Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268351AbUIQEQF (ORCPT ); Fri, 17 Sep 2004 00:16:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268353AbUIQENw (ORCPT ); Fri, 17 Sep 2004 00:13:52 -0400 Received: from [12.177.129.25] ([12.177.129.25]:6340 "EHLO ccure.user-mode-linux.org") by vger.kernel.org with ESMTP id S268370AbUIQENF (ORCPT ); Fri, 17 Sep 2004 00:13:05 -0400 Message-Id: <200409170517.i8H5HM2J005362@ccure.user-mode-linux.org> X-Mailer: exmh version 2.4 06/23/2000 with nmh-1.1-RC1 To: akpm@osdl.org cc: linux-kernel@vger.kernel.org Subject: [PATCH] UML - Comment UML's signal handling Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 17 Sep 2004 01:17:21 -0400 From: Jeff Dike Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1523 Lines: 40 This adds a couple of comments so that people don't get confused into making misguided fixes, and I don't get confused into applying them. Signed-off-by: Jeff Dike Index: 2.6.9-rc2/arch/um/kernel/signal_user.c =================================================================== --- 2.6.9-rc2.orig/arch/um/kernel/signal_user.c 2004-09-16 22:59:06.000000000 -0400 +++ 2.6.9-rc2/arch/um/kernel/signal_user.c 2004-09-16 22:59:24.000000000 -0400 @@ -80,6 +80,12 @@ change_signals(SIG_UNBLOCK); } +/* These are the asynchronous signals. SIGVTALRM and SIGARLM are handled + * together under SIGVTALRM_BIT. SIGPROF is excluded because we want to + * be able to profile all of UML, not just the non-critical sections. If + * profiling is not thread-safe, then that is not my problem. We can disable + * profiling when SMP is enabled in that case. + */ #define SIGIO_BIT 0 #define SIGVTALRM_BIT 1 @@ -114,6 +120,11 @@ sigaddset(&mask, SIGVTALRM); sigaddset(&mask, SIGALRM); } + + /* This is safe - sigprocmask is guaranteed to copy locally the + * value of new_set, do his work and then, at the end, write to + * old_set. + */ if(sigprocmask(SIG_UNBLOCK, &mask, &mask) < 0) panic("Failed to enable signals"); ret = enable_mask(&mask); - 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/