[v7,05/16] module: make module_memory_{alloc,free} more self-contained

Commit Message

Mike Rapoport April 29, 2024, 12:16 p.m. UTC

From: "Mike Rapoport (IBM)" <[e-mail]>

Move the logic related to the memory allocation and freeing into
module_memory_alloc() and module_memory_free().

Signed-off-by: Mike Rapoport (IBM) <[e-mail]>
---
 kernel/module/main.c | 64 +++++++++++++++++++++++++++-----------------
 1 file changed, 39 insertions(+), 25 deletions(-)

Comments

Philippe Mathieu-Daudé April 30, 2024, 12:41 p.m. UTC | #1

On 29/4/24 14:16, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[e-mail]>
> 
> Move the logic related to the memory allocation and freeing into
> module_memory_alloc() and module_memory_free().
> 
> Signed-off-by: Mike Rapoport (IBM) <[e-mail]>
> ---
>   kernel/module/main.c | 64 +++++++++++++++++++++++++++-----------------
>   1 file changed, 39 insertions(+), 25 deletions(-)

Nice code simplification.

Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>

Patch

diff --git a/kernel/module/main.c b/kernel/module/main.c
index e1e8a7a9d6c1..5b82b069e0d3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1203,15 +1203,44 @@  static bool mod_mem_use_vmalloc(enum mod_mem_type type)
 		mod_mem_type_is_core_data(type);
 }
 
-static void *module_memory_alloc(unsigned int size, enum mod_mem_type type)
+static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
 {
+	unsigned int size = PAGE_ALIGN(mod->mem[type].size);
+	void *ptr;
+
+	mod->mem[type].size = size;
+
 	if (mod_mem_use_vmalloc(type))
-		return vzalloc(size);
-	return module_alloc(size);
+		ptr = vmalloc(size);
+	else
+		ptr = module_alloc(size);
+
+	if (!ptr)
+		return -ENOMEM;
+
+	/*
+	 * The pointer to these blocks of memory are stored on the module
+	 * structure and we keep that around so long as the module is
+	 * around. We only free that memory when we unload the module.
+	 * Just mark them as not being a leak then. The .init* ELF
+	 * sections *do* get freed after boot so we *could* treat them
+	 * slightly differently with kmemleak_ignore() and only grey
+	 * them out as they work as typical memory allocations which
+	 * *do* eventually get freed, but let's just keep things simple
+	 * and avoid *any* false positives.
+	 */
+	kmemleak_not_leak(ptr);
+
+	memset(ptr, 0, size);
+	mod->mem[type].base = ptr;
+
+	return 0;
 }
 
-static void module_memory_free(void *ptr, enum mod_mem_type type)
+static void module_memory_free(struct module *mod, enum mod_mem_type type)
 {
+	void *ptr = mod->mem[type].base;
+
 	if (mod_mem_use_vmalloc(type))
 		vfree(ptr);
 	else
@@ -1229,12 +1258,12 @@  static void free_mod_mem(struct module *mod)
 		/* 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);
+			module_memory_free(mod, 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);
+	module_memory_free(mod, MOD_DATA);
 }
 
 /* Free a module, remove from lists, etc. */
@@ -2225,7 +2254,6 @@  static int find_module_sections(struct module *mod, struct load_info *info)
 static int move_module(struct module *mod, struct load_info *info)
 {
 	int i;
-	void *ptr;
 	enum mod_mem_type t = 0;
 	int ret = -ENOMEM;
 
@@ -2234,26 +2262,12 @@  static int move_module(struct module *mod, struct load_info *info)
 			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);
-		/*
-                 * The pointer to these blocks of memory are stored on the module
-                 * structure and we keep that around so long as the module is
-                 * around. We only free that memory when we unload the module.
-                 * Just mark them as not being a leak then. The .init* ELF
-                 * sections *do* get freed after boot so we *could* treat them
-                 * slightly differently with kmemleak_ignore() and only grey
-                 * them out as they work as typical memory allocations which
-                 * *do* eventually get freed, but let's just keep things simple
-                 * and avoid *any* false positives.
-		 */
-		kmemleak_not_leak(ptr);
-		if (!ptr) {
+
+		ret = module_memory_alloc(mod, type);
+		if (ret) {
 			t = type;
 			goto out_enomem;
 		}
-		memset(ptr, 0, mod->mem[type].size);
-		mod->mem[type].base = ptr;
 	}
 
 	/* Transfer each section which specifies SHF_ALLOC */
@@ -2296,7 +2310,7 @@  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);
+		module_memory_free(mod, t);
 	return ret;
 }