[PATCH 132] change ptrace_report_signal() to use user_single_step_siginfo()

[Oleg Nesterov]

Change ptrace_report_signal() to report SIGTRAP via
user_single_step_siginfo() + force_sig_info().

---

 kernel/ptrace.c |   24 +++++++++---------------
 1 file changed, 9 insertions(+), 15 deletions(-)

--- PU/kernel/ptrace.c~132_USER_SINGLE_STEP_INFO        2009-11-13 
22:35:40.000000000 +0100
+++ PU/kernel/ptrace.c  2009-11-13 22:44:10.000000000 +0100
@@ -451,16 +451,10 @@ static u32 ptrace_report_exec(enum utrac
        return UTRACE_STOP;
 }
 
-static void fill_sigtrap_info(struct task_struct *task, siginfo_t *info)
+static void ptrace_send_sigtrap(struct task_struct *task, siginfo_t *info)
 {
-#ifdef CONFIG_X86
-       task->thread.trap_no = 1;
-       task->thread.error_code = 0;
-#endif
-       memset(info, 0, sizeof(*info));
-       info->si_signo = SIGTRAP;
-       info->si_code  = TRAP_BRKPT;
-       info->si_addr  = (void __user*)KSTK_EIP(task);
+       user_single_step_siginfo(task, task_pt_regs(task), info);
+       force_sig_info(SIGTRAP, info, task);
 }
 
 static enum utrace_signal_action resume_signal(struct task_struct *task,
@@ -534,13 +528,13 @@ static u32 ptrace_report_signal(u32 acti
 
        case UTRACE_SIGNAL_REPORT:
                if (!ctx->siginfo) {
-                       if (!ctx->signr)
-                               return resume | UTRACE_SIGNAL_IGN;
+                       if (ctx->signr) {
+                               /* set by ptrace_resume(SYSCALL_EXIT) */
+                               WARN_ON(ctx->signr != SIGTRAP);
+                               ptrace_send_sigtrap(task, info);
+                       }
 
-                       WARN_ON(ctx->signr != SIGTRAP);
-                       /* set by ptrace_resume(PTRACE_EVENT_SYSCALL_EXIT) */
-                       fill_sigtrap_info(task, info);
-                       break;
+                       return resume | UTRACE_SIGNAL_IGN;
                }
 
                if (WARN_ON(ctx->siginfo != info))