From: Robert Love <rml@ufl.edu>
To: Robert Love <rml@tech9.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH][RFC] preemptive kernel: ptrace fix
Date: 23 Sep 2001 01:18:08 -0400 [thread overview]
Message-ID: <1001222290.864.3.camel@phantasy> (raw)
In-Reply-To: <1001217135.1390.19.camel@phantasy>
In-Reply-To: <1001217135.1390.19.camel@phantasy>
On Sat, 2001-09-22 at 23:52, Robert Love wrote:
> However, doing an `strace strace whatever' (ie, stracing strace), it
> still enters a stopped state about 20% of the time (before the patch, it
> locked almost 100%). I can't figure out why. Comments?
I fixed it. I am not overly sure why it fixes it, but the following
patch (on top of the previous) fixes all the ptrace problems I can find.
In auditing the code, I fixed another problem which I will explain...
I'll put out a final patch in a bit...
diff -urN linux-2.4.9-ac14-preempt/arch/i386/kernel/signal.c linux/arch/i386/kernel/signal.c
--- linux-2.4.9-ac14-preempt/arch/i386/kernel/signal.c Sat Sep 22 23:20:41 2001
+++ linux/arch/i386/kernel/signal.c Sun Sep 23 00:51:15 2001
@@ -611,9 +611,11 @@
if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
/* Let the debugger run. */
current->exit_code = signr;
+ ctx_sw_off();
current->state = TASK_STOPPED;
notify_parent(current, SIGCHLD);
schedule();
+ ctx_sw_on();
/* We're back. Did the debugger cancel the sig? */
if (!(signr = current->exit_code))
@@ -667,11 +669,13 @@
/* FALLTHRU */
case SIGSTOP:
+ ctx_sw_off();
current->state = TASK_STOPPED;
current->exit_code = signr;
if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))
notify_parent(current, SIGCHLD);
schedule();
+ ctx_sw_on();
continue;
case SIGQUIT: case SIGILL: case SIGTRAP:
--
Robert M. Love
rml at ufl.edu
rml at tech9.net
prev parent reply other threads:[~2001-09-23 5:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-23 3:52 [PATCH][RFC] preemptive kernel: ptrace fix Robert Love
2001-09-23 5:18 ` Robert Love [this message]
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