module: refactor load_module part 2
Here's a second one. It's slightly less trivial - since we now have error
cases - and equally untested so it may well be totally broken. But it also
cleans up a bit more, and avoids one of the goto targets, because the
"move_module()" helper now does both allocations or none.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/kernel/module.c b/kernel/module.c
index 12905ed..19ddcb0 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2082,7 +2082,8 @@
#ifdef CONFIG_DEBUG_KMEMLEAK
static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
- Elf_Shdr *sechdrs, char *secstrings)
+ const Elf_Shdr *sechdrs,
+ const char *secstrings)
{
unsigned int i;
@@ -2102,7 +2103,8 @@
}
#else
static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
- Elf_Shdr *sechdrs, char *secstrings)
+ Elf_Shdr *sechdrs,
+ const char *secstrings)
{
}
#endif
@@ -2172,6 +2174,70 @@
#endif
}
+static struct module *move_module(struct module *mod,
+ Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ const char *secstrings, unsigned modindex)
+{
+ int i;
+ void *ptr;
+
+ /* Do the allocs. */
+ ptr = module_alloc_update_bounds(mod->core_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 ERR_PTR(-ENOMEM);
+
+ memset(ptr, 0, mod->core_size);
+ mod->module_core = ptr;
+
+ ptr = module_alloc_update_bounds(mod->init_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.
+ */
+ kmemleak_ignore(ptr);
+ if (!ptr && mod->init_size) {
+ module_free(mod, mod->module_core);
+ return ERR_PTR(-ENOMEM);
+ }
+ memset(ptr, 0, mod->init_size);
+ mod->module_init = ptr;
+
+ /* Transfer each section which specifies SHF_ALLOC */
+ DEBUGP("final section addresses:\n");
+ for (i = 0; i < hdr->e_shnum; i++) {
+ void *dest;
+
+ if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+ continue;
+
+ if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
+ dest = mod->module_init
+ + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
+ else
+ dest = mod->module_core + sechdrs[i].sh_entsize;
+
+ if (sechdrs[i].sh_type != SHT_NOBITS)
+ memcpy(dest, (void *)sechdrs[i].sh_addr,
+ sechdrs[i].sh_size);
+ /* Update sh_addr to point to copy in image. */
+ sechdrs[i].sh_addr = (unsigned long)dest;
+ DEBUGP("\t0x%lx %s\n",
+ sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
+ }
+ /* Module has been moved. */
+ mod = (void *)sechdrs[modindex].sh_addr;
+ kmemleak_load_module(mod, hdr, sechdrs, secstrings);
+ return mod;
+}
+
/* Allocate and load the module: note that size of section 0 is always
zero, and we rely on this for optional sections. */
static noinline struct module *load_module(void __user *umod,
@@ -2188,7 +2254,6 @@
unsigned int modindex, versindex, infoindex, pcpuindex;
struct module *mod;
long err = 0;
- void *ptr = NULL; /* Stops spurious gcc warning */
unsigned long symoffs, stroffs, *strmap;
void __percpu *percpu;
struct _ddebug *debug = NULL;
@@ -2342,61 +2407,12 @@
symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
secstrings, &stroffs, strmap);
- /* Do the allocs. */
- ptr = module_alloc_update_bounds(mod->core_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) {
- err = -ENOMEM;
+ /* Allocate and move to the final place */
+ mod = move_module(mod, hdr, sechdrs, secstrings, modindex);
+ if (IS_ERR(mod)) {
+ err = PTR_ERR(mod);
goto free_percpu;
}
- memset(ptr, 0, mod->core_size);
- mod->module_core = ptr;
-
- ptr = module_alloc_update_bounds(mod->init_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.
- */
- kmemleak_ignore(ptr);
- if (!ptr && mod->init_size) {
- err = -ENOMEM;
- goto free_core;
- }
- memset(ptr, 0, mod->init_size);
- mod->module_init = ptr;
-
- /* Transfer each section which specifies SHF_ALLOC */
- DEBUGP("final section addresses:\n");
- for (i = 0; i < hdr->e_shnum; i++) {
- void *dest;
-
- if (!(sechdrs[i].sh_flags & SHF_ALLOC))
- continue;
-
- if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
- dest = mod->module_init
- + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
- else
- dest = mod->module_core + sechdrs[i].sh_entsize;
-
- if (sechdrs[i].sh_type != SHT_NOBITS)
- memcpy(dest, (void *)sechdrs[i].sh_addr,
- sechdrs[i].sh_size);
- /* Update sh_addr to point to copy in image. */
- sechdrs[i].sh_addr = (unsigned long)dest;
- DEBUGP("\t0x%lx %s\n",
- sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
- }
- /* Module has been moved. */
- mod = (void *)sechdrs[modindex].sh_addr;
- kmemleak_load_module(mod, hdr, sechdrs, secstrings);
#if defined(CONFIG_MODULE_UNLOAD)
mod->refptr = alloc_percpu(struct module_ref);
@@ -2580,7 +2596,6 @@
free_init:
#endif
module_free(mod, mod->module_init);
- free_core:
module_free(mod, mod->module_core);
/* mod will be freed with core. Don't access it beyond this line! */
free_percpu: