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authorSong Liu <song@kernel.org>2023-02-07 01:28:02 +0100
committerLuis Chamberlain <mcgrof@kernel.org>2023-03-09 21:55:15 +0100
commitac3b43283923440900b4f36ca5f9f0b1ca43b70e (patch)
tree32430a7fa302c652cd2fc675dc0435e0792b9710 /kernel/module
parentLinux 6.3-rc1 (diff)
downloadlinux-ac3b43283923440900b4f36ca5f9f0b1ca43b70e.tar.xz
linux-ac3b43283923440900b4f36ca5f9f0b1ca43b70e.zip
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/module')
-rw-r--r--kernel/module/internal.h40
-rw-r--r--kernel/module/kallsyms.c58
-rw-r--r--kernel/module/kdb.c17
-rw-r--r--kernel/module/main.c375
-rw-r--r--kernel/module/procfs.c16
-rw-r--r--kernel/module/strict_rwx.c99
-rw-r--r--kernel/module/tree_lookup.c39
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)