alpha: Enable system-call auditing support.

Signed-off-by: Zhenglong.cai <zhenglong.cai@cs2c.com.cn>
Signed-off-by: Matt Turner <mattst88@gmail.com>

arch/alpha/kernel/Makefile

@@ -17,6 +17,7 @@ obj-$(CONFIG_SRM_ENV)	+= srm_env.o
 obj-$(CONFIG_MODULES)	+= module.o
 obj-$(CONFIG_PERF_EVENTS) += perf_event.o
 obj-$(CONFIG_RTC_DRV_ALPHA) += rtc.o
+obj-$(CONFIG_AUDIT)	+= audit.o
 
 ifdef CONFIG_ALPHA_GENERIC
 

arch/alpha/kernel/audit.c

@@ -0,0 +1,60 @@
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/audit.h>
+#include <asm/unistd.h>
+
+static unsigned dir_class[] = {
+#include <asm-generic/audit_dir_write.h>
+~0U
+};
+
+static unsigned read_class[] = {
+#include <asm-generic/audit_read.h>
+~0U
+};
+
+static unsigned write_class[] = {
+#include <asm-generic/audit_write.h>
+~0U
+};
+
+static unsigned chattr_class[] = {
+#include <asm-generic/audit_change_attr.h>
+~0U
+};
+
+static unsigned signal_class[] = {
+#include <asm-generic/audit_signal.h>
+~0U
+};
+
+int audit_classify_arch(int arch)
+{
+	return 0;
+}
+
+int audit_classify_syscall(int abi, unsigned syscall)
+{
+	switch(syscall) {
+	case __NR_open:
+		return 2;
+	case __NR_openat:
+		return 3;
+	case __NR_execve:
+		return 5;
+	default:
+		return 0;
+	}
+}
+
+static int __init audit_classes_init(void)
+{
+	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);
+	audit_register_class(AUDIT_CLASS_CHATTR, chattr_class);
+	audit_register_class(AUDIT_CLASS_SIGNAL, signal_class);
+	return 0;
+}
+
+__initcall(audit_classes_init);

arch/alpha/kernel/entry.S

@@ -465,7 +465,11 @@ entSys:
 	.cfi_rel_offset	$16, SP_OFF+24
 	.cfi_rel_offset	$17, SP_OFF+32
 	.cfi_rel_offset	$18, SP_OFF+40
-	blbs	$3, strace
+#ifdef CONFIG_AUDITSYSCALL
+	lda     $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
+	and     $3, $6, $3
+#endif
+	bne     $3, strace
 	beq	$4, 1f
 	ldq	$27, 0($5)
 1:	jsr	$26, ($27), alpha_ni_syscall

arch/alpha/kernel/ptrace.c

@@ -14,6 +14,7 @@
 #include <linux/security.h>
 #include <linux/signal.h>
 #include <linux/tracehook.h>
+#include <linux/audit.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -316,15 +317,18 @@ long arch_ptrace(struct task_struct *child, long request,
 asmlinkage unsigned long syscall_trace_enter(void)
 {
 	unsigned long ret = 0;
+	struct pt_regs *regs = current_pt_regs();
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 	    tracehook_report_syscall_entry(current_pt_regs()))
 		ret = -1UL;
+	audit_syscall_entry(AUDIT_ARCH_ALPHA, regs->r0, regs->r16, regs->r17, regs->r18, regs->r19);
 	return ret ?: current_pt_regs()->r0;
 }
 
 asmlinkage void
 syscall_trace_leave(void)
 {
+	audit_syscall_exit(current_pt_regs());
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall_exit(current_pt_regs(), 0);
 }