From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 28 Nov 2002 01:50:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 28 Nov 2002 01:50:53 -0500 Received: from dp.samba.org ([66.70.73.150]:11460 "EHLO lists.samba.org") by vger.kernel.org with ESMTP id ; Thu, 28 Nov 2002 01:50:52 -0500 From: Rusty Russell To: Ricky Beam Cc: torvalds@transmeta.com, linux-kernel@vger.kernel.org Subject: [PATCH] Kallsyms in modules fix Date: Thu, 28 Nov 2002 17:57:25 +1100 Message-Id: <20021128065813.93AFD2C050@lists.samba.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Previous version was referencing freed memory, and usually got symbol sizes wrong. Linus, please apply. Thanks to Ricky Beam for the excellent bug report, Rusty. -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. Name: Kallsyms inside module fix Author: Rusty Russell Status: Tested on 2.5.50 D: Two fixes. Firstly, set ALLOC on the right section so we actually D: keep the symbol names and don't deref a freed section, and secondly D: get the symbol size (more) correct. diff -urNp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.50/kernel/module.c working-2.5.50-ksymoops/kernel/module.c --- linux-2.5.50/kernel/module.c Mon Nov 25 08:44:19 2002 +++ working-2.5.50-ksymoops/kernel/module.c Thu Nov 28 16:22:56 2002 @@ -892,7 +892,7 @@ static struct module *load_module(void * } #ifdef CONFIG_KALLSYMS /* symbol and string tables for decoding later. */ - if (sechdrs[i].sh_type == SHT_SYMTAB || i == hdr->e_shstrndx) + if (sechdrs[i].sh_type == SHT_SYMTAB || i == strindex) sechdrs[i].sh_flags |= SHF_ALLOC; #endif #ifndef CONFIG_MODULE_UNLOAD @@ -1165,7 +1165,14 @@ static const char *get_ksymbol(struct mo unsigned long *size, unsigned long *offset) { - unsigned int i, next = 0, best = 0; + unsigned int i, best = 0; + unsigned long nextval; + + /* At worse, next value is at end of module */ + if (inside_core(mod, addr)) + nextval = (unsigned long)mod->module_core+mod->core_size; + else + nextval = (unsigned long)mod->module_init+mod->init_size; /* Scan for closest preceeding symbol, and next symbol. (ELF starts real symbols at 1). */ @@ -1177,22 +1186,14 @@ static const char *get_ksymbol(struct mo && mod->symtab[i].st_value > mod->symtab[best].st_value) best = i; if (mod->symtab[i].st_value > addr - && mod->symtab[i].st_value < mod->symtab[next].st_value) - next = i; + && mod->symtab[i].st_value < nextval) + nextval = mod->symtab[i].st_value; } if (!best) return NULL; - if (!next) { - /* Last symbol? It ends at the end of the module then. */ - if (inside_core(mod, addr)) - *size = mod->module_core+mod->core_size - (void*)addr; - else - *size = mod->module_init+mod->init_size - (void*)addr; - } else - *size = mod->symtab[next].st_value - addr; - + *size = nextval - mod->symtab[best].st_value; *offset = addr - mod->symtab[best].st_value; return mod->strtab + mod->symtab[best].st_name; }