Add library support for aarch64-unknown-linux-pauthtest

library/std/src/sys/pal/unix/stack_overflow.rs

@@ -409,9 +409,15 @@ mod imp {
 
         unsafe {
             // this way someone on any unix-y OS can check that all these compile
-            if cfg!(all(target_os = "linux", not(target_env = "musl"))) {
+            if cfg!(all(
+                target_os = "linux",
+                not(any(target_env = "musl", target_env = "pauthtest"))
+            )) {
                 install_main_guard_linux(page_size)
-            } else if cfg!(all(target_os = "linux", target_env = "musl")) {
+            } else if cfg!(all(
+                target_os = "linux",
+                any(target_env = "musl", target_env = "pauthtest")
+            )) {
                 install_main_guard_linux_musl(page_size)
             } else if cfg!(target_os = "freebsd") {
                 #[cfg(not(target_os = "freebsd"))]
@@ -588,7 +594,10 @@ mod imp {
             let mut guardsize = 0;
             assert_eq!(libc::pthread_attr_getguardsize(attr.as_ptr(), &mut guardsize), 0);
             if guardsize == 0 {
-                if cfg!(all(target_os = "linux", target_env = "musl")) {
+                if cfg!(all(
+                    target_os = "linux",
+                    any(target_env = "musl", target_env = "pauthtest")
+                )) {
                     // musl versions before 1.1.19 always reported guard
                     // size obtained from pthread_attr_get_np as zero.
                     // Use page size as a fallback.
@@ -604,7 +613,10 @@ mod imp {
             let stackaddr = stackptr.addr();
             ret = if cfg!(any(target_os = "freebsd", target_os = "netbsd", target_os = "hurd")) {
                 Some(stackaddr - guardsize..stackaddr)
-            } else if cfg!(all(target_os = "linux", target_env = "musl")) {
+            } else if cfg!(all(
+                target_os = "linux",
+                any(target_env = "musl", target_env = "pauthtest")
+            )) {
                 Some(stackaddr - guardsize..stackaddr)
             } else if cfg!(all(target_os = "linux", any(target_env = "gnu", target_env = "uclibc")))
             {

library/std/src/sys/personality/gcc.rs

@@ -89,6 +89,34 @@ const UNWIND_DATA_REG: (i32, i32) = (10, 11); // x10, x11
 #[cfg(any(target_arch = "loongarch32", target_arch = "loongarch64"))]
 const UNWIND_DATA_REG: (i32, i32) = (4, 5); // a0, a1
 
+unsafe fn sign_lpad(context: *mut uw::_Unwind_Context, lpad: *const u8) -> *const u8 {
+    cfg_select! {
+        all(target_env = "pauthtest", target_arch = "aarch64") => {
+            // DWARF register number for SP on AArch64.
+            const SP_REG: i32 = 31;
+
+            unsafe {
+                let sp = uw::_Unwind_GetGR(context, SP_REG) as u64;
+                let mut addr = lpad as usize;
+
+                // `pacib` corresponds to `ptrauth_key_process_dependent_code` in <ptrauth.h>.
+                core::arch::asm!(
+                    "pacib {addr}, {sp}",
+                    addr = inout(reg) addr,
+                    sp = in(reg) sp,
+                    options(nostack, preserves_flags)
+                );
+
+                lpad.with_addr(addr)
+            }
+        }
+        _ => {
+            let _ = context;
+            lpad
+        }
+    }
+}
+
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:
 // https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc
 // https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c
@@ -239,7 +267,8 @@ cfg_select! {
                                 exception_object.cast(),
                             );
                             uw::_Unwind_SetGR(context, UNWIND_DATA_REG.1, core::ptr::null());
-                            uw::_Unwind_SetIP(context, lpad);
+                            let maybe_signed_lpad = sign_lpad(context, lpad);
+                            uw::_Unwind_SetIP(context, maybe_signed_lpad);
                             uw::_URC_INSTALL_CONTEXT
                         }
                         EHAction::Terminate => uw::_URC_FATAL_PHASE2_ERROR,

library/std/tests/pipe_subprocess.rs

@@ -12,10 +12,15 @@ fn main() {
 
         fn parent() {
             let me = env::current_exe().unwrap();
+            // If `runner` is set up for current target, we'll be executing `./runner ./test`, not
+            // just `./test`. For such a case, use the same arguments for child to avoid executing
+            // `runner` without actual executable.
+            let args = env::args();
 
             let (rx, tx) = pipe().unwrap();
             assert!(
                 process::Command::new(me)
+                    .args(args)
                     .env("I_AM_THE_CHILD", "1")
                     .stdout(tx)
                     .status()

library/std/tests/process_spawning.rs

@@ -26,8 +26,16 @@ fn issue_15149() {
         env::join_paths(paths).unwrap()
     };
 
-    let child_output =
-        process::Command::new("mytest").env("PATH", &path).arg("child").output().unwrap();
+    // If `runner` is set up for current target, we'll be executing `./runner ./test`, not
+    // just `./test`. For such a case, use the same arguments for child to avoid executing
+    // `runner` without actual executable.
+    let args = env::args();
+    let child_output = process::Command::new("mytest")
+        .args(args)
+        .env("PATH", &path)
+        .arg("child")
+        .output()
+        .unwrap();
 
     assert!(
         child_output.status.success(),

library/std_detect/src/detect/os/linux/auxvec.rs

@@ -51,7 +51,7 @@ pub(crate) struct AuxVec {
 /// Note that run-time feature detection is not invoked for features that can
 /// be detected at compile-time.
 ///
-///  Note: We always directly use `getauxval` on `*-linux-{gnu,musl,ohos}*` and
+///  Note: We always directly use `getauxval` on `*-linux-{gnu,musl,ohos,pauthtest}*` and
 /// `*-android*` targets rather than `dlsym` it because we can safely assume
 /// `getauxval` is linked to the binary.
 /// - `*-linux-gnu*` targets ([since Rust 1.64](https://blog.rust-lang.org/2022/08/01/Increasing-glibc-kernel-requirements.html))
@@ -125,7 +125,7 @@ fn getauxval(key: usize) -> Result<usize, ()> {
         any(
             all(
                 target_os = "linux",
-                any(target_env = "gnu", target_env = "musl", target_env = "ohos"),
+                any(target_env = "gnu", target_env = "musl", target_env = "ohos", target_env = "pauthtest"),
             ),
             target_os = "android",
         ) => {

library/unwind/src/lib.rs

@@ -94,6 +94,11 @@ cfg_select! {
     }
 }
 
+// For pauthtest the only supported unwinding mechanism is provided by libunwind.
+#[cfg(target_env = "pauthtest")]
+#[link(name = "unwind")]
+unsafe extern "C" {}
+
 // This is the same as musl except that we default to using the system libunwind
 // instead of libgcc.
 #[cfg(target_env = "ohos")]