From ad60e8b6340ac72d51adaa175483e6379b6bbc57 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 4 May 2024 13:33:12 +0200
Subject: [PATCH] Revert "moving out sched_getaffinity interception from
 linux'shim, FreeBSD supporting it too."

This reverts commit c1a3f8576ea12b0bed68ad3dedf4069ca3d9816f.
---
 src/shims/unix/foreign_items.rs       | 19 -------------------
 src/shims/unix/linux/foreign_items.rs | 13 +++++++++++++
 2 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/src/shims/unix/foreign_items.rs b/src/shims/unix/foreign_items.rs
index bd299aaa12..b07f596c74 100644
--- a/src/shims/unix/foreign_items.rs
+++ b/src/shims/unix/foreign_items.rs
@@ -724,25 +724,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 }
             }
 
-            "sched_getaffinity" => {
-                // FreeBSD supports it as well since 13.1 (as a wrapper of cpuset_getaffinity)
-                if !matches!(&*this.tcx.sess.target.os, "linux" | "freebsd") {
-                    throw_unsup_format!(
-                        "`sched_getaffinity` is not supported on {}",
-                        this.tcx.sess.target.os
-                    );
-                }
-                let [pid, cpusetsize, mask] =
-                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                this.read_scalar(pid)?.to_i32()?;
-                this.read_target_usize(cpusetsize)?;
-                this.deref_pointer_as(mask, this.libc_ty_layout("cpu_set_t"))?;
-                // FIXME: we just return an error; `num_cpus` then falls back to `sysconf`.
-                let einval = this.eval_libc("EINVAL");
-                this.set_last_error(einval)?;
-                this.write_scalar(Scalar::from_i32(-1), dest)?;
-            }
-
             // Platform-specific shims
             _ => {
                 let target_os = &*this.tcx.sess.target.os;
diff --git a/src/shims/unix/linux/foreign_items.rs b/src/shims/unix/linux/foreign_items.rs
index 497e8bee70..0d4c7ce112 100644
--- a/src/shims/unix/linux/foreign_items.rs
+++ b/src/shims/unix/linux/foreign_items.rs
@@ -195,6 +195,19 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
                 this.write_scalar(Scalar::from_i32(SIGRTMAX), dest)?;
             }
+            "sched_getaffinity" => {
+                // This shim isn't useful, aside from the fact that it makes `num_cpus`
+                // fall back to `sysconf` where it will successfully determine the number of CPUs.
+                let [pid, cpusetsize, mask] =
+                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                this.read_scalar(pid)?.to_i32()?;
+                this.read_target_usize(cpusetsize)?;
+                this.deref_pointer_as(mask, this.libc_ty_layout("cpu_set_t"))?;
+                // FIXME: we just return an error.
+                let einval = this.eval_libc("EINVAL");
+                this.set_last_error(einval)?;
+                this.write_scalar(Scalar::from_i32(-1), dest)?;
+            }
 
             // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
             // These shims are enabled only when the caller is in the standard library.