991c98b..48896db 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -182,6 +182,11 @@ config AUDIT_GENERIC
depends on AUDIT && !AUDIT_ARCH
default y
+config AUDIT_COMPAT_GENERIC
+ bool
+ depends on AUDIT_GENERIC && COMPAT
+ default y
+
config RANDOM32_SELFTEST
bool "PRNG perform self test on init"
default n
diff --git a/lib/Makefile b/lib/Makefile
index a459c31..972552b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o
obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o
obj-$(CONFIG_SMP) += percpu_counter.o
obj-$(CONFIG_AUDIT_GENERIC) += audit.o
+obj-$(CONFIG_AUDIT_COMPAT_GENERIC) += compat_audit.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
diff --git a/lib/audit.c b/lib/audit.c
index 76bbed4..1d726a2 100644
--- a/lib/audit.c
+++ b/lib/audit.c
@@ -30,11 +30,17 @@ static unsigned signal_class[] = {
int audit_classify_arch(int arch)
{
- return 0;
+ if (audit_is_compat(arch))
+ return 1;
+ else
+ return 0;
}
int audit_classify_syscall(int abi, unsigned syscall)
{
+ if (audit_is_compat(abi))
+ return audit_classify_compat_syscall(abi, syscall);
+
switch(syscall) {
#ifdef __NR_open
case __NR_open:
@@ -57,6 +63,13 @@ int audit_classify_syscall(int abi, unsigned syscall)
static int __init audit_classes_init(void)
{
+#ifdef CONFIG_AUDIT_COMPAT_GENERIC
+ audit_register_class(AUDIT_CLASS_WRITE_32, compat_write_class);
+ audit_register_class(AUDIT_CLASS_READ_32, compat_read_class);
+ audit_register_class(AUDIT_CLASS_DIR_WRITE_32, compat_dir_class);
+ audit_register_class(AUDIT_CLASS_CHATTR_32, compat_chattr_class);
+ audit_register_class(AUDIT_CLASS_SIGNAL_32, compat_signal_class);
+#endif
audit_register_class(AUDIT_CLASS_WRITE, write_class);
audit_register_class(AUDIT_CLASS_READ, read_class);
audit_register_class(AUDIT_CLASS_DIR_WRITE, dir_class);
diff --git a/lib/compat_audit.c b/lib/compat_audit.c
new file mode 100644
index 0000000..873f75b
--- /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;
+ }
+}
--
1.7.9.5