Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6.git] / kernel / module.c
index fe748a8..c968d36 100644 (file)
@@ -370,8 +370,6 @@ EXPORT_SYMBOL_GPL(find_module);
 
 #ifdef CONFIG_SMP
 
-#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
-
 static void *percpu_modalloc(unsigned long size, unsigned long align,
                             const char *name)
 {
@@ -395,154 +393,6 @@ static void percpu_modfree(void *freeme)
        free_percpu(freeme);
 }
 
-#else /* ... CONFIG_HAVE_LEGACY_PER_CPU_AREA */
-
-/* Number of blocks used and allocated. */
-static unsigned int pcpu_num_used, pcpu_num_allocated;
-/* Size of each block.  -ve means used. */
-static int *pcpu_size;
-
-static int split_block(unsigned int i, unsigned short size)
-{
-       /* Reallocation required? */
-       if (pcpu_num_used + 1 > pcpu_num_allocated) {
-               int *new;
-
-               new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
-                              GFP_KERNEL);
-               if (!new)
-                       return 0;
-
-               pcpu_num_allocated *= 2;
-               pcpu_size = new;
-       }
-
-       /* Insert a new subblock */
-       memmove(&pcpu_size[i+1], &pcpu_size[i],
-               sizeof(pcpu_size[0]) * (pcpu_num_used - i));
-       pcpu_num_used++;
-
-       pcpu_size[i+1] -= size;
-       pcpu_size[i] = size;
-       return 1;
-}
-
-static inline unsigned int block_size(int val)
-{
-       if (val < 0)
-               return -val;
-       return val;
-}
-
-static void *percpu_modalloc(unsigned long size, unsigned long align,
-                            const char *name)
-{
-       unsigned long extra;
-       unsigned int i;
-       void *ptr;
-       int cpu;
-
-       if (align > PAGE_SIZE) {
-               printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
-                      name, align, PAGE_SIZE);
-               align = PAGE_SIZE;
-       }
-
-       ptr = __per_cpu_start;
-       for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
-               /* Extra for alignment requirement. */
-               extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
-               BUG_ON(i == 0 && extra != 0);
-
-               if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
-                       continue;
-
-               /* Transfer extra to previous block. */
-               if (pcpu_size[i-1] < 0)
-                       pcpu_size[i-1] -= extra;
-               else
-                       pcpu_size[i-1] += extra;
-               pcpu_size[i] -= extra;
-               ptr += extra;
-
-               /* Split block if warranted */
-               if (pcpu_size[i] - size > sizeof(unsigned long))
-                       if (!split_block(i, size))
-                               return NULL;
-
-               /* add the per-cpu scanning areas */
-               for_each_possible_cpu(cpu)
-                       kmemleak_alloc(ptr + per_cpu_offset(cpu), size, 0,
-                                      GFP_KERNEL);
-
-               /* Mark allocated */
-               pcpu_size[i] = -pcpu_size[i];
-               return ptr;
-       }
-
-       printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
-              size);
-       return NULL;
-}
-
-static void percpu_modfree(void *freeme)
-{
-       unsigned int i;
-       void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
-       int cpu;
-
-       /* First entry is core kernel percpu data. */
-       for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
-               if (ptr == freeme) {
-                       pcpu_size[i] = -pcpu_size[i];
-                       goto free;
-               }
-       }
-       BUG();
-
- free:
-       /* remove the per-cpu scanning areas */
-       for_each_possible_cpu(cpu)
-               kmemleak_free(freeme + per_cpu_offset(cpu));
-
-       /* Merge with previous? */
-       if (pcpu_size[i-1] >= 0) {
-               pcpu_size[i-1] += pcpu_size[i];
-               pcpu_num_used--;
-               memmove(&pcpu_size[i], &pcpu_size[i+1],
-                       (pcpu_num_used - i) * sizeof(pcpu_size[0]));
-               i--;
-       }
-       /* Merge with next? */
-       if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
-               pcpu_size[i] += pcpu_size[i+1];
-               pcpu_num_used--;
-               memmove(&pcpu_size[i+1], &pcpu_size[i+2],
-                       (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
-       }
-}
-
-static int percpu_modinit(void)
-{
-       pcpu_num_used = 2;
-       pcpu_num_allocated = 2;
-       pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
-                           GFP_KERNEL);
-       /* Static in-kernel percpu data (used). */
-       pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
-       /* Free room. */
-       pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
-       if (pcpu_size[1] < 0) {
-               printk(KERN_ERR "No per-cpu room for modules.\n");
-               pcpu_num_used = 1;
-       }
-
-       return 0;
-}
-__initcall(percpu_modinit);
-
-#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
-
 static unsigned int find_pcpusec(Elf_Ehdr *hdr,
                                 Elf_Shdr *sechdrs,
                                 const char *secstrings)
@@ -624,9 +474,10 @@ static void module_unload_init(struct module *mod)
 
        INIT_LIST_HEAD(&mod->modules_which_use_me);
        for_each_possible_cpu(cpu)
-               local_set(__module_ref_addr(mod, cpu), 0);
+               per_cpu_ptr(mod->refptr, cpu)->count = 0;
+
        /* Hold reference count during initialization. */
-       local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
+       __this_cpu_write(mod->refptr->count, 1);
        /* Backwards compatibility macros put refcount during init. */
        mod->waiter = current;
 }
@@ -769,7 +620,7 @@ unsigned int module_refcount(struct module *mod)
        int cpu;
 
        for_each_possible_cpu(cpu)
-               total += local_read(__module_ref_addr(mod, cpu));
+               total += per_cpu_ptr(mod->refptr, cpu)->count;
        return total;
 }
 EXPORT_SYMBOL(module_refcount);
@@ -946,14 +797,15 @@ static struct module_attribute refcnt = {
 void module_put(struct module *module)
 {
        if (module) {
-               unsigned int cpu = get_cpu();
-               local_dec(__module_ref_addr(module, cpu));
+               preempt_disable();
+               __this_cpu_dec(module->refptr->count);
+
                trace_module_put(module, _RET_IP_,
-                                local_read(__module_ref_addr(module, cpu)));
+                                __this_cpu_read(module->refptr->count));
                /* Maybe they're waiting for us to drop reference? */
                if (unlikely(!module_is_live(module)))
                        wake_up_process(module->waiter);
-               put_cpu();
+               preempt_enable();
        }
 }
 EXPORT_SYMBOL(module_put);
@@ -1030,11 +882,23 @@ static int try_to_force_load(struct module *mod, const char *reason)
 }
 
 #ifdef CONFIG_MODVERSIONS
+/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
+static unsigned long maybe_relocated(unsigned long crc,
+                                    const struct module *crc_owner)
+{
+#ifdef ARCH_RELOCATES_KCRCTAB
+       if (crc_owner == NULL)
+               return crc - (unsigned long)reloc_start;
+#endif
+       return crc;
+}
+
 static int check_version(Elf_Shdr *sechdrs,
                         unsigned int versindex,
                         const char *symname,
                         struct module *mod, 
-                        const unsigned long *crc)
+                        const unsigned long *crc,
+                        const struct module *crc_owner)
 {
        unsigned int i, num_versions;
        struct modversion_info *versions;
@@ -1055,10 +919,10 @@ static int check_version(Elf_Shdr *sechdrs,
                if (strcmp(versions[i].name, symname) != 0)
                        continue;
 
-               if (versions[i].crc == *crc)
+               if (versions[i].crc == maybe_relocated(*crc, crc_owner))
                        return 1;
                DEBUGP("Found checksum %lX vs module %lX\n",
-                      *crc, versions[i].crc);
+                      maybe_relocated(*crc, crc_owner), versions[i].crc);
                goto bad_version;
        }
 
@@ -1081,7 +945,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
        if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
                         &crc, true, false))
                BUG();
-       return check_version(sechdrs, versindex, "module_layout", mod, crc);
+       return check_version(sechdrs, versindex, "module_layout", mod, crc,
+                            NULL);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -1099,7 +964,8 @@ static inline int check_version(Elf_Shdr *sechdrs,
                                unsigned int versindex,
                                const char *symname,
                                struct module *mod, 
-                               const unsigned long *crc)
+                               const unsigned long *crc,
+                               const struct module *crc_owner)
 {
        return 1;
 }
@@ -1134,8 +1000,8 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
        /* use_module can fail due to OOM,
           or module initialization or unloading */
        if (sym) {
-               if (!check_version(sechdrs, versindex, name, mod, crc) ||
-                   !use_module(mod, owner))
+               if (!check_version(sechdrs, versindex, name, mod, crc, owner)
+                   || !use_module(mod, owner))
                        sym = NULL;
        }
        return sym;
@@ -1146,6 +1012,12 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
  * J. Corbet <corbet@lwn.net>
  */
 #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
+
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+       return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+
 struct module_sect_attr
 {
        struct module_attribute mattr;
@@ -1187,7 +1059,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
 
        /* Count loaded sections and allocate structures */
        for (i = 0; i < nsect; i++)
-               if (sechdrs[i].sh_flags & SHF_ALLOC)
+               if (!sect_empty(&sechdrs[i]))
                        nloaded++;
        size[0] = ALIGN(sizeof(*sect_attrs)
                        + nloaded * sizeof(sect_attrs->attrs[0]),
@@ -1205,7 +1077,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
        sattr = &sect_attrs->attrs[0];
        gattr = &sect_attrs->grp.attrs[0];
        for (i = 0; i < nsect; i++) {
-               if (! (sechdrs[i].sh_flags & SHF_ALLOC))
+               if (sect_empty(&sechdrs[i]))
                        continue;
                sattr->address = sechdrs[i].sh_addr;
                sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
@@ -1213,6 +1085,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect,
                if (sattr->name == NULL)
                        goto out;
                sect_attrs->nsections++;
+               sysfs_attr_init(&sattr->mattr.attr);
                sattr->mattr.show = module_sect_show;
                sattr->mattr.store = NULL;
                sattr->mattr.attr.name = sattr->name;
@@ -1289,7 +1162,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
        /* Count notes sections and allocate structures.  */
        notes = 0;
        for (i = 0; i < nsect; i++)
-               if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
+               if (!sect_empty(&sechdrs[i]) &&
                    (sechdrs[i].sh_type == SHT_NOTE))
                        ++notes;
 
@@ -1305,9 +1178,10 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
        notes_attrs->notes = notes;
        nattr = &notes_attrs->attrs[0];
        for (loaded = i = 0; i < nsect; ++i) {
-               if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+               if (sect_empty(&sechdrs[i]))
                        continue;
                if (sechdrs[i].sh_type == SHT_NOTE) {
+                       sysfs_bin_attr_init(nattr);
                        nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
                        nattr->attr.mode = S_IRUGO;
                        nattr->size = sechdrs[i].sh_size;
@@ -1380,6 +1254,7 @@ int module_add_modinfo_attrs(struct module *mod)
                if (!attr->test ||
                    (attr->test && attr->test(mod))) {
                        memcpy(temp_attr, attr, sizeof(*temp_attr));
+                       sysfs_attr_init(&temp_attr->attr);
                        error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
                        ++temp_attr;
                }
@@ -1527,9 +1402,9 @@ static void free_module(struct module *mod)
        kfree(mod->args);
        if (mod->percpu)
                percpu_modfree(mod->percpu);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+#if defined(CONFIG_MODULE_UNLOAD)
        if (mod->refptr)
-               percpu_modfree(mod->refptr);
+               free_percpu(mod->refptr);
 #endif
        /* Free lock-classes: */
        lockdep_free_key_range(mod->module_core, mod->core_size);
@@ -1992,12 +1867,14 @@ static inline unsigned long layout_symtab(struct module *mod,
                                          Elf_Shdr *sechdrs,
                                          unsigned int symindex,
                                          unsigned int strindex,
-                                         const Elf_Hdr *hdr,
+                                         const Elf_Ehdr *hdr,
                                          const char *secstrings,
                                          unsigned long *pstroffs,
                                          unsigned long *strmap)
 {
+       return 0;
 }
+
 static inline void add_kallsyms(struct module *mod,
                                Elf_Shdr *sechdrs,
                                unsigned int shnum,
@@ -2041,9 +1918,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
        unsigned int i;
 
        /* only scan the sections containing data */
-       kmemleak_scan_area(mod->module_core, (unsigned long)mod -
-                          (unsigned long)mod->module_core,
-                          sizeof(struct module), GFP_KERNEL);
+       kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
 
        for (i = 1; i < hdr->e_shnum; i++) {
                if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -2052,8 +1927,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
                    && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
                        continue;
 
-               kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
-                                  (unsigned long)mod->module_core,
+               kmemleak_scan_area((void *)sechdrs[i].sh_addr,
                                   sechdrs[i].sh_size, GFP_KERNEL);
        }
 }
@@ -2081,9 +1955,8 @@ static noinline struct module *load_module(void __user *umod,
        struct module *mod;
        long err = 0;
        void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
-#ifdef CONFIG_KALLSYMS
        unsigned long symoffs, stroffs, *strmap;
-#endif
+
        mm_segment_t old_fs;
 
        DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
@@ -2294,9 +2167,8 @@ static noinline struct module *load_module(void __user *umod,
        mod = (void *)sechdrs[modindex].sh_addr;
        kmemleak_load_module(mod, hdr, sechdrs, secstrings);
 
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
-       mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
-                                     mod->name);
+#if defined(CONFIG_MODULE_UNLOAD)
+       mod->refptr = alloc_percpu(struct module_ref);
        if (!mod->refptr) {
                err = -ENOMEM;
                goto free_init;
@@ -2382,6 +2254,12 @@ static noinline struct module *load_module(void __user *umod,
                                         "_ftrace_events",
                                         sizeof(*mod->trace_events),
                                         &mod->num_trace_events);
+       /*
+        * This section contains pointers to allocated objects in the trace
+        * code and not scanning it leads to false positives.
+        */
+       kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
+                          mod->num_trace_events, GFP_KERNEL);
 #endif
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
        /* sechdrs[0].sh_size is always zero */
@@ -2522,8 +2400,8 @@ static noinline struct module *load_module(void __user *umod,
        kobject_put(&mod->mkobj.kobj);
  free_unload:
        module_unload_free(mod);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
-       percpu_modfree(mod->refptr);
+#if defined(CONFIG_MODULE_UNLOAD)
+       free_percpu(mod->refptr);
  free_init:
 #endif
        module_free(mod, mod->module_init);