From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 28 Jan 2008 16:38:29 -0500 From: Jeff Dike Message-ID: <20080128213829.GA10251@c2.user-mode-linux.org> Mime-Version: 1.0 Content-Disposition: inline Subject: [uml-devel] [RFC PATCH 4/10] SKAS4 - Work around compat PTRACE_GETSIGINFO bug List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: uml-user , uml-devel copy_siginfo_to_user correctly strips off the high bits of si->si_code before copying it to userspace. Unfortunately, ptrace32_siginfo calls copy_siginfo_to_user to put the siginfo into a temporary userspace buffer and counts on the high bits still being present so that it may initialize the union in the final 32-bit siginfo. This patch works around this problem by having copy_siginfo_to_user copy si->si_code intact to userspace. This introduces a bug in native 64-bit PTRACE_GETSIGINFO, but I haven't noticed anything being bothered by it. diff --git a/kernel/signal.c b/kernel/signal.c index 1e067a1..28813b1 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2088,7 +2088,7 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) */ err = __put_user(from->si_signo, &to->si_signo); err |= __put_user(from->si_errno, &to->si_errno); - err |= __put_user((short)from->si_code, &to->si_code); + err |= __put_user(from->si_code, &to->si_code); switch (from->si_code & __SI_MASK) { case __SI_KILL: err |= __put_user(from->si_pid, &to->si_pid); ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel