Add support for mips

[saprette]

Hello,

I'm trying to compile Rocket for an Omega2, but it's failing as the ring dependency will not cross compile. Would you have some pointer? Many thanks!

I've been able to cross compile and run an http server on the Omega2 with hello world examples using tiny_http and iron latest but I have an issue cross compiling Rocket due to 'failed to run custom build command for ring v0.11.0' (it does work if I don't cross compile on my laptop).
I've installed rust & cargo using rustup and I updated them before trying to build Rocket today.

sam@sam:~/omega/Rocket/examples/hello_world$ cargo build --target=mipsel-unknown-linux-musl 
   Compiling toml v0.4.2
   Compiling url v1.5.1
   Compiling ring v0.11.0
error: failed to run custom build command for `ring v0.11.0`
process didn't exit successfully: `/home/sam/omega/Rocket/target/debug/build/ring-a7af99b63f4ef999/build-script-build` (exit code: 101)
--- stderr
thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:335:20
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
             at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at /checkout/src/libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at /checkout/src/libstd/sys_common/backtrace.rs:60
             at /checkout/src/libstd/panicking.rs:380
   3: std::panicking::default_hook
             at /checkout/src/libstd/panicking.rs:396
   4: std::panicking::rust_panic_with_hook
             at /checkout/src/libstd/panicking.rs:611
   5: std::panicking::begin_panic_new
             at /checkout/src/libstd/panicking.rs:553
   6: std::panicking::begin_panic_fmt
             at /checkout/src/libstd/panicking.rs:521
   7: rust_begin_unwind
             at /checkout/src/libstd/panicking.rs:497
   8: core::panicking::panic_fmt
             at /checkout/src/libcore/panicking.rs:92
   9: core::panicking::panic
             at /checkout/src/libcore/panicking.rs:51
  10: <core::option::Option<T>>::unwrap
             at /checkout/src/libcore/macros.rs:22
  11: build_script_build::build_c_code
             at ./build.rs:413
  12: build_script_build::ring_build_rs_main::{{closure}}
             at ./build.rs:343
  13: <rayon_core::job::StackJob<L, F, R> as rayon_core::job::Job>::execute::{{closure}}
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/job.rs:99
  14: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
             at /checkout/src/libstd/panic.rs:296
  15: std::panicking::try::do_call
             at /checkout/src/libstd/panicking.rs:479
  16: __rust_maybe_catch_panic
             at /checkout/src/libpanic_unwind/lib.rs:98
  17: std::panicking::try
             at /checkout/src/libstd/panicking.rs:458
  18: std::panic::catch_unwind
             at /checkout/src/libstd/panic.rs:361
  19: rayon_core::unwind::halt_unwinding
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/unwind.rs:19
  20: <rayon_core::job::StackJob<L, F, R> as rayon_core::job::Job>::execute
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/job.rs:99
  21: rayon_core::job::JobRef::execute
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/job.rs:55
  22: rayon_core::registry::WorkerThread::execute
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/registry.rs:476
  23: rayon_core::registry::WorkerThread::wait_until_cold
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/registry.rs:460
  24: rayon_core::registry::WorkerThread::wait_until
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/registry.rs:436
  25: rayon_core::registry::main_loop
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/registry.rs:559
  26: rayon_core::registry::Registry::new::{{closure}}
             at /home/sam/.cargo/registry/src/github.com-1ecc6299db9ec823/rayon-core-1.2.1/src/registry.rs:145

warning: build failed, waiting for other jobs to finish...
error: build failed

[saprette]

It is failing here
https://github.com/briansmith/ring/blob/master/build.rs#L413

Looks like because misp is not expected / supported.
https://github.com/briansmith/ring/blob/master/build.rs#L278

[briansmith]

We can and should add support for MIPS. It mostly involves adding the OpenSSL assembly language code from OpenSSL back, and adding some fallback Rust or C code for ChaCha20-Poly1305.

[saprette]

I'm a complete newbie in rust so sorry if I'm wrong.
Does it mean that I need to add these

sam@sam:~/omega/openssl$ find . -name "mips"
./crypto/poly1305/asm/poly1305-mips.pl
./crypto/bn/asm/mips-mont.pl
./crypto/bn/asm/mips.pl
./crypto/aes/asm/aes-mips.pl
./crypto/mips_arch.h
./crypto/sha/asm/sha512-mips.pl
./crypto/sha/asm/sha1-mips.pl

And update build.rs as it is done for ARM?

This is what I tried here

master...saprette:mips

but got this

--- stderr
MIPS64 only at crypto/poly1305/asm/poly1305-mips.pl line 61.
thread '' panicked at 'execution failed', build.rs:668:8

[NilsLattek]

Any update on this?

[pietro]

from crypto/poly1305/asm/poly1305-mips.pl :

$flavour = shift || "o32"; # supported flavours are o32,n32,64,nubi32,nubi64

die "MIPS64 only" unless ($flavour =~ /64|n32/i);

So you have to choose one of the MIPS64 flavours. BTW, you defined as linux32 as the flavour for all mips builds, which seems to be wrong given the above comment.

[athei]

If I understand the last post correctly we can have full support on mips32 except for poly1305 which BoringSSL only supports on mips64?

[jkilpatr]

why isn't there a generic Rust implementation of these algorithms? Native assembly speed is all fine and good but having a fallback is also important.

[briansmith]

In terms of the Rust --target flag, which MIPS targets do you need to support?

[jkilpatr]

@briansmith

mips-unknown-linux-musl
mips64-unknown-linux-gnuabi64
mips64el-unknown-linux-gnuabi64
mipsel-unknown-linux-musl