From 4fd3e4ef1f7e94299b42c2f473e196d0b8c114d0 Mon Sep 17 00:00:00 2001 From: Wanlong Gao Date: Fri, 30 Jun 2017 22:07:03 +0800 Subject: [PATCH] modpost: abort if module name is too long Module name has a limited length, but currently the build system allows the build finishing even if the module name is too long. CC /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.c:9:2: warning: initializer-string for array of chars is too long [enabled by default] .name = KBUILD_MODNAME, ^ but it's merely a warning. This patch adds the check of the module name length in modpost and stops the build properly. Signed-off-by: Wanlong Gao Signed-off-by: Jessica Yu --- scripts/mod/modpost.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 48397feb08fb..301c27740c5c 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -47,6 +47,12 @@ enum export { export_unused_gpl, export_gpl_future, export_unknown }; +/* 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)) + #define PRINTF __attribute__ ((format (printf, 1, 2))) PRINTF void fatal(const char *fmt, ...) @@ -2116,6 +2122,23 @@ static void check_exports(struct module *mod) } } +static int check_modname_len(struct module *mod) +{ + const char *mod_name; + + mod_name = strrchr(mod->name, '/'); + if (mod_name == NULL) + mod_name = mod->name; + else + mod_name++; + if (strlen(mod_name) >= MODULE_NAME_LEN) { + merror("module name is too long [%s.ko]\n", mod->name); + return 1; + } + + return 0; +} + /** * Header for the generated file **/ @@ -2155,11 +2178,6 @@ 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 **/ @@ -2490,6 +2508,7 @@ int main(int argc, char **argv) buf.pos = 0; + err |= check_modname_len(mod); add_header(&buf, mod); add_intree_flag(&buf, !external_module); add_staging_flag(&buf, mod->name);