Re: [PATCH 1/7] powerpc/build: put sys_call_table in .data.rel.ro if RELOCATABLE

On Thu Sep 15, 2022 at 10:51 PM AEST, Michael Ellerman wrote:

Christophe Leroy [off-list ref] writes:

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Le 14/09/2022 à 17:47, Nicholas Piggin a écrit :

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Const function pointers live in .data.rel.ro rather than .rodata because
they must be relocated. This change prevents powerpc/32 from generating
R_PPC_UADDR32 relocations (which are not handled). The sys_call_table is
moved to writeable memory, but a later change will move it back.

Aren't you missing commit c7acee3d2f12 ("powerpc: align syscall table 
for ppc32") ?

That's in fixes. I'll sort it out when I apply this, or when I merge
fixes into next.

Yeah that explains the relocations I was seeing, I should have dug
further into that, so they're really unrelated to this patch.

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I can't see any R_PPC_UADDR32 relocations generated by ppc4xx_defconfig 
+ CONFIG_RELOCATABLE unless I revert that commit.

Presumably this change accidentally aligns the syscall table.

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After this patch, 44x_defconfig + CONFIG_RELOCATABLE boots to busybox.

 
So that's probably just because of the alignment too.

I think this patch should go after .data.rel.ro is made read only.

Yeah that should be fine.

Thanks,
Nick