From 88173507e4fc1e7ecd111b0565e8cba0cb7dae6d Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 8 Feb 2008 04:18:41 -0800 Subject: [PATCH] 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. [akinobu.mita@gmail.com: fix __find_symbl() error checks] Cc: Mathieu Desnoyers Cc: Kay Sievers Cc: Rusty Russell Cc: Andi Kleen Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index bd60278ee703..dc04d4d88d02 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -290,7 +290,7 @@ static unsigned long __find_symbol(const char *name, } } DEBUGP("Failed to find symbol %s\n", name); - return 0; + return -ENOENT; } /* Search for module by name: must hold module_mutex. */ @@ -783,7 +783,7 @@ 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(); @@ -929,7 +929,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, 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); @@ -978,12 +979,12 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs, ret = __find_symbol(name, &owner, &crc, !(mod->taints & TAINT_PROPRIETARY_MODULE)); - if (ret) { + if (!IS_ERR_VALUE(ret)) { /* use_module can fail due to OOM, or module initialization or unloading */ if (!check_version(sechdrs, versindex, name, mod, crc) || !use_module(mod, owner)) - ret = 0; + ret = -EINVAL; } return ret; } @@ -1371,7 +1372,9 @@ void *__symbol_get(const char *symbol) preempt_disable(); value = __find_symbol(symbol, &owner, &crc, 1); - if (value && strong_try_module_get(owner) != 0) + if (IS_ERR_VALUE(value)) + value = 0; + else if (strong_try_module_get(owner)) value = 0; preempt_enable(); @@ -1391,14 +1394,16 @@ static int verify_export_symbols(struct module *mod) 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; @@ -1448,7 +1453,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs, 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) -- 2.20.1