On architectures such as ARM that have a list of symbols exported from
assembler in a separate C file, we get a lot of new warnings:
WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_uidivmod" [vmlinux] is a static (unknown)
WARNING: "__udivsi3" [vmlinux] is a static (unknown)
WARNING: "_change_bit" [vmlinux] is a static (unknown)
WARNING: "__aeabi_idiv" [vmlinux] is a static (unknown)
WARNING: "__umodsi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_uidiv" [vmlinux] is a static (unknown)
WARNING: "__aeabi_idivmod" [vmlinux] is a static (unknown)
WARNING: "__muldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
WARNING: "__raw_writesb" [vmlinux] is a static (unknown)
WARNING: "__raw_readsb" [vmlinux] is a static (unknown)
...
This is not helpful, as these are clearly not static symbols
at all. Suppress the warning in a case like this.
Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* functions")
Signed-off-by: Arnd Bergmann <[email protected]>
---
scripts/mod/modpost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 76c221dd9b2b..4265dd924933 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2543,7 +2543,7 @@ int main(int argc, char **argv)
struct symbol *s = symbolhash[n];
while (s) {
- if (s->is_static)
+ if (s->is_static && s->export != export_unknown)
warn("\"%s\" [%s] is a static %s\n",
s->name, s->module->name,
export_str(s->export));
--
2.20.0
Hi,
On 06.09.2019 18:10, Arnd Bergmann wrote:
> On architectures such as ARM that have a list of symbols exported from
> assembler in a separate C file, we get a lot of new warnings:
>
> WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
> WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_uidivmod" [vmlinux] is a static (unknown)
> WARNING: "__udivsi3" [vmlinux] is a static (unknown)
> WARNING: "_change_bit" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_idiv" [vmlinux] is a static (unknown)
> WARNING: "__umodsi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_uidiv" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_idivmod" [vmlinux] is a static (unknown)
> WARNING: "__muldi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
> WARNING: "__raw_writesb" [vmlinux] is a static (unknown)
> WARNING: "__raw_readsb" [vmlinux] is a static (unknown)
> ...
>
> This is not helpful, as these are clearly not static symbols
> at all. Suppress the warning in a case like this.
>
It looks very similar to this discussion https://lkml.org/lkml/2019/7/30/112
Could you please write the steps to reproduce the warnings?
Now, I'm trying to build linux-next (host Ubuntu 19.04 x86_64) with:
$ make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi-
But I can't get these warnings.
I would like to check the type of this asm symbols. It seems like they
are STT_NOTYPE. In this case the fix could also involve ELF_ST_TYPE check.
Thanks,
Denis
> Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* functions")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> scripts/mod/modpost.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 76c221dd9b2b..4265dd924933 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -2543,7 +2543,7 @@ int main(int argc, char **argv)
> struct symbol *s = symbolhash[n];
>
> while (s) {
> - if (s->is_static)
> + if (s->is_static && s->export != export_unknown)
> warn("\"%s\" [%s] is a static %s\n",
> s->name, s->module->name,
> export_str(s->export));
>
On 07.09.2019 01:39, Denis Efremov wrote:
> Hi,
>
> On 06.09.2019 18:10, Arnd Bergmann wrote:
>> On architectures such as ARM that have a list of symbols exported from
>> assembler in a separate C file, we get a lot of new warnings:
>>
>> WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
>> WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_uidivmod" [vmlinux] is a static (unknown)
>> WARNING: "__udivsi3" [vmlinux] is a static (unknown)
>> WARNING: "_change_bit" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_idiv" [vmlinux] is a static (unknown)
>> WARNING: "__umodsi3" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_uidiv" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_idivmod" [vmlinux] is a static (unknown)
>> WARNING: "__muldi3" [vmlinux] is a static (unknown)
>> WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
>> WARNING: "__raw_writesb" [vmlinux] is a static (unknown)
>> WARNING: "__raw_readsb" [vmlinux] is a static (unknown)
>> ...
>>
>> This is not helpful, as these are clearly not static symbols
>> at all. Suppress the warning in a case like this.
>>
>
> It looks very similar to this discussion https://lkml.org/lkml/2019/7/30/112
>
> Could you please write the steps to reproduce the warnings?
> Now, I'm trying to build linux-next (host Ubuntu 19.04 x86_64) with:
> $ make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi-
> But I can't get these warnings.
Tried defconfig, allyesconfig.
>
> I would like to check the type of this asm symbols. It seems like they
> are STT_NOTYPE. In this case the fix could also involve ELF_ST_TYPE check.
>
Ah, I forgot that we don't check the type at all, so this is not the case.
But still, I would like to test what if the remove binding check at all?
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 76c221dd9b2b..97dbcebf2338 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1987,14 +1987,12 @@ static void read_symbols(const char *modname)
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
unsigned char bind = ELF_ST_BIND(sym->st_info);
- if (bind == STB_GLOBAL || bind == STB_WEAK) {
struct symbol *s =
find_symbol(remove_dot(info.strtab +
sym->st_name));
if (s)
s->is_static = 0;
- }
}
if (!is_vmlinux(modname) || vmlinux_section_warnings)
Thanks,
Denis
>
>> Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* functions")
>> Signed-off-by: Arnd Bergmann <[email protected]>
>> ---
>> scripts/mod/modpost.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
>> index 76c221dd9b2b..4265dd924933 100644
>> --- a/scripts/mod/modpost.c
>> +++ b/scripts/mod/modpost.c
>> @@ -2543,7 +2543,7 @@ int main(int argc, char **argv)
>> struct symbol *s = symbolhash[n];
>>
>> while (s) {
>> - if (s->is_static)
>> + if (s->is_static && s->export != export_unknown)
>> warn("\"%s\" [%s] is a static %s\n",
>> s->name, s->module->name,
>> export_str(s->export));
>>
On Sat, Sep 7, 2019 at 7:28 AM Denis Efremov <[email protected]> wrote:
> On 07.09.2019 01:39, Denis Efremov wrote:
> >> This is not helpful, as these are clearly not static symbols
> >> at all. Suppress the warning in a case like this.
> >>
> >
> > It looks very similar to this discussion https://lkml.org/lkml/2019/7/30/112
> >
> > Could you please write the steps to reproduce the warnings?
>
> > Now, I'm trying to build linux-next (host Ubuntu 19.04 x86_64) with:
> > $ make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi-
> > But I can't get these warnings.
>
> Tried defconfig, allyesconfig.
I only have one randconfig build that caused these, see
http://paste.ubuntu.com/p/D6w8RNS7MG/ for the .config
I was building linux-next with the clang-9 toolchain from http://apt.llvm.org,
but that should not matter here.
> > I would like to check the type of this asm symbols. It seems like they
> > are STT_NOTYPE. In this case the fix could also involve ELF_ST_TYPE check.
> >
>
> Ah, I forgot that we don't check the type at all, so this is not the case.
> But still, I would like to test what if the remove binding check at all?
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 76c221dd9b2b..97dbcebf2338 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -1987,14 +1987,12 @@ static void read_symbols(const char *modname)
> for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
> unsigned char bind = ELF_ST_BIND(sym->st_info);
>
> - if (bind == STB_GLOBAL || bind == STB_WEAK) {
> struct symbol *s =
> find_symbol(remove_dot(info.strtab +
> sym->st_name));
>
> if (s)
> s->is_static = 0;
> - }
> }
>
> if (!is_vmlinux(modname) || vmlinux_section_warnings)
Unfortunately, I still get the same warnings, plus one about modpost.c:
scripts/mod/modpost.c:1988:17: warning: unused variable ‘bind’
[-Wunused-variable]
WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_uidivmod" [vmlinux] is a static (unknown)
WARNING: "__udivsi3" [vmlinux] is a static (unknown)
WARNING: "_change_bit" [vmlinux] is a static (unknown)
WARNING: "__aeabi_idiv" [vmlinux] is a static (unknown)
WARNING: "__umodsi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_uidiv" [vmlinux] is a static (unknown)
WARNING: "__aeabi_idivmod" [vmlinux] is a static (unknown)
WARNING: "__muldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
WARNING: "__raw_writesb" [vmlinux] is a static (unknown)
WARNING: "__raw_readsb" [vmlinux] is a static (unknown)
WARNING: "__ucmpdi2" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lmul" [vmlinux] is a static (unknown)
WARNING: "__divsi3" [vmlinux] is a static (unknown)
WARNING: "__modsi3" [vmlinux] is a static (unknown)
WARNING: "_test_and_change_bit" [vmlinux] is a static (unknown)
WARNING: "__bswapdi2" [vmlinux] is a static (unknown)
WARNING: "__bswapsi2" [vmlinux] is a static (unknown)
WARNING: "__ashldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsl" [vmlinux] is a static (unknown)
WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
WARNING: "__aeabi_uidivmod" [vmlinux] is a static (unknown)
WARNING: "__udivsi3" [vmlinux] is a static (unknown)
WARNING: "_change_bit" [vmlinux] is a static (unknown)
WARNING: "__aeabi_idiv" [vmlinux] is a static (unknown)
WARNING: "__umodsi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_uidiv" [vmlinux] is a static (unknown)
WARNING: "__aeabi_idivmod" [vmlinux] is a static (unknown)
WARNING: "__muldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
WARNING: "__raw_writesb" [vmlinux] is a static (unknown)
WARNING: "__raw_readsb" [vmlinux] is a static (unknown)
WARNING: "__ucmpdi2" [vmlinux] is a static (unknown)
WARNING: "__aeabi_lmul" [vmlinux] is a static (unknown)
WARNING: "__divsi3" [vmlinux] is a static (unknown)
WARNING: "__modsi3" [vmlinux] is a static (unknown)
WARNING: "_test_and_change_bit" [vmlinux] is a static (unknown)
WARNING: "__bswapdi2" [vmlinux] is a static (unknown)
WARNING: "__bswapsi2" [vmlinux] is a static (unknown)
WARNING: "__ashldi3" [vmlinux] is a static (unknown)
WARNING: "__aeabi_llsl" [vmlinux] is a static (unknown)
Arnd
On 06.09.2019 18:10, Arnd Bergmann wrote:
> On architectures such as ARM that have a list of symbols exported
> from assembler in a separate C file, we get a lot of new warnings:
>
> WARNING: "__ashrdi3" [vmlinux] is a static (unknown) WARNING:
> "__lshrdi3" [vmlinux] is a static (unknown) WARNING: "__aeabi_llsr"
> [vmlinux] is a static (unknown) WARNING: "__aeabi_lasr" [vmlinux] is
> a static (unknown) WARNING: "__aeabi_uidivmod" [vmlinux] is a static
> (unknown) WARNING: "__udivsi3" [vmlinux] is a static (unknown)
> WARNING: "_change_bit" [vmlinux] is a static (unknown) WARNING:
> "__aeabi_idiv" [vmlinux] is a static (unknown) WARNING: "__umodsi3"
> [vmlinux] is a static (unknown) WARNING: "__aeabi_uidiv" [vmlinux] is
> a static (unknown) WARNING: "__aeabi_idivmod" [vmlinux] is a static
> (unknown) WARNING: "__muldi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown) WARNING:
> "__raw_writesb" [vmlinux] is a static (unknown) WARNING:
> "__raw_readsb" [vmlinux] is a static (unknown) ...
>
> This is not helpful, as these are clearly not static symbols at all.
> Suppress the warning in a case like this.
>
> Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL*
> functions") Signed-off-by: Arnd Bergmann <[email protected]>
Tested-by: Denis Efremov <[email protected]>
What I could add here is that all these symbols are:
$ nm vmlinux | grep '__ashrdi3\|__lshrdi3\|__aeabi_llsr\|...'
cd63c845 A __crc___aeabi_lasr
76cf47f6 A __crc___aeabi_llsl
8a4fa83b A __crc___aeabi_llsr
44643b93 A __crc___aeabi_lmul
f564412a A __crc___aeabi_ulcmp
40f07981 A __crc___ashldi3
edd9106d A __crc___ashrdi3
389ecf9e A __crc___bswapdi2
f1ea6f1c A __crc___bswapsi2
14d4a9c5 A __crc__change_bit
ff67b37f A __crc___lshrdi3
800e4ffa A __crc___muldi3
f7163ec9 A __crc___raw_readsb
f0ed2ef4 A __crc___raw_writesb
ffb94ef0 A __crc__test_and_change_bit
7cc035a7 A __crc___ucmpdi2
There is no ksymtab, kstrtab for them and there is
no the exact symbols, only crc.
Thus they get to the symbolhash table from
handle_modversions() -> sym_update_crc().
Since there is no the exact symbols, e.g. like
nm vmlinux | grep __kmalloc
2d6fcc06 A __crc___kmalloc
c01c922d T __kmalloc <---
c0749192 r __kstrtab___kmalloc
c073c7c4 r __ksymtab___kmalloc
we can't check them in this cycle:
// check for static EXPORT_SYMBOL_* functions && global vars
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
and they are automatically marked as static.
That's all so far, I don't know is it correct to have only
__crc* or not for a symbol.
Just a sidenote:
arch/arm/kernel/armksyms.c states that these are
/*
* libgcc functions - functions that are used internally by the
* compiler...
Thanks,
Denis
> --- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1
> deletion(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index
> 76c221dd9b2b..4265dd924933 100644 --- a/scripts/mod/modpost.c +++
> b/scripts/mod/modpost.c @@ -2543,7 +2543,7 @@ int main(int argc, char
> **argv) struct symbol *s = symbolhash[n];
>
> while (s) { - if (s->is_static) + if (s->is_static && s->export
> != export_unknown) warn("\"%s\" [%s] is a static %s\n", s->name,
> s->module->name, export_str(s->export));
>
On Sat, Sep 7, 2019 at 12:11 AM Arnd Bergmann <[email protected]> wrote:
>
> On architectures such as ARM that have a list of symbols exported from
> assembler in a separate C file, we get a lot of new warnings:
>
> WARNING: "__ashrdi3" [vmlinux] is a static (unknown)
> WARNING: "__lshrdi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_llsr" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_lasr" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_uidivmod" [vmlinux] is a static (unknown)
> WARNING: "__udivsi3" [vmlinux] is a static (unknown)
> WARNING: "_change_bit" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_idiv" [vmlinux] is a static (unknown)
> WARNING: "__umodsi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_uidiv" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_idivmod" [vmlinux] is a static (unknown)
> WARNING: "__muldi3" [vmlinux] is a static (unknown)
> WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown)
> WARNING: "__raw_writesb" [vmlinux] is a static (unknown)
> WARNING: "__raw_readsb" [vmlinux] is a static (unknown)
> ...
>
> This is not helpful, as these are clearly not static symbols
> at all. Suppress the warning in a case like this.
>
> Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* functions")
> Signed-off-by: Arnd Bergmann <[email protected]>
This patch is not root-causing the problem,
rather it is hiding it.
I posted a real fix:
https://patchwork.kernel.org/patch/11137689/
> ---
> scripts/mod/modpost.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 76c221dd9b2b..4265dd924933 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -2543,7 +2543,7 @@ int main(int argc, char **argv)
> struct symbol *s = symbolhash[n];
>
> while (s) {
> - if (s->is_static)
> + if (s->is_static && s->export != export_unknown)
> warn("\"%s\" [%s] is a static %s\n",
> s->name, s->module->name,
> export_str(s->export));
> --
> 2.20.0
>
--
Best Regards
Masahiro Yamada