[MIPS] hsdis need non-executable PT_GNU_STACK support

[Leslie Zhai]

Hi all,

hsdis PrintLIRWithAssembly failed to work for mips64el after upgraded to 
jdk8u181-b13.

http://mail.openjdk.java.net/pipermail/jdk8u-dev/2018-August/007753.html

The root cause is the patch [MIPS] Enable non-executable PT_GNU_STACK 
support, contributed by Faraz in 2016 February, had not been merged by 
GCC toolchain upstream.

https://gcc.gnu.org/ml/gcc-patches/2016-02/msg00444.html

And Maciej also need to increase `MAJOR_VERSION` to check whether or not 
support IFUNC, unfortunately still not merged by upstream.

https://sourceware.org/ml/libc-alpha/2016-12/msg00856.html

But I would apply the patch and rebuild gcc-8.1, binutils-gdb-2.30, 
glibc-2.27, to support Faraz, Joseph and Maciej :)

Thanks for your great job!


在 2018年08月14日 14:15, Florian Weimer 写道:
On 08/14/2018 04:08 AM, Leslie Zhai wrote:
But workaround for mips64el's PrintLIRWithAssembly is adding 
-Wl,-z,noexecstack linking flag, strangely X86 does *not* need such 
flag, so I am investigating the root cause.

MIPS soft-float apparently needs an executable stack:

<https://sourceware.org/ml/libc-alpha/2016-01/msg00567.html>
<https://sourceware.org/ml/libc-alpha/2016-01/msg00719.html>

This could be why the toolchain does not specify a non-executable 
stack by default.

Florian

--
Regards,
Leslie Zhai