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Date: Mon, 8 Aug 2016 17:35:03 +1000
From: Anton Blanchard <anton@samba.org>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: <linuxppc-dev@ozlabs.org>, haokexin@gmail.com,
 aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [PATCH v3 19/21] powerpc: Add option to use jump label for
 mmu_has_feature()
Message-ID: <20160808173503.58ce7571@kryten>
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Hi,

> This patch causes an oops when building with the gold linker:

Found the problem. On binutils .meminit.text is within _stext/_etext:

  [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
  [ 3] .meminit.text     PROGBITS        c000000000989d14 999d14 00225c 00  AX  0   0  4

c000000000990000 R _etext

But on gold it is not:

c000000000970000 A _etext

  [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
  [ 3] .meminit.text     PROGBITS        c000000000970bcc 980bcc 002220 00  AX  0   0  4

As a result kernel_text_address() returns false, and
__jump_label_update() fails to update:

    if (entry->code && kernel_text_address(entry->code))
            arch_jump_label_transform(entry, jump_label_type(entry));

Seems like we get the correct layout on binutils by luck and we
need to explicitly handle .meminit.text.

Anton