Add support for s390x architecture. (#1431)

### Description of changes: 

Add support for s390x architecture.

This is pretty trivial change (a few defines), since the big-endian
support was previously added for PowerPC architectures.


### Call-outs:

There is a false-positive error when compiling using
`s390x-linux-gnu-gcc-11` with `-O3` (i.e. `Release` profile):
```
crypto/pem/pem_lib.c:705:11: error: ‘strncmp’ of strings of length 1 and 9 and bound of 9 evaluates to nonzero [-Werror=string-compare]
 705 |       if (strncmp(buf, "-----END ", 9) == 0) {
     |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
```
but there are no issues when using `-O2` or when building with
`s390x-linux-gnu-gcc-12`.


### Testing:

All tests from `run_cross_tests.sh`, i.e.
```
crypto/crypto_test --gtest_also_run_disabled_tests
crypto/urandom_test
crypto/mem_test
crypto/mem_set_test
crypto/dynamic_loading_test

ssl/ssl_test
ssl/integration_test
```
passed, with the exception of `BIOTest.InvokeConnectCallback`, which
fails for me on all platforms.


By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license and the ISC license.


cc @andrewhop @justsmth

---------

Signed-off-by: Piotr Sikora <piotr@aviatrix.com>
Co-authored-by: Justin Smith <justsmth@amazon.com>
Co-authored-by: Justin W Smith <103147162+justsmth@users.noreply.github.com>

.github/workflows/cross-test.yml

@@ -48,3 +48,20 @@ jobs:
       - uses: actions/checkout@v4
       - name: PPC64LE Build/Test
         run: tests/ci/run_cross_tests.sh ppc64le powerpc64le-unknown-linux-gnu "-DCMAKE_BUILD_TYPE=Release" "-DCMAKE_BUILD_TYPE=Release -DFIPS=1 -DBUILD_SHARED_LIBS=1"
+  s390x-non-fips-build-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install qemu
+        run: |
+          sudo apt-get update
+          sudo apt-get -y install qemu-user qemu-user-binfmt
+      - uses: actions/checkout@v4
+      - name: s390x Build/Test
+# The flag below is set to avoid the following error with GCC 11.4.0:
+#
+#  /home/runner/work/aws-lc/aws-lc/crypto/pem/pem_lib.c:705:11: error: 'strncmp' of strings of length 1 and 9 and bound of 9 evaluates to nonzero [-Werror=string-compare]
+#  705 |       if (strncmp(buf, "-----END ", 9) == 0) {
+#      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        env:
+          CFLAGS: "-Wno-string-compare"
+        run: tests/ci/run_cross_tests.sh s390x s390x-ibm-linux-gnu "-DCMAKE_BUILD_TYPE=Release"

CMakeLists.txt

@@ -764,6 +764,8 @@ elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "powerpc64le|ppc64le")
   set(ARCH "ppc64le")
 elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "riscv64")
   set(ARCH "riscv64")
+elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "s390x")
+  set(ARCH "s390x")
 elseif (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "loongarch64")
   set(ARCH "loongarch64")
 else()

crypto/fipsmodule/rand/getrandom_fillin.h

@@ -34,6 +34,8 @@
 #define EXPECTED_NR_getrandom 359
 #elif defined(OPENSSL_RISCV64)
 #define EXPECTED_NR_getrandom 278
+#elif defined(OPENSSL_S390X)
+#define EXPECTED_NR_getrandom 349
 #elif defined(OPENSSL_LOONGARCH64)
 #define EXPECTED_NR_getrandom 278
 #endif

include/openssl/target.h

@@ -45,6 +45,10 @@
 #define OPENSSL_32_BIT
 #define OPENSSL_PPC32BE
 #define OPENSSL_BIG_ENDIAN
+#elif defined(__s390x__)
+#define OPENSSL_64_BIT
+#define OPENSSL_S390X
+#define OPENSSL_BIG_ENDIAN
 #elif defined(__MIPSEL__) && !defined(__LP64__)
 #define OPENSSL_32_BIT
 #define OPENSSL_MIPS

tests/ci/run_cross_tests.sh

@@ -51,6 +51,8 @@ set(ENABLE_EXPERIMENTAL_BIG_ENDIAN_SUPPORT true)
 set(CMAKE_GENERATOR Ninja)
 EOF
 
+cat ${TARGET_CPU}.cmake
+
 export QEMU_LD_PREFIX="${SCRATCH_FOLDER}/${TARGET_PLATFORM}/${TARGET_PLATFORM}/sysroot"
 export LD_LIBRARY_PATH="${SCRATCH_FOLDER}/${TARGET_PLATFORM}/${TARGET_PLATFORM}/sysroot/lib"
 

tests/docker_images/linux-ppc/ubuntu-x-tools/ppc.cmake

@@ -9,3 +9,4 @@ set(CMAKE_CXX_COMPILER /powerpc-unknown-linux-gnu/bin/powerpc-unknown-linux-gnu-
 # Specify the sysroot for the target system
 set(CMAKE_SYSROOT /powerpc-unknown-linux-gnu/powerpc-unknown-linux-gnu/sysroot)
 set(CMAKE_GENERATOR Ninja)
+set(ENABLE_EXPERIMENTAL_BIG_ENDIAN_SUPPORT true)

tests/docker_images/linux-ppc64/ubuntu-x-tools/ppc64.cmake

@@ -9,3 +9,4 @@ set(CMAKE_CXX_COMPILER /powerpc64-unknown-linux-gnu/bin/powerpc64-unknown-linux-
 # Specify the sysroot for the target system
 set(CMAKE_SYSROOT /powerpc64-unknown-linux-gnu/powerpc64-unknown-linux-gnu/sysroot/)
 set(CMAKE_GENERATOR Ninja)
+set(ENABLE_EXPERIMENTAL_BIG_ENDIAN_SUPPORT true)

tests/docker_images/linux-s390x/build_images.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR ISC
+
+set -ex
+
+# Note:
+# After host reboot, qemu registration may need to be performed.
+# `docker run --rm --privileged multiarch/qemu-user-static --reset -p yes`
+
+# On Linux, you can see which architectures that qemu is registered for by looking
+# under `/proc/sys/fs/binfmt_misc`.
+
+# If needed, you can clear these entries using the following command:
+# `sudo find /proc/sys/fs/binfmt_misc -type f -name 'qemu-*' -exec sh -c 'echo -1 > {}' \;`
+
+# Log Docker hub limit https://docs.docker.com/docker-hub/download-rate-limit/#how-can-i-check-my-current-rate
+TOKEN=$(curl "https://auth.docker.io/token?service=registry.docker.io&scope=repository:ratelimitpreview/test:pull" | jq -r .token)
+curl --head -H "Authorization: Bearer $TOKEN" https://registry-1.docker.io/v2/ratelimitpreview/test/manifests/latest
+
+SCRIPT_DIR=$(dirname "$(readlink -f "${0}")")
+
+docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+
+ARCH_NAME=s390x
+
+X_TOOLS_FILE=${ARCH_NAME}-x-tools
+if [ ! -f "./ubuntu-x-tools/${X_TOOLS_FILE}.tar.xz" ]; then
+  wget "https://aws-libcrypto.s3.us-west-2.amazonaws.com/cross-compile-toolchains/host-x86_64-pc-linux-gnu/${X_TOOLS_FILE}.tar.xz"
+  mv ${X_TOOLS_FILE}.tar.xz ./ubuntu-x-tools/
+fi
+
+BUILDER_NAME=${ARCH_NAME}-builder
+if ! docker buildx inspect ${BUILDER_NAME}; then
+    docker buildx create --name ${BUILDER_NAME} --use
+fi
+
+docker buildx build -t ubuntu-${ARCH_NAME}:test "${SCRIPT_DIR}"/ubuntu-test --load
+docker buildx build -t ubuntu-${ARCH_NAME}:x-tools "${SCRIPT_DIR}"/ubuntu-x-tools --load
+
+docker buildx rm ${BUILDER_NAME}

tests/docker_images/linux-s390x/ubuntu-test/Dockerfile

@@ -0,0 +1,23 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR ISC
+
+FROM --platform=$BUILDPLATFORM s390x/ubuntu
+
+SHELL ["/bin/bash", "-c"]
+
+# Note: valgind was not available on this platform
+RUN apt-get update && apt-get install -y  \
+    git gcc g++ cmake golang gdb gdbserver \
+    libclang-dev clang \
+    build-essential \
+    ssh \
+    rsync \
+    tar \
+    python3 \
+     && apt-get clean
+
+EXPOSE 7777
+
+ENV GOCACHE=/tmp
+
+CMD ["/bin/bash"]

tests/docker_images/linux-s390x/ubuntu-x-tools/Dockerfile

@@ -0,0 +1,40 @@
+# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0 OR ISC
+
+FROM ubuntu:22.04
+
+RUN apt-get update && apt-get install -y  \
+    git cmake golang gdb gdbserver valgrind \
+    libclang1 \
+    build-essential \
+    ssh \
+    rsync \
+    tar \
+    python3 \
+    xz-utils \
+    ninja-build
+
+RUN apt-get install -y \
+    qemu-system-s390x \
+    qemu-user \
+    qemu-user-binfmt
+
+RUN apt-get clean
+
+COPY s390x-x-tools.tar.xz /
+RUN tar Jxvf s390x-x-tools.tar.xz -C / && rm /s390x-x-tools.tar.xz
+COPY s390x.cmake /
+
+EXPOSE 1234
+
+ENV GOCACHE=/tmp \
+    CMAKE_TOOLCHAIN_FILE=/s390x.cmake \
+    CMAKE_SYSTEM_NAME=Linux \
+    CMAKE_SYSTEM_PROCESSOR=s390x \
+    PATH="${PATH}:/s390x-ibm-linux-gnu/bin/" \
+    CMAKE_C_COMPILER=/s390x-ibm-linux-gnu/bin/s390x-ibm-linux-gnu-gcc \
+    CMAKE_CXX_COMPILER=/s390x-ibm-linux-gnu/bin/s390x-ibm-linux-gnu-g++ \
+    CMAKE_SYSROOT=/s390x-ibm-linux-gnu/s390x-ibm-linux-gnu/sysroot \
+    CMAKE_GENERATOR=Ninja
+
+CMD ["/bin/bash"]

tests/docker_images/linux-s390x/ubuntu-x-tools/s390x.cmake

@@ -0,0 +1,12 @@
+# Specify the target system
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR s390x)
+
+# Specify the cross-compiler
+set(CMAKE_C_COMPILER /s390x-ibm-linux-gnu/bin/s390x-ibm-linux-gnu-gcc)
+set(CMAKE_CXX_COMPILER /s390x-ibm-linux-gnu/bin/s390x-ibm-linux-gnu-g++)
+
+# Specify the sysroot for the target system
+set(CMAKE_SYSROOT /s390x-ibm-linux-gnu/s390x-ibm-linux-gnu/sysroot)
+set(CMAKE_GENERATOR Ninja)
+set(ENABLE_EXPERIMENTAL_BIG_ENDIAN_SUPPORT true)