From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754587AbaGHMHQ (ORCPT ); Tue, 8 Jul 2014 08:07:16 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:46769 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753948AbaGHMHK (ORCPT ); Tue, 8 Jul 2014 08:07:10 -0400 Message-ID: <53BBDEE6.1080800@hitachi.com> Date: Tue, 08 Jul 2014 21:07:02 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Benjamin Herrenschmidt , Paul Mackerras , Tony Luck Cc: Jeremy Fitzhardinge , linux-ia64@vger.kernel.org, sparse@chrisli.org, "H. Peter Anvin" , Ingo Molnar , linux-tip-commits@vger.kernel.org, Michael Ellerman , akataria@vmware.com, anil.s.keshavamurthy@intel.com, "Suzuki K. Poulose" , Fenghua Yu , Arnd Bergmann , Rusty Russell , Chris Wright , yrl.pp-manager.tt@hitachi.com, Thomas Gleixner , Tony Luck , Kevin Hao , Ananth N Mavinakayanahalli , linuxppc-dev@lists.ozlabs.org, rdunlap@infradead.org, Linux Kernel Mailing List , dl9pf@gmx.de, Andrew Morton , Linus Torvalds , "David S. Miller" Subject: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64 References: <1404276081.7254.1.camel@concordia> <20140702070029.14689.18485.stgit@kbuild-fedora.novalocal> In-Reply-To: <20140702070029.14689.18485.stgit@kbuild-fedora.novalocal> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping? This patch can be applied without 1/2, and will fix ia64/ppc64 problem. Thank you, (2014/07/02 16:00), Masami Hiramatsu wrote: > On ia64 and ppc64, the function pointer does not point the > entry address of the function, but the address of function > discriptor (which contains the entry address and misc > data.) Since the kprobes passes the function pointer stored > by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for > initalizing its blacklist, it fails and reports many errors > as below. > > Failed to find blacklist 0001013168300000 > Failed to find blacklist 0001013000f0a000 > Failed to find blacklist 000101315f70a000 > Failed to find blacklist 000101324c80a000 > Failed to find blacklist 0001013063f0a000 > Failed to find blacklist 000101327800a000 > Failed to find blacklist 0001013277f0a000 > Failed to find blacklist 000101315a70a000 > Failed to find blacklist 0001013277e0a000 > Failed to find blacklist 000101305a20a000 > Failed to find blacklist 0001013277d0a000 > Failed to find blacklist 00010130bdc0a000 > Failed to find blacklist 00010130dc20a000 > Failed to find blacklist 000101309a00a000 > Failed to find blacklist 0001013277c0a000 > Failed to find blacklist 0001013277b0a000 > Failed to find blacklist 0001013277a0a000 > Failed to find blacklist 000101327790a000 > Failed to find blacklist 000101303140a000 > Failed to find blacklist 0001013a3280a000 > > To fix this bug, this introduces function_entry() macro to > retrieve the entry address from the given function pointer, > and uses for kallsyms_lookup_size_offset() while initializing > blacklist. > > Changes in v5: > - Use arch_deref_entry_point() instead of function_entry(). > > Changes in v4: > - Add kernel_text_address() check for verifying the address. > - Moved on the latest linus tree. > > Changes in v3: > - Fix a bug to get blacklist address based on function entry > instead of function descriptor. (Suzuki's work, Thanks!) > > Changes in V2: > - Use function_entry() macro when lookin up symbols instead > of storing it. > - Update for the latest -next. > > Signed-off-by: Masami Hiramatsu > Reported-by: Tony Luck > Tested-by: Tony Luck > Cc: Michael Ellerman > Cc: Suzuki K. Poulose > Cc: Tony Luck > Cc: Fenghua Yu > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Ananth N Mavinakayanahalli > Cc: Kevin Hao > Cc: linux-ia64@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: linuxppc-dev@lists.ozlabs.org > --- > kernel/kprobes.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 3214289..ec370cc 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -32,6 +32,7 @@ > * added function-return probes. > */ > #include > +#include > #include > #include > #include > @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start, > { > unsigned long *iter; > struct kprobe_blacklist_entry *ent; > - unsigned long offset = 0, size = 0; > + unsigned long entry, offset = 0, size = 0; > > for (iter = start; iter < end; iter++) { > - if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) { > - pr_err("Failed to find blacklist %p\n", (void *)*iter); > + entry = arch_deref_entry_point((void *)*iter); > + > + if (!kernel_text_address(entry) || > + !kallsyms_lookup_size_offset(entry, &size, &offset)) { > + pr_err("Failed to find blacklist at %p\n", > + (void *)entry); > continue; > } > > ent = kmalloc(sizeof(*ent), GFP_KERNEL); > if (!ent) > return -ENOMEM; > - ent->start_addr = *iter; > - ent->end_addr = *iter + size; > + ent->start_addr = entry; > + ent->end_addr = entry + size; > INIT_LIST_HEAD(&ent->list); > list_add_tail(&ent->list, &kprobe_blacklist); > } > > > -- > 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/ > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com