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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-31 11:42:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-31 11:42:13 -0800
commitddaefe8947b48b638f726cf89730ecc1000ebcc3 (patch)
treebb05a5fce7b944a25f63432be3c33d52e3b3cd02
parentc5951e7c8ee5cb04b8b41c32bf567b90117a2124 (diff)
parent6080d608eeff7cb5090a2ddbaf723bfb0ff133fc (diff)
Merge tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu: "Summary of modules changes for the 5.6 merge window: - Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings to indicate to the linker that it can perform string deduplication (i.e., duplicate strings are reduced to a single copy in the string table). This means any repeated namespace string would be merged to just one entry in __ksymtab_strings. - Various code cleanups and small fixes (fix small memleak in error path, improve moduleparam docs, silence rcu warnings, improve error logging)" * tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module.h: Annotate mod_kallsyms with __rcu module: avoid setting info->name early in case we can fall back to info->mod->name modsign: print module name along with error message kernel/module: Fix memleak in module_add_modinfo_attrs() export.h: reduce __ksymtab_strings string duplication by using "MS" section flags moduleparam: fix kerneldoc modules: lockdep: Suppress suspicious RCU usage warning
-rw-r--r--include/asm-generic/export.h8
-rw-r--r--include/linux/export.h33
-rw-r--r--include/linux/module.h2
-rw-r--r--include/linux/moduleparam.h82
-rw-r--r--kernel/module.c22
5 files changed, 119 insertions, 28 deletions
diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
index afddc5442e92..365345f9a9e3 100644
--- a/include/asm-generic/export.h
+++ b/include/asm-generic/export.h
@@ -27,9 +27,11 @@
.endm
/*
- * note on .section use: @progbits vs %progbits nastiness doesn't matter,
- * since we immediately emit into those sections anyway.
+ * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
+ * section flag requires it. Use '%progbits' instead of '@progbits' since the
+ * former apparently works on all arches according to the binutils source.
*/
+
.macro ___EXPORT_SYMBOL name,val,sec
#ifdef CONFIG_MODULES
.section ___ksymtab\sec+\name,"a"
@@ -37,7 +39,7 @@
__ksymtab_\name:
__put \val, __kstrtab_\name
.previous
- .section __ksymtab_strings,"a"
+ .section __ksymtab_strings,"aMS",%progbits,1
__kstrtab_\name:
.asciz "\name"
.previous
diff --git a/include/linux/export.h b/include/linux/export.h
index 627841448293..fceb5e855717 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -82,16 +82,29 @@ struct kernel_symbol {
#else
-/* For every exported symbol, place a struct in the __ksymtab section */
-#define ___EXPORT_SYMBOL(sym, sec, ns) \
- extern typeof(sym) sym; \
- __CRC_SYMBOL(sym, sec); \
- static const char __kstrtab_##sym[] \
- __attribute__((section("__ksymtab_strings"), used, aligned(1))) \
- = #sym; \
- static const char __kstrtabns_##sym[] \
- __attribute__((section("__ksymtab_strings"), used, aligned(1))) \
- = ns; \
+/*
+ * For every exported symbol, do the following:
+ *
+ * - If applicable, place a CRC entry in the __kcrctab section.
+ * - Put the name of the symbol and namespace (empty string "" for none) in
+ * __ksymtab_strings.
+ * - Place a struct kernel_symbol entry in the __ksymtab section.
+ *
+ * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
+ * section flag requires it. Use '%progbits' instead of '@progbits' since the
+ * former apparently works on all arches according to the binutils source.
+ */
+#define ___EXPORT_SYMBOL(sym, sec, ns) \
+ extern typeof(sym) sym; \
+ extern const char __kstrtab_##sym[]; \
+ extern const char __kstrtabns_##sym[]; \
+ __CRC_SYMBOL(sym, sec); \
+ asm(" .section \"__ksymtab_strings\",\"aMS\",%progbits,1 \n" \
+ "__kstrtab_" #sym ": \n" \
+ " .asciz \"" #sym "\" \n" \
+ "__kstrtabns_" #sym ": \n" \
+ " .asciz \"" ns "\" \n" \
+ " .previous \n"); \
__KSYMTAB_ENTRY(sym, sec)
#endif
diff --git a/include/linux/module.h b/include/linux/module.h
index 0c7366c317bd..edc63e6ff531 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -429,7 +429,7 @@ struct module {
#ifdef CONFIG_KALLSYMS
/* Protected by RCU and/or module_mutex: use rcu_dereference() */
- struct mod_kallsyms *kallsyms;
+ struct mod_kallsyms __rcu *kallsyms;
struct mod_kallsyms core_kallsyms;
/* Section attributes */
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index e5c3e23919b8..3ef917ff0964 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -128,6 +128,9 @@ struct kparam_array
/**
* module_param_unsafe - same as module_param but taints kernel
+ * @name: the variable to alter, and exposed parameter name.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
*/
#define module_param_unsafe(name, type, perm) \
module_param_named_unsafe(name, name, type, perm)
@@ -150,6 +153,10 @@ struct kparam_array
/**
* module_param_named_unsafe - same as module_param_named but taints kernel
+ * @name: a valid C identifier which is the parameter name.
+ * @value: the actual lvalue to alter.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
*/
#define module_param_named_unsafe(name, value, type, perm) \
param_check_##type(name, &(value)); \
@@ -160,6 +167,7 @@ struct kparam_array
* module_param_cb - general callback for a module/cmdline parameter
* @name: a valid C identifier which is the parameter name.
* @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
* @perm: visibility in sysfs.
*
* The ops can have NULL set or get functions.
@@ -171,36 +179,96 @@ struct kparam_array
__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
KERNEL_PARAM_FL_UNSAFE)
+#define __level_param_cb(name, ops, arg, perm, level) \
+ __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
/**
- * <level>_param_cb - general callback for a module/cmdline parameter
- * to be evaluated before certain initcall level
+ * core_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before core initcall level
* @name: a valid C identifier which is the parameter name.
* @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
* @perm: visibility in sysfs.
*
* The ops can have NULL set or get functions.
*/
-#define __level_param_cb(name, ops, arg, perm, level) \
- __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
-
#define core_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 1)
+/**
+ * postcore_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before postcore initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
#define postcore_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 2)
+/**
+ * arch_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before arch initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
#define arch_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 3)
+/**
+ * subsys_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before subsys initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
#define subsys_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 4)
+/**
+ * fs_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before fs initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
#define fs_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 5)
+/**
+ * device_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before device initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
#define device_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 6)
+/**
+ * late_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before late initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @arg: args for @ops
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
#define late_param_cb(name, ops, arg, perm) \
__level_param_cb(name, ops, arg, perm, 7)
@@ -263,6 +331,10 @@ static inline void kernel_param_unlock(struct module *mod)
/**
* core_param_unsafe - same as core_param but taints kernel
+ * @name: the name of the cmdline and sysfs parameter (often the same as var)
+ * @var: the variable
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs
*/
#define core_param_unsafe(name, var, type, perm) \
param_check_##type(name, &(var)); \
diff --git a/kernel/module.c b/kernel/module.c
index ac058a5ad1d1..90ec5ab60255 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -214,7 +214,8 @@ static struct module *mod_find(unsigned long addr)
{
struct module *mod;
- list_for_each_entry_rcu(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list,
+ lockdep_is_held(&module_mutex)) {
if (within_module(addr, mod))
return mod;
}
@@ -448,7 +449,8 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
return true;
- list_for_each_entry_rcu(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list,
+ lockdep_is_held(&module_mutex)) {
struct symsearch arr[] = {
{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
NOT_GPL_ONLY, false },
@@ -616,7 +618,8 @@ static struct module *find_module_all(const char *name, size_t len,
module_assert_mutex_or_preempt();
- list_for_each_entry_rcu(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list,
+ lockdep_is_held(&module_mutex)) {
if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
continue;
if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
@@ -1781,6 +1784,8 @@ static int module_add_modinfo_attrs(struct module *mod)
error_out:
if (i > 0)
module_remove_modinfo_attrs(mod, --i);
+ else
+ kfree(mod->modinfo_attrs);
return error;
}
@@ -2834,7 +2839,7 @@ static int module_sig_check(struct load_info *info, int flags)
reason = "Loading of module with unavailable key";
decide:
if (is_module_sig_enforced()) {
- pr_notice("%s is rejected\n", reason);
+ pr_notice("%s: %s is rejected\n", info->name, reason);
return -EKEYREJECTED;
}
@@ -3011,9 +3016,7 @@ static int setup_load_info(struct load_info *info, int flags)
/* Try to find a name early so we can log errors with a module name */
info->index.info = find_sec(info, ".modinfo");
- if (!info->index.info)
- info->name = "(missing .modinfo section)";
- else
+ if (info->index.info)
info->name = get_modinfo(info, "name");
/* Find internal symbols and strings. */
@@ -3028,14 +3031,15 @@ static int setup_load_info(struct load_info *info, int flags)
}
if (info->index.sym == 0) {
- pr_warn("%s: module has no symbols (stripped?)\n", info->name);
+ pr_warn("%s: module has no symbols (stripped?)\n",
+ info->name ?: "(missing .modinfo section or name field)");
return -ENOEXEC;
}
info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
if (!info->index.mod) {
pr_warn("%s: No module found in object\n",
- info->name ?: "(missing .modinfo name field)");
+ info->name ?: "(missing .modinfo section or name field)");
return -ENOEXEC;
}
/* This is temporary: point mod into copy of data. */