1 files changed, 40 insertions, 0 deletions

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 8a4ae8e73213..d882b833dbdb 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -27,6 +27,7 @@
 #include <linux/smp.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
+#include <linux/seccomp.h>
 #include <linux/security.h>
 #include <linux/init.h>
 #include <linux/signal.h>
@@ -551,6 +552,32 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset,
         return ret;
 }
 
+static int system_call_get(struct task_struct *target,
+                           const struct user_regset *regset,
+                           unsigned int pos, unsigned int count,
+                           void *kbuf, void __user *ubuf)
+{
+        int syscallno = task_pt_regs(target)->syscallno;
+
+        return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                   &syscallno, 0, -1);
+}
+
+static int system_call_set(struct task_struct *target,
+                           const struct user_regset *regset,
+                           unsigned int pos, unsigned int count,
+                           const void *kbuf, const void __user *ubuf)
+{
+        int syscallno, ret;
+
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
+        if (ret)
+                return ret;
+
+        task_pt_regs(target)->syscallno = syscallno;
+        return ret;
+}
+
 enum aarch64_regset {
         REGSET_GPR,
         REGSET_FPR,
@@ -559,6 +586,7 @@ enum aarch64_regset {
         REGSET_HW_BREAK,
         REGSET_HW_WATCH,
 #endif
+        REGSET_SYSTEM_CALL,
 };
 
 static const struct user_regset aarch64_regsets[] = {
@@ -608,6 +636,14 @@ static const struct user_regset aarch64_regsets[] = {
                 .set = hw_break_set,
         },
 #endif
+        [REGSET_SYSTEM_CALL] = {
+                .core_note_type = NT_ARM_SYSTEM_CALL,
+                .n = 1,
+                .size = sizeof(int),
+                .align = sizeof(int),
+                .get = system_call_get,
+                .set = system_call_set,
+        },
 };
 
 static const struct user_regset_view user_aarch64_view = {
@@ -1114,6 +1150,10 @@ static void tracehook_report_syscall(struct pt_regs *regs,
 
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
+        /* Do the secure computing check first; failures should be fast. */
+        if (secure_computing() == -1)
+                return -1;
+
         if (test_thread_flag(TIF_SYSCALL_TRACE))
                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);