Create x86_64-unknown-linux-gnu{m,t}san target which enables {M,T}SAN by default

Similar like we've done it for `x86_64-unknown-linux-gnuasan`, in order
to distribute sanitizer instrumented standard libraries without
introducing new rustc flags, this adds a new dedicated target. With the
target, we can distribute the instrumented standard libraries through
a separate rustup component.

compiler/rustc_target/src/spec/mod.rs

@@ -1815,6 +1815,8 @@ fn $module() {
     ("x86_64-pc-cygwin", x86_64_pc_cygwin),
 
     ("x86_64-unknown-linux-gnuasan", x86_64_unknown_linux_gnuasan),
+    ("x86_64-unknown-linux-gnumsan", x86_64_unknown_linux_gnumsan),
+    ("x86_64-unknown-linux-gnutsan", x86_64_unknown_linux_gnutsan),
 }
 
 /// Cow-Vec-Str: Cow<'static, [Cow<'static, str>]>

compiler/rustc_target/src/spec/targets/x86_64_unknown_linux_gnumsan.rs

@@ -0,0 +1,16 @@
+use crate::spec::{SanitizerSet, Target, TargetMetadata};
+
+pub(crate) fn target() -> Target {
+    let mut base = super::x86_64_unknown_linux_gnu::target();
+    base.metadata = TargetMetadata {
+        description: Some(
+            "64-bit Linux (kernel 3.2+, glibc 2.17+) with MSAN enabled by default".into(),
+        ),
+        tier: Some(2),
+        host_tools: Some(false),
+        std: Some(true),
+    };
+    base.supported_sanitizers = SanitizerSet::MEMORY;
+    base.default_sanitizers = SanitizerSet::MEMORY;
+    base
+}

compiler/rustc_target/src/spec/targets/x86_64_unknown_linux_gnutsan.rs

@@ -0,0 +1,16 @@
+use crate::spec::{SanitizerSet, Target, TargetMetadata};
+
+pub(crate) fn target() -> Target {
+    let mut base = super::x86_64_unknown_linux_gnu::target();
+    base.metadata = TargetMetadata {
+        description: Some(
+            "64-bit Linux (kernel 3.2+, glibc 2.17+) with TSAN enabled by default".into(),
+        ),
+        tier: Some(2),
+        host_tools: Some(false),
+        std: Some(true),
+    };
+    base.supported_sanitizers = SanitizerSet::THREAD;
+    base.default_sanitizers = SanitizerSet::THREAD;
+    base
+}

src/bootstrap/src/core/build_steps/llvm.rs

@@ -1552,6 +1552,8 @@ fn supported_sanitizers(
             &["asan", "dfsan", "lsan", "msan", "safestack", "tsan", "rtsan"],
         ),
         "x86_64-unknown-linux-gnuasan" => common_libs("linux", "x86_64", &["asan"]),
+        "x86_64-unknown-linux-gnumsan" => common_libs("linux", "x86_64", &["msan"]),
+        "x86_64-unknown-linux-gnutsan" => common_libs("linux", "x86_64", &["tsan"]),
         "x86_64-unknown-linux-musl" => {
             common_libs("linux", "x86_64", &["asan", "lsan", "msan", "tsan"])
         }

src/bootstrap/src/core/sanity.rs

@@ -37,6 +37,8 @@ pub struct Finder {
 /// when the newly-bumped stage 0 compiler now knows about the formerly-missing targets.
 const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
+    "x86_64-unknown-linux-gnumsan",
+    "x86_64-unknown-linux-gnutsan",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM

src/ci/docker/host-x86_64/dist-various-2/Dockerfile

@@ -126,6 +126,8 @@ ENV TARGETS=$TARGETS,x86_64-unknown-uefi
 ENV TARGETS=$TARGETS,riscv64gc-unknown-linux-musl
 
 ENV TARGETS_SANITIZERS=x86_64-unknown-linux-gnuasan
+ENV TARGETS_SANITIZERS=$TARGETS_SANITIZERS,x86_64-unknown-linux-gnumsan
+ENV TARGETS_SANITIZERS=$TARGETS_SANITIZERS,x86_64-unknown-linux-gnutsan
 
 # As per https://bugs.launchpad.net/ubuntu/+source/gcc-defaults/+bug/1300211
 # we need asm in the search path for gcc-9 (for gnux32) but not in the search path of the

src/doc/rustc/src/SUMMARY.md

@@ -155,5 +155,7 @@
     - [x86_64-unknown-linux-none](platform-support/x86_64-unknown-linux-none.md)
     - [x86_64-unknown-none](platform-support/x86_64-unknown-none.md)
     - [x86_64-unknown-linux-gnuasan](platform-support/x86_64-unknown-linux-gnuasan.md)
+    - [x86_64-unknown-linux-gnumsan](platform-support/x86_64-unknown-linux-gnumsan.md)
+    - [x86_64-unknown-linux-gnutsan](platform-support/x86_64-unknown-linux-gnutsan.md)
     - [xtensa-\*-none-elf](platform-support/xtensa.md)
     - [\*-nuttx-\*](platform-support/nuttx.md)

src/doc/rustc/src/platform-support.md

@@ -216,6 +216,8 @@ target | std | notes
 [`x86_64-fortanix-unknown-sgx`](platform-support/x86_64-fortanix-unknown-sgx.md) | ✓ | [Fortanix ABI] for 64-bit Intel SGX
 [`x86_64-linux-android`](platform-support/android.md) | ✓ | 64-bit x86 Android
 [`x86_64-unknown-linux-gnuasan`](platform-support/x86_64-unknown-linux-gnuasan.md) | ✓ | 64-bit Linux (kernel 3.2+, glibc 2.17+) with ASAN enabled by default
+[`x86_64-unknown-linux-gnumsan`](platform-support/x86_64-unknown-linux-gnumsan.md) | ✓ | 64-bit Linux (kernel 3.2+, glibc 2.17+) with MSAN enabled by default
+[`x86_64-unknown-linux-gnutsan`](platform-support/x86_64-unknown-linux-gnutsan.md) | ✓ | 64-bit Linux (kernel 3.2+, glibc 2.17+) with TSAN enabled by default
 [`x86_64-unknown-fuchsia`](platform-support/fuchsia.md) | ✓ | 64-bit x86 Fuchsia
 `x86_64-unknown-linux-gnux32` | ✓ | 64-bit Linux (x32 ABI) (kernel 4.15+, glibc 2.27)
 [`x86_64-unknown-none`](platform-support/x86_64-unknown-none.md) | * | Freestanding/bare-metal x86_64, softfloat

src/doc/rustc/src/platform-support/x86_64-unknown-linux-gnumsan.md

@@ -0,0 +1,56 @@
+# `x86_64-unknown-linux-gnumsan`
+
+**Tier: 2**
+
+Target mirroring `x86_64-unknown-linux-gnu` with MemorySanitizer enabled by
+default.
+The goal of this target is to allow shipping MSAN-instrumented standard
+libraries through rustup, enabling a fully instrumented binary without requiring
+nightly features (build-std).
+Once build-std stabilizes, this target is no longer needed and will be removed.
+
+## Target maintainers
+
+- [@jakos-sec](https://github.com/jakos-sec)
+- [@1c3t3a](https://github.com/1c3t3a)
+- [@rust-lang/project-exploit-mitigations][project-exploit-mitigations]
+
+## Requirements
+
+The target is for cross-compilation only. Host tools are not supported, since
+there is no need to have the host tools instrumented with MSAN. std is fully
+supported.
+
+In all other aspects the target is equivalent to `x86_64-unknown-linux-gnu`.
+
+## Building the target
+
+The target can be built by enabling it for a rustc build:
+
+```toml
+[build]
+target = ["x86_64-unknown-linux-gnumsan"]
+```
+
+## Building Rust programs
+
+Rust programs can be compiled by adding this target via rustup:
+
+```sh
+$ rustup target add x86_64-unknown-linux-gnumsan
+```
+
+and then compiling with the target:
+
+```sh
+$ rustc foo.rs --target x86_64-unknown-linux-gnumsan
+```
+
+## Testing
+
+Created binaries will run on Linux without any external requirements.
+
+## Cross-compilation toolchains and C code
+
+The target supports C code and should use the same toolchain target as
+`x86_64-unknown-linux-gnu`.

src/doc/rustc/src/platform-support/x86_64-unknown-linux-gnutsan.md

@@ -0,0 +1,56 @@
+# `x86_64-unknown-linux-gnutsan`
+
+**Tier: 2**
+
+Target mirroring `x86_64-unknown-linux-gnu` with ThreadSanitizer enabled by
+default.
+The goal of this target is to allow shipping TSAN-instrumented standard
+libraries through rustup, enabling a fully instrumented binary without requiring
+nightly features (build-std).
+Once build-std stabilizes, this target is no longer needed and will be removed.
+
+## Target maintainers
+
+- [@jakos-sec](https://github.com/jakos-sec)
+- [@1c3t3a](https://github.com/1c3t3a)
+- [@rust-lang/project-exploit-mitigations][project-exploit-mitigations]
+
+## Requirements
+
+The target is for cross-compilation only. Host tools are not supported, since
+there is no need to have the host tools instrumented with TSAN. std is fully
+supported.
+
+In all other aspects the target is equivalent to `x86_64-unknown-linux-gnu`.
+
+## Building the target
+
+The target can be built by enabling it for a rustc build:
+
+```toml
+[build]
+target = ["x86_64-unknown-linux-gnutsan"]
+```
+
+## Building Rust programs
+
+Rust programs can be compiled by adding this target via rustup:
+
+```sh
+$ rustup target add x86_64-unknown-linux-gnutsan
+```
+
+and then compiling with the target:
+
+```sh
+$ rustc foo.rs --target x86_64-unknown-linux-gnutsan
+```
+
+## Testing
+
+Created binaries will run on Linux without any external requirements.
+
+## Cross-compilation toolchains and C code
+
+The target supports C code and should use the same toolchain target as
+`x86_64-unknown-linux-gnu`.

tests/assembly-llvm/targets/targets-elf.rs

@@ -709,6 +709,12 @@
 //@ revisions: x86_64_unknown_linux_gnuasan
 //@ [x86_64_unknown_linux_gnuasan] compile-flags: --target x86_64-unknown-linux-gnuasan
 //@ [x86_64_unknown_linux_gnuasan] needs-llvm-components: x86
+//@ revisions: x86_64_unknown_linux_gnumsan
+//@ [x86_64_unknown_linux_gnumsan] compile-flags: --target x86_64-unknown-linux-gnumsan
+//@ [x86_64_unknown_linux_gnumsan] needs-llvm-components: x86
+//@ revisions: x86_64_unknown_linux_gnutsan
+//@ [x86_64_unknown_linux_gnutsan] compile-flags: --target x86_64-unknown-linux-gnutsan
+//@ [x86_64_unknown_linux_gnutsan] needs-llvm-components: x86
 //@ revisions: x86_64_unknown_linux_musl
 //@ [x86_64_unknown_linux_musl] compile-flags: --target x86_64-unknown-linux-musl
 //@ [x86_64_unknown_linux_musl] needs-llvm-components: x86