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-rw-r--r--kernel/module.c159
1 files changed, 149 insertions, 10 deletions
diff --git a/kernel/module.c b/kernel/module.c
index e6bc4b28aa6..5a29397ca4b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1797,6 +1797,17 @@ static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
}
}
+static void free_modinfo(struct module *mod)
+{
+ struct module_attribute *attr;
+ int i;
+
+ for (i = 0; (attr = modinfo_attrs[i]); i++) {
+ if (attr->free)
+ attr->free(mod);
+ }
+}
+
#ifdef CONFIG_KALLSYMS
/* lookup symbol in given range of kernel_symbols */
@@ -1862,13 +1873,93 @@ static char elf_type(const Elf_Sym *sym,
return '?';
}
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+ unsigned int shnum)
+{
+ const Elf_Shdr *sec;
+
+ if (src->st_shndx == SHN_UNDEF
+ || src->st_shndx >= shnum
+ || !src->st_name)
+ return false;
+
+ sec = sechdrs + src->st_shndx;
+ if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+ || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+ || (sec->sh_entsize & INIT_OFFSET_MASK))
+ return false;
+
+ return true;
+}
+
+static unsigned long layout_symtab(struct module *mod,
+ Elf_Shdr *sechdrs,
+ unsigned int symindex,
+ unsigned int strindex,
+ const Elf_Ehdr *hdr,
+ const char *secstrings,
+ unsigned long *pstroffs,
+ unsigned long *strmap)
+{
+ unsigned long symoffs;
+ Elf_Shdr *symsect = sechdrs + symindex;
+ Elf_Shdr *strsect = sechdrs + strindex;
+ const Elf_Sym *src;
+ const char *strtab;
+ unsigned int i, nsrc, ndst;
+
+ /* Put symbol section at end of init part of module. */
+ symsect->sh_flags |= SHF_ALLOC;
+ symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
+ symindex) | INIT_OFFSET_MASK;
+ DEBUGP("\t%s\n", secstrings + symsect->sh_name);
+
+ src = (void *)hdr + symsect->sh_offset;
+ nsrc = symsect->sh_size / sizeof(*src);
+ strtab = (void *)hdr + strsect->sh_offset;
+ for (ndst = i = 1; i < nsrc; ++i, ++src)
+ if (is_core_symbol(src, sechdrs, hdr->e_shnum)) {
+ unsigned int j = src->st_name;
+
+ while(!__test_and_set_bit(j, strmap) && strtab[j])
+ ++j;
+ ++ndst;
+ }
+
+ /* Append room for core symbols at end of core part. */
+ symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
+ mod->core_size = symoffs + ndst * sizeof(Elf_Sym);
+
+ /* Put string table section at end of init part of module. */
+ strsect->sh_flags |= SHF_ALLOC;
+ strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
+ strindex) | INIT_OFFSET_MASK;
+ DEBUGP("\t%s\n", secstrings + strsect->sh_name);
+
+ /* Append room for core symbols' strings at end of core part. */
+ *pstroffs = mod->core_size;
+ __set_bit(0, strmap);
+ mod->core_size += bitmap_weight(strmap, strsect->sh_size);
+
+ return symoffs;
+}
+
static void add_kallsyms(struct module *mod,
Elf_Shdr *sechdrs,
+ unsigned int shnum,
unsigned int symindex,
unsigned int strindex,
- const char *secstrings)
+ unsigned long symoffs,
+ unsigned long stroffs,
+ const char *secstrings,
+ unsigned long *strmap)
{
- unsigned int i;
+ unsigned int i, ndst;
+ const Elf_Sym *src;
+ Elf_Sym *dst;
+ char *s;
mod->symtab = (void *)sechdrs[symindex].sh_addr;
mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
@@ -1878,13 +1969,44 @@ static void add_kallsyms(struct module *mod,
for (i = 0; i < mod->num_symtab; i++)
mod->symtab[i].st_info
= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
+
+ mod->core_symtab = dst = mod->module_core + symoffs;
+ src = mod->symtab;
+ *dst = *src;
+ for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
+ if (!is_core_symbol(src, sechdrs, shnum))
+ continue;
+ dst[ndst] = *src;
+ dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name);
+ ++ndst;
+ }
+ mod->core_num_syms = ndst;
+
+ mod->core_strtab = s = mod->module_core + stroffs;
+ for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i)
+ if (test_bit(i, strmap))
+ *++s = mod->strtab[i];
}
#else
+static inline unsigned long layout_symtab(struct module *mod,
+ Elf_Shdr *sechdrs,
+ unsigned int symindex,
+ unsigned int strindex,
+ const Elf_Hdr *hdr,
+ const char *secstrings,
+ unsigned long *pstroffs,
+ unsigned long *strmap)
+{
+}
static inline void add_kallsyms(struct module *mod,
Elf_Shdr *sechdrs,
+ unsigned int shnum,
unsigned int symindex,
unsigned int strindex,
- const char *secstrings)
+ unsigned long symoffs,
+ unsigned long stroffs,
+ const char *secstrings,
+ const unsigned long *strmap)
{
}
#endif /* CONFIG_KALLSYMS */
@@ -1959,6 +2081,9 @@ 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",
@@ -2040,11 +2165,6 @@ static noinline struct module *load_module(void __user *umod,
/* Don't keep modinfo and version sections. */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
-#ifdef CONFIG_KALLSYMS
- /* Keep symbol and string tables for decoding later. */
- sechdrs[symindex].sh_flags |= SHF_ALLOC;
- sechdrs[strindex].sh_flags |= SHF_ALLOC;
-#endif
/* Check module struct version now, before we try to use module. */
if (!check_modstruct_version(sechdrs, versindex, mod)) {
@@ -2080,6 +2200,13 @@ static noinline struct module *load_module(void __user *umod,
goto free_hdr;
}
+ strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
+ * sizeof(long), GFP_KERNEL);
+ if (!strmap) {
+ err = -ENOMEM;
+ goto free_mod;
+ }
+
if (find_module(mod->name)) {
err = -EEXIST;
goto free_mod;
@@ -2109,6 +2236,8 @@ static noinline struct module *load_module(void __user *umod,
this is done generically; there doesn't appear to be any
special cases for the architectures. */
layout_sections(mod, hdr, sechdrs, secstrings);
+ symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
+ secstrings, &stroffs, strmap);
/* Do the allocs. */
ptr = module_alloc_update_bounds(mod->core_size);
@@ -2313,7 +2442,10 @@ static noinline struct module *load_module(void __user *umod,
percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
sechdrs[pcpuindex].sh_size);
- add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
+ add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
+ symoffs, stroffs, secstrings, strmap);
+ kfree(strmap);
+ strmap = NULL;
if (!mod->taints) {
struct _ddebug *debug;
@@ -2385,13 +2517,14 @@ static noinline struct module *load_module(void __user *umod,
synchronize_sched();
module_arch_cleanup(mod);
cleanup:
+ free_modinfo(mod);
kobject_del(&mod->mkobj.kobj);
kobject_put(&mod->mkobj.kobj);
free_unload:
module_unload_free(mod);
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
- free_init:
percpu_modfree(mod->refptr);
+ free_init:
#endif
module_free(mod, mod->module_init);
free_core:
@@ -2402,6 +2535,7 @@ static noinline struct module *load_module(void __user *umod,
percpu_modfree(percpu);
free_mod:
kfree(args);
+ kfree(strmap);
free_hdr:
vfree(hdr);
return ERR_PTR(err);
@@ -2491,6 +2625,11 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
/* Drop initial reference. */
module_put(mod);
trim_init_extable(mod);
+#ifdef CONFIG_KALLSYMS
+ mod->num_symtab = mod->core_num_syms;
+ mod->symtab = mod->core_symtab;
+ mod->strtab = mod->core_strtab;
+#endif
module_free(mod, mod->module_init);
mod->module_init = NULL;
mod->init_size = 0;