Merge tag 'dt2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

[platform/kernel/linux-starfive.git] / arch / arm / kernel / ptrace.c

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 739db3a..03deeff 100644 (file)
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -916,16 +916,11 @@ enum ptrace_syscall_dir {
        PTRACE_SYSCALL_EXIT,
 };
 
-static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
-                               enum ptrace_syscall_dir dir)
+static int tracehook_report_syscall(struct pt_regs *regs,
+                                   enum ptrace_syscall_dir dir)
 {
        unsigned long ip;
 
-       current_thread_info()->syscall = scno;
-
-       if (!test_thread_flag(TIF_SYSCALL_TRACE))
-               return scno;
-
        /*
         * IP is used to denote syscall entry/exit:
         * IP = 0 -> entry, =1 -> exit
@@ -944,19 +939,41 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
 
 asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
 {
-       scno = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);
+       current_thread_info()->syscall = scno;
+
+       /* Do the secure computing check first; failures should be fast. */
+       if (secure_computing(scno) == -1)
+               return -1;
+
+       if (test_thread_flag(TIF_SYSCALL_TRACE))
+               scno = tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+
        if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
                trace_sys_enter(regs, scno);
+
        audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,
                            regs->ARM_r2, regs->ARM_r3);
+
        return scno;
 }
 
-asmlinkage int syscall_trace_exit(struct pt_regs *regs, int scno)
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
-       scno = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_EXIT);
-       if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-               trace_sys_exit(regs, scno);
+       /*
+        * Audit the syscall before anything else, as a debugger may
+        * come in and change the current registers.
+        */
        audit_syscall_exit(regs);
-       return scno;
+
+       /*
+        * Note that we haven't updated the ->syscall field for the
+        * current thread. This isn't a problem because it will have
+        * been set on syscall entry and there hasn't been an opportunity
+        * for a PTRACE_SET_SYSCALL since then.
+        */
+       if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+               trace_sys_exit(regs, regs_return_value(regs));
+
+       if (test_thread_flag(TIF_SYSCALL_TRACE))
+               tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
 }