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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Peter Zijlstra <peterz@infradead.org>,
        Sathvika Vasireddy <sv@linux.ibm.com>
Cc:     linuxppc-dev@lists.ozlabs.org, jpoimboe@redhat.com,
        linux-kernel@vger.kernel.org, aik@ozlabs.ru, mingo@redhat.com,
        christophe.leroy@csgroup.eu, rostedt@goodmis.org, mbenes@suse.cz,
        npiggin@gmail.com, chenzhongjin@huawei.com,
        naveen.n.rao@linux.vnet.ibm.com
Subject: Re: [PATCH v2 07/16] powerpc: Skip objtool from running on VDSO files
In-Reply-To: <YxEFxJk+2fog+oRx@hirez.programming.kicks-ass.net>
References: <20220829055223.24767-1-sv@linux.ibm.com>
 <20220829055223.24767-8-sv@linux.ibm.com>
 <YxEFxJk+2fog+oRx@hirez.programming.kicks-ass.net>
Date:   Fri, 02 Sep 2022 17:40:24 +1000
Message-ID: <87r10uteaf.fsf@mpe.ellerman.id.au>
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Peter Zijlstra <peterz@infradead.org> writes:
> On Mon, Aug 29, 2022 at 11:22:14AM +0530, Sathvika Vasireddy wrote:
>> Do not run objtool on VDSO files, by using
>> OBJECT_FILES_NON_STANDARD
>> 
>> Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
>> ---
>>  arch/powerpc/kernel/vdso/Makefile | 2 ++
>>  1 file changed, 2 insertions(+)
>> 
>> diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
>> index 096b0bf1335f..a49a0d6a1c53 100644
>> --- a/arch/powerpc/kernel/vdso/Makefile
>> +++ b/arch/powerpc/kernel/vdso/Makefile
>> @@ -102,3 +102,5 @@ quiet_cmd_vdso64ld_and_check = VDSO64L $@
>>        cmd_vdso64ld_and_check = $(VDSOCC) $(c_flags) $(CC64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^) ; $(cmd_vdso_check)
>>  quiet_cmd_vdso64as = VDSO64A $@
>>        cmd_vdso64as = $(VDSOCC) $(a_flags) $(CC64FLAGS) $(AS64FLAGS) -c -o $@ $<
>> +
>> +OBJECT_FILES_NON_STANDARD := y
>
> Just to clarify; your linker script will place the VDSO in .rodata or a
> similar !.text section, right?

Not the linker script, but we incbin it into .data.

See arch/powerpc/kernel/vdso64_wrapper.S

cheers