[0.19] build: Allow export of environ symbols and work around rv64 toolchain issue #18175

1. 
   luke-jr commented at 5:44 PM on February 18, 2020: member

   Trivial backport of #17569

2. build: Allow export of environ symbols

   Github-Pull: #17569
   Rebased-From: f6e42256fe8900ed90f9644906b77f97e1600952

   102547606f
3. build: Add NX workaround for RV64

   Work around https://bugs.launchpad.net/ubuntu/+source/gcc-8-cross-ports/+bug/1853740.
   
   Github-Pull: #17569
   Rebased-From: eafd2593674b6890418a50eadf69425071b824e4

   a0aad741ec
4. luke-jr requested review from MarcoFalke on Feb 18, 2020
5. luke-jr requested review from laanwj on Feb 18, 2020
6. DrahtBot added the label Build system on Feb 18, 2020
7. DrahtBot added the label Scripts and tools on Feb 18, 2020
8. fanquake added the label Backport on Feb 18, 2020
9. 
   fanquake commented at 12:55 PM on February 20, 2020: member

   Is backporting either of these really required?

   The changes that necessitated https://github.com/bitcoin/bitcoin/commit/f6e42256fe8900ed90f9644906b77f97e1600952 (https://github.com/bitcoin/bitcoin/pull/18175/commits/102547606f512f791ded0a610afe9f41b3ef2666 here) are not in the 0.19 branch.

   As for https://github.com/bitcoin/bitcoin/pull/17569/commits/eafd2593674b6890418a50eadf69425071b824e4, the 0.19.1rc2 RISCV binaries still have GNU_STACK marked as RW, because we're still receiving it from OpenSSL:

   /usr/local/Cellar/llvm/9.0.1/bin/llvm-readelf -lW bitcoind
   <trim>
    GNU_STACK      0x000000 0x0000000000000000 0x0000000000000000 0x000000 0x000000 RW  0x10
   

   I agree that having noexecstack applied via OpenSSL isn't clear, but it's unlikely that any further build system changes will occur in the 0.19 branch.

10. 
    luke-jr commented at 7:04 PM on February 21, 2020: member

    @laanwj Feel free to reopen if you disagree.

11. luke-jr closed this on Feb 21, 2020

    ---

12. DrahtBot locked this on Feb 15, 2022

Review Requested
laanwjMarcoFalke