On 2017/5/31 11:30, Jessica Yu wrote:
> +++ Wanlong Gao [31/05/17 10:23 +0800]:
>> Hi Jessica,
>>
>> On 2017/5/29 17:10, Jessica Yu wrote:
>>> +++ Xie XiuQi [20/05/17 15:46 +0800]:
>>>> From: Wanlong Gao <[email protected]>
>>>>
>>>> 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 <[email protected]>
>>>> Signed-off-by: Xie XiuQi <[email protected]>
>>>> ---
>>>> 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 <[email protected]>
>> Tested-by: Wanlong Gao <[email protected]>
>
> Sure, thanks for testing. I'll go ahead and format this into a proper
> patch and resend.
Please wait, I just found that this patch makes the built module can't
be inserted by the following error:
# insmod abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabc.ko
insmod: ERROR: could not insert module
abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabc.ko: Invalid parameters
# dmesg
abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabc: Unknown symbol
__fentry__ (err -22)
Thanks,
Wanlong Gao
>
> Jessica
>
>>>
>>> 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
>>>>
>>>
>>> .
>>>
>>
>
> .
>
