lkml.org 
[lkml]   [2003]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectPtrace updates: PTRACE_GETSIGINFO [2/5]
This patch adds PTRACE_GETSIGINFO and PTRACE_SETSIGINFO, as suggested by
someone on linux-kernel (discussion between Andi Kleen and Roland McGrath, I
think). You can use these to query the information about a signal or forge
it, which is useful if (for instance) a debugger needs to queue a signal
for later delivery.
This implements the feature for all architectures which use the generic
get_signal_to_deliver. Doing it for the rest is straightforward.

# --------------------------------------------
# 03/01/18 drow@nevyn.them.org 1.958
# Add PTRACE_GETSIGINFO and PTRACE_SETSIGINFO
#
# These new ptrace commands allow a debugger to control signals more precisely;
# for instance, store a signal and deliver it later, as if it had come from the
# original outside process or in response to the same faulting memory access.
# --------------------------------------------
diff -Nru a/include/linux/ptrace.h b/include/linux/ptrace.h
--- a/include/linux/ptrace.h Thu Feb 6 16:57:36 2003
+++ b/include/linux/ptrace.h Thu Feb 6 16:57:36 2003
@@ -26,6 +26,8 @@
/* 0x4200-0x4300 are reserved for architecture-independent additions. */
#define PTRACE_SETOPTIONS 0x4200
#define PTRACE_GETEVENTMSG 0x4201
+#define PTRACE_GETSIGINFO 0x4202
+#define PTRACE_SETSIGINFO 0x4203

/* options set using PTRACE_SETOPTIONS */
#define PTRACE_O_TRACESYSGOOD 0x00000001
diff -Nru a/include/linux/sched.h b/include/linux/sched.h
--- a/include/linux/sched.h Thu Feb 6 16:57:36 2003
+++ b/include/linux/sched.h Thu Feb 6 16:57:36 2003
@@ -400,6 +400,7 @@
struct backing_dev_info *backing_dev_info;

unsigned long ptrace_message;
+ siginfo_t *last_siginfo; /* For ptrace use. */
};

extern void __put_task_struct(struct task_struct *tsk);
diff -Nru a/kernel/ptrace.c b/kernel/ptrace.c
--- a/kernel/ptrace.c Thu Feb 6 16:57:36 2003
+++ b/kernel/ptrace.c Thu Feb 6 16:57:36 2003
@@ -286,6 +286,23 @@
return 0;
}

+static int ptrace_getsiginfo(struct task_struct *child, long data)
+{
+ if (child->last_siginfo == NULL)
+ return -EINVAL;
+ return copy_siginfo_to_user ((siginfo_t *) data, child->last_siginfo);
+}
+
+static int ptrace_setsiginfo(struct task_struct *child, long data)
+{
+ if (child->last_siginfo == NULL)
+ return -EINVAL;
+ if (copy_from_user (child->last_siginfo, (siginfo_t *) data,
+ sizeof (siginfo_t)) != 0)
+ return -EFAULT;
+ return 0;
+}
+
int ptrace_request(struct task_struct *child, long request,
long addr, long data)
{
@@ -300,6 +317,12 @@
break;
case PTRACE_GETEVENTMSG:
ret = put_user(child->ptrace_message, (unsigned long *) data);
+ break;
+ case PTRACE_GETSIGINFO:
+ ret = ptrace_getsiginfo(child, data);
+ break;
+ case PTRACE_SETSIGINFO:
+ ret = ptrace_setsiginfo(child, data);
break;
default:
break;
diff -Nru a/kernel/signal.c b/kernel/signal.c
--- a/kernel/signal.c Thu Feb 6 16:57:36 2003
+++ b/kernel/signal.c Thu Feb 6 16:57:36 2003
@@ -1244,10 +1244,13 @@
if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
/* Let the debugger run. */
current->exit_code = signr;
+ current->last_siginfo = info;
set_current_state(TASK_STOPPED);
notify_parent(current, SIGCHLD);
schedule();

+ current->last_siginfo = NULL;
+
/* We're back. Did the debugger cancel the sig? */
signr = current->exit_code;
if (signr == 0)
@@ -1258,7 +1261,10 @@
if (signr == SIGSTOP)
continue;

- /* Update the siginfo structure. Is this good? */
+ /* Update the siginfo structure if the signal has
+ changed. If the debugger wanted something
+ specific in the siginfo structure then it should
+ have updated *info via PTRACE_SETSIGINFO. */
if (signr != info->si_signo) {
info->si_signo = signr;
info->si_errno = 0;
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:33    [from the cache]
©2003-2011 Jasper Spaans