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List: illumos-developer
Subject: Re: [developer] [REVIEW] 7323 ld(1) -zignore can erroneously discard init and fini arrays as unrefer
From: "Richard Lowe" <richlowe () richlowe ! net>
Date: 2016-08-24 20:12:10
Message-ID: CAA7J0x_2LMYOJWyV+nG1G3=zfG6Y-7pJM6FJfy2PUFGcqijMbQ () mail ! gmail ! com
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Instruction alignment shouldn't matter, but crti had 16 and I wanted to
draw attention to it.
Thanks
On Wed, Aug 24, 2016, 16:03 Patrick Mooney <patrick.mooney@joyent.com>
wrote:
> Looks good, modulo the XXX comment on the .align directive.
> (Alignment for the instructions themselves doesn't seem like it would
> matter in this case?)
>
> On 24 August 2016 at 14:38, Richard Lowe <richlowe@richlowe.net> wrote:
>
>> webrev: http://cr.illumos.org/~webrev/richlowe/il_7323
>>
>> bugs:
>> 7324 stack needs to be sufficiently aligned for SSE before init_array
>> are called
>> 7322 ld(1) gets init/fini array section names wrong
>> 7323 ld(1) -zignore can erroneously discard init and fini arrays as
>> unreferenced
>>
>> This fixes a couple of bugs found by the OI folks due to GCC 5.4 using
>> .init_array rather than .init. Firstly we were discarding them in the
>> face of -zignore (they will have no traditional references, only being
>> referenced by the dynamic tag), secondly we had not aligned the stack
>> sufficiently for any functions called from them to use SIMD instructions.
>> Thirdly, I noticed by chance that we mis-named them in the manual page.
>>
>> Robert has looked at 7324, which mirrors a fix he made to the CRT for
>> .init, Alexander has tested 7324 and 7323 with the problematic GCC version
>> and the affected pdns_recursor software.
>>
>> Thanks,
>>
>> -- Rich
>> --
>>
>> -- Rich
>>
>
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--
-- Rich
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[Attachment #3 (text/html)]
<html><html><p dir="ltr">Instruction alignment shouldn't matter, but crti had 16 \
and I wanted to draw attention to it. <p dir="ltr">Thanks<br /><div \
class="gmail_quote"><div dir="ltr">On Wed, Aug 24, 2016, 16:03 Patrick Mooney <<a \
href="mailto:patrick.mooney@joyent.com">patrick.mooney@joyent.com</a>> wrote:<br \
/></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc \
solid;padding-left:1ex"><div dir="ltr"><div>Looks good, modulo the XXX comment on the \
.align directive.<br /></div>(Alignment for the instructions themselves doesn't \
seem like it would matter in this case?)<br /></div><div class="gmail_extra"><br \
/><div class="gmail_quote">On 24 August 2016 at 14:38, Richard Lowe <span \
dir="ltr"><<a href="mailto:richlowe@richlowe.net" \
target="_blank">richlowe@richlowe.net</a>></span> wrote:<br /><blockquote \
class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc \
solid;padding-left:1ex"><div dir="ltr">webrev: <a \
href="http://cr.illumos.org/~webrev/richlowe/il_7323" \
target="_blank">http://cr.illumos.org/~webrev/richlowe/il_7323</a><div><br \
/></div><div>bugs:</div><div> 7324 stack needs to be sufficiently aligned for \
SSE before init_array are called</div><div>7322 ld(1) gets init/fini array section \
names wrong</div><div>7323 ld(1) -zignore can erroneously discard init and fini \
arrays as unreferenced</div><div><br /></div><div>This fixes a couple of bugs found \
by the OI folks due to GCC 5.4 using .init_array rather than .init. \
Firstly we were discarding them in the face of -zignore (they will have no \
traditional references, only being referenced by the dynamic tag), secondly we had \
not aligned the stack sufficiently for any functions called from them to use SIMD \
instructions. Thirdly, I noticed by chance that we mis-named them in the manual \
page.</div><div><br /></div><div>Robert has looked at 7324, which mirrors a fix he \
made to the CRT for .init, Alexander has tested 7324 and 7323 with the problematic \
GCC version and the affected pdns_recursor software.</div><div><br \
/></div><div>Thanks,</div><div><br /></div><div>-- Rich</div></div><div dir="ltr">-- \
<br /></div><div data-smartmail="gmail_signature"><p dir="ltr">-- \
Rich</div></blockquote></div><br /></div></blockquote></div><div dir="ltr">-- <br \
/></div><div data-smartmail="gmail_signature"><p dir="ltr">-- Rich</div></html><div \
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