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>

1 files changed, 17 insertions, 22 deletions

diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
index 8ec5cfd604964..277197977d438 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)