Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753842AbYCMIc5 (ORCPT ); Thu, 13 Mar 2008 04:32:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751482AbYCMIct (ORCPT ); Thu, 13 Mar 2008 04:32:49 -0400 Received: from mx1.redhat.com ([66.187.233.31]:59607 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751293AbYCMIcs (ORCPT ); Thu, 13 Mar 2008 04:32:48 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Paul Mackerras , Anton Blanchard Cc: Ingo Molnar , Thomas Gleixner Cc: Andrew Morton Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org X-Fcc: ~/Mail/linus Subject: [PATCH -mm 2/4] ptrace: compat_ptrace_request siginfo In-Reply-To: Roland McGrath's message of Thursday, 13 March 2008 01:31:07 -0700 <20080313083107.8BDE926F992@magilla.localdomain> References: <20080313083107.8BDE926F992@magilla.localdomain> Message-Id: <20080313083243.E551A26F992@magilla.localdomain> Date: Thu, 13 Mar 2008 01:32:43 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4419 Lines: 136 This adds support for PTRACE_GETSIGINFO and PTRACE_SETSIGINFO in compat_ptrace_request. It relies on existing arch definitions for copy_siginfo_to_user32 and copy_siginfo_from_user32. On powerpc, this fixes a longstanding regression of 32-bit ptrace calls on 64-bit kernels vs native calls (64-bit calls or 32-bit kernels). This can be seen in a 32-bit call using PTRACE_GETSIGINFO to examine e.g. siginfo_t.si_addr from a signal that sets it. (This was broken as of 2.6.24 and, I presume, many or all prior versions.) Signed-off-by: Roland McGrath --- kernel/ptrace.c | 48 +++++++++++++++++++++++++++++++++++------------- 1 files changed, 35 insertions(+), 13 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index fdb34e8..67e392e 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -323,9 +323,8 @@ static int ptrace_setoptions(struct task_struct *child, long data) return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; } -static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) +static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) { - siginfo_t lastinfo; int error = -ESRCH; read_lock(&tasklist_lock); @@ -333,31 +332,25 @@ static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) error = -EINVAL; spin_lock_irq(&child->sighand->siglock); if (likely(child->last_siginfo != NULL)) { - lastinfo = *child->last_siginfo; + *info = *child->last_siginfo; error = 0; } spin_unlock_irq(&child->sighand->siglock); } read_unlock(&tasklist_lock); - if (!error) - return copy_siginfo_to_user(data, &lastinfo); return error; } -static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) +static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) { - siginfo_t newinfo; int error = -ESRCH; - if (copy_from_user(&newinfo, data, sizeof (siginfo_t))) - return -EFAULT; - read_lock(&tasklist_lock); if (likely(child->sighand != NULL)) { error = -EINVAL; spin_lock_irq(&child->sighand->siglock); if (likely(child->last_siginfo != NULL)) { - *child->last_siginfo = newinfo; + *child->last_siginfo = *info; error = 0; } spin_unlock_irq(&child->sighand->siglock); @@ -424,6 +417,7 @@ int ptrace_request(struct task_struct *child, long request, long addr, long data) { int ret = -EIO; + siginfo_t siginfo; switch (request) { case PTRACE_PEEKTEXT: @@ -442,12 +436,22 @@ int ptrace_request(struct task_struct *child, long request, case PTRACE_GETEVENTMSG: ret = put_user(child->ptrace_message, (unsigned long __user *) data); break; + case PTRACE_GETSIGINFO: - ret = ptrace_getsiginfo(child, (siginfo_t __user *) data); + ret = ptrace_getsiginfo(child, &siginfo); + if (!ret) + ret = copy_siginfo_to_user((siginfo_t __user *) data, + &siginfo); break; + case PTRACE_SETSIGINFO: - ret = ptrace_setsiginfo(child, (siginfo_t __user *) data); + if (copy_from_user(&siginfo, (siginfo_t __user *) data, + sizeof siginfo)) + ret = -EFAULT; + else + ret = ptrace_setsiginfo(child, &siginfo); break; + case PTRACE_DETACH: /* detach a process that was attached. */ ret = ptrace_detach(child, data); break; @@ -616,6 +620,7 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, { compat_ulong_t __user *datap = compat_ptr(data); compat_ulong_t word; + siginfo_t siginfo; int ret; switch (request) { @@ -638,6 +643,23 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, ret = put_user((compat_ulong_t) child->ptrace_message, datap); break; + case PTRACE_GETSIGINFO: + ret = ptrace_getsiginfo(child, &siginfo); + if (!ret) + ret = copy_siginfo_to_user32( + (struct compat_siginfo __user *) datap, + &siginfo); + break; + + case PTRACE_SETSIGINFO: + memset(&siginfo, 0, sizeof siginfo); + if (copy_siginfo_from_user32( + &siginfo, (struct compat_siginfo __user *) datap)) + ret = -EFAULT; + else + ret = ptrace_setsiginfo(child, &siginfo); + break; + default: ret = ptrace_request(child, request, addr, data); } -- 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/