From patchwork Wed Sep 20 16:29:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Senozhatsky X-Patchwork-Id: 816362 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xy57b605dz9t2Q for ; Thu, 21 Sep 2017 02:39:55 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="qT+NjFfZ"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3xy57b2WdHzDqY3 for ; Thu, 21 Sep 2017 02:39:55 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="qT+NjFfZ"; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:400e:c05::242; helo=mail-pg0-x242.google.com; envelope-from=sergey.senozhatsky@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="qT+NjFfZ"; dkim-atps=neutral Received: from mail-pg0-x242.google.com (mail-pg0-x242.google.com [IPv6:2607:f8b0:400e:c05::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xy4vx3Pv0zDqXp for ; Thu, 21 Sep 2017 02:29:49 +1000 (AEST) Received: by mail-pg0-x242.google.com with SMTP id d8so1911938pgt.3 for ; Wed, 20 Sep 2017 09:29:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=CnpHgZ2+ZTbCeZd1Ck+ekMy+VDRmM6IJjtCT7xMUDx0=; b=qT+NjFfZCLQ+T28UFYOveLZbPebjdNHNDpSawkskKAh78+fZUB7mF6vKhqke6hUtE+ t8KLdhyP2uSNMiOzmf5qo3TXOMY4x0ZNGV9iovw5+ElQ46EMoKEXzZxzII+LQ87Lma6O 16wqhqrmam07MQtdAL9DzybtPJ0SnRRjc3IMsSwU0EHIUj/TagxQyzWCqq0HaupEmE4F k89vTKN1T1LwBwqS/LfRJqOpGiJSXiYR2vH7wpAIChBWhOoARyqx0B/m2K5oTY2b6h8k G788Kbsx+l/2NdSdgNd7/TZXzZM/1M+coMb2fBzvLdrnVVNGvmBixyPddhC+IDcnUplX SgEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=CnpHgZ2+ZTbCeZd1Ck+ekMy+VDRmM6IJjtCT7xMUDx0=; b=l+YZhT8CjAV1FfKkWHulo9e/zRi89IZTJ8Ei7b4yGwrqgTGc6cyueR6uLSuC+feyQa BiEUY2us1Z0wdBs/SV/UvYYGVjxSPfPlWO4x3NpN5U2/FqU0VD0QMlHK9a2dWGTGnjRz IiihsSI3hexIDQLKcn565KqovhYRtFLseq8YYYkiRGF0yPnSHNS8hBS7z8rstxH5Zoxy xPxc4XkV9VO+xBmu07DCzEXc/eAP3t/e3Q86qB3rpm8Z45S1H765Yvt9zsFLT+C+XOrc 1Ofyoi9YbZac8dM75GK4loBEsr7H7bcdxLubbTr1rjua9OGzf7ncwFxug1l6Q2ALC9ob 4cUw== X-Gm-Message-State: AHPjjUhHZ2jmqW0semJaZm86z/xrZKc7a7xDPBNM5iW47Hozz5PyVpeh UKMhQMLk3MVBrvX7r8M2GNY= X-Google-Smtp-Source: AOwi7QCrWWE7JWto/ELgrvGD7Q73g/KaZRTUdedeG7gRRvMzwtVaqTFnXpCqR3nF+W0msrQuVMrdsg== X-Received: by 10.84.194.1 with SMTP id g1mr2651908pld.74.1505924987817; Wed, 20 Sep 2017 09:29:47 -0700 (PDT) Received: from localhost.localdomain ([121.137.63.184]) by smtp.gmail.com with ESMTPSA id c185sm8890567pfb.57.2017.09.20.09.29.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Sep 2017 09:29:47 -0700 (PDT) From: Sergey Senozhatsky To: Tony Luck , Fenghua Yu , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , James Bottomley , Helge Deller Subject: [RFC][PATCH v2 4/7] powerpc64: Add .opd based function descriptor dereference Date: Thu, 21 Sep 2017 01:29:06 +0900 Message-Id: <20170920162910.32053-5-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170920162910.32053-1-sergey.senozhatsky@gmail.com> References: <20170920162910.32053-1-sergey.senozhatsky@gmail.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Petr Mladek , linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, Alexei Starovoitov , Steven Rostedt , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Jessica Yu , Andrew Morton , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" We are moving towards separate kernel and module function descriptor dereference callbacks. This patch enables it for powerpc64. For pointers that belong to the kernel - Added __start_opd and __end_opd pointers, to track the kernel .opd section address range; - Added dereference_kernel_function_descriptor(). Now we will dereference only function pointers that are within [__start_opd, __end_opd]; For pointers that belong to a module - Added dereference_module_function_descriptor() to handle module function descriptor dereference. Now we will dereference only pointers that are within [module->opd.start, module->opd.end]. Signed-off-by: Sergey Senozhatsky --- arch/powerpc/include/asm/module.h | 3 +++ arch/powerpc/include/asm/sections.h | 11 +++++++++++ arch/powerpc/kernel/module_64.c | 16 ++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 2 ++ 4 files changed, 32 insertions(+) diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h index 6c0132c7212f..7e28442827f1 100644 --- a/arch/powerpc/include/asm/module.h +++ b/arch/powerpc/include/asm/module.h @@ -45,6 +45,9 @@ struct mod_arch_specific { unsigned long tramp; #endif + /* For module function descriptor dereference */ + unsigned long start_opd; + unsigned long end_opd; #else /* powerpc64 */ /* Indices of PLT sections within module. */ unsigned int core_plt_section; diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index 67379b8945e8..6b4ee0d1645f 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -75,6 +75,17 @@ static inline unsigned long dereference_function_descriptor(unsigned long ptr) ptr = (unsigned long)p; return ptr; } + +#undef dereference_kernel_function_descriptor +static inline unsigned long +dereference_kernel_function_descriptor(unsigned long addr) +{ + if (addr < (unsigned long)__start_opd || + addr >= (unsigned long)__end_opd) + return addr; + + return dereference_function_descriptor(addr); +} #endif /* PPC64_ELF_ABI_v1 */ #endif diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 0b0f89685b67..94caec045a90 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -344,6 +344,11 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr, else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0) dedotify_versions((void *)hdr + sechdrs[i].sh_offset, sechdrs[i].sh_size); + else if (!strcmp(secstrings + sechdrs[i].sh_name, ".opd")) { + me->arch.start_opd = sechdrs[i].sh_addr; + me->arch.end_opd = sechdrs[i].sh_addr + + sechdrs[i].sh_size; + } /* We don't handle .init for the moment: rename to _init */ while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) @@ -712,6 +717,17 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, return 0; } +#ifdef PPC64_ELF_ABI_v1 +unsigned long dereference_module_function_descriptor(struct module *mod, + unsigned long addr) +{ + if (addr < mod->arch.start_opd || addr >= mod->arch.end_opd) + return addr; + + return dereference_function_descriptor(addr); +} +#endif /* PPC64_ELF_ABI_v1 */ + #ifdef CONFIG_DYNAMIC_FTRACE #ifdef CC_USING_MPROFILE_KERNEL diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 882628fa6987..70e10251e083 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -277,7 +277,9 @@ SECTIONS } .opd : AT(ADDR(.opd) - LOAD_OFFSET) { + __start_opd = .; *(.opd) + __end_opd = .; } . = ALIGN(256);