seccomp: remove duplicated failure logging

This consolidates the seccomp filter error logging path and adds more
details to the audit log.

Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>

v18: make compat= permanent in the record
v15: added a return code to the audit_seccomp path by wad@chromium.org
     (suggested by eparis@redhat.com)
v*: original by keescook@chromium.org
Signed-off-by: James Morris <james.l.morris@oracle.com>

2 files changed, 7 insertions, 16 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index af1de0f..4b96415 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -67,6 +67,7 @@
 #include <linux/syscalls.h>
 #include <linux/capability.h>
 #include <linux/fs_struct.h>
+#include <linux/compat.h>
 
 #include "audit.h"
 
@@ -2710,13 +2711,16 @@ void audit_core_dumps(long signr)
 	audit_log_end(ab);
 }
 
-void __audit_seccomp(unsigned long syscall)
+void __audit_seccomp(unsigned long syscall, long signr, int code)
 {
 	struct audit_buffer *ab;
 
 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
-	audit_log_abend(ab, "seccomp", SIGKILL);
+	audit_log_abend(ab, "seccomp", signr);
 	audit_log_format(ab, " syscall=%ld", syscall);
+	audit_log_format(ab, " compat=%d", is_compat_task());
+	audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
+	audit_log_format(ab, " code=0x%x", code);
 	audit_log_end(ab);
 }
 
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 0aeec19..0f7c709 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -60,18 +60,6 @@ struct seccomp_filter {
 /* Limit any path through the tree to 256KB worth of instructions. */
 #define MAX_INSNS_PER_PATH ((1 << 18) / sizeof(struct sock_filter))
 
-static void seccomp_filter_log_failure(int syscall)
-{
-	int compat = 0;
-#ifdef CONFIG_COMPAT
-	compat = is_compat_task();
-#endif
-	pr_info("%s[%d]: %ssystem call %d blocked at 0x%lx\n",
-		current->comm, task_pid_nr(current),
-		(compat ? "compat " : ""),
-		syscall, KSTK_EIP(current));
-}
-
 /**
  * get_u32 - returns a u32 offset into data
  * @data: a unsigned 64 bit value
@@ -381,7 +369,6 @@ void __secure_computing(int this_syscall)
 	case SECCOMP_MODE_FILTER:
 		if (seccomp_run_filters(this_syscall) == SECCOMP_RET_ALLOW)
 			return;
-		seccomp_filter_log_failure(this_syscall);
 		exit_sig = SIGSYS;
 		break;
 #endif
@@ -392,7 +379,7 @@ void __secure_computing(int this_syscall)
 #ifdef SECCOMP_DEBUG
 	dump_stack();
 #endif
-	audit_seccomp(this_syscall);
+	audit_seccomp(this_syscall, exit_code, SECCOMP_RET_KILL);
 	do_exit(exit_sig);
 }