1 files changed, 149 insertions, 10 deletions

diff --git a/kernel/module.c b/kernel/module.c
index e6bc4b2..5a29397 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;