From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760238AbYACG2q (ORCPT ); Thu, 3 Jan 2008 01:28:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756373AbYACG2i (ORCPT ); Thu, 3 Jan 2008 01:28:38 -0500 Received: from gw1.cosmosbay.com ([86.65.150.130]:42818 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756174AbYACG2i (ORCPT ); Thu, 3 Jan 2008 01:28:38 -0500 Message-ID: <477C808B.9080704@cosmosbay.com> Date: Thu, 03 Jan 2008 07:28:27 +0100 From: Eric Dumazet User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) MIME-Version: 1.0 To: Andi Kleen CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH] [20/20] x86: Print which shared library/executable faulted in segfault etc. messages References: <20080103149.088038000@suse.de> <20080103005016.4DA4C14D40@wotan.suse.de> In-Reply-To: <20080103005016.4DA4C14D40@wotan.suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (gw1.cosmosbay.com [86.65.150.130]); Thu, 03 Jan 2008 07:28:36 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andi Kleen a écrit : > They now look like > > hal-resmgr[13791]: segfault at 3c rip 2b9c8caec182 rsp 7fff1e825d30 error 4 in libacl.so.1.1.0[2b9c8caea000+6000] > > This makes it easier to pinpoint bugs to specific libraries. > > And printing the offset into a mapping also always allows to find the > correct fault point in a library even with randomized mappings. Previously > there was no way to actually find the correct code address inside > the randomized mapping. > > Relies on earlier patch to shorten the printk formats. > > They are often now longer than 80 characters, but I think that's worth > it. > > Patch for i386 and x86-64. > > Signed-off-by: Andi Kleen > > --- > arch/x86/kernel/signal_32.c | 7 +++++-- > arch/x86/kernel/signal_64.c | 7 +++++-- > arch/x86/kernel/traps_32.c | 7 +++++-- > arch/x86/mm/fault_32.c | 4 +++- > include/linux/mm.h | 1 + > mm/memory.c | 27 +++++++++++++++++++++++++++ > 6 files changed, 46 insertions(+), 7 deletions(-) > > Index: linux/include/linux/mm.h > =================================================================== > --- linux.orig/include/linux/mm.h > +++ linux/include/linux/mm.h > @@ -1145,6 +1145,7 @@ extern int randomize_va_space; > #endif > > const char * arch_vma_name(struct vm_area_struct *vma); > +void print_vma_addr(char *prefix, unsigned long rip); > > struct page *sparse_mem_map_populate(unsigned long pnum, int nid); > pgd_t *vmemmap_pgd_populate(unsigned long addr, int node); > Index: linux/mm/memory.c > =================================================================== > --- linux.orig/mm/memory.c > +++ linux/mm/memory.c > @@ -2746,3 +2746,30 @@ int access_process_vm(struct task_struct > > return buf - old_buf; > } > + > +/* > + * Print the name of a VMA. > + */ > +void print_vma_addr(char *prefix, unsigned long ip) > +{ > + struct mm_struct *mm = current->mm; > + struct vm_area_struct *vma; > + down_read(&mm->mmap_sem); > + vma = find_vma(mm, ip); > + if (vma && vma->vm_file) { > + struct file *f = vma->vm_file; > + char *buf = (char *)__get_free_page(GFP_KERNEL); > + if (buf) { > + char *p, *s; > + p = d_path(f->f_dentry, f->f_vfsmnt, buf, PAGE_SIZE); d_path() can returns an error. You should add : if (IS_ERR(p)) p = "?"; > + s = strrchr(p, '/'); > + if (s) > + p = s+1; > + printk("%s%s[%lx+%lx]", prefix, p, > + vma->vm_start, > + vma->vm_end - vma->vm_start); > + free_page((unsigned long)buf); > + } > + } > + up_read(¤t->mm->mmap_sem); > +} Thank you