From 0b96615cdc091bcef9a48daa455b93631f196dea Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Jan 2021 14:58:27 +0100 Subject: [PATCH] module: pass struct find_symbol_args to find_symbol Simplify the calling convention by passing the find_symbol_args structure to find_symbol instead of initializing it inside the function. Reviewed-by: Miroslav Benes Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu --- kernel/module.c | 113 ++++++++++++++++++++++-------------------------- 1 file changed, 52 insertions(+), 61 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 05e32ecbfc16..2e7ddf544338 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -531,12 +531,7 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms, * Find an exported symbol and return it, along with, (optional) crc and * (optional) module which owns it. Needs preempt disabled or module_mutex. */ -static const struct kernel_symbol *find_symbol(const char *name, - struct module **owner, - const s32 **crc, - enum mod_license *license, - bool gplok, - bool warn) +static bool find_symbol(struct find_symbol_arg *fsa) { static const struct symsearch arr[] = { { __start___ksymtab, __stop___ksymtab, __start___kcrctab, @@ -556,19 +551,14 @@ static const struct kernel_symbol *find_symbol(const char *name, GPL_ONLY, true }, #endif }; - struct find_symbol_arg fsa = { - .name = name, - .gplok = gplok, - .warn = warn, - }; struct module *mod; unsigned int i; module_assert_mutex_or_preempt(); for (i = 0; i < ARRAY_SIZE(arr); i++) - if (find_exported_symbol_in_section(&arr[i], NULL, &fsa)) - goto found; + if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) + return true; list_for_each_entry_rcu(mod, &modules, list, lockdep_is_held(&module_mutex)) { @@ -598,21 +588,12 @@ static const struct kernel_symbol *find_symbol(const char *name, continue; for (i = 0; i < ARRAY_SIZE(arr); i++) - if (find_exported_symbol_in_section(&arr[i], mod, &fsa)) - goto found; + if (find_exported_symbol_in_section(&arr[i], mod, fsa)) + return true; } - pr_debug("Failed to find symbol %s\n", name); - return NULL; - -found: - if (owner) - *owner = fsa.owner; - if (crc) - *crc = fsa.crc; - if (license) - *license = fsa.license; - return fsa.sym; + pr_debug("Failed to find symbol %s\n", fsa->name); + return false; } /* @@ -1074,12 +1055,15 @@ static inline void print_unload_info(struct seq_file *m, struct module *mod) void __symbol_put(const char *symbol) { - struct module *owner; + struct find_symbol_arg fsa = { + .name = symbol, + .gplok = true, + }; preempt_disable(); - if (!find_symbol(symbol, &owner, NULL, NULL, true, false)) + if (!find_symbol(&fsa)) BUG(); - module_put(owner); + module_put(fsa.owner); preempt_enable(); } EXPORT_SYMBOL(__symbol_put); @@ -1348,19 +1332,22 @@ static int check_version(const struct load_info *info, static inline int check_modstruct_version(const struct load_info *info, struct module *mod) { - const s32 *crc; + struct find_symbol_arg fsa = { + .name = "module_layout", + .gplok = true, + }; /* * Since this should be found in kernel (which can't be removed), no * locking is necessary -- use preempt_disable() to placate lockdep. */ preempt_disable(); - if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) { + if (!find_symbol(&fsa)) { preempt_enable(); BUG(); } preempt_enable(); - return check_version(info, "module_layout", mod, crc); + return check_version(info, "module_layout", mod, fsa.crc); } /* First part is kernel version, which we ignore if module has crcs. */ @@ -1454,10 +1441,11 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, const char *name, char ownername[]) { - struct module *owner; - const struct kernel_symbol *sym; - const s32 *crc; - enum mod_license license; + struct find_symbol_arg fsa = { + .name = name, + .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), + .warn = true, + }; int err; /* @@ -1467,42 +1455,40 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, */ sched_annotate_sleep(); mutex_lock(&module_mutex); - sym = find_symbol(name, &owner, &crc, &license, - !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); - if (!sym) + if (!find_symbol(&fsa)) goto unlock; - if (license == GPL_ONLY) + if (fsa.license == GPL_ONLY) mod->using_gplonly_symbols = true; - if (!inherit_taint(mod, owner)) { - sym = NULL; + if (!inherit_taint(mod, fsa.owner)) { + fsa.sym = NULL; goto getname; } - if (!check_version(info, name, mod, crc)) { - sym = ERR_PTR(-EINVAL); + if (!check_version(info, name, mod, fsa.crc)) { + fsa.sym = ERR_PTR(-EINVAL); goto getname; } - err = verify_namespace_is_imported(info, sym, mod); + err = verify_namespace_is_imported(info, fsa.sym, mod); if (err) { - sym = ERR_PTR(err); + fsa.sym = ERR_PTR(err); goto getname; } - err = ref_module(mod, owner); + err = ref_module(mod, fsa.owner); if (err) { - sym = ERR_PTR(err); + fsa.sym = ERR_PTR(err); goto getname; } getname: /* We must make copy under the lock if we failed to get ref. */ - strncpy(ownername, module_name(owner), MODULE_NAME_LEN); + strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); unlock: mutex_unlock(&module_mutex); - return sym; + return fsa.sym; } static const struct kernel_symbol * @@ -2263,16 +2249,19 @@ static void free_module(struct module *mod) void *__symbol_get(const char *symbol) { - struct module *owner; - const struct kernel_symbol *sym; + struct find_symbol_arg fsa = { + .name = symbol, + .gplok = true, + .warn = true, + }; preempt_disable(); - sym = find_symbol(symbol, &owner, NULL, NULL, true, true); - if (sym && strong_try_module_get(owner)) - sym = NULL; + if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) { + preempt_enable(); + return NULL; + } preempt_enable(); - - return sym ? (void *)kernel_symbol_value(sym) : NULL; + return (void *)kernel_symbol_value(fsa.sym); } EXPORT_SYMBOL_GPL(__symbol_get); @@ -2285,7 +2274,6 @@ EXPORT_SYMBOL_GPL(__symbol_get); static int verify_exported_symbols(struct module *mod) { unsigned int i; - struct module *owner; const struct kernel_symbol *s; struct { const struct kernel_symbol *sym; @@ -2302,12 +2290,15 @@ static int verify_exported_symbols(struct module *mod) for (i = 0; i < ARRAY_SIZE(arr); i++) { for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { - if (find_symbol(kernel_symbol_name(s), &owner, NULL, - NULL, true, false)) { + struct find_symbol_arg fsa = { + .name = kernel_symbol_name(s), + .gplok = true, + }; + if (find_symbol(&fsa)) { pr_err("%s: exports duplicate symbol %s" " (owned by %s)\n", mod->name, kernel_symbol_name(s), - module_name(owner)); + module_name(fsa.owner)); return -ENOEXEC; } }