From patchwork Sat Sep 16 03:53:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Senozhatsky X-Patchwork-Id: 9954105 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1BF20603D7 for ; Sat, 16 Sep 2017 03:59:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0DC0C2922D for ; Sat, 16 Sep 2017 03:59:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 02C4E29287; Sat, 16 Sep 2017 03:59:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC1FA292A5 for ; Sat, 16 Sep 2017 03:59:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751925AbdIPD7B (ORCPT ); Fri, 15 Sep 2017 23:59:01 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:37476 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348AbdIPD66 (ORCPT ); Fri, 15 Sep 2017 23:58:58 -0400 Received: by mail-pf0-f196.google.com with SMTP id e69so2068137pfg.4; Fri, 15 Sep 2017 20:58:58 -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=KYXU6Z1rehKcw0LU74adwCML4qq4/Y5wszCe6R2duPs=; b=n79MRlF2JtUgaE8k+s4aCoQUdpFfI/c1g79hYpWqgt00QG0zr4WLO80sOByJPmbwYN Krxcde6niBj9JtrNy5v9Gx8sqNMcQ3eNPDtUxb6yj97f7koH/jllcVEvQD7Df+YgOE30 3H+rz1U2jw5Eo5GI7lP8Tjt6AaOEkTktvtb/MohkEaBRGqwoVGbbs17DRqruD9iDa61f bKP7fD4wQD5t0gaoTQqyTFQsUMqRhIetaqsDfEmWHkW3yV0GdENhfQBXxKvDr9ni4i+7 OyY2N6lNQc5b1+r4KXZ1YTUMHhpFwWOhtg+fecuIR/K1DDTOUK+iWYcO9dwjpG0fS7IQ 5uGw== 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=KYXU6Z1rehKcw0LU74adwCML4qq4/Y5wszCe6R2duPs=; b=UN5aAqS/UuXfRIP6PfsQr+dwooux6911jbux2M8xOSPh8/aCyq/XLeC3Zpnr+Qxl+K oezpSTSF18+j6qgN04By1O/j8EMt57tJyO52vjswqaMQVsHmrUDRuaIq7ksiQBdorCJD cla27imP2skw7bQmjZn1hVG5ijgsphEd0Pn1zt6G16LPDakKmxr1zv9Ja85zA4OStLCX oDhqp21AUOaoIHnSaf3xBIzqRYi/Ioeo57cjwLmJD20uMlUmicrjJUiSrQTLIPlkVun5 OGfHQpO5D/57foxIUQ2jPXdoLpqWhzwSGdxOtCR1OJK2U7H1vmGsA397C2BX5qlmoa2g 57FA== X-Gm-Message-State: AHPjjUiGEysNBoOQ5pDrXekQabI/z/7YJMKFFy7ryBQ79VjdtzMZ6Q8E 4K1P6YtyTlUEXA== X-Google-Smtp-Source: AOwi7QB6S+1oUsVca4OFvW6fapm9NwjRHGXpnapfYqOTzsmAZ/kDoXq7rQV8BPu1IEwaieiW352AsQ== X-Received: by 10.159.194.201 with SMTP id u9mr9387881plz.142.1505534338124; Fri, 15 Sep 2017 20:58:58 -0700 (PDT) Received: from localhost.localdomain ([121.137.63.184]) by smtp.gmail.com with ESMTPSA id 76sm4448230pfp.158.2017.09.15.20.58.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Sep 2017 20:58:57 -0700 (PDT) From: Sergey Senozhatsky To: Tony Luck , Fenghua Yu , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "James E . J . Bottomley" , Helge Deller Cc: Petr Mladek , Steven Rostedt , Andrew Morton , Jessica Yu , Alexei Starovoitov , linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: [PATCH 3/5] powerpc64: Add .opd based function descriptor dereference Date: Sat, 16 Sep 2017 12:53:45 +0900 Message-Id: <20170916035347.19705-4-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170916035347.19705-1-sergey.senozhatsky@gmail.com> References: <20170916035347.19705-1-sergey.senozhatsky@gmail.com> Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 | 13 +++++++++++++ arch/powerpc/kernel/module_64.c | 16 ++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 2 ++ 4 files changed, 34 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 7902d6358854..7cc4db86952b 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -16,6 +16,9 @@ extern char __end_interrupts[]; extern char __prom_init_toc_start[]; extern char __prom_init_toc_end[]; +extern char __start_opd[]; +extern char __end_opd[]; + static inline int in_kernel_text(unsigned long addr) { if (addr >= (unsigned long)_stext && addr < (unsigned long)__init_end) @@ -66,6 +69,8 @@ static inline int overlaps_kvm_tmp(unsigned long start, unsigned long end) #ifdef PPC64_ELF_ABI_v1 #undef dereference_function_descriptor +#undef dereference_kernel_function_descriptor + static inline void *dereference_function_descriptor(void *ptr) { struct ppc64_opd_entry *desc = ptr; @@ -75,6 +80,14 @@ static inline void *dereference_function_descriptor(void *ptr) ptr = p; return ptr; } + +static inline void *dereference_kernel_function_descriptor(void *ptr) +{ + if (ptr < (void *)__start_opd || (void *)__end_opd < ptr) + return ptr; + + return dereference_function_descriptor(ptr); +} #endif /* PPC64_ELF_ABI_v1 */ #endif diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 0b0f89685b67..52aa5d668364 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")==0) { + me->arch.start_opd = sechdrs[i].sh_offset; + me->arch.end_opd = me->arch.start_opd + + 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 || mod->arch.end_opd < addr) + 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);