mrust-libs: add a patch that was omitted by mistake

[Dave Berger <pkgsrc-mrust%web5by5.com@localhost>]

Module Name:	pkgsrc-wip
Committed By:	Dave Berger <pkgsrc-mrust%web5by5.com@localhost>
Pushed By:	dave
Date:		Tue Mar 28 01:03:47 2023 -0400
Changeset:	59b0ce82c1ebfec938eb11ba72d849c55a3331b5

Added Files:
	mrust-libs/patches/patch-.._rustc-1.54.0-src_library_std_src_sys_unix_thread.rs

Log Message:
mrust-libs: add a patch that was omitted by mistake

Aug 18 09:58:52 2022 EDT: patches/patch-.._rustc-1.54.0-src_library_std_src_sys_unix_thread.rs

To see a diff of this commit:
https://wip.pkgsrc.org/cgi-bin/gitweb.cgi?p=pkgsrc-wip.git;a=commitdiff;h=59b0ce82c1ebfec938eb11ba72d849c55a3331b5

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

diffstat:
 ...c-1.54.0-src_library_std_src_sys_unix_thread.rs | 43 ++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diffs:
diff --git a/mrust-libs/patches/patch-.._rustc-1.54.0-src_library_std_src_sys_unix_thread.rs b/mrust-libs/patches/patch-.._rustc-1.54.0-src_library_std_src_sys_unix_thread.rs
new file mode 100644
index 0000000000..84663ada52
--- /dev/null
+++ b/mrust-libs/patches/patch-.._rustc-1.54.0-src_library_std_src_sys_unix_thread.rs
@@ -0,0 +1,43 @@
+$NetBSD$
+
+--- ../rustc-1.54.0-src/library/std/src/sys/unix/thread.rs.orig	2021-07-26 14:43:02.000000000 +0000
++++ ../rustc-1.54.0-src/library/std/src/sys/unix/thread.rs
+@@ -357,6 +357,21 @@ pub mod guard {
+             const GUARD_PAGES: usize = 1;
+             let guard = guardaddr..guardaddr + GUARD_PAGES * page_size;
+             Some(guard)
++        } else if cfg!(target_os = "netbsd") {
++            // [The following should be reviewed/confirmed, -DLB]:
++            // Using the default else clause below, sporadic guard page
++            // errors were occurring during builds of rustc & cargo with
++            // mrustc on NetBSD; however, NetBSD has a kernel-based
++            // guard area mechanism too.  Therefore, try relying on that
++            // instead of the default mmap/mprotect solution; but note:
++            // if userland code changes the stack address, the NetBSD
++            // kernel-based guard mechanism is deactivated (see
++            // pthread_attr_getstack(3)) and the userland code must
++            // manage a guard area itself.  Fortunately, the stack
++            // appears to be unchanged by this version of thread.rs
++            let stackaddr = get_stack_start_aligned()?;
++            let stackaddr = stackaddr as usize;
++            Some(stackaddr - page_size..stackaddr)
+         } else {
+             // Reallocate the last page of the stack.
+             // This ensures SIGBUS will be raised on
+@@ -376,11 +391,16 @@ pub mod guard {
+                 0,
+             );
+             if result != stackaddr || result == MAP_FAILED {
++                println!( "stackaddr = {}", stackaddr as u64 );
++                println!( "mmap() -> result {}", result as u64 );
++                println!( "mmap() -> ERRNO {}", os::errno() as u64 );
+                 panic!("failed to allocate a guard page: {}", io::Error::last_os_error());
+             }
+ 
+             let result = mprotect(stackaddr, page_size, PROT_NONE);
+             if result != 0 {
++                println!( "stackaddr = {}", stackaddr as u64 );
++                println!( "mprotect() -> ERRNO {}", os::errno() as u64 );
+                 panic!("failed to protect the guard page: {}", io::Error::last_os_error());
+             }
+