Modules updates for v5.2

Summary of modules changes for the 5.2 merge window:
 
 - Use a separate table to store symbol types instead of
   hijacking fields in struct Elf_Sym
 
 - Trivial code cleanups
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:

 - Use a separate table to store symbol types instead of hijacking
   fields in struct Elf_Sym

 - Trivial code cleanups

* tag 'modules-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: add stubs for within_module functions
  kallsyms: store type information in its own array
  vmlinux.lds.h: drop unused __vermagic

include/asm-generic/vmlinux.lds.h

@@ -332,7 +332,6 @@
 		__start_rodata = .;					\
 		*(.rodata) *(.rodata.*)					\
 		RO_AFTER_INIT_DATA	/* Read only after init */	\
-		KEEP(*(__vermagic))	/* Kernel version magic */	\
 		. = ALIGN(8);						\
 		__start___tracepoints_ptrs = .;				\
 		KEEP(*(__tracepoints_ptrs)) /* Tracepoints: pointer array */ \

include/linux/module.h

@@ -332,6 +332,7 @@ struct mod_kallsyms {
 	Elf_Sym *symtab;
 	unsigned int num_symtab;
 	char *strtab;
+	char *typetab;
 };
 
 #ifdef CONFIG_LIVEPATCH
@@ -717,6 +718,17 @@ static inline bool within_module_core(unsigned long addr,
 	return false;
 }
 
+static inline bool within_module_init(unsigned long addr,
+				      const struct module *mod)
+{
+	return false;
+}
+
+static inline bool within_module(unsigned long addr, const struct module *mod)
+{
+	return false;
+}
+
 /* Get/put a kernel symbol (calls should be symmetric) */
 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 #define symbol_put(x) do { } while (0)

kernel/module-internal.h

@@ -20,7 +20,7 @@ struct load_info {
 	unsigned long len;
 	Elf_Shdr *sechdrs;
 	char *secstrings, *strtab;
-	unsigned long symoffs, stroffs;
+	unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
 	struct _ddebug *debug;
 	unsigned int num_debug;
 	bool sig_ok;

kernel/module.c

@@ -2642,6 +2642,8 @@ static void layout_symtab(struct module *mod, struct load_info *info)
 	info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
 	info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
 	mod->core_layout.size += strtab_size;
+	info->core_typeoffs = mod->core_layout.size;
+	mod->core_layout.size += ndst * sizeof(char);
 	mod->core_layout.size = debug_align(mod->core_layout.size);
 
 	/* Put string table section at end of init part of module. */
@@ -2655,6 +2657,8 @@ static void layout_symtab(struct module *mod, struct load_info *info)
 				      __alignof__(struct mod_kallsyms));
 	info->mod_kallsyms_init_off = mod->init_layout.size;
 	mod->init_layout.size += sizeof(struct mod_kallsyms);
+	info->init_typeoffs = mod->init_layout.size;
+	mod->init_layout.size += nsrc * sizeof(char);
 	mod->init_layout.size = debug_align(mod->init_layout.size);
 }
 
@@ -2678,20 +2682,23 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
 	mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
 	/* Make sure we get permanent strtab: don't use info->strtab. */
 	mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
+	mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
 
-	/* Set types up while we still have access to sections. */
+	/*
-	for (i = 0; i < mod->kallsyms->num_symtab; i++)
+	 * Now populate the cut down core kallsyms for after init
-		mod->kallsyms->symtab[i].st_size
+	 * and set types up while we still have access to sections.
-			= elf_type(&mod->kallsyms->symtab[i], info);
+	 */
-
-	/* Now populate the cut down core kallsyms for after init. */
 	mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
 	mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
+	mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
 	src = mod->kallsyms->symtab;
 	for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
+		mod->kallsyms->typetab[i] = elf_type(src + i, info);
 		if (i == 0 || is_livepatch_module(mod) ||
 		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
 				   info->index.pcpu)) {
+			mod->core_kallsyms.typetab[ndst] =
+			    mod->kallsyms->typetab[i];
 			dst[ndst] = src[i];
 			dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
 			s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
@@ -4091,7 +4098,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 			const Elf_Sym *sym = &kallsyms->symtab[symnum];
 
 			*value = kallsyms_symbol_value(sym);
-			*type = sym->st_size;
+			*type = kallsyms->typetab[symnum];
 			strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
 			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
 			*exported = is_exported(name, *value, mod);