Hi Jessica,
On 2017/5/29 17:10, Jessica Yu wrote:
> +++ Xie XiuQi [20/05/17 15:46 +0800]:
>> From: Wanlong Gao <gaowanl...@huawei.com>
>>
>> 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 <gaowanl...@huawei.com>
>> Signed-off-by: Xie XiuQi <xiexi...@huawei.com>
>> ---
>> scripts/mod/modpost.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
>> index 30d752a..db11c57 100644
>> --- a/scripts/mod/modpost.c
>> +++ b/scripts/mod/modpost.c
>> @@ -2166,6 +2166,17 @@ static int add_versions(struct buffer *b, struct
>> module *mod)
>> {
>> struct symbol *s, *exp;
>> int err = 0;
>> + 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;
>> + }
>
> Hi Xie,
>
> This check shouldn't be in add_versions() (which does something else
> entirely),
> it should probably be put in a separate helper function called from main. But
> I'm not a big fan of the extra string manipulation to do something this
> simple.
>
> I think this check can be vastly simplified, how about something like the
> following?
This looks better, would you apply your following patch?
Reviewed-by: Wanlong Gao <gaowanl...@huawei.com>
Tested-by: Wanlong Gao <gaowanl...@huawei.com>
Thanks,
Wanlong Gao
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 48397fe..bb09fc7 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -2139,6 +2139,9 @@ static void add_header(struct buffer *b, struct module
> *mod)
> "#endif\n");
> buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
> buf_printf(b, "};\n");
> + buf_printf(b, "\n");
> + buf_printf(b, "static void __attribute__((section(\".discard\"), used))
> __modname_test(void)\n");
> + buf_printf(b, "{ BUILD_BUG_ON(sizeof(KBUILD_MODNAME) > MODULE_NAME_LEN);
> }\n");
> }
>
> static void add_intree_flag(struct buffer *b, int is_intree)
>
> This simply checks if KBUILD_MODNAME > MODULE_NAME_LEN and breaks the build if
> it does.
>
> Jessica
>
>> for (s = mod->unres; s; s = s->next) {
>> exp = find_symbol(s->name);
>> --
>> 1.8.3.1
>>
>
> .
>
