From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757135AbXKTB2f (ORCPT ); Mon, 19 Nov 2007 20:28:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756342AbXKTBOZ (ORCPT ); Mon, 19 Nov 2007 20:14:25 -0500 Received: from relay1.sgi.com ([192.48.171.29]:49891 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756344AbXKTBNm (ORCPT ); Mon, 19 Nov 2007 20:13:42 -0500 Message-Id: <20071120011342.426906810@sgi.com> References: <20071120011132.143632442@sgi.com> User-Agent: quilt/0.46-1 Date: Mon, 19 Nov 2007 17:12:17 -0800 From: clameter@sgi.com From: Christoph Lameter To: ak@suse.de Cc: akpm@linux-foundation.org Cc: travis@sgi.com Cc: Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org Subject: [rfc 45/45] Modules: Hack to handle symbols that have a zero value Content-Disposition: inline; filename=weaky Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The module subsystem cannot handle symbols that are zero. It prints out a message that these symbols are unresolved. Define a constant UNRESOLVED that is used to hold the value used for unresolved symbols. Set it to 1 (its hopefully unlikely that a symbol will have the value 1). This is necessary so that the pda variable which is placed at offset 0 of the per cpu segment is handled correctly. Signed-off-by: Christoph Lameter --- kernel/module.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) Index: linux-2.6/kernel/module.c =================================================================== --- linux-2.6.orig/kernel/module.c 2007-11-19 17:08:40.563625526 -0800 +++ linux-2.6/kernel/module.c 2007-11-19 17:08:40.855625732 -0800 @@ -62,6 +62,7 @@ extern int module_sysfs_initialized; /* If this is set, the section belongs in the init part of the module */ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) +#define UNRESOLVED 1 /* List of modules, protected by module_mutex or preempt_disable * (add/delete uses stop_machine). */ static DEFINE_MUTEX(module_mutex); @@ -285,7 +286,7 @@ static unsigned long __find_symbol(const } } DEBUGP("Failed to find symbol %s\n", name); - return 0; + return UNRESOLVED; } /* Search for module by name: must hold module_mutex. */ @@ -755,7 +756,7 @@ void __symbol_put(const char *symbol) const unsigned long *crc; preempt_disable(); - if (!__find_symbol(symbol, &owner, &crc, 1)) + if (__find_symbol(symbol, &owner, &crc, 1) == UNRESOLVED) BUG(); module_put(owner); preempt_enable(); @@ -899,7 +900,7 @@ static inline int check_modstruct_versio const unsigned long *crc; struct module *owner; - if (!__find_symbol("struct_module", &owner, &crc, 1)) + if (__find_symbol("struct_module", &owner, &crc, 1) == UNRESOLVED) BUG(); return check_version(sechdrs, versindex, "struct_module", mod, crc); @@ -952,7 +953,7 @@ 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 = UNRESOLVED; } return ret; } @@ -1345,14 +1346,14 @@ 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 (__find_symbol(mod->syms[i].name, &owner, &crc, 1) != UNRESOLVED) { 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 (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)!= UNRESOLVED) { name = mod->gpl_syms[i].name; ret = -ENOEXEC; goto dup; @@ -1402,7 +1403,7 @@ static int simplify_symbols(Elf_Shdr *se strtab + sym[i].st_name, mod); /* Ok if resolved. */ - if (sym[i].st_value != 0) + if (sym[i].st_value != UNRESOLVED) break; /* Ok if weak. */ if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK) --