Hi,
lijiang <lijiang@xxxxxxxxxx> writes:
> On Mon, Mar 28, 2022 at 9:57 PM Alexander Egorenkov <egorenar@xxxxxxxxxxxxx>
> wrote:
>
>>
>> > Where does the symbol '.rodata' come from ?
>> > I couldn't find it in x86's vmlinux with nm as well.
>> >
>>
>
> The "nm -a" option may be a good choice.
>
>> On Fedora 34:
>> >
>> > $ nm /usr/lib/debug/lib/modules/5.16.16-100.fc34.x86_64/vmlinux | grep
>> rodata
>> > ffffffff82c1d000 D __end_rodata
>> > ffffffff82e00000 D __end_rodata_aligned
>> > ffffffff82e00000 D __end_rodata_hpage_align
>> > ffffffff81199420 t frob_rodata
>> > ffffffff81c3eec7 T mark_rodata_ro
>> > ffffffff826dd200 D rodata_enabled
>> > ffffffff82e2cec0 d rodata_resource
>> > ffffffff81352690 T rodata_test
>> > ffffffff81c50238 t rodata_test.cold
>> > ffffffff8223d9d0 d rodata_test_data
>> > ffffffff836c2c36 t set_debug_rodata
>> > ffffffff838ff890 d __setup_set_debug_rodata
>> > ffffffff838b4b18 d __setup_str_set_debug_rodata
>> > ffffffff82200000 D __start_rodata
>> >
>> > Regards
>> > Alex
>>
>> Found the reason why all symbols starting with '.' are dropped for s390x
>>
>> /*
>> * Accept or reject a symbol from the kernel namelist.
>> */
>> static int
>> s390x_verify_symbol(const char *name, ulong value, char type)
>> {
>> int i;
>>
>> ...
>>
>> /* throw away all symbols containing a '.' */
>> for(i = 0; i < strlen(name);i++){
>> if(name[i] == '.') <-------------- !!!
>> return FALSE;
>> }
>>
>> return TRUE;
>> }
>>
>>
>> But i have no idea why. Anybody familiar with this ?
>>
>
> I guess that it is to filter out some duplicated or unneeded symbols in
> crash-utility, especially for the old kernel. No more changelogs.
>
> Thanks.
> Lianbo
>
>
>> Thanks
>> Regards
>> Alex
>>
>>
> This Message Is From an External Sender
> This message came from outside your organization.
> On Mon, Mar 28, 2022 at 9:57 PM Alexander Egorenkov <egorenar@xxxxxxxxxxxxx> wrote:
>
> > Where does the symbol '.rodata' come from ?
> > I couldn't find it in x86's vmlinux with nm as well.
> >
>
>
> The "nm -a" option may be a good choice.
>
Thanks!
> > On Fedora 34:
> >
> > $ nm /usr/lib/debug/lib/modules/5.16.16-100.fc34.x86_64/vmlinux | grep rodata
> > ffffffff82c1d000 D __end_rodata
> > ffffffff82e00000 D __end_rodata_aligned
> > ffffffff82e00000 D __end_rodata_hpage_align
> > ffffffff81199420 t frob_rodata
> > ffffffff81c3eec7 T mark_rodata_ro
> > ffffffff826dd200 D rodata_enabled
> > ffffffff82e2cec0 d rodata_resource
> > ffffffff81352690 T rodata_test
> > ffffffff81c50238 t rodata_test.cold
> > ffffffff8223d9d0 d rodata_test_data
> > ffffffff836c2c36 t set_debug_rodata
> > ffffffff838ff890 d __setup_set_debug_rodata
> > ffffffff838b4b18 d __setup_str_set_debug_rodata
> > ffffffff82200000 D __start_rodata
> >
> > Regards
> > Alex
>
> Found the reason why all symbols starting with '.' are dropped for s390x
>
> /*
> * Accept or reject a symbol from the kernel namelist.
> */
> static int
> s390x_verify_symbol(const char *name, ulong value, char type)
> {
> int i;
>
> ...
>
> /* throw away all symbols containing a '.' */
> for(i = 0; i < strlen(name);i++){
> if(name[i] == '.') <-------------- !!!
> return FALSE;
> }
>
> return TRUE;
> }
>
> But i have no idea why. Anybody familiar with this ?
>
>
> I guess that it is to filter out some duplicated or unneeded symbols in crash-utility, especially for the old kernel. No more changelogs.
>
Do you think it makes sense to add an exception for '.rodata' symbol
to s390x_verify_symbol() ? Something like:
if (STREQ(name), ".rodata"))
return TRUE;
I did a quick test and it works on s390x as well.
Thanks
Regards
Alex
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