From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753618Ab0BJNTW (ORCPT ); Wed, 10 Feb 2010 08:19:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:6249 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750868Ab0BJNTV (ORCPT ); Wed, 10 Feb 2010 08:19:21 -0500 Date: Wed, 10 Feb 2010 14:18:26 +0100 From: Oleg Nesterov To: Suresh Siddha Cc: Roland McGrath , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , LKML , hjl.tools@gmail.com Subject: Re: [patch v2 4/4] ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET Message-ID: <20100210131826.GA21196@redhat.com> References: <20100209201309.902050211@sbs-t61.sc.intel.com> <20100209202502.406177090@sbs-t61.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100209202502.406177090@sbs-t61.sc.intel.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/09, Suresh Siddha wrote: > > +#define PTRACE_REGSET_BUF_SIZE(addr) (addr & 0xfffff) > +#define PTRACE_REGSET_TYPE(addr) ((addr >> 20) & 0xfff) > +#define NOTE_TO_REGSET_TYPE(note) (note & 0xfff) > > /* options set using PTRACE_SETOPTIONS */ > #define PTRACE_O_TRACESYSGOOD 0x00000001 > @@ -114,6 +126,8 @@ static inline void ptrace_unlink(struct Well. Personally, I like Roland's suggestion more. How about something like the patch below? I am not sure how should we check the size, see the comment in ptrace_regset(). What do you think? And, I don't understand NOTE_TO_REGSET_TYPE() logic. I mean, I don't know why we should use "->core_note_type & 0xfff". Oleg. --- linux-2.6.32.2/include/linux/ptrace.h~REGSET 2009-12-18 23:27:07.000000000 +0100 +++ linux-2.6.32.2/include/linux/ptrace.h 2010-02-10 14:05:31.000000000 +0100 @@ -27,6 +27,9 @@ #define PTRACE_GETSIGINFO 0x4202 #define PTRACE_SETSIGINFO 0x4203 +#define PTRACE_GETREGSET 0x4204 +#define PTRACE_SETREGSET 0x4205 + /* options set using PTRACE_SETOPTIONS */ #define PTRACE_O_TRACESYSGOOD 0x00000001 #define PTRACE_O_TRACEFORK 0x00000002 --- linux-2.6.32.2/kernel/ptrace.c~REGSET 2009-12-18 23:27:07.000000000 +0100 +++ linux-2.6.32.2/kernel/ptrace.c 2010-02-10 14:08:12.000000000 +0100 @@ -22,7 +22,7 @@ #include #include #include - +#include /* * ptrace a task: make the debugger its new parent and @@ -397,6 +397,50 @@ int ptrace_writedata(struct task_struct return copied; } +static const struct user_regset * +find_regset(const struct user_regset_view *view, unsigned int type) +{ + const struct user_regset *regset; + int n; + + for (n = 0; n < view->n; ++n) { + regset = view->regsets + n; + if (regset->core_note_type == type) + return regset; + } + + return NULL; +} + +static int ptrace_regset(struct task_struct *task, int req, unsigned int type, + struct iovec *uiov) +{ + const struct user_regset_view *view = task_user_regset_view(task); + const struct user_regset *regset = find_regset(view, type); + struct iovec kiov; + + if (!regset) + return -EIO; + + if (copy_from_user(&kiov, uiov, sizeof kiov)) + return -EFAULT; + + // I am not sure. Afaics it is OK to pass the + // size which is less than n * size. If iov_len + // is bigger, we can silently truncate it, or + // even write the correct value back. + + if (kiov.iov_len != regset->n * regset->size) + return -EINVAL; + + if (req == PTRACE_GETREGSET) + return copy_regset_to_user(task, view, type, 0, + kiov.iov_len, kiov.iov_base); + else + return copy_regset_from_user(task, view, type, 0, + kiov.iov_len, kiov.iov_base); +} + static int ptrace_setoptions(struct task_struct *child, long data) { child->ptrace &= ~PT_TRACE_MASK; @@ -525,6 +569,10 @@ int ptrace_request(struct task_struct *c case PTRACE_POKEDATA: return generic_ptrace_pokedata(child, addr, data); + case PTRACE_GETREGSET: + case PTRACE_SETREGSET: + return ptrace_regset(child, request, addr, (void*)data); + #ifdef PTRACE_OLDSETOPTIONS case PTRACE_OLDSETOPTIONS: #endif