Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull mudule updates from Rusty Russell:
 "We get rid of the general module prefix confusion with a binary config
  option, fix a remove/insert race which Never Happens, and (my
  favorite) handle the case when we have too many modules for a single
  commandline.  Seriously, the kernel is full, please go away!"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modpost: fix unwanted VMLINUX_SYMBOL_STR expansion
  X.509: Support parse long form of length octets in Authority Key Identifier
  module: don't unlink the module until we've removed all exposure.
  kernel: kallsyms: memory override issue, need check destination buffer length
  MODSIGN: do not send garbage to stderr when enabling modules signature
  modpost: handle huge numbers of modules.
  modpost: add -T option to read module names from file/stdin.
  modpost: minor cleanup.
  genksyms: pass symbol-prefix instead of arch
  module: fix symbol versioning with symbol prefixes
  CONFIG_SYMBOL_PREFIX: cleanup.

23 files changed, 201 insertions, 139 deletions

diff --git a/Makefile b/Makefile
index 4572f106e30b..878d7aa3d2dd 100644
--- a/Makefile
+++ b/Makefile
@@ -1399,7 +1399,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files))
 # Run depmod only if we have System.map and depmod is executable
 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
-                   $(KERNELRELEASE) "$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))"
+                   $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
 
 # Create temporary dir for module support files
 # clean it up only when building all modules
diff --git a/arch/Kconfig b/arch/Kconfig
index 99f0e17df429..dd0e8eb8042f 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -381,6 +381,12 @@ config MODULES_USE_ELF_REL
 	  Modules only use ELF REL relocations.  Modules with ELF RELA
 	  relocations will give an error.
 
+config HAVE_UNDERSCORE_SYMBOL_PREFIX
+	bool
+	help
+	  Some architectures generate an _ in front of C symbols; things like
+	  module loading and assembly files need to know about this.
+
 #
 # ABI hall of shame
 #
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index c3f2e0bc644a..453ebe46b065 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
-	string
-	default "_"
-
 config MMU
 	def_bool n
 
@@ -33,6 +29,7 @@ config BLACKFIN
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select HAVE_UID16
+	select HAVE_UNDERSCORE_SYMBOL_PREFIX
 	select VIRT_TO_BUS
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select HAVE_GENERIC_HARDIRQS
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 79250de1b12a..303e4f9a79d1 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -12,10 +12,7 @@ config H8300
 	select MODULES_USE_ELF_RELA
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
-
-config SYMBOL_PREFIX
-	string
-	default "_"
+	select HAVE_UNDERSCORE_SYMBOL_PREFIX
 
 config MMU
 	bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index b06b41861aac..6f16c1469327 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
-	string
-	default "_"
-
 config METAG
 	def_bool y
 	select EMBEDDED
@@ -28,6 +24,7 @@ config METAG
 	select HAVE_OPROFILE
 	select HAVE_PERF_EVENTS
 	select HAVE_SYSCALL_TRACEPOINTS
+	select HAVE_UNDERSCORE_SYMBOL_PREFIX
 	select IRQ_DOMAIN
 	select MODULES_USE_ELF_RELA
 	select OF
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 7fabc4c01993..facbf26bc6bb 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -373,6 +373,9 @@ int rsa_extract_mpi(void *context, size_t hdrlen,
 	return 0;
 }
 
+/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
+#define SEQ_TAG_KEYID (ASN1_CONT << 6)
+
 /*
  * Process certificate extensions that are used to qualify the certificate.
  */
@@ -407,21 +410,57 @@ int x509_process_extension(void *context, size_t hdrlen,
 	}
 
 	if (ctx->last_oid == OID_authorityKeyIdentifier) {
+		size_t key_len;
+
 		/* Get hold of the CA key fingerprint */
 		if (vlen < 5)
 			return -EBADMSG;
-		if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)) ||
-		    v[1] != vlen - 2 ||
-		    v[2] != (ASN1_CONT << 6) ||
-		    v[3] != vlen - 4)
+
+		/* Authority Key Identifier must be a Constructed SEQUENCE */
+		if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)))
 			return -EBADMSG;
-		v += 4;
-		vlen -= 4;
 
-		f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
+		/* Authority Key Identifier is not indefinite length */
+		if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
+			return -EBADMSG;
+
+		if (vlen < ASN1_INDEFINITE_LENGTH) {
+			/* Short Form length */
+			if (v[1] != vlen - 2 ||
+			    v[2] != SEQ_TAG_KEYID ||
+			    v[3] > vlen - 4)
+				return -EBADMSG;
+
+			key_len = v[3];
+			v += 4;
+		} else {
+			/* Long Form length */
+			size_t seq_len = 0;
+			size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
+
+			if (sub > 2)
+				return -EBADMSG;
+
+			/* calculate the length from subsequent octets */
+			v += 2;
+			for (i = 0; i < sub; i++) {
+				seq_len <<= 8;
+				seq_len |= v[i];
+			}
+
+			if (seq_len != vlen - 2 - sub ||
+			    v[sub] != SEQ_TAG_KEYID ||
+			    v[sub + 1] > vlen - 4 - sub)
+				return -EBADMSG;
+
+			key_len = v[sub + 1];
+			v += (sub + 2);
+		}
+
+		f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
 		if (!f)
 			return -ENOMEM;
-		for (i = 0; i < vlen; i++)
+		for (i = 0; i < key_len; i++)
 			sprintf(f + i * 2, "%02x", v[i]);
 		pr_debug("authority   %s\n", f);
 		ctx->cert->authority = f;
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 3b9a2843c5f8..74dbb6bcf488 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -204,14 +204,16 @@ static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
 	struct cfi_private *cfi = map->fldrv_priv;
 	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 #ifdef CONFIG_MODULES
-	char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
+	char probename[sizeof(VMLINUX_SYMBOL_STR(cfi_cmdset_%4.4X))];
 	cfi_cmdset_fn_t *probe_function;
 
-	sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
+	sprintf(probename, VMLINUX_SYMBOL_STR(cfi_cmdset_%4.4X), type);
 
 	probe_function = __symbol_get(probename);
 	if (!probe_function) {
-		request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
+		char modname[sizeof("cfi_cmdset_%4.4X")];
+		sprintf(modname, "cfi_cmdset_%4.4X", type);
+		request_module(modname);
 		probe_function = __symbol_get(probename);
 	}
 
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 0501fa3f783d..cccc86ecfeaa 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -1,4 +1,5 @@
 #include <uapi/asm-generic/unistd.h>
+#include <linux/export.h>
 
 /*
  * These are required system calls, we should
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index afa12c7a025c..eb58d2d7d971 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,13 +52,7 @@
 #define LOAD_OFFSET 0
 #endif
 
-#ifndef SYMBOL_PREFIX
-#define VMLINUX_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define VMLINUX_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
 
 /* Align . to a 8 byte boundary equals to maximum function alignment. */
 #define ALIGN_FUNCTION()  . = ALIGN(8)
diff --git a/include/linux/export.h b/include/linux/export.h
index 696c0f48afc7..412cd509effe 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -5,17 +5,24 @@
  * to reduce the amount of pointless cruft we feed to gcc when only
  * exporting a simple symbol or two.
  *
- * If you feel the need to add #include <linux/foo.h> to this file
- * then you are doing something wrong and should go away silently.
+ * Try not to add #includes here.  It slows compilation and makes kernel
+ * hackers place grumpy comments in header files.
  */
 
 /* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
+#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
+#define __VMLINUX_SYMBOL(x) _##x
+#define __VMLINUX_SYMBOL_STR(x) "_" #x
 #else
-#define MODULE_SYMBOL_PREFIX ""
+#define __VMLINUX_SYMBOL(x) x
+#define __VMLINUX_SYMBOL_STR(x) #x
 #endif
 
+/* Indirect, so macros are expanded before pasting. */
+#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
+#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
+
+#ifndef __ASSEMBLY__
 struct kernel_symbol
 {
 	unsigned long value;
@@ -51,7 +58,7 @@ extern struct module __this_module;
 	__CRC_SYMBOL(sym, sec)					\
 	static const char __kstrtab_##sym[]			\
 	__attribute__((section("__ksymtab_strings"), aligned(1))) \
-	= MODULE_SYMBOL_PREFIX #sym;				\
+	= VMLINUX_SYMBOL_STR(sym);				\
 	static const struct kernel_symbol __ksymtab_##sym	\
 	__used							\
 	__attribute__((section("___ksymtab" sec "+" #sym), unused))	\
@@ -85,5 +92,6 @@ extern struct module __this_module;
 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 
 #endif /* CONFIG_MODULES */
+#endif /* !__ASSEMBLY__ */
 
 #endif /* _LINUX_EXPORT_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 6d1844f393c0..e96329ceb28c 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -786,13 +786,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 /* Trap pasters of __FUNCTION__ at compile-time */
 #define __FUNCTION__ (__func__)
 
-/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define SYMBOL_PREFIX ""
-#endif
-
 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index de09dec25ec3..d3e8ad23a8e0 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -3,6 +3,7 @@
 
 #include <linux/compiler.h>
 #include <linux/stringify.h>
+#include <linux/export.h>
 #include <asm/linkage.h>
 
 #ifdef __cplusplus
@@ -15,21 +16,18 @@
 #define asmlinkage CPP_ASMLINKAGE
 #endif
 
-#ifdef CONFIG_SYMBOL_PREFIX
-#define __SYMBOL_NAME(x) CONFIG_SYMBOL_PREFIX __stringify(x)
-#else
-#define __SYMBOL_NAME(x) __stringify(x)
-#endif
-
 #ifndef cond_syscall
-#define cond_syscall(x) asm(".weak\t" __SYMBOL_NAME(x) \
-	"\n\t.set\t" __SYMBOL_NAME(x) "," __SYMBOL_NAME(sys_ni_syscall));
+#define cond_syscall(x)	asm(				\
+	".weak " VMLINUX_SYMBOL_STR(x) "\n\t"		\
+	".set  " VMLINUX_SYMBOL_STR(x) ","		\
+		 VMLINUX_SYMBOL_STR(sys_ni_syscall))
 #endif
 
 #ifndef SYSCALL_ALIAS
-#define SYSCALL_ALIAS(alias, name)				\
-	asm ("\t.globl " __SYMBOL_NAME(alias)			\
-	"\n\t.set\t" __SYMBOL_NAME(alias) "," __SYMBOL_NAME(name))
+#define SYSCALL_ALIAS(alias, name) asm(			\
+	".globl " VMLINUX_SYMBOL_STR(alias) "\n\t"	\
+	".set   " VMLINUX_SYMBOL_STR(alias) ","		\
+		  VMLINUX_SYMBOL_STR(name))
 #endif
 
 #define __page_aligned_data	__section(.data..page_aligned) __aligned(PAGE_SIZE)
diff --git a/include/linux/module.h b/include/linux/module.h
index ead1b5719a12..46f1ea01e6f6 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -190,7 +190,7 @@ extern int modules_disabled; /* for sysctl */
 /* Get/put a kernel symbol (calls must be symmetric) */
 void *__symbol_get(const char *symbol);
 void *__symbol_get_gpl(const char *symbol);
-#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
+#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 
 /* modules using other modules: kdb wants to see this. */
 struct module_use {
@@ -453,7 +453,7 @@ extern void __module_put_and_exit(struct module *mod, long code)
 #ifdef CONFIG_MODULE_UNLOAD
 unsigned long module_refcount(struct module *mod);
 void __symbol_put(const char *symbol);
-#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
+#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 void symbol_put_addr(void *addr);
 
 /* Sometimes we know we already have a refcount, and it's easier not
diff --git a/kernel/Makefile b/kernel/Makefile
index d1574d47cf27..271fd3119af9 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -176,7 +176,7 @@ signing_key.priv signing_key.x509: x509.genkey
 	openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
 		-batch -x509 -config x509.genkey \
 		-outform DER -out signing_key.x509 \
-		-keyout signing_key.priv
+		-keyout signing_key.priv 2>&1
 	@echo "###"
 	@echo "### Key pair generated."
 	@echo "###"
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 2169feeba529..3127ad52cdb2 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -84,9 +84,11 @@ static int is_ksym_addr(unsigned long addr)
 
 /*
  * Expand a compressed symbol data into the resulting uncompressed string,
+ * if uncompressed string is too long (>= maxlen), it will be truncated,
  * given the offset to where the symbol is in the compressed stream.
  */
-static unsigned int kallsyms_expand_symbol(unsigned int off, char *result)
+static unsigned int kallsyms_expand_symbol(unsigned int off,
+					   char *result, size_t maxlen)
 {
 	int len, skipped_first = 0;
 	const u8 *tptr, *data;
@@ -113,15 +115,20 @@ static unsigned int kallsyms_expand_symbol(unsigned int off, char *result)
 
 		while (*tptr) {
 			if (skipped_first) {
+				if (maxlen <= 1)
+					goto tail;
 				*result = *tptr;
 				result++;
+				maxlen--;
 			} else
 				skipped_first = 1;
 			tptr++;
 		}
 	}
 
-	*result = '\0';
+tail:
+	if (maxlen)
+		*result = '\0';
 
 	/* Return to offset to the next symbol. */
 	return off;
@@ -176,7 +183,7 @@ unsigned long kallsyms_lookup_name(const char *name)
 	unsigned int off;
 
 	for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
-		off = kallsyms_expand_symbol(off, namebuf);
+		off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
 
 		if (strcmp(namebuf, name) == 0)
 			return kallsyms_addresses[i];
@@ -195,7 +202,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
 	int ret;
 
 	for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
-		off = kallsyms_expand_symbol(off, namebuf);
+		off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
 		ret = fn(data, namebuf, NULL, kallsyms_addresses[i]);
 		if (ret != 0)
 			return ret;
@@ -294,7 +301,8 @@ const char *kallsyms_lookup(unsigned long addr,
 
 		pos = get_symbol_pos(addr, symbolsize, offset);
 		/* Grab name */
-		kallsyms_expand_symbol(get_symbol_offset(pos), namebuf);
+		kallsyms_expand_symbol(get_symbol_offset(pos),
+				       namebuf, KSYM_NAME_LEN);
 		if (modname)
 			*modname = NULL;
 		return namebuf;
@@ -315,7 +323,8 @@ int lookup_symbol_name(unsigned long addr, char *symname)
 
 		pos = get_symbol_pos(addr, NULL, NULL);
 		/* Grab name */
-		kallsyms_expand_symbol(get_symbol_offset(pos), symname);
+		kallsyms_expand_symbol(get_symbol_offset(pos),
+				       symname, KSYM_NAME_LEN);
 		return 0;
 	}
 	/* See if it's in a module. */
@@ -333,7 +342,8 @@ int lookup_symbol_attrs(unsigned long addr, unsigned long *size,
 
 		pos = get_symbol_pos(addr, size, offset);
 		/* Grab name */
-		kallsyms_expand_symbol(get_symbol_offset(pos), name);
+		kallsyms_expand_symbol(get_symbol_offset(pos),
+				       name, KSYM_NAME_LEN);
 		modname[0] = '\0';
 		return 0;
 	}
@@ -463,7 +473,7 @@ static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
 
 	iter->type = kallsyms_get_symbol_type(off);
 
-	off = kallsyms_expand_symbol(off, iter->name);
+	off = kallsyms_expand_symbol(off, iter->name, ARRAY_SIZE(iter->name));
 
 	return off - iter->nameoff;
 }
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
index 246b4c6e6135..4a9a86d12c8b 100644
--- a/kernel/modsign_certificate.S
+++ b/kernel/modsign_certificate.S
@@ -1,15 +1,8 @@
-/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */
-#ifndef SYMBOL_PREFIX
-#define ASM_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
 
 #define GLOBAL(name)	\
-	.globl ASM_SYMBOL(name);	\
-	ASM_SYMBOL(name):
+	.globl VMLINUX_SYMBOL(name);	\
+	VMLINUX_SYMBOL(name):
 
 	.section ".init.data","aw"
 
diff --git a/kernel/module.c b/kernel/module.c
index 0925c9a71975..b049939177f6 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1209,10 +1209,11 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 
 	/* Since this should be found in kernel (which can't be removed),
 	 * no locking is necessary. */
-	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
 			 &crc, true, false))
 		BUG();
-	return check_version(sechdrs, versindex, "module_layout", mod, crc,
+	return check_version(sechdrs, versindex,
+			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
 			     NULL);
 }
 
@@ -1861,12 +1862,12 @@ static void free_module(struct module *mod)
 {
 	trace_module_free(mod);
 
-	/* Delete from various lists */
-	mutex_lock(&module_mutex);
-	stop_machine(__unlink_module, mod, NULL);
-	mutex_unlock(&module_mutex);
 	mod_sysfs_teardown(mod);
 
+	/* We leave it in list to prevent duplicate loads, but make sure
+	 * that noone uses it while it's being deconstructed. */
+	mod->state = MODULE_STATE_UNFORMED;
+
 	/* Remove dynamic debug info */
 	ddebug_remove_module(mod->name);
 
@@ -1879,6 +1880,11 @@ static void free_module(struct module *mod)
 	/* Free any allocated parameters. */
 	destroy_params(mod->kp, mod->num_kp);
 
+	/* Now we can delete it from the lists */
+	mutex_lock(&module_mutex);
+	stop_machine(__unlink_module, mod, NULL);
+	mutex_unlock(&module_mutex);
+
 	/* This may be NULL, but that's OK */
 	unset_module_init_ro_nx(mod);
 	module_free(mod, mod->module_init);
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 0e801c3cdaf8..d5d859c80729 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -211,7 +211,8 @@ $(obj)/%.i: $(src)/%.c FORCE
 
 cmd_gensymtypes =                                                           \
     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
-    $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH)                              \
+    $(GENKSYMS) $(if $(1), -T $(2))                                         \
+     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
      $(if $(KBUILD_PRESERVE),-p)                                            \
      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
 
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 3e73dfd838cd..51bb3de680b6 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -119,13 +119,6 @@ _c_flags += $(if $(patsubst n%,, \
 		$(CFLAGS_GCOV))
 endif
 
-ifdef CONFIG_SYMBOL_PREFIX
-_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
-_cpp_flags += $(_sym_flags)
-_a_flags += $(_sym_flags)
-endif
-
-
 # If building the kernel in a separate objtree expand all occurrences
 # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
 
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index cf82c832458f..8dcdca27d836 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -60,7 +60,8 @@ kernelsymfile := $(objtree)/Module.symvers
 modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
 
 # Step 1), find all modules listed in $(MODVERDIR)/
-__modules := $(sort $(shell grep -h '\.ko$$' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
+MODLISTCMD := find $(MODVERDIR) -name '*.mod' | xargs -r grep -h '\.ko$$' | sort -u
+__modules := $(shell $(MODLISTCMD))
 modules   := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
 
 # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
@@ -78,12 +79,13 @@ modpost = scripts/mod/modpost                    \
  $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \
  $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
 
+# We can go over command line length here, so be careful.
 quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
-      cmd_modpost = $(modpost) -s
+      cmd_modpost = $(MODLISTCMD) | sed 's/\.ko$$/.o/' | $(modpost) -s -T -
 
 PHONY += __modpost
 __modpost: $(modules:.ko=.o) FORCE
-	$(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
+	$(call cmd,modpost) $(wildcard vmlinux)
 
 quiet_cmd_kernel-mod = MODPOST $@
       cmd_kernel-mod = $(modpost) $@
diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
index d25e4a118d37..88632df4381b 100644
--- a/scripts/genksyms/genksyms.c
+++ b/scripts/genksyms/genksyms.c
@@ -45,7 +45,6 @@ int in_source_file;
 
 static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
 	   flag_preserve, flag_warnings;
-static const char *arch = "";
 static const char *mod_prefix = "";
 
 static int errors;
@@ -731,7 +730,7 @@ static void genksyms_usage(void)
 {
 	fputs("Usage:\n" "genksyms [-adDTwqhV] > /path/to/.tmp_obj.ver\n" "\n"
 #ifdef __GNU_LIBRARY__
-	      "  -a, --arch            Select architecture\n"
+	      "  -s, --symbol-prefix   Select symbol prefix\n"
 	      "  -d, --debug           Increment the debug level (repeatable)\n"
 	      "  -D, --dump            Dump expanded symbol defs (for debugging only)\n"
 	      "  -r, --reference file  Read reference symbols from a file\n"
@@ -742,7 +741,7 @@ static void genksyms_usage(void)
 	      "  -h, --help            Print this message\n"
 	      "  -V, --version         Print the release version\n"
 #else				/* __GNU_LIBRARY__ */
-	      "  -a                    Select architecture\n"
+	      "  -s                    Select symbol prefix\n"
 	      "  -d                    Increment the debug level (repeatable)\n"
 	      "  -D                    Dump expanded symbol defs (for debugging only)\n"
 	      "  -r file               Read reference symbols from a file\n"
@@ -763,7 +762,7 @@ int main(int argc, char **argv)
 
 #ifdef __GNU_LIBRARY__
 	struct option long_opts[] = {
-		{"arch", 1, 0, 'a'},
+		{"symbol-prefix", 1, 0, 's'},
 		{"debug", 0, 0, 'd'},
 		{"warnings", 0, 0, 'w'},
 		{"quiet", 0, 0, 'q'},
@@ -776,14 +775,14 @@ int main(int argc, char **argv)
 		{0, 0, 0, 0}
 	};
 
-	while ((o = getopt_long(argc, argv, "a:dwqVDr:T:ph",
+	while ((o = getopt_long(argc, argv, "s:dwqVDr:T:ph",
 				&long_opts[0], NULL)) != EOF)
 #else				/* __GNU_LIBRARY__ */
-	while ((o = getopt(argc, argv, "a:dwqVDr:T:ph")) != EOF)
+	while ((o = getopt(argc, argv, "s:dwqVDr:T:ph")) != EOF)
 #endif				/* __GNU_LIBRARY__ */
 		switch (o) {
-		case 'a':
-			arch = optarg;
+		case 's':
+			mod_prefix = optarg;
 			break;
 		case 'd':
 			flag_debug++;
@@ -826,9 +825,6 @@ int main(int argc, char **argv)
 			genksyms_usage();
 			return 1;
 		}
-	if ((strcmp(arch, "h8300") == 0) || (strcmp(arch, "blackfin") == 0) ||
-	    (strcmp(arch, "metag") == 0))
-		mod_prefix = "_";
 	{
 		extern int yydebug;
 		extern int yy_flex_debug;
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 3d569d6022c2..014994936b1c 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -74,9 +74,8 @@ kallsyms()
 	info KSYM ${2}
 	local kallsymopt;
 
-	if [ -n "${CONFIG_SYMBOL_PREFIX}" ]; then
-		kallsymopt="${kallsymopt} \
-			    --symbol-prefix=${CONFIG_SYMBOL_PREFIX}"
+	if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
+		kallsymopt="${kallsymopt} --symbol-prefix=_"
 	fi
 
 	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 78b30c1548e9..a4be8e112bb6 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -15,17 +15,12 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <string.h>
+#include <limits.h>
+#include <stdbool.h>
 #include "modpost.h"
 #include "../../include/generated/autoconf.h"
 #include "../../include/linux/license.h"
-
-/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define MODULE_SYMBOL_PREFIX ""
-#endif
-
+#include "../../include/linux/export.h"
 
 /* Are we using CONFIG_MODVERSIONS? */
 int modversions = 0;
@@ -85,6 +80,14 @@ PRINTF void merror(const char *fmt, ...)
 	va_end(arglist);
 }
 
+static inline bool strends(const char *str, const char *postfix)
+{
+	if (strlen(str) < strlen(postfix))
+		return false;
+
+	return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
+}
+
 static int is_vmlinux(const char *modname)
 {
 	const char *myname;
@@ -120,22 +123,20 @@ static struct module *find_module(char *modname)
 	return mod;
 }
 
-static struct module *new_module(char *modname)
+static struct module *new_module(const char *modname)
 {
 	struct module *mod;
-	char *p, *s;
+	char *p;
 
 	mod = NOFAIL(malloc(sizeof(*mod)));
 	memset(mod, 0, sizeof(*mod));
 	p = NOFAIL(strdup(modname));
 
 	/* strip trailing .o */
-	s = strrchr(p, '.');
-	if (s != NULL)
-		if (strcmp(s, ".o") == 0) {
-			*s = '\0';
-			mod->is_dot_o = 1;
-		}
+	if (strends(p, ".o")) {
+		p[strlen(p) - 2] = '\0';
+		mod->is_dot_o = 1;
+	}
 
 	/* add to list */
 	mod->name = p;
@@ -562,7 +563,7 @@ static void parse_elf_finish(struct elf_info *info)
 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 {
 	/* ignore __this_module, it will be resolved shortly */
-	if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+	if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
 		return 1;
 	/* ignore global offset table */
 	if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
@@ -583,8 +584,8 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 	return 0;
 }
 
-#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
-#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
+#define CRC_PFX     VMLINUX_SYMBOL_STR(__crc_)
+#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
 
 static void handle_modversions(struct module *mod, struct elf_info *info,
 			       Elf_Sym *sym, const char *symname)
@@ -637,14 +638,15 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 		}
 #endif
 
-		if (memcmp(symname, MODULE_SYMBOL_PREFIX,
-			   strlen(MODULE_SYMBOL_PREFIX)) == 0) {
-			mod->unres =
-			  alloc_symbol(symname +
-			               strlen(MODULE_SYMBOL_PREFIX),
-			               ELF_ST_BIND(sym->st_info) == STB_WEAK,
-			               mod->unres);
-		}
+#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
+		if (symname[0] != '_')
+			break;
+		else
+			symname++;
+#endif
+		mod->unres = alloc_symbol(symname,
+					  ELF_ST_BIND(sym->st_info) == STB_WEAK,
+					  mod->unres);
 		break;
 	default:
 		/* All exported symbols */
@@ -652,9 +654,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 			sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 					export);
 		}
-		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+		if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
 			mod->has_init = 1;
-		if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+		if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
 			mod->has_cleanup = 1;
 		break;
 	}
@@ -1762,6 +1764,27 @@ static void read_symbols(char *modname)
 		mod->unres = alloc_symbol("module_layout", 0, mod->unres);
 }
 
+static void read_symbols_from_files(const char *filename)
+{
+	FILE *in = stdin;
+	char fname[PATH_MAX];
+
+	if (strcmp(filename, "-") != 0) {
+		in = fopen(filename, "r");
+		if (!in)
+			fatal("Can't open filenames file %s: %m", filename);
+	}
+
+	while (fgets(fname, PATH_MAX, in) != NULL) {
+		if (strends(fname, "\n"))
+			fname[strlen(fname)-1] = '\0';
+		read_symbols(fname);
+	}
+
+	if (in != stdin)
+		fclose(in);
+}
+
 #define SZ 500
 
 /* We first write the generated file into memory using the
@@ -1934,7 +1957,8 @@ static int add_versions(struct buffer *b, struct module *mod)
 				s->name, mod->name);
 			continue;
 		}
-		buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
+		buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
+			   s->crc, s->name);
 	}
 
 	buf_printf(b, "};\n");
@@ -2122,13 +2146,13 @@ int main(int argc, char **argv)
 	struct module *mod;
 	struct buffer buf = { };
 	char *kernel_read = NULL, *module_read = NULL;
-	char *dump_write = NULL;
+	char *dump_write = NULL, *files_source = NULL;
 	int opt;
 	int err;
 	struct ext_sym_list *extsym_iter;
 	struct ext_sym_list *extsym_start = NULL;
 
-	while ((opt = getopt(argc, argv, "i:I:e:msSo:awM:K:")) != -1) {
+	while ((opt = getopt(argc, argv, "i:I:e:msST:o:awM:K:")) != -1) {
 		switch (opt) {
 		case 'i':
 			kernel_read = optarg;
@@ -2160,6 +2184,9 @@ int main(int argc, char **argv)
 		case 'S':
 			sec_mismatch_verbose = 0;
 			break;
+		case 'T':
+			files_source = optarg;
+			break;
 		case 'w':
 			warn_unresolved = 1;
 			break;
@@ -2182,6 +2209,9 @@ int main(int argc, char **argv)
 	while (optind < argc)
 		read_symbols(argv[optind++]);
 
+	if (files_source)
+		read_symbols_from_files(files_source);
+
 	for (mod = modules; mod; mod = mod->next) {
 		if (mod->skip)
 			continue;