From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3880FC3A5A9 for ; Tue, 5 May 2020 02:04:37 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ACFA2206D7 for ; Tue, 5 May 2020 02:04:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACFA2206D7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=popple.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49GNMP6bbgzDqWZ for ; Tue, 5 May 2020 12:04:33 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49GNKg2JNCzDqT4 for ; Tue, 5 May 2020 12:03:03 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=popple.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 49GNKf54D2z9sSs; Tue, 5 May 2020 12:03:02 +1000 (AEST) From: Alistair Popple To: Jordan Niethe Subject: Re: [PATCH v7 17/28] powerpc: Introduce a function for reporting instruction length Date: Tue, 05 May 2020 12:02:59 +1000 Message-ID: <3087823.8VYvvlUQXN@townsend> In-Reply-To: <20200501034220.8982-18-jniethe5@gmail.com> References: <20200501034220.8982-1-jniethe5@gmail.com> <20200501034220.8982-18-jniethe5@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: npiggin@gmail.com, bala24@linux.ibm.com, naveen.n.rao@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, dja@axtens.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Looks good, Reviewed-by: Alistair Popple On Friday, 1 May 2020 1:42:09 PM AEST Jordan Niethe wrote: > Currently all instructions have the same length, but in preparation for > prefixed instructions introduce a function for returning instruction > length. > > Signed-off-by: Jordan Niethe > --- > v6: - feature-fixups.c: do_final_fixups(): use here > - ppc_inst_len(): change return type from bool to int > - uprobes: Use ppc_inst_read() before calling ppc_inst_len() > --- > arch/powerpc/include/asm/inst.h | 5 +++++ > arch/powerpc/kernel/kprobes.c | 6 ++++-- > arch/powerpc/kernel/uprobes.c | 2 +- > arch/powerpc/lib/feature-fixups.c | 14 +++++++------- > 4 files changed, 17 insertions(+), 10 deletions(-) > > diff --git a/arch/powerpc/include/asm/inst.h > b/arch/powerpc/include/asm/inst.h index 0d581b332c20..2f3c9d5bcf7c 100644 > --- a/arch/powerpc/include/asm/inst.h > +++ b/arch/powerpc/include/asm/inst.h > @@ -17,6 +17,11 @@ static inline u32 ppc_inst_val(struct ppc_inst x) > return x.val; > } > > +static inline int ppc_inst_len(struct ppc_inst x) > +{ > + return sizeof(struct ppc_inst); > +} > + > static inline int ppc_inst_primary_opcode(struct ppc_inst x) > { > return ppc_inst_val(x) >> 26; > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c > index a72c8e1a42ad..33d54b091c70 100644 > --- a/arch/powerpc/kernel/kprobes.c > +++ b/arch/powerpc/kernel/kprobes.c > @@ -462,14 +462,16 @@ NOKPROBE_SYMBOL(trampoline_probe_handler); > */ > int kprobe_post_handler(struct pt_regs *regs) > { > + int len; > struct kprobe *cur = kprobe_running(); > struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); > > if (!cur || user_mode(regs)) > return 0; > > + len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn)); > /* make sure we got here for instruction we have a kprobe on */ > - if (((unsigned long)cur->ainsn.insn + 4) != regs->nip) > + if (((unsigned long)cur->ainsn.insn + len) != regs->nip) > return 0; > > if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { > @@ -478,7 +480,7 @@ int kprobe_post_handler(struct pt_regs *regs) > } > > /* Adjust nip to after the single-stepped instruction */ > - regs->nip = (unsigned long)cur->addr + 4; > + regs->nip = (unsigned long)cur->addr + len; > regs->msr |= kcb->kprobe_saved_msr; > > /*Restore back the original saved kprobes variables and continue. */ > diff --git a/arch/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c > index 6893d40a48c5..83e883e1a42d 100644 > --- a/arch/powerpc/kernel/uprobes.c > +++ b/arch/powerpc/kernel/uprobes.c > @@ -112,7 +112,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, > struct pt_regs *regs) * support doesn't exist and have to fix-up the next > instruction * to be executed. > */ > - regs->nip = utask->vaddr + MAX_UINSN_BYTES; > + regs->nip = utask->vaddr + ppc_inst_len(ppc_inst_read(&auprobe->insn)); > > user_disable_single_step(current); > return 0; > diff --git a/arch/powerpc/lib/feature-fixups.c > b/arch/powerpc/lib/feature-fixups.c index 13ec3264a565..f4845e740338 100644 > --- a/arch/powerpc/lib/feature-fixups.c > +++ b/arch/powerpc/lib/feature-fixups.c > @@ -390,20 +390,20 @@ void do_lwsync_fixups(unsigned long value, void > *fixup_start, void *fixup_end) static void do_final_fixups(void) > { > #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE) > - struct ppc_inst *src, *dest; > - unsigned long length; > + struct ppc_inst inst, *src, *dest, *end; > > if (PHYSICAL_START == 0) > return; > > src = (struct ppc_inst *)(KERNELBASE + PHYSICAL_START); > dest = (struct ppc_inst *)KERNELBASE; > - length = (__end_interrupts - _stext) / sizeof(struct ppc_inst); > + end = (void *)src + (__end_interrupts - _stext); > > - while (length--) { > - raw_patch_instruction(dest, ppc_inst_read(src)); > - src++; > - dest++; > + while (src < end) { > + inst = ppc_inst_read(src); > + raw_patch_instruction(dest, inst); > + src = (void *)src + ppc_inst_len(inst); > + dest = (void *)dest + ppc_inst_len(inst); > } > #endif > }