| Message ID | 20220222141303.1392190-12-atomlin@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | module: core code clean up | expand |
Le 22/02/2022 à 15:13, Aaron Tomlin a écrit : > No functional change. > > This patch migrates module sysfs support out of core code into > kernel/module/sysfs.c. In addition simple code refactoring to > make this possible. > > Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > kernel/module/Makefile | 1 + > kernel/module/internal.h | 21 ++ > kernel/module/main.c | 469 +-------------------------------------- > kernel/module/sysfs.c | 436 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 461 insertions(+), 466 deletions(-) > create mode 100644 kernel/module/sysfs.c > > diff --git a/kernel/module/Makefile b/kernel/module/Makefile > index 94296c98a67f..cf8dcdc6b55f 100644 > --- a/kernel/module/Makefile > +++ b/kernel/module/Makefile > @@ -16,3 +16,4 @@ obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o > obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o > obj-$(CONFIG_KALLSYMS) += kallsyms.o > obj-$(CONFIG_PROC_FS) += procfs.o > +obj-$(CONFIG_SYSFS) += sysfs.o > diff --git a/kernel/module/internal.h b/kernel/module/internal.h > index 6af40c2d145f..62d749ef695e 100644 > --- a/kernel/module/internal.h > +++ b/kernel/module/internal.h > @@ -34,6 +34,9 @@ > extern struct mutex module_mutex; > extern struct list_head modules; > > +extern struct module_attribute *modinfo_attrs[]; > +extern size_t modinfo_attrs_count; > + > /* Provided by the linker */ > extern const struct kernel_symbol __start___ksymtab[]; > extern const struct kernel_symbol __stop___ksymtab[]; > @@ -204,3 +207,21 @@ static inline void init_build_id(struct module *mod, const struct load_info *inf > static inline void layout_symtab(struct module *mod, struct load_info *info) { } > static inline void add_kallsyms(struct module *mod, const struct load_info *info) { } > #endif /* CONFIG_KALLSYMS */ > + > +#ifdef CONFIG_SYSFS > +int mod_sysfs_setup(struct module *mod, const struct load_info *info, > + struct kernel_param *kparam, unsigned int num_params); > +void mod_sysfs_teardown(struct module *mod); > +void init_param_lock(struct module *mod); > +#else /* !CONFIG_SYSFS */ > +static inline int mod_sysfs_setup(struct module *mod, > + const struct load_info *info, > + struct kernel_param *kparam, > + unsigned int num_params) > +{ > + return 0; > +} > + > +static inline void mod_sysfs_teardown(struct module *mod) { } > +static inline void init_param_lock(struct module *mod) { } > +#endif /* CONFIG_SYSFS */ > diff --git a/kernel/module/main.c b/kernel/module/main.c > index 44b6fd1acc44..b8a59b5c3e3a 100644 > --- a/kernel/module/main.c > +++ b/kernel/module/main.c > @@ -14,9 +14,7 @@ > #include <linux/init.h> > #include <linux/kallsyms.h> > #include <linux/buildid.h> > -#include <linux/file.h> > #include <linux/fs.h> > -#include <linux/sysfs.h> > #include <linux/kernel.h> > #include <linux/kernel_read_file.h> > #include <linux/slab.h> > @@ -989,7 +987,7 @@ static ssize_t show_taint(struct module_attribute *mattr, > static struct module_attribute modinfo_taint = > __ATTR(taint, 0444, show_taint, NULL); > > -static struct module_attribute *modinfo_attrs[] = { > +struct module_attribute *modinfo_attrs[] = { > &module_uevent, > &modinfo_version, > &modinfo_srcversion, > @@ -1003,6 +1001,8 @@ static struct module_attribute *modinfo_attrs[] = { > NULL, > }; > > +size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs); > + > static const char vermagic[] = VERMAGIC_STRING; > > static int try_to_force_load(struct module *mod, const char *reason) > @@ -1253,469 +1253,6 @@ resolve_symbol_wait(struct module *mod, > return ksym; > } > > -/* > - * /sys/module/foo/sections stuff > - * J. Corbet <corbet@lwn.net> > - */ > -#ifdef CONFIG_SYSFS > - > -#ifdef CONFIG_KALLSYMS > -struct module_sect_attr { > - struct bin_attribute battr; > - unsigned long address; > -}; > - > -struct module_sect_attrs { > - struct attribute_group grp; > - unsigned int nsections; > - struct module_sect_attr attrs[]; > -}; > - > -#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) > -static ssize_t module_sect_read(struct file *file, struct kobject *kobj, > - struct bin_attribute *battr, > - char *buf, loff_t pos, size_t count) > -{ > - struct module_sect_attr *sattr = > - container_of(battr, struct module_sect_attr, battr); > - char bounce[MODULE_SECT_READ_SIZE + 1]; > - size_t wrote; > - > - if (pos != 0) > - return -EINVAL; > - > - /* > - * Since we're a binary read handler, we must account for the > - * trailing NUL byte that sprintf will write: if "buf" is > - * too small to hold the NUL, or the NUL is exactly the last > - * byte, the read will look like it got truncated by one byte. > - * Since there is no way to ask sprintf nicely to not write > - * the NUL, we have to use a bounce buffer. > - */ > - wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", > - kallsyms_show_value(file->f_cred) > - ? (void *)sattr->address : NULL); > - count = min(count, wrote); > - memcpy(buf, bounce, count); > - > - return count; > -} > - > -static void free_sect_attrs(struct module_sect_attrs *sect_attrs) > -{ > - unsigned int section; > - > - for (section = 0; section < sect_attrs->nsections; section++) > - kfree(sect_attrs->attrs[section].battr.attr.name); > - kfree(sect_attrs); > -} > - > -static void add_sect_attrs(struct module *mod, const struct load_info *info) > -{ > - unsigned int nloaded = 0, i, size[2]; > - struct module_sect_attrs *sect_attrs; > - struct module_sect_attr *sattr; > - struct bin_attribute **gattr; > - > - /* Count loaded sections and allocate structures */ > - for (i = 0; i < info->hdr->e_shnum; i++) > - if (!sect_empty(&info->sechdrs[i])) > - nloaded++; > - size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), > - sizeof(sect_attrs->grp.bin_attrs[0])); > - size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); > - sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); > - if (sect_attrs == NULL) > - return; > - > - /* Setup section attributes. */ > - sect_attrs->grp.name = "sections"; > - sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; > - > - sect_attrs->nsections = 0; > - sattr = §_attrs->attrs[0]; > - gattr = §_attrs->grp.bin_attrs[0]; > - for (i = 0; i < info->hdr->e_shnum; i++) { > - Elf_Shdr *sec = &info->sechdrs[i]; > - if (sect_empty(sec)) > - continue; > - sysfs_bin_attr_init(&sattr->battr); > - sattr->address = sec->sh_addr; > - sattr->battr.attr.name = > - kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); > - if (sattr->battr.attr.name == NULL) > - goto out; > - sect_attrs->nsections++; > - sattr->battr.read = module_sect_read; > - sattr->battr.size = MODULE_SECT_READ_SIZE; > - sattr->battr.attr.mode = 0400; > - *(gattr++) = &(sattr++)->battr; > - } > - *gattr = NULL; > - > - if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) > - goto out; > - > - mod->sect_attrs = sect_attrs; > - return; > - out: > - free_sect_attrs(sect_attrs); > -} > - > -static void remove_sect_attrs(struct module *mod) > -{ > - if (mod->sect_attrs) { > - sysfs_remove_group(&mod->mkobj.kobj, > - &mod->sect_attrs->grp); > - /* > - * We are positive that no one is using any sect attrs > - * at this point. Deallocate immediately. > - */ > - free_sect_attrs(mod->sect_attrs); > - mod->sect_attrs = NULL; > - } > -} > - > -/* > - * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. > - */ > - > -struct module_notes_attrs { > - struct kobject *dir; > - unsigned int notes; > - struct bin_attribute attrs[]; > -}; > - > -static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, > - struct bin_attribute *bin_attr, > - char *buf, loff_t pos, size_t count) > -{ > - /* > - * The caller checked the pos and count against our size. > - */ > - memcpy(buf, bin_attr->private + pos, count); > - return count; > -} > - > -static void free_notes_attrs(struct module_notes_attrs *notes_attrs, > - unsigned int i) > -{ > - if (notes_attrs->dir) { > - while (i-- > 0) > - sysfs_remove_bin_file(notes_attrs->dir, > - ¬es_attrs->attrs[i]); > - kobject_put(notes_attrs->dir); > - } > - kfree(notes_attrs); > -} > - > -static void add_notes_attrs(struct module *mod, const struct load_info *info) > -{ > - unsigned int notes, loaded, i; > - struct module_notes_attrs *notes_attrs; > - struct bin_attribute *nattr; > - > - /* failed to create section attributes, so can't create notes */ > - if (!mod->sect_attrs) > - return; > - > - /* Count notes sections and allocate structures. */ > - notes = 0; > - for (i = 0; i < info->hdr->e_shnum; i++) > - if (!sect_empty(&info->sechdrs[i]) && > - (info->sechdrs[i].sh_type == SHT_NOTE)) > - ++notes; > - > - if (notes == 0) > - return; > - > - notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), > - GFP_KERNEL); > - if (notes_attrs == NULL) > - return; > - > - notes_attrs->notes = notes; > - nattr = ¬es_attrs->attrs[0]; > - for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { > - if (sect_empty(&info->sechdrs[i])) > - continue; > - if (info->sechdrs[i].sh_type == SHT_NOTE) { > - sysfs_bin_attr_init(nattr); > - nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; > - nattr->attr.mode = S_IRUGO; > - nattr->size = info->sechdrs[i].sh_size; > - nattr->private = (void *) info->sechdrs[i].sh_addr; > - nattr->read = module_notes_read; > - ++nattr; > - } > - ++loaded; > - } > - > - notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); > - if (!notes_attrs->dir) > - goto out; > - > - for (i = 0; i < notes; ++i) > - if (sysfs_create_bin_file(notes_attrs->dir, > - ¬es_attrs->attrs[i])) > - goto out; > - > - mod->notes_attrs = notes_attrs; > - return; > - > - out: > - free_notes_attrs(notes_attrs, i); > -} > - > -static void remove_notes_attrs(struct module *mod) > -{ > - if (mod->notes_attrs) > - free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); > -} > - > -#else > - > -static inline void add_sect_attrs(struct module *mod, > - const struct load_info *info) > -{ > -} > - > -static inline void remove_sect_attrs(struct module *mod) > -{ > -} > - > -static inline void add_notes_attrs(struct module *mod, > - const struct load_info *info) > -{ > -} > - > -static inline void remove_notes_attrs(struct module *mod) > -{ > -} > -#endif /* CONFIG_KALLSYMS */ > - > -static void del_usage_links(struct module *mod) > -{ > -#ifdef CONFIG_MODULE_UNLOAD > - struct module_use *use; > - > - mutex_lock(&module_mutex); > - list_for_each_entry(use, &mod->target_list, target_list) > - sysfs_remove_link(use->target->holders_dir, mod->name); > - mutex_unlock(&module_mutex); > -#endif > -} > - > -static int add_usage_links(struct module *mod) > -{ > - int ret = 0; > -#ifdef CONFIG_MODULE_UNLOAD > - struct module_use *use; > - > - mutex_lock(&module_mutex); > - list_for_each_entry(use, &mod->target_list, target_list) { > - ret = sysfs_create_link(use->target->holders_dir, > - &mod->mkobj.kobj, mod->name); > - if (ret) > - break; > - } > - mutex_unlock(&module_mutex); > - if (ret) > - del_usage_links(mod); > -#endif > - return ret; > -} > - > -static void module_remove_modinfo_attrs(struct module *mod, int end); > - > -static int module_add_modinfo_attrs(struct module *mod) > -{ > - struct module_attribute *attr; > - struct module_attribute *temp_attr; > - int error = 0; > - int i; > - > - mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * > - (ARRAY_SIZE(modinfo_attrs) + 1)), > - GFP_KERNEL); > - if (!mod->modinfo_attrs) > - return -ENOMEM; > - > - temp_attr = mod->modinfo_attrs; > - for (i = 0; (attr = modinfo_attrs[i]); i++) { > - if (!attr->test || attr->test(mod)) { > - memcpy(temp_attr, attr, sizeof(*temp_attr)); > - sysfs_attr_init(&temp_attr->attr); > - error = sysfs_create_file(&mod->mkobj.kobj, > - &temp_attr->attr); > - if (error) > - goto error_out; > - ++temp_attr; > - } > - } > - > - return 0; > - > -error_out: > - if (i > 0) > - module_remove_modinfo_attrs(mod, --i); > - else > - kfree(mod->modinfo_attrs); > - return error; > -} > - > -static void module_remove_modinfo_attrs(struct module *mod, int end) > -{ > - struct module_attribute *attr; > - int i; > - > - for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { > - if (end >= 0 && i > end) > - break; > - /* pick a field to test for end of list */ > - if (!attr->attr.name) > - break; > - sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); > - if (attr->free) > - attr->free(mod); > - } > - kfree(mod->modinfo_attrs); > -} > - > -static void mod_kobject_put(struct module *mod) > -{ > - DECLARE_COMPLETION_ONSTACK(c); > - mod->mkobj.kobj_completion = &c; > - kobject_put(&mod->mkobj.kobj); > - wait_for_completion(&c); > -} > - > -static int mod_sysfs_init(struct module *mod) > -{ > - int err; > - struct kobject *kobj; > - > - if (!module_sysfs_initialized) { > - pr_err("%s: module sysfs not initialized\n", mod->name); > - err = -EINVAL; > - goto out; > - } > - > - kobj = kset_find_obj(module_kset, mod->name); > - if (kobj) { > - pr_err("%s: module is already loaded\n", mod->name); > - kobject_put(kobj); > - err = -EINVAL; > - goto out; > - } > - > - mod->mkobj.mod = mod; > - > - memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); > - mod->mkobj.kobj.kset = module_kset; > - err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, > - "%s", mod->name); > - if (err) > - mod_kobject_put(mod); > - > -out: > - return err; > -} > - > -static int mod_sysfs_setup(struct module *mod, > - const struct load_info *info, > - struct kernel_param *kparam, > - unsigned int num_params) > -{ > - int err; > - > - err = mod_sysfs_init(mod); > - if (err) > - goto out; > - > - mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); > - if (!mod->holders_dir) { > - err = -ENOMEM; > - goto out_unreg; > - } > - > - err = module_param_sysfs_setup(mod, kparam, num_params); > - if (err) > - goto out_unreg_holders; > - > - err = module_add_modinfo_attrs(mod); > - if (err) > - goto out_unreg_param; > - > - err = add_usage_links(mod); > - if (err) > - goto out_unreg_modinfo_attrs; > - > - add_sect_attrs(mod, info); > - add_notes_attrs(mod, info); > - > - return 0; > - > -out_unreg_modinfo_attrs: > - module_remove_modinfo_attrs(mod, -1); > -out_unreg_param: > - module_param_sysfs_remove(mod); > -out_unreg_holders: > - kobject_put(mod->holders_dir); > -out_unreg: > - mod_kobject_put(mod); > -out: > - return err; > -} > - > -static void mod_sysfs_fini(struct module *mod) > -{ > - remove_notes_attrs(mod); > - remove_sect_attrs(mod); > - mod_kobject_put(mod); > -} > - > -static void init_param_lock(struct module *mod) > -{ > - mutex_init(&mod->param_lock); > -} > -#else /* !CONFIG_SYSFS */ > - > -static int mod_sysfs_setup(struct module *mod, > - const struct load_info *info, > - struct kernel_param *kparam, > - unsigned int num_params) > -{ > - return 0; > -} > - > -static void mod_sysfs_fini(struct module *mod) > -{ > -} > - > -static void module_remove_modinfo_attrs(struct module *mod, int end) > -{ > -} > - > -static void del_usage_links(struct module *mod) > -{ > -} > - > -static void init_param_lock(struct module *mod) > -{ > -} > -#endif /* CONFIG_SYSFS */ > - > -static void mod_sysfs_teardown(struct module *mod) > -{ > - del_usage_links(mod); > - module_remove_modinfo_attrs(mod, -1); > - module_param_sysfs_remove(mod); > - kobject_put(mod->mkobj.drivers_dir); > - kobject_put(mod->holders_dir); > - mod_sysfs_fini(mod); > -} > - > /* > * LKM RO/NX protection: protect module's text/ro-data > * from modification and any data from execution. > diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c > new file mode 100644 > index 000000000000..ce68f821dcd1 > --- /dev/null > +++ b/kernel/module/sysfs.c > @@ -0,0 +1,436 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Module sysfs support > + * > + * Copyright (C) 2008 Rusty Russell > + */ > + > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/fs.h> > +#include <linux/sysfs.h> > +#include <linux/slab.h> > +#include <linux/kallsyms.h> > +#include <linux/mutex.h> > +#include "internal.h" > + > +/* > + * /sys/module/foo/sections stuff > + * J. Corbet <corbet@lwn.net> > + */ > +#ifdef CONFIG_KALLSYMS > +struct module_sect_attr { > + struct bin_attribute battr; > + unsigned long address; > +}; > + > +struct module_sect_attrs { > + struct attribute_group grp; > + unsigned int nsections; > + struct module_sect_attr attrs[]; > +}; > + > +#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) > +static ssize_t module_sect_read(struct file *file, struct kobject *kobj, > + struct bin_attribute *battr, > + char *buf, loff_t pos, size_t count) > +{ > + struct module_sect_attr *sattr = > + container_of(battr, struct module_sect_attr, battr); > + char bounce[MODULE_SECT_READ_SIZE + 1]; > + size_t wrote; > + > + if (pos != 0) > + return -EINVAL; > + > + /* > + * Since we're a binary read handler, we must account for the > + * trailing NUL byte that sprintf will write: if "buf" is > + * too small to hold the NUL, or the NUL is exactly the last > + * byte, the read will look like it got truncated by one byte. > + * Since there is no way to ask sprintf nicely to not write > + * the NUL, we have to use a bounce buffer. > + */ > + wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", > + kallsyms_show_value(file->f_cred) > + ? (void *)sattr->address : NULL); > + count = min(count, wrote); > + memcpy(buf, bounce, count); > + > + return count; > +} > + > +static void free_sect_attrs(struct module_sect_attrs *sect_attrs) > +{ > + unsigned int section; > + > + for (section = 0; section < sect_attrs->nsections; section++) > + kfree(sect_attrs->attrs[section].battr.attr.name); > + kfree(sect_attrs); > +} > + > +static void add_sect_attrs(struct module *mod, const struct load_info *info) > +{ > + unsigned int nloaded = 0, i, size[2]; > + struct module_sect_attrs *sect_attrs; > + struct module_sect_attr *sattr; > + struct bin_attribute **gattr; > + > + /* Count loaded sections and allocate structures */ > + for (i = 0; i < info->hdr->e_shnum; i++) > + if (!sect_empty(&info->sechdrs[i])) > + nloaded++; > + size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), > + sizeof(sect_attrs->grp.bin_attrs[0])); > + size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); > + sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); > + if (!sect_attrs) > + return; > + > + /* Setup section attributes. */ > + sect_attrs->grp.name = "sections"; > + sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; > + > + sect_attrs->nsections = 0; > + sattr = §_attrs->attrs[0]; > + gattr = §_attrs->grp.bin_attrs[0]; > + for (i = 0; i < info->hdr->e_shnum; i++) { > + Elf_Shdr *sec = &info->sechdrs[i]; > + > + if (sect_empty(sec)) > + continue; > + sysfs_bin_attr_init(&sattr->battr); > + sattr->address = sec->sh_addr; > + sattr->battr.attr.name = > + kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); > + if (!sattr->battr.attr.name) > + goto out; > + sect_attrs->nsections++; > + sattr->battr.read = module_sect_read; > + sattr->battr.size = MODULE_SECT_READ_SIZE; > + sattr->battr.attr.mode = 0400; > + *(gattr++) = &(sattr++)->battr; > + } > + *gattr = NULL; > + > + if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) > + goto out; > + > + mod->sect_attrs = sect_attrs; > + return; > +out: > + free_sect_attrs(sect_attrs); > +} > + > +static void remove_sect_attrs(struct module *mod) > +{ > + if (mod->sect_attrs) { > + sysfs_remove_group(&mod->mkobj.kobj, > + &mod->sect_attrs->grp); > + /* > + * We are positive that no one is using any sect attrs > + * at this point. Deallocate immediately. > + */ > + free_sect_attrs(mod->sect_attrs); > + mod->sect_attrs = NULL; > + } > +} > + > +/* > + * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. > + */ > + > +struct module_notes_attrs { > + struct kobject *dir; > + unsigned int notes; > + struct bin_attribute attrs[]; > +}; > + > +static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t count) > +{ > + /* > + * The caller checked the pos and count against our size. > + */ > + memcpy(buf, bin_attr->private + pos, count); > + return count; > +} > + > +static void free_notes_attrs(struct module_notes_attrs *notes_attrs, > + unsigned int i) > +{ > + if (notes_attrs->dir) { > + while (i-- > 0) > + sysfs_remove_bin_file(notes_attrs->dir, > + ¬es_attrs->attrs[i]); > + kobject_put(notes_attrs->dir); > + } > + kfree(notes_attrs); > +} > + > +static void add_notes_attrs(struct module *mod, const struct load_info *info) > +{ > + unsigned int notes, loaded, i; > + struct module_notes_attrs *notes_attrs; > + struct bin_attribute *nattr; > + > + /* failed to create section attributes, so can't create notes */ > + if (!mod->sect_attrs) > + return; > + > + /* Count notes sections and allocate structures. */ > + notes = 0; > + for (i = 0; i < info->hdr->e_shnum; i++) > + if (!sect_empty(&info->sechdrs[i]) && > + info->sechdrs[i].sh_type == SHT_NOTE) > + ++notes; > + > + if (notes == 0) > + return; > + > + notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), > + GFP_KERNEL); > + if (!notes_attrs) > + return; > + > + notes_attrs->notes = notes; > + nattr = ¬es_attrs->attrs[0]; > + for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { > + if (sect_empty(&info->sechdrs[i])) > + continue; > + if (info->sechdrs[i].sh_type == SHT_NOTE) { > + sysfs_bin_attr_init(nattr); > + nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; > + nattr->attr.mode = 0444; > + nattr->size = info->sechdrs[i].sh_size; > + nattr->private = (void *)info->sechdrs[i].sh_addr; > + nattr->read = module_notes_read; > + ++nattr; > + } > + ++loaded; > + } > + > + notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); > + if (!notes_attrs->dir) > + goto out; > + > + for (i = 0; i < notes; ++i) > + if (sysfs_create_bin_file(notes_attrs->dir, > + ¬es_attrs->attrs[i])) > + goto out; > + > + mod->notes_attrs = notes_attrs; > + return; > + > +out: > + free_notes_attrs(notes_attrs, i); > +} > + > +static void remove_notes_attrs(struct module *mod) > +{ > + if (mod->notes_attrs) > + free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); > +} > + > +#else /* !CONFIG_KALLSYMS */ > +static inline void add_sect_attrs(struct module *mod, const struct load_info *info) { } > +static inline void remove_sect_attrs(struct module *mod) { } > +static inline void add_notes_attrs(struct module *mod, const struct load_info *info) { } > +static inline void remove_notes_attrs(struct module *mod) { } > +#endif /* CONFIG_KALLSYMS */ > + > +static void del_usage_links(struct module *mod) > +{ > +#ifdef CONFIG_MODULE_UNLOAD > + struct module_use *use; > + > + mutex_lock(&module_mutex); > + list_for_each_entry(use, &mod->target_list, target_list) > + sysfs_remove_link(use->target->holders_dir, mod->name); > + mutex_unlock(&module_mutex); > +#endif > +} > + > +static int add_usage_links(struct module *mod) > +{ > + int ret = 0; > +#ifdef CONFIG_MODULE_UNLOAD > + struct module_use *use; > + > + mutex_lock(&module_mutex); > + list_for_each_entry(use, &mod->target_list, target_list) { > + ret = sysfs_create_link(use->target->holders_dir, > + &mod->mkobj.kobj, mod->name); > + if (ret) > + break; > + } > + mutex_unlock(&module_mutex); > + if (ret) > + del_usage_links(mod); > +#endif > + return ret; > +} > + > +static void module_remove_modinfo_attrs(struct module *mod, int end) > +{ > + struct module_attribute *attr; > + int i; > + > + for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { > + if (end >= 0 && i > end) > + break; > + /* pick a field to test for end of list */ > + if (!attr->attr.name) > + break; > + sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); > + if (attr->free) > + attr->free(mod); > + } > + kfree(mod->modinfo_attrs); > +} > + > +static int module_add_modinfo_attrs(struct module *mod) > +{ > + struct module_attribute *attr; > + struct module_attribute *temp_attr; > + int error = 0; > + int i; > + > + mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * > + (modinfo_attrs_count + 1)), > + GFP_KERNEL); > + if (!mod->modinfo_attrs) > + return -ENOMEM; > + > + temp_attr = mod->modinfo_attrs; > + for (i = 0; (attr = modinfo_attrs[i]); i++) { > + if (!attr->test || attr->test(mod)) { > + memcpy(temp_attr, attr, sizeof(*temp_attr)); > + sysfs_attr_init(&temp_attr->attr); > + error = sysfs_create_file(&mod->mkobj.kobj, > + &temp_attr->attr); > + if (error) > + goto error_out; > + ++temp_attr; > + } > + } > + > + return 0; > + > +error_out: > + if (i > 0) > + module_remove_modinfo_attrs(mod, --i); > + else > + kfree(mod->modinfo_attrs); > + return error; > +} > + > +static void mod_kobject_put(struct module *mod) > +{ > + DECLARE_COMPLETION_ONSTACK(c); > + > + mod->mkobj.kobj_completion = &c; > + kobject_put(&mod->mkobj.kobj); > + wait_for_completion(&c); > +} > + > +static int mod_sysfs_init(struct module *mod) > +{ > + int err; > + struct kobject *kobj; > + > + if (!module_sysfs_initialized) { > + pr_err("%s: module sysfs not initialized\n", mod->name); > + err = -EINVAL; > + goto out; > + } > + > + kobj = kset_find_obj(module_kset, mod->name); > + if (kobj) { > + pr_err("%s: module is already loaded\n", mod->name); > + kobject_put(kobj); > + err = -EINVAL; > + goto out; > + } > + > + mod->mkobj.mod = mod; > + > + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); > + mod->mkobj.kobj.kset = module_kset; > + err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, > + "%s", mod->name); > + if (err) > + mod_kobject_put(mod); > + > +out: > + return err; > +} > + > +int mod_sysfs_setup(struct module *mod, > + const struct load_info *info, > + struct kernel_param *kparam, > + unsigned int num_params) > +{ > + int err; > + > + err = mod_sysfs_init(mod); > + if (err) > + goto out; > + > + mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); > + if (!mod->holders_dir) { > + err = -ENOMEM; > + goto out_unreg; > + } > + > + err = module_param_sysfs_setup(mod, kparam, num_params); > + if (err) > + goto out_unreg_holders; > + > + err = module_add_modinfo_attrs(mod); > + if (err) > + goto out_unreg_param; > + > + err = add_usage_links(mod); > + if (err) > + goto out_unreg_modinfo_attrs; > + > + add_sect_attrs(mod, info); > + add_notes_attrs(mod, info); > + > + return 0; > + > +out_unreg_modinfo_attrs: > + module_remove_modinfo_attrs(mod, -1); > +out_unreg_param: > + module_param_sysfs_remove(mod); > +out_unreg_holders: > + kobject_put(mod->holders_dir); > +out_unreg: > + mod_kobject_put(mod); > +out: > + return err; > +} > + > +static void mod_sysfs_fini(struct module *mod) > +{ > + remove_notes_attrs(mod); > + remove_sect_attrs(mod); > + mod_kobject_put(mod); > +} > + > +void mod_sysfs_teardown(struct module *mod) > +{ > + del_usage_links(mod); > + module_remove_modinfo_attrs(mod, -1); > + module_param_sysfs_remove(mod); > + kobject_put(mod->mkobj.drivers_dir); > + kobject_put(mod->holders_dir); > + mod_sysfs_fini(mod); > +} > + > +void init_param_lock(struct module *mod) > +{ > + mutex_init(&mod->param_lock); > +}
diff --git a/kernel/module/Makefile b/kernel/module/Makefile index 94296c98a67f..cf8dcdc6b55f 100644 --- a/kernel/module/Makefile +++ b/kernel/module/Makefile @@ -16,3 +16,4 @@ obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_PROC_FS) += procfs.o +obj-$(CONFIG_SYSFS) += sysfs.o diff --git a/kernel/module/internal.h b/kernel/module/internal.h index 6af40c2d145f..62d749ef695e 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -34,6 +34,9 @@ extern struct mutex module_mutex; extern struct list_head modules; +extern struct module_attribute *modinfo_attrs[]; +extern size_t modinfo_attrs_count; + /* Provided by the linker */ extern const struct kernel_symbol __start___ksymtab[]; extern const struct kernel_symbol __stop___ksymtab[]; @@ -204,3 +207,21 @@ static inline void init_build_id(struct module *mod, const struct load_info *inf static inline void layout_symtab(struct module *mod, struct load_info *info) { } static inline void add_kallsyms(struct module *mod, const struct load_info *info) { } #endif /* CONFIG_KALLSYMS */ + +#ifdef CONFIG_SYSFS +int mod_sysfs_setup(struct module *mod, const struct load_info *info, + struct kernel_param *kparam, unsigned int num_params); +void mod_sysfs_teardown(struct module *mod); +void init_param_lock(struct module *mod); +#else /* !CONFIG_SYSFS */ +static inline int mod_sysfs_setup(struct module *mod, + const struct load_info *info, + struct kernel_param *kparam, + unsigned int num_params) +{ + return 0; +} + +static inline void mod_sysfs_teardown(struct module *mod) { } +static inline void init_param_lock(struct module *mod) { } +#endif /* CONFIG_SYSFS */ diff --git a/kernel/module/main.c b/kernel/module/main.c index 44b6fd1acc44..b8a59b5c3e3a 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -14,9 +14,7 @@ #include <linux/init.h> #include <linux/kallsyms.h> #include <linux/buildid.h> -#include <linux/file.h> #include <linux/fs.h> -#include <linux/sysfs.h> #include <linux/kernel.h> #include <linux/kernel_read_file.h> #include <linux/slab.h> @@ -989,7 +987,7 @@ static ssize_t show_taint(struct module_attribute *mattr, static struct module_attribute modinfo_taint = __ATTR(taint, 0444, show_taint, NULL); -static struct module_attribute *modinfo_attrs[] = { +struct module_attribute *modinfo_attrs[] = { &module_uevent, &modinfo_version, &modinfo_srcversion, @@ -1003,6 +1001,8 @@ static struct module_attribute *modinfo_attrs[] = { NULL, }; +size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs); + static const char vermagic[] = VERMAGIC_STRING; static int try_to_force_load(struct module *mod, const char *reason) @@ -1253,469 +1253,6 @@ resolve_symbol_wait(struct module *mod, return ksym; } -/* - * /sys/module/foo/sections stuff - * J. Corbet <corbet@lwn.net> - */ -#ifdef CONFIG_SYSFS - -#ifdef CONFIG_KALLSYMS -struct module_sect_attr { - struct bin_attribute battr; - unsigned long address; -}; - -struct module_sect_attrs { - struct attribute_group grp; - unsigned int nsections; - struct module_sect_attr attrs[]; -}; - -#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) -static ssize_t module_sect_read(struct file *file, struct kobject *kobj, - struct bin_attribute *battr, - char *buf, loff_t pos, size_t count) -{ - struct module_sect_attr *sattr = - container_of(battr, struct module_sect_attr, battr); - char bounce[MODULE_SECT_READ_SIZE + 1]; - size_t wrote; - - if (pos != 0) - return -EINVAL; - - /* - * Since we're a binary read handler, we must account for the - * trailing NUL byte that sprintf will write: if "buf" is - * too small to hold the NUL, or the NUL is exactly the last - * byte, the read will look like it got truncated by one byte. - * Since there is no way to ask sprintf nicely to not write - * the NUL, we have to use a bounce buffer. - */ - wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", - kallsyms_show_value(file->f_cred) - ? (void *)sattr->address : NULL); - count = min(count, wrote); - memcpy(buf, bounce, count); - - return count; -} - -static void free_sect_attrs(struct module_sect_attrs *sect_attrs) -{ - unsigned int section; - - for (section = 0; section < sect_attrs->nsections; section++) - kfree(sect_attrs->attrs[section].battr.attr.name); - kfree(sect_attrs); -} - -static void add_sect_attrs(struct module *mod, const struct load_info *info) -{ - unsigned int nloaded = 0, i, size[2]; - struct module_sect_attrs *sect_attrs; - struct module_sect_attr *sattr; - struct bin_attribute **gattr; - - /* Count loaded sections and allocate structures */ - for (i = 0; i < info->hdr->e_shnum; i++) - if (!sect_empty(&info->sechdrs[i])) - nloaded++; - size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), - sizeof(sect_attrs->grp.bin_attrs[0])); - size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); - sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); - if (sect_attrs == NULL) - return; - - /* Setup section attributes. */ - sect_attrs->grp.name = "sections"; - sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; - - sect_attrs->nsections = 0; - sattr = §_attrs->attrs[0]; - gattr = §_attrs->grp.bin_attrs[0]; - for (i = 0; i < info->hdr->e_shnum; i++) { - Elf_Shdr *sec = &info->sechdrs[i]; - if (sect_empty(sec)) - continue; - sysfs_bin_attr_init(&sattr->battr); - sattr->address = sec->sh_addr; - sattr->battr.attr.name = - kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); - if (sattr->battr.attr.name == NULL) - goto out; - sect_attrs->nsections++; - sattr->battr.read = module_sect_read; - sattr->battr.size = MODULE_SECT_READ_SIZE; - sattr->battr.attr.mode = 0400; - *(gattr++) = &(sattr++)->battr; - } - *gattr = NULL; - - if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) - goto out; - - mod->sect_attrs = sect_attrs; - return; - out: - free_sect_attrs(sect_attrs); -} - -static void remove_sect_attrs(struct module *mod) -{ - if (mod->sect_attrs) { - sysfs_remove_group(&mod->mkobj.kobj, - &mod->sect_attrs->grp); - /* - * We are positive that no one is using any sect attrs - * at this point. Deallocate immediately. - */ - free_sect_attrs(mod->sect_attrs); - mod->sect_attrs = NULL; - } -} - -/* - * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. - */ - -struct module_notes_attrs { - struct kobject *dir; - unsigned int notes; - struct bin_attribute attrs[]; -}; - -static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t pos, size_t count) -{ - /* - * The caller checked the pos and count against our size. - */ - memcpy(buf, bin_attr->private + pos, count); - return count; -} - -static void free_notes_attrs(struct module_notes_attrs *notes_attrs, - unsigned int i) -{ - if (notes_attrs->dir) { - while (i-- > 0) - sysfs_remove_bin_file(notes_attrs->dir, - ¬es_attrs->attrs[i]); - kobject_put(notes_attrs->dir); - } - kfree(notes_attrs); -} - -static void add_notes_attrs(struct module *mod, const struct load_info *info) -{ - unsigned int notes, loaded, i; - struct module_notes_attrs *notes_attrs; - struct bin_attribute *nattr; - - /* failed to create section attributes, so can't create notes */ - if (!mod->sect_attrs) - return; - - /* Count notes sections and allocate structures. */ - notes = 0; - for (i = 0; i < info->hdr->e_shnum; i++) - if (!sect_empty(&info->sechdrs[i]) && - (info->sechdrs[i].sh_type == SHT_NOTE)) - ++notes; - - if (notes == 0) - return; - - notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), - GFP_KERNEL); - if (notes_attrs == NULL) - return; - - notes_attrs->notes = notes; - nattr = ¬es_attrs->attrs[0]; - for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { - if (sect_empty(&info->sechdrs[i])) - continue; - if (info->sechdrs[i].sh_type == SHT_NOTE) { - sysfs_bin_attr_init(nattr); - nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; - nattr->attr.mode = S_IRUGO; - nattr->size = info->sechdrs[i].sh_size; - nattr->private = (void *) info->sechdrs[i].sh_addr; - nattr->read = module_notes_read; - ++nattr; - } - ++loaded; - } - - notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); - if (!notes_attrs->dir) - goto out; - - for (i = 0; i < notes; ++i) - if (sysfs_create_bin_file(notes_attrs->dir, - ¬es_attrs->attrs[i])) - goto out; - - mod->notes_attrs = notes_attrs; - return; - - out: - free_notes_attrs(notes_attrs, i); -} - -static void remove_notes_attrs(struct module *mod) -{ - if (mod->notes_attrs) - free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); -} - -#else - -static inline void add_sect_attrs(struct module *mod, - const struct load_info *info) -{ -} - -static inline void remove_sect_attrs(struct module *mod) -{ -} - -static inline void add_notes_attrs(struct module *mod, - const struct load_info *info) -{ -} - -static inline void remove_notes_attrs(struct module *mod) -{ -} -#endif /* CONFIG_KALLSYMS */ - -static void del_usage_links(struct module *mod) -{ -#ifdef CONFIG_MODULE_UNLOAD - struct module_use *use; - - mutex_lock(&module_mutex); - list_for_each_entry(use, &mod->target_list, target_list) - sysfs_remove_link(use->target->holders_dir, mod->name); - mutex_unlock(&module_mutex); -#endif -} - -static int add_usage_links(struct module *mod) -{ - int ret = 0; -#ifdef CONFIG_MODULE_UNLOAD - struct module_use *use; - - mutex_lock(&module_mutex); - list_for_each_entry(use, &mod->target_list, target_list) { - ret = sysfs_create_link(use->target->holders_dir, - &mod->mkobj.kobj, mod->name); - if (ret) - break; - } - mutex_unlock(&module_mutex); - if (ret) - del_usage_links(mod); -#endif - return ret; -} - -static void module_remove_modinfo_attrs(struct module *mod, int end); - -static int module_add_modinfo_attrs(struct module *mod) -{ - struct module_attribute *attr; - struct module_attribute *temp_attr; - int error = 0; - int i; - - mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * - (ARRAY_SIZE(modinfo_attrs) + 1)), - GFP_KERNEL); - if (!mod->modinfo_attrs) - return -ENOMEM; - - temp_attr = mod->modinfo_attrs; - for (i = 0; (attr = modinfo_attrs[i]); i++) { - if (!attr->test || attr->test(mod)) { - memcpy(temp_attr, attr, sizeof(*temp_attr)); - sysfs_attr_init(&temp_attr->attr); - error = sysfs_create_file(&mod->mkobj.kobj, - &temp_attr->attr); - if (error) - goto error_out; - ++temp_attr; - } - } - - return 0; - -error_out: - if (i > 0) - module_remove_modinfo_attrs(mod, --i); - else - kfree(mod->modinfo_attrs); - return error; -} - -static void module_remove_modinfo_attrs(struct module *mod, int end) -{ - struct module_attribute *attr; - int i; - - for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { - if (end >= 0 && i > end) - break; - /* pick a field to test for end of list */ - if (!attr->attr.name) - break; - sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); - if (attr->free) - attr->free(mod); - } - kfree(mod->modinfo_attrs); -} - -static void mod_kobject_put(struct module *mod) -{ - DECLARE_COMPLETION_ONSTACK(c); - mod->mkobj.kobj_completion = &c; - kobject_put(&mod->mkobj.kobj); - wait_for_completion(&c); -} - -static int mod_sysfs_init(struct module *mod) -{ - int err; - struct kobject *kobj; - - if (!module_sysfs_initialized) { - pr_err("%s: module sysfs not initialized\n", mod->name); - err = -EINVAL; - goto out; - } - - kobj = kset_find_obj(module_kset, mod->name); - if (kobj) { - pr_err("%s: module is already loaded\n", mod->name); - kobject_put(kobj); - err = -EINVAL; - goto out; - } - - mod->mkobj.mod = mod; - - memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); - mod->mkobj.kobj.kset = module_kset; - err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, - "%s", mod->name); - if (err) - mod_kobject_put(mod); - -out: - return err; -} - -static int mod_sysfs_setup(struct module *mod, - const struct load_info *info, - struct kernel_param *kparam, - unsigned int num_params) -{ - int err; - - err = mod_sysfs_init(mod); - if (err) - goto out; - - mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); - if (!mod->holders_dir) { - err = -ENOMEM; - goto out_unreg; - } - - err = module_param_sysfs_setup(mod, kparam, num_params); - if (err) - goto out_unreg_holders; - - err = module_add_modinfo_attrs(mod); - if (err) - goto out_unreg_param; - - err = add_usage_links(mod); - if (err) - goto out_unreg_modinfo_attrs; - - add_sect_attrs(mod, info); - add_notes_attrs(mod, info); - - return 0; - -out_unreg_modinfo_attrs: - module_remove_modinfo_attrs(mod, -1); -out_unreg_param: - module_param_sysfs_remove(mod); -out_unreg_holders: - kobject_put(mod->holders_dir); -out_unreg: - mod_kobject_put(mod); -out: - return err; -} - -static void mod_sysfs_fini(struct module *mod) -{ - remove_notes_attrs(mod); - remove_sect_attrs(mod); - mod_kobject_put(mod); -} - -static void init_param_lock(struct module *mod) -{ - mutex_init(&mod->param_lock); -} -#else /* !CONFIG_SYSFS */ - -static int mod_sysfs_setup(struct module *mod, - const struct load_info *info, - struct kernel_param *kparam, - unsigned int num_params) -{ - return 0; -} - -static void mod_sysfs_fini(struct module *mod) -{ -} - -static void module_remove_modinfo_attrs(struct module *mod, int end) -{ -} - -static void del_usage_links(struct module *mod) -{ -} - -static void init_param_lock(struct module *mod) -{ -} -#endif /* CONFIG_SYSFS */ - -static void mod_sysfs_teardown(struct module *mod) -{ - del_usage_links(mod); - module_remove_modinfo_attrs(mod, -1); - module_param_sysfs_remove(mod); - kobject_put(mod->mkobj.drivers_dir); - kobject_put(mod->holders_dir); - mod_sysfs_fini(mod); -} - /* * LKM RO/NX protection: protect module's text/ro-data * from modification and any data from execution. diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c new file mode 100644 index 000000000000..ce68f821dcd1 --- /dev/null +++ b/kernel/module/sysfs.c @@ -0,0 +1,436 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Module sysfs support + * + * Copyright (C) 2008 Rusty Russell + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/sysfs.h> +#include <linux/slab.h> +#include <linux/kallsyms.h> +#include <linux/mutex.h> +#include "internal.h" + +/* + * /sys/module/foo/sections stuff + * J. Corbet <corbet@lwn.net> + */ +#ifdef CONFIG_KALLSYMS +struct module_sect_attr { + struct bin_attribute battr; + unsigned long address; +}; + +struct module_sect_attrs { + struct attribute_group grp; + unsigned int nsections; + struct module_sect_attr attrs[]; +}; + +#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) +static ssize_t module_sect_read(struct file *file, struct kobject *kobj, + struct bin_attribute *battr, + char *buf, loff_t pos, size_t count) +{ + struct module_sect_attr *sattr = + container_of(battr, struct module_sect_attr, battr); + char bounce[MODULE_SECT_READ_SIZE + 1]; + size_t wrote; + + if (pos != 0) + return -EINVAL; + + /* + * Since we're a binary read handler, we must account for the + * trailing NUL byte that sprintf will write: if "buf" is + * too small to hold the NUL, or the NUL is exactly the last + * byte, the read will look like it got truncated by one byte. + * Since there is no way to ask sprintf nicely to not write + * the NUL, we have to use a bounce buffer. + */ + wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", + kallsyms_show_value(file->f_cred) + ? (void *)sattr->address : NULL); + count = min(count, wrote); + memcpy(buf, bounce, count); + + return count; +} + +static void free_sect_attrs(struct module_sect_attrs *sect_attrs) +{ + unsigned int section; + + for (section = 0; section < sect_attrs->nsections; section++) + kfree(sect_attrs->attrs[section].battr.attr.name); + kfree(sect_attrs); +} + +static void add_sect_attrs(struct module *mod, const struct load_info *info) +{ + unsigned int nloaded = 0, i, size[2]; + struct module_sect_attrs *sect_attrs; + struct module_sect_attr *sattr; + struct bin_attribute **gattr; + + /* Count loaded sections and allocate structures */ + for (i = 0; i < info->hdr->e_shnum; i++) + if (!sect_empty(&info->sechdrs[i])) + nloaded++; + size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), + sizeof(sect_attrs->grp.bin_attrs[0])); + size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); + sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); + if (!sect_attrs) + return; + + /* Setup section attributes. */ + sect_attrs->grp.name = "sections"; + sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; + + sect_attrs->nsections = 0; + sattr = §_attrs->attrs[0]; + gattr = §_attrs->grp.bin_attrs[0]; + for (i = 0; i < info->hdr->e_shnum; i++) { + Elf_Shdr *sec = &info->sechdrs[i]; + + if (sect_empty(sec)) + continue; + sysfs_bin_attr_init(&sattr->battr); + sattr->address = sec->sh_addr; + sattr->battr.attr.name = + kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); + if (!sattr->battr.attr.name) + goto out; + sect_attrs->nsections++; + sattr->battr.read = module_sect_read; + sattr->battr.size = MODULE_SECT_READ_SIZE; + sattr->battr.attr.mode = 0400; + *(gattr++) = &(sattr++)->battr; + } + *gattr = NULL; + + if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) + goto out; + + mod->sect_attrs = sect_attrs; + return; +out: + free_sect_attrs(sect_attrs); +} + +static void remove_sect_attrs(struct module *mod) +{ + if (mod->sect_attrs) { + sysfs_remove_group(&mod->mkobj.kobj, + &mod->sect_attrs->grp); + /* + * We are positive that no one is using any sect attrs + * at this point. Deallocate immediately. + */ + free_sect_attrs(mod->sect_attrs); + mod->sect_attrs = NULL; + } +} + +/* + * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. + */ + +struct module_notes_attrs { + struct kobject *dir; + unsigned int notes; + struct bin_attribute attrs[]; +}; + +static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t count) +{ + /* + * The caller checked the pos and count against our size. + */ + memcpy(buf, bin_attr->private + pos, count); + return count; +} + +static void free_notes_attrs(struct module_notes_attrs *notes_attrs, + unsigned int i) +{ + if (notes_attrs->dir) { + while (i-- > 0) + sysfs_remove_bin_file(notes_attrs->dir, + ¬es_attrs->attrs[i]); + kobject_put(notes_attrs->dir); + } + kfree(notes_attrs); +} + +static void add_notes_attrs(struct module *mod, const struct load_info *info) +{ + unsigned int notes, loaded, i; + struct module_notes_attrs *notes_attrs; + struct bin_attribute *nattr; + + /* failed to create section attributes, so can't create notes */ + if (!mod->sect_attrs) + return; + + /* Count notes sections and allocate structures. */ + notes = 0; + for (i = 0; i < info->hdr->e_shnum; i++) + if (!sect_empty(&info->sechdrs[i]) && + info->sechdrs[i].sh_type == SHT_NOTE) + ++notes; + + if (notes == 0) + return; + + notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), + GFP_KERNEL); + if (!notes_attrs) + return; + + notes_attrs->notes = notes; + nattr = ¬es_attrs->attrs[0]; + for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { + if (sect_empty(&info->sechdrs[i])) + continue; + if (info->sechdrs[i].sh_type == SHT_NOTE) { + sysfs_bin_attr_init(nattr); + nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; + nattr->attr.mode = 0444; + nattr->size = info->sechdrs[i].sh_size; + nattr->private = (void *)info->sechdrs[i].sh_addr; + nattr->read = module_notes_read; + ++nattr; + } + ++loaded; + } + + notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); + if (!notes_attrs->dir) + goto out; + + for (i = 0; i < notes; ++i) + if (sysfs_create_bin_file(notes_attrs->dir, + ¬es_attrs->attrs[i])) + goto out; + + mod->notes_attrs = notes_attrs; + return; + +out: + free_notes_attrs(notes_attrs, i); +} + +static void remove_notes_attrs(struct module *mod) +{ + if (mod->notes_attrs) + free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); +} + +#else /* !CONFIG_KALLSYMS */ +static inline void add_sect_attrs(struct module *mod, const struct load_info *info) { } +static inline void remove_sect_attrs(struct module *mod) { } +static inline void add_notes_attrs(struct module *mod, const struct load_info *info) { } +static inline void remove_notes_attrs(struct module *mod) { } +#endif /* CONFIG_KALLSYMS */ + +static void del_usage_links(struct module *mod) +{ +#ifdef CONFIG_MODULE_UNLOAD + struct module_use *use; + + mutex_lock(&module_mutex); + list_for_each_entry(use, &mod->target_list, target_list) + sysfs_remove_link(use->target->holders_dir, mod->name); + mutex_unlock(&module_mutex); +#endif +} + +static int add_usage_links(struct module *mod) +{ + int ret = 0; +#ifdef CONFIG_MODULE_UNLOAD + struct module_use *use; + + mutex_lock(&module_mutex); + list_for_each_entry(use, &mod->target_list, target_list) { + ret = sysfs_create_link(use->target->holders_dir, + &mod->mkobj.kobj, mod->name); + if (ret) + break; + } + mutex_unlock(&module_mutex); + if (ret) + del_usage_links(mod); +#endif + return ret; +} + +static void module_remove_modinfo_attrs(struct module *mod, int end) +{ + struct module_attribute *attr; + int i; + + for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { + if (end >= 0 && i > end) + break; + /* pick a field to test for end of list */ + if (!attr->attr.name) + break; + sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); + if (attr->free) + attr->free(mod); + } + kfree(mod->modinfo_attrs); +} + +static int module_add_modinfo_attrs(struct module *mod) +{ + struct module_attribute *attr; + struct module_attribute *temp_attr; + int error = 0; + int i; + + mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * + (modinfo_attrs_count + 1)), + GFP_KERNEL); + if (!mod->modinfo_attrs) + return -ENOMEM; + + temp_attr = mod->modinfo_attrs; + for (i = 0; (attr = modinfo_attrs[i]); i++) { + if (!attr->test || attr->test(mod)) { + memcpy(temp_attr, attr, sizeof(*temp_attr)); + sysfs_attr_init(&temp_attr->attr); + error = sysfs_create_file(&mod->mkobj.kobj, + &temp_attr->attr); + if (error) + goto error_out; + ++temp_attr; + } + } + + return 0; + +error_out: + if (i > 0) + module_remove_modinfo_attrs(mod, --i); + else + kfree(mod->modinfo_attrs); + return error; +} + +static void mod_kobject_put(struct module *mod) +{ + DECLARE_COMPLETION_ONSTACK(c); + + mod->mkobj.kobj_completion = &c; + kobject_put(&mod->mkobj.kobj); + wait_for_completion(&c); +} + +static int mod_sysfs_init(struct module *mod) +{ + int err; + struct kobject *kobj; + + if (!module_sysfs_initialized) { + pr_err("%s: module sysfs not initialized\n", mod->name); + err = -EINVAL; + goto out; + } + + kobj = kset_find_obj(module_kset, mod->name); + if (kobj) { + pr_err("%s: module is already loaded\n", mod->name); + kobject_put(kobj); + err = -EINVAL; + goto out; + } + + mod->mkobj.mod = mod; + + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); + mod->mkobj.kobj.kset = module_kset; + err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, + "%s", mod->name); + if (err) + mod_kobject_put(mod); + +out: + return err; +} + +int mod_sysfs_setup(struct module *mod, + const struct load_info *info, + struct kernel_param *kparam, + unsigned int num_params) +{ + int err; + + err = mod_sysfs_init(mod); + if (err) + goto out; + + mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); + if (!mod->holders_dir) { + err = -ENOMEM; + goto out_unreg; + } + + err = module_param_sysfs_setup(mod, kparam, num_params); + if (err) + goto out_unreg_holders; + + err = module_add_modinfo_attrs(mod); + if (err) + goto out_unreg_param; + + err = add_usage_links(mod); + if (err) + goto out_unreg_modinfo_attrs; + + add_sect_attrs(mod, info); + add_notes_attrs(mod, info); + + return 0; + +out_unreg_modinfo_attrs: + module_remove_modinfo_attrs(mod, -1); +out_unreg_param: + module_param_sysfs_remove(mod); +out_unreg_holders: + kobject_put(mod->holders_dir); +out_unreg: + mod_kobject_put(mod); +out: + return err; +} + +static void mod_sysfs_fini(struct module *mod) +{ + remove_notes_attrs(mod); + remove_sect_attrs(mod); + mod_kobject_put(mod); +} + +void mod_sysfs_teardown(struct module *mod) +{ + del_usage_links(mod); + module_remove_modinfo_attrs(mod, -1); + module_param_sysfs_remove(mod); + kobject_put(mod->mkobj.drivers_dir); + kobject_put(mod->holders_dir); + mod_sysfs_fini(mod); +} + +void init_param_lock(struct module *mod) +{ + mutex_init(&mod->param_lock); +}
No functional change. This patch migrates module sysfs support out of core code into kernel/module/sysfs.c. In addition simple code refactoring to make this possible. Signed-off-by: Aaron Tomlin <atomlin@redhat.com> --- kernel/module/Makefile | 1 + kernel/module/internal.h | 21 ++ kernel/module/main.c | 469 +-------------------------------------- kernel/module/sysfs.c | 436 ++++++++++++++++++++++++++++++++++++ 4 files changed, 461 insertions(+), 466 deletions(-) create mode 100644 kernel/module/sysfs.c