From 5cfb203a304deaaa8c7c5368722b214d24583137 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Sat, 8 Aug 2015 15:16:20 +0930 Subject: [PATCH] modpost: abort if a module symbol is too long Module symbols have a limited length, but currently the build system allows the build finishing even if the driver code contains a too long symbol name, which eventually overflows the modversion_info[] item. The compiler may catch at compiling *.mod.c like CC xxx.mod.o xxx.mod.c:18:16: warning: initializer-string for array of chars is too long but it's merely a warning. This patch adds the check of the symbol length in modpost and stops the build properly. Currently MODULE_NAME_LEN is defined in modpost.c instead of referring to the definition in kernel header because including linux/module.h is messy and we must cover cross-compilation. Signed-off-by: Takashi Iwai Signed-off-by: Rusty Russell --- scripts/mod/modpost.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 12d3db3bd46b..d583c98fde31 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -2133,6 +2133,11 @@ static void add_staging_flag(struct buffer *b, const char *name) buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); } +/* In kernel, this size is defined in linux/module.h; + * here we use Elf_Addr instead of long for covering cross-compile + */ +#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) + /** * Record CRCs for unresolved symbols **/ @@ -2177,6 +2182,12 @@ static int add_versions(struct buffer *b, struct module *mod) s->name, mod->name); continue; } + if (strlen(s->name) >= MODULE_NAME_LEN) { + merror("too long symbol \"%s\" [%s.ko]\n", + s->name, mod->name); + err = 1; + break; + } buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n", s->crc, s->name); } -- 2.20.1