diff options
author | Song Liu <song@kernel.org> | 2023-02-06 16:28:02 -0800 |
---|---|---|
committer | Luis Chamberlain <mcgrof@kernel.org> | 2023-03-09 12:55:15 -0800 |
commit | ac3b43283923440900b4f36ca5f9f0b1ca43b70e (patch) | |
tree | 32430a7fa302c652cd2fc675dc0435e0792b9710 /kernel | |
parent | fe15c26ee26efa11741a7b632e9f23b01aca4cc6 (diff) |
module: replace module_layout with module_memory
module_layout manages different types of memory (text, data, rodata, etc.)
in one allocation, which is problematic for some reasons:
1. It is hard to enable CONFIG_STRICT_MODULE_RWX.
2. It is hard to use huge pages in modules (and not break strict rwx).
3. Many archs uses module_layout for arch-specific data, but it is not
obvious how these data are used (are they RO, RX, or RW?)
Improve the scenario by replacing 2 (or 3) module_layout per module with
up to 7 module_memory per module:
MOD_TEXT,
MOD_DATA,
MOD_RODATA,
MOD_RO_AFTER_INIT,
MOD_INIT_TEXT,
MOD_INIT_DATA,
MOD_INIT_RODATA,
and allocating them separately. This adds slightly more entries to
mod_tree (from up to 3 entries per module, to up to 7 entries per
module). However, this at most adds a small constant overhead to
__module_address(), which is expected to be fast.
Various archs use module_layout for different data. These data are put
into different module_memory based on their location in module_layout.
IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT;
data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc.
module_memory simplifies quite some of the module code. For example,
ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a
different allocator for the data. kernel/module/strict_rwx.c is also
much cleaner with module_memory.
Signed-off-by: Song Liu <song@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/module/internal.h | 40 | ||||
-rw-r--r-- | kernel/module/kallsyms.c | 58 | ||||
-rw-r--r-- | kernel/module/kdb.c | 17 | ||||
-rw-r--r-- | kernel/module/main.c | 375 | ||||
-rw-r--r-- | kernel/module/procfs.c | 16 | ||||
-rw-r--r-- | kernel/module/strict_rwx.c | 99 | ||||
-rw-r--r-- | kernel/module/tree_lookup.c | 39 |
7 files changed, 294 insertions, 350 deletions
diff --git a/kernel/module/internal.h b/kernel/module/internal.h index 2e2bf236f558..c6c44ceca07a 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -17,27 +17,19 @@ #define ARCH_SHF_SMALL 0 #endif -/* If this is set, the section belongs in the init part of the module */ -#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG - 1)) -/* Maximum number of characters written by module_flags() */ -#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) - -#ifndef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC -#define data_layout core_layout -#endif - /* - * Modules' sections will be aligned on page boundaries - * to ensure complete separation of code and data, but - * only when CONFIG_STRICT_MODULE_RWX=y + * Use highest 4 bits of sh_entsize to store the mod_mem_type of this + * section. This leaves 28 bits for offset on 32-bit systems, which is + * about 256 MiB (WARN_ON_ONCE if we exceed that). */ -static inline unsigned int strict_align(unsigned int size) -{ - if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) - return PAGE_ALIGN(size); - else - return size; -} + +#define SH_ENTSIZE_TYPE_BITS 4 +#define SH_ENTSIZE_TYPE_SHIFT (BITS_PER_LONG - SH_ENTSIZE_TYPE_BITS) +#define SH_ENTSIZE_TYPE_MASK ((1UL << SH_ENTSIZE_TYPE_BITS) - 1) +#define SH_ENTSIZE_OFFSET_MASK ((1UL << (BITS_PER_LONG - SH_ENTSIZE_TYPE_BITS)) - 1) + +/* Maximum number of characters written by module_flags() */ +#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) extern struct mutex module_mutex; extern struct list_head modules; @@ -101,8 +93,8 @@ int try_to_force_load(struct module *mod, const char *reason); bool find_symbol(struct find_symbol_arg *fsa); struct module *find_module_all(const char *name, size_t len, bool even_unformed); int cmp_name(const void *name, const void *sym); -long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr, - unsigned int section); +long module_get_offset_and_type(struct module *mod, enum mod_mem_type type, + Elf_Shdr *sechdr, unsigned int section); char *module_flags(struct module *mod, char *buf, bool show_state); size_t module_flags_taint(unsigned long taints, char *buf); @@ -190,10 +182,13 @@ struct mod_tree_root { #endif unsigned long addr_min; unsigned long addr_max; +#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC + unsigned long data_addr_min; + unsigned long data_addr_max; +#endif }; extern struct mod_tree_root mod_tree; -extern struct mod_tree_root mod_data_tree; #ifdef CONFIG_MODULES_TREE_LOOKUP void mod_tree_insert(struct module *mod); @@ -224,7 +219,6 @@ void module_enable_nx(const struct module *mod); void module_enable_x(const struct module *mod); int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod); -bool module_check_misalignment(const struct module *mod); #ifdef CONFIG_MODULE_SIG int module_sig_check(struct load_info *info, int flags); diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index ab2376a1be88..8e89f459ffdd 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -78,6 +78,7 @@ static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, unsigned int shnum, unsigned int pcpundx) { const Elf_Shdr *sec; + enum mod_mem_type type; if (src->st_shndx == SHN_UNDEF || src->st_shndx >= shnum || @@ -90,11 +91,12 @@ static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, #endif sec = sechdrs + src->st_shndx; + type = sec->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT; if (!(sec->sh_flags & SHF_ALLOC) #ifndef CONFIG_KALLSYMS_ALL || !(sec->sh_flags & SHF_EXECINSTR) #endif - || (sec->sh_entsize & INIT_OFFSET_MASK)) + || mod_mem_type_is_init(type)) return false; return true; @@ -113,11 +115,13 @@ void layout_symtab(struct module *mod, struct load_info *info) Elf_Shdr *strsect = info->sechdrs + info->index.str; const Elf_Sym *src; unsigned int i, nsrc, ndst, strtab_size = 0; + struct module_memory *mod_mem_data = &mod->mem[MOD_DATA]; + struct module_memory *mod_mem_init_data = &mod->mem[MOD_INIT_DATA]; /* Put symbol section at end of init part of module. */ symsect->sh_flags |= SHF_ALLOC; - symsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, symsect, - info->index.sym) | INIT_OFFSET_MASK; + symsect->sh_entsize = module_get_offset_and_type(mod, MOD_INIT_DATA, + symsect, info->index.sym); pr_debug("\t%s\n", info->secstrings + symsect->sh_name); src = (void *)info->hdr + symsect->sh_offset; @@ -134,28 +138,27 @@ void layout_symtab(struct module *mod, struct load_info *info) } /* Append room for core symbols at end of core part. */ - info->symoffs = ALIGN(mod->data_layout.size, symsect->sh_addralign ?: 1); - info->stroffs = mod->data_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); - mod->data_layout.size += strtab_size; + info->symoffs = ALIGN(mod_mem_data->size, symsect->sh_addralign ?: 1); + info->stroffs = mod_mem_data->size = info->symoffs + ndst * sizeof(Elf_Sym); + mod_mem_data->size += strtab_size; /* Note add_kallsyms() computes strtab_size as core_typeoffs - stroffs */ - info->core_typeoffs = mod->data_layout.size; - mod->data_layout.size += ndst * sizeof(char); - mod->data_layout.size = strict_align(mod->data_layout.size); + info->core_typeoffs = mod_mem_data->size; + mod_mem_data->size += ndst * sizeof(char); /* Put string table section at end of init part of module. */ strsect->sh_flags |= SHF_ALLOC; - strsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, strsect, - info->index.str) | INIT_OFFSET_MASK; + strsect->sh_entsize = module_get_offset_and_type(mod, MOD_INIT_DATA, + strsect, info->index.str); pr_debug("\t%s\n", info->secstrings + strsect->sh_name); /* We'll tack temporary mod_kallsyms on the end. */ - mod->init_layout.size = ALIGN(mod->init_layout.size, - __alignof__(struct mod_kallsyms)); - info->mod_kallsyms_init_off = mod->init_layout.size; - mod->init_layout.size += sizeof(struct mod_kallsyms); - info->init_typeoffs = mod->init_layout.size; - mod->init_layout.size += nsrc * sizeof(char); - mod->init_layout.size = strict_align(mod->init_layout.size); + mod_mem_init_data->size = ALIGN(mod_mem_init_data->size, + __alignof__(struct mod_kallsyms)); + info->mod_kallsyms_init_off = mod_mem_init_data->size; + + mod_mem_init_data->size += sizeof(struct mod_kallsyms); + info->init_typeoffs = mod_mem_init_data->size; + mod_mem_init_data->size += nsrc * sizeof(char); } /* @@ -171,9 +174,11 @@ void add_kallsyms(struct module *mod, const struct load_info *info) char *s; Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; unsigned long strtab_size; + void *data_base = mod->mem[MOD_DATA].base; + void *init_data_base = mod->mem[MOD_INIT_DATA].base; /* Set up to point into init section. */ - mod->kallsyms = (void __rcu *)mod->init_layout.base + + mod->kallsyms = (void __rcu *)init_data_base + info->mod_kallsyms_init_off; rcu_read_lock(); @@ -183,15 +188,15 @@ void add_kallsyms(struct module *mod, const struct load_info *info) /* Make sure we get permanent strtab: don't use info->strtab. */ rcu_dereference(mod->kallsyms)->strtab = (void *)info->sechdrs[info->index.str].sh_addr; - rcu_dereference(mod->kallsyms)->typetab = mod->init_layout.base + info->init_typeoffs; + rcu_dereference(mod->kallsyms)->typetab = init_data_base + info->init_typeoffs; /* * Now populate the cut down core kallsyms for after init * and set types up while we still have access to sections. */ - mod->core_kallsyms.symtab = dst = mod->data_layout.base + info->symoffs; - mod->core_kallsyms.strtab = s = mod->data_layout.base + info->stroffs; - mod->core_kallsyms.typetab = mod->data_layout.base + info->core_typeoffs; + mod->core_kallsyms.symtab = dst = data_base + info->symoffs; + mod->core_kallsyms.strtab = s = data_base + info->stroffs; + mod->core_kallsyms.typetab = data_base + info->core_typeoffs; strtab_size = info->core_typeoffs - info->stroffs; src = rcu_dereference(mod->kallsyms)->symtab; for (ndst = i = 0; i < rcu_dereference(mod->kallsyms)->num_symtab; i++) { @@ -267,12 +272,15 @@ static const char *find_kallsyms_symbol(struct module *mod, unsigned int i, best = 0; unsigned long nextval, bestval; struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); + struct module_memory *mod_mem; /* At worse, next value is at end of module */ if (within_module_init(addr, mod)) - nextval = (unsigned long)mod->init_layout.base + mod->init_layout.text_size; + mod_mem = &mod->mem[MOD_INIT_TEXT]; else - nextval = (unsigned long)mod->core_layout.base + mod->core_layout.text_size; + mod_mem = &mod->mem[MOD_TEXT]; + + nextval = (unsigned long)mod_mem->base + mod_mem->size; bestval = kallsyms_symbol_value(&kallsyms->symtab[best]); diff --git a/kernel/module/kdb.c b/kernel/module/kdb.c index f4317f92e189..995c32d3698f 100644 --- a/kernel/module/kdb.c +++ b/kernel/module/kdb.c @@ -26,10 +26,11 @@ int kdb_lsmod(int argc, const char **argv) if (mod->state == MODULE_STATE_UNFORMED) continue; - kdb_printf("%-20s%8u", mod->name, mod->core_layout.size); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - kdb_printf("/%8u", mod->data_layout.size); -#endif + kdb_printf("%-20s%8u", mod->name, mod->mem[MOD_TEXT].size); + kdb_printf("/%8u", mod->mem[MOD_RODATA].size); + kdb_printf("/%8u", mod->mem[MOD_RO_AFTER_INIT].size); + kdb_printf("/%8u", mod->mem[MOD_DATA].size); + kdb_printf(" 0x%px ", (void *)mod); #ifdef CONFIG_MODULE_UNLOAD kdb_printf("%4d ", module_refcount(mod)); @@ -40,10 +41,10 @@ int kdb_lsmod(int argc, const char **argv) kdb_printf(" (Loading)"); else kdb_printf(" (Live)"); - kdb_printf(" 0x%px", mod->core_layout.base); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - kdb_printf("/0x%px", mod->data_layout.base); -#endif + kdb_printf(" 0x%px", mod->mem[MOD_TEXT].base); + kdb_printf("/0x%px", mod->mem[MOD_RODATA].base); + kdb_printf("/0x%px", mod->mem[MOD_RO_AFTER_INIT].base); + kdb_printf("/0x%px", mod->mem[MOD_DATA].base); #ifdef CONFIG_MODULE_UNLOAD { diff --git a/kernel/module/main.c b/kernel/module/main.c index d3be89de706d..2724bc1b9a90 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -80,12 +80,6 @@ struct mod_tree_root mod_tree __cacheline_aligned = { .addr_min = -1UL, }; -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC -struct mod_tree_root mod_data_tree __cacheline_aligned = { - .addr_min = -1UL, -}; -#endif - struct symsearch { const struct kernel_symbol *start, *stop; const s32 *crcs; @@ -93,14 +87,24 @@ struct symsearch { }; /* - * Bounds of module text, for speeding up __module_address. + * Bounds of module memory, for speeding up __module_address. * Protected by module_mutex. */ -static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_root *tree) +static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base, + unsigned int size, struct mod_tree_root *tree) { unsigned long min = (unsigned long)base; unsigned long max = min + size; +#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC + if (mod_mem_type_is_core_data(type)) { + if (min < tree->data_addr_min) + tree->data_addr_min = min; + if (max > tree->data_addr_max) + tree->data_addr_max = max; + return; + } +#endif if (min < tree->addr_min) tree->addr_min = min; if (max > tree->addr_max) @@ -109,12 +113,12 @@ static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_r static void mod_update_bounds(struct module *mod) { - __mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree); - if (mod->init_layout.size) - __mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree); -#endif + for_each_mod_mem_type(type) { + struct module_memory *mod_mem = &mod->mem[type]; + + if (mod_mem->size) + __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree); + } } /* Block module loading/unloading? */ @@ -926,7 +930,13 @@ struct module_attribute module_uevent = static ssize_t show_coresize(struct module_attribute *mattr, struct module_kobject *mk, char *buffer) { - return sprintf(buffer, "%u\n", mk->mod->core_layout.size); + unsigned int size = mk->mod->mem[MOD_TEXT].size; + + if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) { + for_class_mod_mem_type(type, core_data) + size += mk->mod->mem[type].size; + } + return sprintf(buffer, "%u\n", size); } static struct module_attribute modinfo_coresize = @@ -936,7 +946,11 @@ static struct module_attribute modinfo_coresize = static ssize_t show_datasize(struct module_attribute *mattr, struct module_kobject *mk, char *buffer) { - return sprintf(buffer, "%u\n", mk->mod->data_layout.size); + unsigned int size = 0; + + for_class_mod_mem_type(type, core_data) + size += mk->mod->mem[type].size; + return sprintf(buffer, "%u\n", size); } static struct module_attribute modinfo_datasize = @@ -946,7 +960,11 @@ static struct module_attribute modinfo_datasize = static ssize_t show_initsize(struct module_attribute *mattr, struct module_kobject *mk, char *buffer) { - return sprintf(buffer, "%u\n", mk->mod->init_layout.size); + unsigned int size = 0; + + for_class_mod_mem_type(type, init) + size += mk->mod->mem[type].size; + return sprintf(buffer, "%u\n", size); } static struct module_attribute modinfo_initsize = @@ -1143,6 +1161,46 @@ void __weak module_arch_freeing_init(struct module *mod) { } +static bool mod_mem_use_vmalloc(enum mod_mem_type type) +{ + return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) && + mod_mem_type_is_core_data(type); +} + +static void *module_memory_alloc(unsigned int size, enum mod_mem_type type) +{ + if (mod_mem_use_vmalloc(type)) + return vzalloc(size); + return module_alloc(size); +} + +static void module_memory_free(void *ptr, enum mod_mem_type type) +{ + if (mod_mem_use_vmalloc(type)) + vfree(ptr); + else + module_memfree(ptr); +} + +static void free_mod_mem(struct module *mod) +{ + for_each_mod_mem_type(type) { + struct module_memory *mod_mem = &mod->mem[type]; + + if (type == MOD_DATA) + continue; + + /* Free lock-classes; relies on the preceding sync_rcu(). */ + lockdep_free_key_range(mod_mem->base, mod_mem->size); + if (mod_mem->size) + module_memory_free(mod_mem->base, type); + } + + /* MOD_DATA hosts mod, so free it at last */ + lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size); + module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA); +} + /* Free a module, remove from lists, etc. */ static void free_module(struct module *mod) { @@ -1189,18 +1247,10 @@ static void free_module(struct module *mod) /* This may be empty, but that's OK */ module_arch_freeing_init(mod); - module_memfree(mod->init_layout.base); kfree(mod->args); percpu_modfree(mod); - /* Free lock-classes; relies on the preceding sync_rcu(). */ - lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size); - - /* Finally, free the core (containing the module structure) */ - module_memfree(mod->core_layout.base); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - vfree(mod->data_layout.base); -#endif + free_mod_mem(mod); } void *__symbol_get(const char *symbol) @@ -1387,16 +1437,18 @@ unsigned int __weak arch_mod_section_prepend(struct module *mod, return 0; } -/* Update size with this section: return offset. */ -long module_get_offset(struct module *mod, unsigned int *size, - Elf_Shdr *sechdr, unsigned int section) +long module_get_offset_and_type(struct module *mod, enum mod_mem_type type, + Elf_Shdr *sechdr, unsigned int section) { - long ret; + long offset; + long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT; - *size += arch_mod_section_prepend(mod, section); - ret = ALIGN(*size, sechdr->sh_addralign ?: 1); - *size = ret + sechdr->sh_size; - return ret; + mod->mem[type].size += arch_mod_section_prepend(mod, section); + offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1); + mod->mem[type].size = offset + sechdr->sh_size; + + WARN_ON_ONCE(offset & mask); + return offset | mask; } static bool module_init_layout_section(const char *sname) @@ -1408,15 +1460,11 @@ static bool module_init_layout_section(const char *sname) return module_init_section(sname); } -/* - * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld - * might -- code, read-only data, read-write data, small data. Tally - * sizes, and place the offsets into sh_entsize fields: high bit means it - * belongs in init. - */ -static void layout_sections(struct module *mod, struct load_info *info) +static void __layout_sections(struct module *mod, struct load_info *info, bool is_init) { - static unsigned long const masks[][2] = { + unsigned int m, i; + + static const unsigned long masks[][2] = { /* * NOTE: all executable code must be the first section * in this array; otherwise modify the text_size @@ -1428,84 +1476,63 @@ static void layout_sections(struct module *mod, struct load_info *info) { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, { ARCH_SHF_SMALL | SHF_ALLOC, 0 } }; - unsigned int m, i; - - for (i = 0; i < info->hdr->e_shnum; i++) - info->sechdrs[i].sh_entsize = ~0UL; + static const int core_m_to_mem_type[] = { + MOD_TEXT, + MOD_RODATA, + MOD_RO_AFTER_INIT, + MOD_DATA, + MOD_INVALID, /* This is needed to match the masks array */ + }; + static const int init_m_to_mem_type[] = { + MOD_INIT_TEXT, + MOD_INIT_RODATA, + MOD_INVALID, + MOD_INIT_DATA, + MOD_INVALID, /* This is needed to match the masks array */ + }; - pr_debug("Core section allocation order:\n"); for (m = 0; m < ARRAY_SIZE(masks); ++m) { + enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m]; + for (i = 0; i < info->hdr->e_shnum; ++i) { Elf_Shdr *s = &info->sechdrs[i]; const char *sname = info->secstrings + s->sh_name; - unsigned int *sizep; if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL - || module_init_layout_section(sname)) + || is_init != module_init_layout_section(sname)) continue; - sizep = m ? &mod->data_layout.size : &mod->core_layout.size; - s->sh_entsize = module_get_offset(mod, sizep, s, i); - pr_debug("\t%s\n", sname); - } - switch (m) { - case 0: /* executable */ - mod->core_layout.size = strict_align(mod->core_layout.size); - mod->core_layout.text_size = mod->core_layout.size; - break; - case 1: /* RO: text and ro-data */ - mod->data_layout.size = strict_align(mod->data_layout.size); - mod->data_layout.ro_size = mod->data_layout.size; - break; - case 2: /* RO after init */ - mod->data_layout.size = strict_align(mod->data_layout.size); - mod->data_layout.ro_after_init_size = mod->data_layout.size; - break; - case 4: /* whole core */ - mod->data_layout.size = strict_align(mod->data_layout.size); - break; - } - } - - pr_debug("Init section allocation order:\n"); - for (m = 0; m < ARRAY_SIZE(masks); ++m) { - for (i = 0; i < info->hdr->e_shnum; ++i) { - Elf_Shdr *s = &info->sechdrs[i]; - const char *sname = info->secstrings + s->sh_name; - if ((s->sh_flags & masks[m][0]) != masks[m][0] - || (s->sh_flags & masks[m][1]) - || s->sh_entsize != ~0UL - || !module_init_layout_section(sname)) + if (WARN_ON_ONCE(type == MOD_INVALID)) continue; - s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i) - | INIT_OFFSET_MASK); + + s->sh_entsize = module_get_offset_and_type(mod, type, s, i); pr_debug("\t%s\n", sname); } - switch (m) { - case 0: /* executable */ - mod->init_layout.size = strict_align(mod->init_layout.size); - mod->init_layout.text_size = mod->init_layout.size; - break; - case 1: /* RO: text and ro-data */ - mod->init_layout.size = strict_align(mod->init_layout.size); - mod->init_layout.ro_size = mod->init_layout.size; - break; - case 2: - /* - * RO after init doesn't apply to init_layout (only - * core_layout), so it just takes the value of ro_size. - */ - mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; - break; - case 4: /* whole init */ - mod->init_layout.size = strict_align(mod->init_layout.size); - break; - } } } +/* + * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld + * might -- code, read-only data, read-write data, small data. Tally + * sizes, and place the offsets into sh_entsize fields: high bit means it + * belongs in init. + */ +static void layout_sections(struct module *mod, struct load_info *info) +{ + unsigned int i; + + for (i = 0; i < info->hdr->e_shnum; i++) + info->sechdrs[i].sh_entsize = ~0UL; + + pr_debug("Core section allocation order:\n"); + __layout_sections(mod, info, false); + + pr_debug("Init section allocation order:\n"); + __layout_sections(mod, info, true); +} + static void set_license(struct module *mod, const char *license) { if (!license) @@ -2122,72 +2149,41 @@ static int move_module(struct module *mod, struct load_info *info) { int i; void *ptr; + enum mod_mem_type t; - /* Do the allocs. */ - ptr = module_alloc(mod->core_layout.size); - /* - * The pointer to this block is stored in the module structure - * which is inside the block. Just mark it as not being a - * leak. - */ - kmemleak_not_leak(ptr); - if (!ptr) - return -ENOMEM; - - memset(ptr, 0, mod->core_layout.size); - mod->core_layout.base = ptr; + for_each_mod_mem_type(type) { + if (!mod->mem[type].size) { + mod->mem[type].base = NULL; + continue; + } + mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size); + ptr = module_memory_alloc(mod->mem[type].size, type); - if (mod->init_layout.size) { - ptr = module_alloc(mod->init_layout.size); /* * The pointer to this block is stored in the module structure - * which is inside the block. This block doesn't need to be - * scanned as it contains data and code that will be freed - * after the module is initialized. + * which is inside the block. Just mark it as not being a + * leak. */ kmemleak_ignore(ptr); if (!ptr) { - module_memfree(mod->core_layout.base); - return -ENOMEM; + t = type; + goto out_enomem; } - memset(ptr, 0, mod->init_layout.size); - mod->init_layout.base = ptr; - } else - mod->init_layout.base = NULL; - -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - /* Do the allocs. */ - ptr = vzalloc(mod->data_layout.size); - /* - * The pointer to this block is stored in the module structure - * which is inside the block. Just mark it as not being a - * leak. - */ - kmemleak_not_leak(ptr); - if (!ptr) { - module_memfree(mod->core_layout.base); - module_memfree(mod->init_layout.base); - return -ENOMEM; + memset(ptr, 0, mod->mem[type].size); + mod->mem[type].base = ptr; } - mod->data_layout.base = ptr; -#endif /* Transfer each section which specifies SHF_ALLOC */ pr_debug("final section addresses:\n"); for (i = 0; i < info->hdr->e_shnum; i++) { void *dest; Elf_Shdr *shdr = &info->sechdrs[i]; + enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT; if (!(shdr->sh_flags & SHF_ALLOC)) continue; - if (shdr->sh_entsize & INIT_OFFSET_MASK) - dest = mod->init_layout.base - + (shdr->sh_entsize & ~INIT_OFFSET_MASK); - else if (!(shdr->sh_flags & SHF_EXECINSTR)) - dest = mod->data_layout.base + shdr->sh_entsize; - else - dest = mod->core_layout.base + shdr->sh_entsize; + dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK); if (shdr->sh_type != SHT_NOBITS) memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); @@ -2198,6 +2194,10 @@ static int move_module(struct module *mod, struct load_info *info) } return 0; +out_enomem: + for (t--; t >= 0; t--) + module_memory_free(mod->mem[t].base, t); + return -ENOMEM; } static int check_module_license_and_versions(struct module *mod) @@ -2242,12 +2242,14 @@ static void flush_module_icache(const struct module *mod) * Do it before processing of module parameters, so the module * can provide parameter accessor functions of its own. */ - if (mod->init_layout.base) - flush_icache_range((unsigned long)mod->init_layout.base, - (unsigned long)mod->init_layout.base - + mod->init_layout.size); - flush_icache_range((unsigned long)mod->core_layout.base, - (unsigned long)mod->core_layout.base + mod->core_layout.size); + for_each_mod_mem_type(type) { + const struct module_memory *mod_mem = &mod->mem[type]; + + if (mod_mem->size) { + flush_icache_range((unsigned long)mod_mem->base, + (unsigned long)mod_mem->base + mod_mem->size); + } + } } bool __weak module_elf_check_arch(Elf_Ehdr *hdr) @@ -2350,11 +2352,8 @@ static void module_deallocate(struct module *mod, struct load_info *info) { percpu_modfree(mod); module_arch_freeing_init(mod); - module_memfree(mod->init_layout.base); - module_memfree(mod->core_layout.base); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - vfree(mod->data_layout.base); -#endif + + free_mod_mem(mod); } int __weak module_finalize(const Elf_Ehdr *hdr, @@ -2415,7 +2414,9 @@ static void do_mod_ctors(struct module *mod) /* For freeing module_init on success, in case kallsyms traversing */ struct mod_initfree { struct llist_node node; - void *module_init; + void *init_text; + void *init_data; + void *init_rodata; }; static void do_free_init(struct work_struct *w) @@ -2429,7 +2430,9 @@ static void do_free_init(struct work_struct *w) llist_for_each_safe(pos, n, list) { initfree = container_of(pos, struct mod_initfree, node); - module_memfree(initfree->module_init); + module_memfree(initfree->init_text); + module_memfree(initfree->init_data); + module_memfree(initfree->init_rodata); kfree(initfree); } } @@ -2456,7 +2459,9 @@ static noinline int do_init_module(struct module *mod) ret = -ENOMEM; goto fail; } - freeinit->module_init = mod->init_layout.base; + freeinit->init_text = mod->mem[MOD_INIT_TEXT].base; + freeinit->init_data = mod->mem[MOD_INIT_DATA].base; + freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base; do_mod_ctors(mod); /* Start the module */ @@ -2492,8 +2497,8 @@ static noinline int do_init_module(struct module *mod) if (!mod->async_probe_requested) async_synchronize_full(); - ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + - mod->init_layout.size); + ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base, + mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size); mutex_lock(&module_mutex); /* Drop initial reference. */ module_put(mod); @@ -2505,11 +2510,10 @@ static noinline int do_init_module(struct module *mod) module_enable_ro(mod, true); mod_tree_remove_init(mod); module_arch_freeing_init(mod); - mod->init_layout.base = NULL; - mod->init_layout.size = 0; - mod->init_layout.ro_size = 0; - mod->init_layout.ro_after_init_size = 0; - mod->init_layout.text_size = 0; + for_class_mod_mem_type(type, init) { + mod->mem[type].base = NULL; + mod->mem[type].size = 0; + } #ifdef CONFIG_DEBUG_INFO_BTF_MODULES /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */ mod->btf_data = NULL; @@ -2628,9 +2632,6 @@ static int complete_formation(struct module *mod, struct load_info *info) module_bug_finalize(info->hdr, info->sechdrs, mod); module_cfi_finalize(info->hdr, info->sechdrs, mod); - if (module_check_misalignment(mod)) - goto out_misaligned; - module_enable_ro(mod, false); module_enable_nx(mod); module_enable_x(mod); @@ -2644,8 +2645,6 @@ static int complete_formation(struct module *mod, struct load_info *info) return 0; -out_misaligned: - err = -EINVAL; out: mutex_unlock(&module_mutex); return err; @@ -2909,7 +2908,10 @@ static int load_module(struct load_info *info, const char __user *uargs, mutex_unlock(&module_mutex); free_module: /* Free lock-classes; relies on the preceding sync_rcu() */ - lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size); + for_class_mod_mem_type(type, core_data) { + lockdep_free_key_range(mod->mem[type].base, + mod->mem[type].size); + } module_deallocate(mod, info); free_copy: @@ -3060,20 +3062,21 @@ bool is_module_address(unsigned long addr) struct module *__module_address(unsigned long addr) { struct module *mod; - struct mod_tree_root *tree; if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max) - tree = &mod_tree; + goto lookup; + #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max) - tree = &mod_data_tree; + if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max) + goto lookup; #endif - else - return NULL; + return NULL; + +lookup: module_assert_mutex_or_preempt(); - mod = mod_find(addr, tree); + mod = mod_find(addr, &mod_tree); if (mod) { BUG_ON(!within_module(addr, mod)); if (mod->state == MODULE_STATE_UNFORMED) @@ -3113,8 +3116,8 @@ struct module *__module_text_address(unsigned long addr) struct module *mod = __module_address(addr); if (mod) { /* Make sure it's within the text section. */ - if (!within(addr, mod->init_layout.base, mod->init_layout.text_size) - && !within(addr, mod->core_layout.base, mod->core_layout.text_size)) + if (!within_module_mem_type(addr, mod, MOD_TEXT) && + !within_module_mem_type(addr, mod, MOD_INIT_TEXT)) mod = NULL; } return mod; diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c index cf5b9f1e6ec4..0a4841e88adb 100644 --- a/kernel/module/procfs.c +++ b/kernel/module/procfs.c @@ -62,6 +62,15 @@ static void m_stop(struct seq_file *m, void *p) mutex_unlock(&module_mutex); } +static unsigned int module_total_size(struct module *mod) +{ + int size = 0; + + for_each_mod_mem_type(type) + size += mod->mem[type].size; + return size; +} + static int m_show(struct seq_file *m, void *p) { struct module *mod = list_entry(p, struct module, list); @@ -73,10 +82,7 @@ static int m_show(struct seq_file *m, void *p) if (mod->state == MODULE_STATE_UNFORMED) return 0; - size = mod->init_layout.size + mod->core_layout.size; -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - size += mod->data_layout.size; -#endif + size = module_total_size(mod); seq_printf(m, "%s %u", mod->name, size); print_unload_info(m, mod); @@ -86,7 +92,7 @@ static int m_show(struct seq_file *m, void *p) mod->state == MODULE_STATE_COMING ? "Loading" : "Live"); /* Used by oprofile and other similar tools. */ - value = m->private ? NULL : mod->core_layout.base; + value = m->private ? NULL : mod->mem[MOD_TEXT].base; seq_printf(m, " 0x%px", value); /* Taints info */ diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c index 14fbea66f12f..a2b656b4e3d2 100644 --- a/kernel/module/strict_rwx.c +++ b/kernel/module/strict_rwx.c @@ -11,82 +11,25 @@ #include <linux/set_memory.h> #include "internal.h" -/* - * LKM RO/NX protection: protect module's text/ro-data - * from modification and any data from execution. - * - * General layout of module is: - * [text] [read-only-data] [ro-after-init] [writable data] - * text_size -----^ ^ ^ ^ - * ro_size ------------------------| | | - * ro_after_init_size -----------------------------| | - * size -----------------------------------------------------------| - * - * These values are always page-aligned (as is base) when - * CONFIG_STRICT_MODULE_RWX is set. - */ +static void module_set_memory(const struct module *mod, enum mod_mem_type type, + int (*set_memory)(unsigned long start, int num_pages)) +{ + const struct module_memory *mod_mem = &mod->mem[type]; + + set_vm_flush_reset_perms(mod_mem->base); + set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT); +} /* * Since some arches are moving towards PAGE_KERNEL module allocations instead - * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() independent of + * of PAGE_KERNEL_EXEC, keep module_enable_x() independent of * CONFIG_STRICT_MODULE_RWX because they are needed regardless of whether we * are strict. */ -static void frob_text(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - set_memory((unsigned long)layout->base, - PAGE_ALIGN(layout->text_size) >> PAGE_SHIFT); -} - -static void frob_rodata(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - set_memory((unsigned long)layout->base + layout->text_size, - (layout->ro_size - layout->text_size) >> PAGE_SHIFT); -} - -static void frob_ro_after_init(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - set_memory((unsigned long)layout->base + layout->ro_size, - (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); -} - -static void frob_writable_data(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - set_memory((unsigned long)layout->base + layout->ro_after_init_size, - (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); -} - -static bool layout_check_misalignment(const struct module_layout *layout) -{ - return WARN_ON(!PAGE_ALIGNED(layout->base)) || - WARN_ON(!PAGE_ALIGNED(layout->text_size)) || - WARN_ON(!PAGE_ALIGNED(layout->ro_size)) || - WARN_ON(!PAGE_ALIGNED(layout->ro_after_init_size)) || - WARN_ON(!PAGE_ALIGNED(layout->size)); -} - -bool module_check_misalignment(const struct module *mod) -{ - if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) - return false; - - return layout_check_misalignment(&mod->core_layout) || - layout_check_misalignment(&mod->data_layout) || - layout_check_misalignment(&mod->init_layout); -} - void module_enable_x(const struct module *mod) { - if (!PAGE_ALIGNED(mod->core_layout.base) || - !PAGE_ALIGNED(mod->init_layout.base)) - return; - - frob_text(&mod->core_layout, set_memory_x); - frob_text(&mod->init_layout, set_memory_x); + for_class_mod_mem_type(type, text) + module_set_memory(mod, type, set_memory_x); } void module_enable_ro(const struct module *mod, bool after_init) @@ -98,16 +41,13 @@ void module_enable_ro(const struct module *mod, bool after_init) return; #endif - set_vm_flush_reset_perms(mod->core_layout.base); - set_vm_flush_reset_perms(mod->init_layout.base); - frob_text(&mod->core_layout, set_memory_ro); - - frob_rodata(&mod->data_layout, set_memory_ro); - frob_text(&mod->init_layout, set_memory_ro); - frob_rodata(&mod->init_layout, set_memory_ro); + module_set_memory(mod, MOD_TEXT, set_memory_ro); + module_set_memory(mod, MOD_INIT_TEXT, set_memory_ro); + module_set_memory(mod, MOD_RODATA, set_memory_ro); + module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro); if (after_init) - frob_ro_after_init(&mod->data_layout, set_memory_ro); + module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro); } void module_enable_nx(const struct module *mod) @@ -115,11 +55,8 @@ void module_enable_nx(const struct module *mod) if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) return; - frob_rodata(&mod->data_layout, set_memory_nx); - frob_ro_after_init(&mod->data_layout, set_memory_nx); - frob_writable_data(&mod->data_layout, set_memory_nx); - frob_rodata(&mod->init_layout, set_memory_nx); - frob_writable_data(&mod->init_layout, set_memory_nx); + for_class_mod_mem_type(type, data) + module_set_memory(mod, type, set_memory_nx); } int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c index 8ec5cfd60496..277197977d43 100644 --- a/kernel/module/tree_lookup.c +++ b/kernel/module/tree_lookup.c @@ -21,16 +21,16 @@ static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) { - struct module_layout *layout = container_of(n, struct module_layout, mtn.node); + struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node); - return (unsigned long)layout->base; + return (unsigned long)mod_mem->base; } static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) { - struct module_layout *layout = container_of(n, struct module_layout, mtn.node); + struct module_memory *mod_mem = container_of(n, struct module_memory, mtn.node); - return (unsigned long)layout->size; + return (unsigned long)mod_mem->size; } static __always_inline bool @@ -77,32 +77,27 @@ static void __mod_tree_remove(struct mod_tree_node *node, struct mod_tree_root * */ void mod_tree_insert(struct module *mod) { - mod->core_layout.mtn.mod = mod; - mod->init_layout.mtn.mod = mod; - - __mod_tree_insert(&mod->core_layout.mtn, &mod_tree); - if (mod->init_layout.size) - __mod_tree_insert(&mod->init_layout.mtn, &mod_tree); - -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - mod->data_layout.mtn.mod = mod; - __mod_tree_insert(&mod->data_layout.mtn, &mod_data_tree); -#endif + for_each_mod_mem_type(type) { + mod->mem[type].mtn.mod = mod; + if (mod->mem[type].size) + __mod_tree_insert(&mod->mem[type].mtn, &mod_tree); + } } void mod_tree_remove_init(struct module *mod) { - if (mod->init_layout.size) - __mod_tree_remove(&mod->init_layout.mtn, &mod_tree); + for_class_mod_mem_type(type, init) { + if (mod->mem[type].size) + __mod_tree_remove(&mod->mem[type].mtn, &mod_tree); + } } void mod_tree_remove(struct module *mod) { - __mod_tree_remove(&mod->core_layout.mtn, &mod_tree); - mod_tree_remove_init(mod); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - __mod_tree_remove(&mod->data_layout.mtn, &mod_data_tree); -#endif + for_each_mod_mem_type(type) { + if (mod->mem[type].size) + __mod_tree_remove(&mod->mem[type].mtn, &mod_tree); + } } struct module *mod_find(unsigned long addr, struct mod_tree_root *tree) |