Messages in this thread Patch in this message | | | Date | Wed, 21 Nov 2007 13:02:09 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: Modules: Handle symbols that have a zero value |
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On Wed, 21 Nov 2007, Mathieu Desnoyers wrote:
> return -ENOENT; > > directly ? > > (ERR_PTR() in linux/err.h is a simple cast from long to void*).
Right and there is also IS_ERR_VALUE. Thanks for the feedback. New version:
Modules: Handle symbols that have a zero value
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.
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Kay Sievers <kay.sievers@vrfy.org Signed-off-by: Christoph Lameter <clameter@sgi.com>
--- 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 2007-11-21 12:58:33.095608448 -0800 +++ linux-2.6/kernel/module.c 2007-11-21 13:00:30.199108674 -0800 @@ -285,7 +285,7 @@ static unsigned long __find_symbol(const } } DEBUGP("Failed to find symbol %s\n", name); - return 0; + return -ENOENT; } /* Search for module by name: must hold module_mutex. */ @@ -756,7 +756,7 @@ void __symbol_put(const char *symbol) const unsigned long *crc; preempt_disable(); - if (!__find_symbol(symbol, &owner, &crc, 1)) + if (IS_ERR_VALUE(__find_symbol(symbol, &owner, &crc, 1))) BUG(); module_put(owner); preempt_enable(); @@ -902,7 +902,8 @@ static inline int check_modstruct_versio const unsigned long *crc; struct module *owner; - if (!__find_symbol("struct_module", &owner, &crc, 1)) + if (IS_ERR_VALUE(__find_symbol("struct_module", + &owner, &crc, 1))) BUG(); return check_version(sechdrs, versindex, "struct_module", mod, crc); @@ -955,7 +956,7 @@ 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 = -EINVAL; } return ret; } @@ -1348,14 +1349,16 @@ 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_VALUE(__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_VALUE(__find_symbol(mod->gpl_syms[i].name, + &owner, &crc, 1))) { name = mod->gpl_syms[i].name; ret = -ENOEXEC; goto dup; @@ -1405,7 +1408,7 @@ 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_VALUE(sym[i].st_value)) break; /* Ok if weak. */ if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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