void ptrace_disable(struct task_struct *child)
{
clear_singlestep(child);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
}
/*
wake_up_process(child);
break;
+ case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */
case PTRACE_SINGLESTEP: /* set the trap flag. */
ret = -EIO;
if (!valid_signal(data))
break;
- clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+
+ if (request == PTRACE_SYSEMU_SINGLESTEP)
+ set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+ else
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
set_singlestep(child);
child->exit_code = data;
__attribute__((regparm(3)))
int do_syscall_trace(struct pt_regs *regs, int entryexit)
{
- int is_sysemu, is_singlestep, ret = 0;
+ int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU), ret = 0;
+ /* With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
+ * interception. */
+ int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
+
/* do the secure computing check first */
secure_computing(regs->orig_eax);
- if (unlikely(current->audit_context) && entryexit)
- audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax);
+ if (unlikely(current->audit_context)) {
+ if (entryexit)
+ audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax);
+ /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
+ * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
+ * not used, entry.S will call us only on syscall exit, not
+ * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
+ * calling send_sigtrap() on syscall entry.
+ *
+ * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
+ * is_singlestep is false, despite his name, so we will still do
+ * the correct thing.
+ */
+ else if (is_singlestep)
+ goto out;
+ }
if (!(current->ptrace & PT_PTRACED))
goto out;
- is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
- is_singlestep = test_thread_flag(TIF_SINGLESTEP);
+ /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
+ * and then is resumed with SYSEMU_SINGLESTEP, it will come in
+ * here. We have to check this and return */
+ if (is_sysemu && entryexit)
+ return 0;
/* Fake a debug trap */
if (is_singlestep)
if (ret == 0)
return 0;
+ regs->orig_eax = -1; /* force skip of syscall restarting */
if (unlikely(current->audit_context))
audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax);
return 1;