From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757169AbXKUF5L (ORCPT ); Wed, 21 Nov 2007 00:57:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753936AbXKUF4w (ORCPT ); Wed, 21 Nov 2007 00:56:52 -0500 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:35800 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752579AbXKUF4v (ORCPT ); Wed, 21 Nov 2007 00:56:51 -0500 Date: Tue, 20 Nov 2007 21:56:47 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: akpm@linux-foundation.org cc: linux-kernel@vger.kernel.org, Kay Sievers , Mathieu Desnoyers Subject: Modules: Handle symbols that have a zero value Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Another issue that I encountered with the cpu_alloc stuff. The module subsystem cannot handle symbols that are zero. If symbols are present that have a zero value then the module resolver prints out a message that these symbols are unresolved. Use ERR_PTR to return an error code instead of 0. This is a bit awkward since the addresses are handled as unsigned longs. So we need to convert them everywhere. The idea top use ERR_PTR is from Mathieu. Cc: Mathieu Desnoyers Cc: Kay Sievers Signed-off-by: Christoph Lameter --- kernel/module.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) Index: linux-2.6/kernel/module.c =================================================================== --- linux-2.6.orig/kernel/module.c 2007-11-20 21:06:29.856965949 -0800 +++ linux-2.6/kernel/module.c 2007-11-20 21:16:53.001715887 -0800 @@ -285,7 +285,7 @@ static unsigned long __find_symbol(const } } DEBUGP("Failed to find symbol %s\n", name); - return 0; + return (unsigned long)ERR_PTR(-ENOENT); } /* Search for module by name: must hold module_mutex. */ @@ -648,7 +648,7 @@ void __symbol_put(const char *symbol) const unsigned long *crc; preempt_disable(); - if (!__find_symbol(symbol, &owner, &crc, 1)) + if (IS_ERR((void *)__find_symbol(symbol, &owner, &crc, 1))) BUG(); module_put(owner); preempt_enable(); @@ -792,7 +792,8 @@ static inline int check_modstruct_versio const unsigned long *crc; struct module *owner; - if (!__find_symbol("struct_module", &owner, &crc, 1)) + if (IS_ERR((void *)__find_symbol("struct_module", + &owner, &crc, 1))) BUG(); return check_version(sechdrs, versindex, "struct_module", mod, crc); @@ -845,7 +846,7 @@ static unsigned long resolve_symbol(Elf_ /* use_module can fail due to OOM, or module unloading */ if (!check_version(sechdrs, versindex, name, mod, crc) || !use_module(mod, owner)) - ret = 0; + ret = (unsigned long)ERR_PTR(-EINVAL); } return ret; } @@ -1238,14 +1239,16 @@ static int verify_export_symbols(struct const unsigned long *crc; for (i = 0; i < mod->num_syms; i++) - if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) { + if (!IS_ERR((void *)__find_symbol(mod->syms[i].name, + &owner, &crc, 1))) { name = mod->syms[i].name; ret = -ENOEXEC; goto dup; } for (i = 0; i < mod->num_gpl_syms; i++) - if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) { + if (!IS_ERR((void *)__find_symbol(mod->gpl_syms[i].name, + &owner, &crc, 1))) { name = mod->gpl_syms[i].name; ret = -ENOEXEC; goto dup; @@ -1295,7 +1298,7 @@ static int simplify_symbols(Elf_Shdr *se strtab + sym[i].st_name, mod); /* Ok if resolved. */ - if (sym[i].st_value != 0) + if (!IS_ERR((void *)sym[i].st_value)) break; /* Ok if weak. */ if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)