Rollup merge of #73171 - tblah:riscv-qemu-test, r=pietroalbini

RISC-V Emulated Testing

Adds a disabled docker image on which to run RISC-V tests. Based on the armhf image.

Test using
```
./src/ci/docker/run.sh riscv64gc-linux
```

cc: @msizanoen1

7 files changed, 322 insertions, 17 deletions

diff --git a/src/bootstrap/configure.py b/src/bootstrap/configure.py
index d1e53db573e..47673ce1e87 100755
--- a/src/bootstrap/configure.py
+++ b/src/bootstrap/configure.py
@@ -141,6 +141,8 @@ v("qemu-armhf-rootfs", "target.arm-unknown-linux-gnueabihf.qemu-rootfs",
   "rootfs in qemu testing, you probably don't want to use this")
 v("qemu-aarch64-rootfs", "target.aarch64-unknown-linux-gnu.qemu-rootfs",
   "rootfs in qemu testing, you probably don't want to use this")
+v("qemu-riscv64-rootfs", "target.riscv64gc-unknown-linux-gnu.qemu-rootfs",
+  "rootfs in qemu testing, you probably don't want to use this")
 v("experimental-targets", "llvm.experimental-targets",
   "experimental LLVM targets to build")
 v("release-channel", "rust.channel", "the name of the release channel to build")
diff --git a/src/ci/docker/disabled/riscv64gc-linux/0001-Remove-stime-function-calls.patch b/src/ci/docker/disabled/riscv64gc-linux/0001-Remove-stime-function-calls.patch
new file mode 100644
index 00000000000..08d0c5b2cac
--- /dev/null
+++ b/src/ci/docker/disabled/riscv64gc-linux/0001-Remove-stime-function-calls.patch
@@ -0,0 +1,96 @@
+From c820da85c65c7f3aa9e9cb3ed71ada69bf9b783e Mon Sep 17 00:00:00 2001
+From: Alistair Francis <alistair.francis@wdc.com>
+Date: Tue, 19 Nov 2019 13:06:40 +0100
+Subject: [PATCH] Remove stime() function calls
+
+stime() has been deprecated in glibc 2.31 and replaced with
+clock_settime(). Let's replace the stime() function calls with
+clock_settime() in preperation.
+
+function                                             old     new   delta
+rdate_main                                           197     224     +27
+clock_settime                                          -      27     +27
+date_main                                            926     941     +15
+stime                                                 37       -     -37
+------------------------------------------------------------------------------
+(add/remove: 2/2 grow/shrink: 2/0 up/down: 69/-37)             Total: 32 bytes
+
+Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+
+[Tom Eccles: adjust patch context to apply on top of 1.31.1-stable]
+Signed-off-by: Tom Eccles <tom.eccles@codethink.co.uk>
+---
+ coreutils/date.c         | 6 +++++-
+ libbb/missing_syscalls.c | 8 --------
+ util-linux/rdate.c       | 8 ++++++--
+ 3 files changed, 11 insertions(+), 11 deletions(-)
+
+diff --git a/coreutils/date.c b/coreutils/date.c
+index 3414d38ae..4ade6abb4 100644
+--- a/coreutils/date.c
++++ b/coreutils/date.c
+@@ -279,6 +279,9 @@ int date_main(int argc UNUSED_PARAM, char **argv)
+ 		time(&ts.tv_sec);
+ #endif
+ 	}
++#if !ENABLE_FEATURE_DATE_NANO
++	ts.tv_nsec = 0;
++#endif
+ 	localtime_r(&ts.tv_sec, &tm_time);
+ 
+ 	/* If date string is given, update tm_time, and maybe set date */
+@@ -301,9 +304,10 @@ int date_main(int argc UNUSED_PARAM, char **argv)
+ 		if (date_str[0] != '@')
+ 			tm_time.tm_isdst = -1;
+ 		ts.tv_sec = validate_tm_time(date_str, &tm_time);
++		ts.tv_nsec = 0;
+ 
+ 		/* if setting time, set it */
+-		if ((opt & OPT_SET) && stime(&ts.tv_sec) < 0) {
++		if ((opt & OPT_SET) && clock_settime(CLOCK_REALTIME, &ts) < 0) {
+ 			bb_perror_msg("can't set date");
+ 		}
+ 	}
+diff --git a/libbb/missing_syscalls.c b/libbb/missing_syscalls.c
+index 87cf59b3d..dc40d9155 100644
+--- a/libbb/missing_syscalls.c
++++ b/libbb/missing_syscalls.c
+@@ -15,14 +15,6 @@ pid_t getsid(pid_t pid)
+ 	return syscall(__NR_getsid, pid);
+ }
+ 
+-int stime(const time_t *t)
+-{
+-	struct timeval tv;
+-	tv.tv_sec = *t;
+-	tv.tv_usec = 0;
+-	return settimeofday(&tv, NULL);
+-}
+-
+ int sethostname(const char *name, size_t len)
+ {
+ 	return syscall(__NR_sethostname, name, len);
+diff --git a/util-linux/rdate.c b/util-linux/rdate.c
+index 70f829e7f..878375d78 100644
+--- a/util-linux/rdate.c
++++ b/util-linux/rdate.c
+@@ -95,9 +95,13 @@ int rdate_main(int argc UNUSED_PARAM, char **argv)
+ 	if (!(flags & 2)) { /* no -p (-s may be present) */
+ 		if (time(NULL) == remote_time)
+ 			bb_error_msg("current time matches remote time");
+-		else
+-			if (stime(&remote_time) < 0)
++		else {
++			struct timespec ts;
++			ts.tv_sec = remote_time;
++			ts.tv_nsec = 0;
++			if (clock_settime(CLOCK_REALTIME, &ts) < 0)
+ 				bb_perror_msg_and_die("can't set time of day");
++		}
+ 	}
+ 
+ 	if (flags != 1) /* not lone -s */
+-- 
+2.25.1
+
diff --git a/src/ci/docker/disabled/riscv64gc-linux/Dockerfile b/src/ci/docker/disabled/riscv64gc-linux/Dockerfile
new file mode 100644
index 00000000000..f21dc2ba309
--- /dev/null
+++ b/src/ci/docker/disabled/riscv64gc-linux/Dockerfile
@@ -0,0 +1,102 @@
+# based on armhf-gnu/Dockerfile
+FROM ubuntu:20.04
+
+RUN echo 'debconf debconf/frontend select Noninteractive' | debconf-set-selections
+RUN apt-get update -y && apt-get install -y --no-install-recommends \
+    bc \
+    bison \
+    ca-certificates \
+    cmake \
+    cpio \
+    curl \
+    debian-ports-archive-keyring \
+    debootstrap \
+    flex \
+    gcc \
+    gcc-riscv64-linux-gnu \
+    git \
+    g++-riscv64-linux-gnu \
+    g++ \
+    libc6-dev \
+    libc6-dev-riscv64-cross \
+    make \
+    patch \
+    python3 \
+    qemu-system-misc \
+    xz-utils
+
+ENV ARCH=riscv
+ENV CROSS_COMPILE=riscv64-linux-gnu-
+
+WORKDIR /build
+
+# From https://github.com/michaeljclark/busybear-linux/blob/master/conf/linux.config
+COPY riscv64gc-linux/linux.config /build
+
+# Compile the kernel that we're going to be emulating with. This is
+# basically just done to be compatible with the QEMU target that we're going
+# to be using when running tests.
+RUN curl https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.6.16.tar.xz | tar xJf - && \
+    cp linux.config linux-5.6.16/.config && \
+    cd /build/linux-5.6.16 && \
+    make olddefconfig && \
+    make -j$(nproc) vmlinux
+RUN cp linux-5.6.16/vmlinux /tmp
+RUN rm -rf linux-5.6.16
+
+# Compile an instance of busybox as this provides a lightweight system and init
+# binary which we will boot into. Only trick here is configuring busybox to
+# build static binaries.
+RUN curl https://busybox.net/downloads/busybox-1.31.1.tar.bz2 | tar xjf -
+COPY riscv64gc-linux/0001-Remove-stime-function-calls.patch /build/busybox-1.31.1/
+RUN cd /build/busybox-1.31.1 && \
+    patch -p1 -i 0001-Remove-stime-function-calls.patch && \
+    make defconfig && \
+    sed -i 's/.*CONFIG_STATIC.*/CONFIG_STATIC=y/' .config && \
+    make -j$(nproc) && \
+    make install && \
+    mv _install /tmp/rootfs && \
+    cd /build && \
+    rm -rf busybox-1.31.1
+
+# Download the ubuntu rootfs, which we'll use as a chroot for all our tests
+# This is only needed to provide /lib/* and /usr/lib/*
+WORKDIR /tmp
+RUN debootstrap --variant=minbase --arch=riscv64 --foreign focal /tmp/rootfs/ubuntu
+RUN cd rootfs && mkdir proc sys dev etc etc/init.d
+# rootfs/ubuntu/proc is in a weird state (access fails with ELOOP) until
+# rootfs/ubuntu/debootstrap/debootstrap --second-stage is run (under emulation),
+# but this takes ages. Instead hack it into a good enough state.
+# /proc is used by std::env::current_exe() (which is roughly
+# `readlink /proc/self/exe`)
+RUN cd rootfs/ubuntu && rm -rf proc && mkdir proc
+
+# Copy over our init script, which starts up our test server and also a few other
+# misc tasks
+COPY scripts/qemu-bare-bones-rcS rootfs/etc/init.d/rcS
+RUN chmod +x rootfs/etc/init.d/rcS
+
+# Helper to quickly fill the entropy pool in the kernel
+COPY scripts/qemu-bare-bones-addentropy.c /tmp/addentropy.c
+RUN riscv64-linux-gnu-gcc addentropy.c -o rootfs/addentropy -static
+
+# download and build the riscv bootloader
+RUN git clone https://github.com/riscv/riscv-pk
+WORKDIR /tmp/riscv-pk
+# nothing special about this revision: it is just master at the time of writing
+# v1.0.0 doesn't build
+RUN git checkout 5d9ed238e1cabfbca3c47f50d32894ce94bfc304
+RUN mkdir build && cd build && \
+    ../configure --with-payload=/tmp/vmlinux --host=riscv64-linux-gnu && \
+    make -j$(nproc) && \
+    cp bbl /tmp
+WORKDIR /tmp
+RUN rm -rf /tmp/riscv-pk
+
+COPY scripts/sccache.sh /scripts/
+RUN sh /scripts/sccache.sh
+
+ENV RUST_CONFIGURE_ARGS --qemu-riscv64-rootfs=/tmp/rootfs
+ENV SCRIPT python3 ../x.py test --target riscv64gc-unknown-linux-gnu
+
+ENV NO_CHANGE_USER=1
diff --git a/src/ci/docker/disabled/riscv64gc-linux/linux.config b/src/ci/docker/disabled/riscv64gc-linux/linux.config
new file mode 100644
index 00000000000..5142664742f
--- /dev/null
+++ b/src/ci/docker/disabled/riscv64gc-linux/linux.config
@@ -0,0 +1,51 @@
+CONFIG_DEFAULT_HOSTNAME="busybear"
+CONFIG_SYSVIPC=y
+CONFIG_POSIX_MQUEUE=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
+CONFIG_CGROUPS=y
+CONFIG_CGROUP_SCHED=y
+CONFIG_CFS_BANDWIDTH=y
+CONFIG_CGROUP_BPF=y
+CONFIG_NAMESPACES=y
+CONFIG_USER_NS=y
+CONFIG_CHECKPOINT_RESTORE=y
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_EXPERT=y
+CONFIG_BPF_SYSCALL=y
+CONFIG_SMP=y
+CONFIG_MODULES=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_PACKET_DIAG=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+CONFIG_NETLINK_DIAG=y
+# CONFIG_WIRELESS is not set
+CONFIG_PCI=y
+CONFIG_DEVTMPFS=y
+CONFIG_BLK_DEV_LOOP=y
+CONFIG_VIRTIO_BLK=y
+CONFIG_NETDEVICES=y
+CONFIG_VIRTIO_NET=y
+# CONFIG_ETHERNET is not set
+# CONFIG_WLAN is not set
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_HVC_RISCV_SBI=y
+# CONFIG_HW_RANDOM is not set
+# CONFIG_USB_SUPPORT is not set
+CONFIG_VIRTIO_MMIO=y
+CONFIG_SIFIVE_PLIC=y
+CONFIG_RAS=y
+CONFIG_EXT2_FS=y
+CONFIG_EXT3_FS=y
+CONFIG_EXT4_FS_POSIX_ACL=y
+CONFIG_AUTOFS4_FS=y
+CONFIG_MSDOS_FS=y
+CONFIG_VFAT_FS=y
+CONFIG_TMPFS=y
+# CONFIG_CRYPTO_ECHAINIV is not set
+# CONFIG_CRYPTO_HW is not set
+CONFIG_PRINTK_TIME=y
diff --git a/src/libstd/sys/unix/process/process_common.rs b/src/libstd/sys/unix/process/process_common.rs
index 2d7267263de..6e33cdd3c48 100644
--- a/src/libstd/sys/unix/process/process_common.rs
+++ b/src/libstd/sys/unix/process/process_common.rs
@@ -428,6 +428,7 @@ mod tests {
     // ignored there.
     #[cfg_attr(target_arch = "arm", ignore)]
     #[cfg_attr(target_arch = "aarch64", ignore)]
+    #[cfg_attr(target_arch = "riscv64", ignore)]
     fn test_process_mask() {
         unsafe {
             // Test to make sure that a signal mask does not get inherited.
diff --git a/src/libstd/time.rs b/src/libstd/time.rs
index 295ebcbb729..84fa35e01bb 100644
--- a/src/libstd/time.rs
+++ b/src/libstd/time.rs
@@ -811,11 +811,11 @@ mod tests {
 
         // Right now for CI this test is run in an emulator, and apparently the
         // aarch64 emulator's sense of time is that we're still living in the
-        // 70s.
+        // 70s. This is also true for riscv (also qemu)
         //
         // Otherwise let's assume that we're all running computers later than
         // 2000.
-        if !cfg!(target_arch = "aarch64") {
+        if !cfg!(target_arch = "aarch64") && !cfg!(target_arch = "riscv64") {
             assert!(a > thirty_years);
         }
 
diff --git a/src/tools/remote-test-client/src/main.rs b/src/tools/remote-test-client/src/main.rs
index efc29163455..1fafe109d34 100644
--- a/src/tools/remote-test-client/src/main.rs
+++ b/src/tools/remote-test-client/src/main.rs
@@ -107,13 +107,23 @@ fn start_android_emulator(server: &Path) {
     Command::new("adb").arg("shell").arg("/data/tmp/testd").spawn().unwrap();
 }
 
-fn start_qemu_emulator(target: &str, rootfs: &Path, server: &Path, tmpdir: &Path) {
+fn prepare_rootfs(target: &str, rootfs: &Path, server: &Path, rootfs_img: &Path) {
+    t!(fs::copy(server, rootfs.join("testd")));
+
+    match target {
+        "arm-unknown-linux-gnueabihf" | "aarch64-unknown-linux-gnu" => {
+            prepare_rootfs_cpio(rootfs, rootfs_img)
+        }
+        "riscv64gc-unknown-linux-gnu" => prepare_rootfs_ext4(rootfs, rootfs_img),
+        _ => panic!("{} is not supported", target),
+    }
+}
+
+fn prepare_rootfs_cpio(rootfs: &Path, rootfs_img: &Path) {
     // Generate a new rootfs image now that we've updated the test server
     // executable. This is the equivalent of:
     //
     //      find $rootfs -print 0 | cpio --null -o --format=newc > rootfs.img
-    t!(fs::copy(server, rootfs.join("testd")));
-    let rootfs_img = tmpdir.join("rootfs.img");
     let mut cmd = Command::new("cpio");
     cmd.arg("--null")
         .arg("-o")
@@ -128,6 +138,38 @@ fn start_qemu_emulator(target: &str, rootfs: &Path, server: &Path, tmpdir: &Path
     t!(io::copy(&mut child.stdout.take().unwrap(), &mut t!(File::create(&rootfs_img))));
     assert!(t!(child.wait()).success());
 
+    fn add_files(w: &mut dyn Write, root: &Path, cur: &Path) {
+        for entry in t!(cur.read_dir()) {
+            let entry = t!(entry);
+            let path = entry.path();
+            let to_print = path.strip_prefix(root).unwrap();
+            t!(write!(w, "{}\u{0}", to_print.to_str().unwrap()));
+            if t!(entry.file_type()).is_dir() {
+                add_files(w, root, &path);
+            }
+        }
+    }
+}
+
+fn prepare_rootfs_ext4(rootfs: &Path, rootfs_img: &Path) {
+    let mut dd = Command::new("dd");
+    dd.arg("if=/dev/zero")
+        .arg(&format!("of={}", rootfs_img.to_string_lossy()))
+        .arg("bs=1M")
+        .arg("count=1024");
+    let mut dd_child = t!(dd.spawn());
+    assert!(t!(dd_child.wait()).success());
+
+    let mut mkfs = Command::new("mkfs.ext4");
+    mkfs.arg("-d").arg(rootfs).arg(rootfs_img);
+    let mut mkfs_child = t!(mkfs.spawn());
+    assert!(t!(mkfs_child.wait()).success());
+}
+
+fn start_qemu_emulator(target: &str, rootfs: &Path, server: &Path, tmpdir: &Path) {
+    let rootfs_img = &tmpdir.join("rootfs.img");
+    prepare_rootfs(target, rootfs, server, rootfs_img);
+
     // Start up the emulator, in the background
     match target {
         "arm-unknown-linux-gnueabihf" => {
@@ -170,19 +212,30 @@ fn start_qemu_emulator(target: &str, rootfs: &Path, server: &Path, tmpdir: &Path
                 .arg("virtio-net-device,netdev=net0,mac=00:00:00:00:00:00");
             t!(cmd.spawn());
         }
-        _ => panic!("cannot start emulator for: {}" < target),
-    }
-
-    fn add_files(w: &mut dyn Write, root: &Path, cur: &Path) {
-        for entry in t!(cur.read_dir()) {
-            let entry = t!(entry);
-            let path = entry.path();
-            let to_print = path.strip_prefix(root).unwrap();
-            t!(write!(w, "{}\u{0}", to_print.to_str().unwrap()));
-            if t!(entry.file_type()).is_dir() {
-                add_files(w, root, &path);
-            }
+        "riscv64gc-unknown-linux-gnu" => {
+            let mut cmd = Command::new("qemu-system-riscv64");
+            cmd.arg("-nographic")
+                .arg("-machine")
+                .arg("virt")
+                .arg("-m")
+                .arg("1024")
+                .arg("-bios")
+                .arg("none")
+                .arg("-kernel")
+                .arg("/tmp/bbl")
+                .arg("-append")
+                .arg("quiet console=ttyS0 root=/dev/vda rw")
+                .arg("-netdev")
+                .arg("user,id=net0,hostfwd=tcp::12345-:12345")
+                .arg("-device")
+                .arg("virtio-net-device,netdev=net0,mac=00:00:00:00:00:00")
+                .arg("-device")
+                .arg("virtio-blk-device,drive=hd0")
+                .arg("-drive")
+                .arg(&format!("file={},format=raw,id=hd0", &rootfs_img.to_string_lossy()));
+            t!(cmd.spawn());
         }
+        _ => panic!("cannot start emulator for: {}", target),
     }
 }