Re: xtensa-fsf-ld: dangerous relocation: call8: call target out of range

[Max Filippov <jcmvbkbc at gmail dot com>]

On Mon, Jul 16, 2012 at 10:51 PM, Sterling Augustine
<augustine.sterling@gmail.com> wrote:
> On Mon, Jul 16, 2012 at 8:31 AM, Max Filippov <jcmvbkbc@gmail.com> wrote:
>>
>> Sorry, missed CC to you.
>>
>> ---------- Forwarded message ----------
>> From: Max Filippov <jcmvbkbc@gmail.com>
>> Date: Mon, Jul 16, 2012 at 6:26 PM
>> Subject: xtensa-fsf-ld: dangerous relocation: call8: call target out of range
>> To: binutils@sourceware.org
>> Cc: Marc Gauthier <marc@tensilica.com>
>>
>>
>> Hello.
>>
>> I'm trying to build linux kernel for FSF xtensa core using binutils-2.22.
>> In the final linking step I get the following error:
>>
>> + /home/dumb/ws/tensilica/tools/xtensa-toolchain-build/build-xtensa-fsf-elf/root/bin/xtensa-fsf-elf-ld
>> --build-id -o .tmp_vmlinux2 -T
>> /home/dumb/ws/tensilica/linux/linux-build/fsf/defconfig/arch/xtensa/kernel/vmlinux.lds
>> arch/xtensa/kernel/head.o init/built-in.o --start-group usr/built-in.o
>> arch/xtensa/kernel/built-in.o arch/xtensa/mm/built-in.o
>> arch/xtensa/platforms/iss/built-in.o kernel/built-in.o mm/built-in.o
>> fs/built-in.o ipc/built-in.o security/built-in.o crypto/built-in.o
>> block/built-in.o lib/lib.a arch/xtensa/lib/lib.a
>> /home/dumb/ws/tensilica/tools/xtensa-toolchain-build/build-xtensa-fsf-elf/root/lib/gcc/xtensa-fsf-elf/4.6.3/libgcc.a
>> lib/built-in.o arch/xtensa/lib/built-in.o
>> /home/dumb/ws/tensilica/tools/xtensa-toolchain-build/build-xtensa-fsf-elf/root/lib/gcc/xtensa-fsf-elf/4.6.3/libgcc.a
>> drivers/built-in.o sound/built-in.o firmware/built-in.o net/built-in.o
>> --end-group .tmp_kallsyms1.o
>> net/built-in.o: In function `fib_net_init':
>> fib_frontend.c:(.init.text+0x1553): dangerous relocation: call8: call
>> target out of range: (.text+0x3eb38)
>>
>> If I add --no-relax ld option to this link step everything works fine.
>>
>> Referenced portion of the object file (net/built-in.o) looks like this:
>>
>>     1550:       180000          l32r    a8, fffc1550
>> <unregister_net_sysctl_table+0xfff6eb90>
>>                         1550: R_XTENSA_SLOT0_OP .init.literal+0x5a0
>>                         1550: R_XTENSA_ASM_EXPAND       fib_trie_table
>>     1553:       0b8000          callx8  a8
>>     1556:       caa3            beqz.n  a10, 157d <fib_net_init+0x5d>
>>
>> Can anybody suggest the way to debug/fix it?
>
> Looks like a linker bug to me. Quite likely the relaxer is
> mis-estimating the distance to the call target, and converting the
> l32r-callx8 sequence to a single call8 which can't reach. In the short
> tem, --no-relax-ld is your only option. Your code will be slightly
> larger and slightly slower, but it shouldn't be a dealbreaker.

Thanks for the answer.

> In the longer term, someone at Tensilica will need to submit a patch,
> so full repro instructions would be very good here. I think Tensilica

I have a tagged linux tree and mostly scripted build procedure which I
can share.

> might maintain some private patches, but I don't know if they have
> anything addresses this one. Marc?
>
> Sterling

-- 
Thanks.
-- Max