Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754070AbaF3DOs (ORCPT ); Sun, 29 Jun 2014 23:14:48 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:40499 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752688AbaF3DOo (ORCPT ); Sun, 29 Jun 2014 23:14:44 -0400 Message-ID: <53B0D61B.9010104@hitachi.com> Date: Mon, 30 Jun 2014 12:14:35 +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 v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64 References: <20140620022307.23075.55858.stgit@kbuild-fedora.novalocal> In-Reply-To: <20140620022307.23075.55858.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? :) (2014/06/20 11:23), 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 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 > --- > arch/ia64/include/asm/types.h | 2 ++ > arch/powerpc/include/asm/types.h | 11 +++++++++++ > include/linux/types.h | 4 ++++ > kernel/kprobes.c | 15 ++++++++++----- > 4 files changed, 27 insertions(+), 5 deletions(-) > > diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h > index 4c351b1..95279dd 100644 > --- a/arch/ia64/include/asm/types.h > +++ b/arch/ia64/include/asm/types.h > @@ -27,5 +27,7 @@ struct fnptr { > unsigned long gp; > }; > > +#define function_entry(fn) (((struct fnptr *)(fn))->ip) > + > #endif /* !__ASSEMBLY__ */ > #endif /* _ASM_IA64_TYPES_H */ > diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h > index bfb6ded..8b89d65 100644 > --- a/arch/powerpc/include/asm/types.h > +++ b/arch/powerpc/include/asm/types.h > @@ -25,6 +25,17 @@ typedef struct { > unsigned long env; > } func_descr_t; > > +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1) > +/* > + * On PPC64 ABIv1 the function pointer actually points to the > + * function's descriptor. The first entry in the descriptor is the > + * address of the function text. > + */ > +#define function_entry(fn) (((func_descr_t *)(fn))->entry) > +#else > +#define function_entry(fn) ((unsigned long)(fn)) > +#endif > + > #endif /* __ASSEMBLY__ */ > > #endif /* _ASM_POWERPC_TYPES_H */ > diff --git a/include/linux/types.h b/include/linux/types.h > index a0bb704..3b95369 100644 > --- a/include/linux/types.h > +++ b/include/linux/types.h > @@ -213,5 +213,9 @@ struct callback_head { > }; > #define rcu_head callback_head > > +#ifndef function_entry > +#define function_entry(fn) ((unsigned long)(fn)) > +#endif > + > #endif /* __ASSEMBLY__ */ > #endif /* _LINUX_TYPES_H */ > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 3214289..7412535 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 = function_entry(*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); > } > > > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- 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/