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module: replace module_layout with module_memory

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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>
This commit is contained in:
Song Liu
2023-02-06 16:28:02 -08:00
committed by Luis Chamberlain
parent fe15c26ee2
commit ac3b432839
18 changed files with 437 additions and 477 deletions
Download Patch File Download Diff File Expand all files Collapse all files

89
include/linux/module.h
View File

@@ -320,17 +320,47 @@ struct mod_tree_node {
struct latch_tree_node node;
};
struct module_layout {
/* The actual code + data. */
enum mod_mem_type {
MOD_TEXT = 0,
MOD_DATA,
MOD_RODATA,
MOD_RO_AFTER_INIT,
MOD_INIT_TEXT,
MOD_INIT_DATA,
MOD_INIT_RODATA,
MOD_MEM_NUM_TYPES,
MOD_INVALID = -1,
};
#define mod_mem_type_is_init(type) \
((type) == MOD_INIT_TEXT || \
(type) == MOD_INIT_DATA || \
(type) == MOD_INIT_RODATA)
#define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
#define mod_mem_type_is_text(type) \
((type) == MOD_TEXT || \
(type) == MOD_INIT_TEXT)
#define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
#define mod_mem_type_is_core_data(type) \
(mod_mem_type_is_core(type) && \
mod_mem_type_is_data(type))
#define for_each_mod_mem_type(type) \
for (enum mod_mem_type (type) = 0; \
(type) < MOD_MEM_NUM_TYPES; (type)++)
#define for_class_mod_mem_type(type, class) \
for_each_mod_mem_type(type) \
if (mod_mem_type_is_##class(type))
struct module_memory {
void *base;
/* Total size. */
unsigned int size;
/* The size of the executable code. */
unsigned int text_size;
/* Size of RO section of the module (text+rodata) */
unsigned int ro_size;
/* Size of RO after init section */
unsigned int ro_after_init_size;
#ifdef CONFIG_MODULES_TREE_LOOKUP
struct mod_tree_node mtn;
@@ -339,9 +369,9 @@ struct module_layout {
#ifdef CONFIG_MODULES_TREE_LOOKUP
/* Only touch one cacheline for common rbtree-for-core-layout case. */
#define __module_layout_align ____cacheline_aligned
#define __module_memory_align ____cacheline_aligned
#else
#define __module_layout_align
#define __module_memory_align
#endif
struct mod_kallsyms {
@@ -426,12 +456,7 @@ struct module {
/* Startup function. */
int (*init)(void);
/* Core layout: rbtree is accessed frequently, so keep together. */
struct module_layout core_layout __module_layout_align;
struct module_layout init_layout;
#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
struct module_layout data_layout;
#endif
struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
/* Arch-specific module values */
struct mod_arch_specific arch;
@@ -581,23 +606,35 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
bool is_module_percpu_address(unsigned long addr);
bool is_module_text_address(unsigned long addr);
static inline bool within_module_mem_type(unsigned long addr,
const struct module *mod,
enum mod_mem_type type)
{
unsigned long base, size;
base = (unsigned long)mod->mem[type].base;
size = mod->mem[type].size;
return addr - base < size;
}
static inline bool within_module_core(unsigned long addr,
const struct module *mod)
{
#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
if ((unsigned long)mod->data_layout.base <= addr &&
addr < (unsigned long)mod->data_layout.base + mod->data_layout.size)
return true;
#endif
return (unsigned long)mod->core_layout.base <= addr &&
addr < (unsigned long)mod->core_layout.base + mod->core_layout.size;
for_class_mod_mem_type(type, core) {
if (within_module_mem_type(addr, mod, type))
return true;
}
return false;
}
static inline bool within_module_init(unsigned long addr,
const struct module *mod)
{
return (unsigned long)mod->init_layout.base <= addr &&
addr < (unsigned long)mod->init_layout.base + mod->init_layout.size;
for_class_mod_mem_type(type, init) {
if (within_module_mem_type(addr, mod, type))
return true;
}
return false;
}
static inline bool within_module(unsigned long addr, const struct module *mod)