From 1dde2576ecb4410250250e1b44c1478925a0da6a Mon Sep 17 00:00:00 2001
From: Zack Winter <3457246+zackwintermdb@users.noreply.github.com>
Date: Thu, 2 May 2024 19:00:58 -0700
Subject: [PATCH] SERVER-90036 Set glibc.pthread.rseq on evergreen variants
 with glibc version >= 2.34 (#21713)

GitOrigin-RevId: 376c345d34577098b95aedbc9daa2a7b937497f4
---
 evergreen/prelude.sh                      |  1 +
 evergreen/prelude_system_env_variables.sh | 25 +++++++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100755 evergreen/prelude_system_env_variables.sh

diff --git a/evergreen/prelude.sh b/evergreen/prelude.sh
index eb671d4b5ae..b935774f10a 100755
--- a/evergreen/prelude.sh
+++ b/evergreen/prelude.sh
@@ -12,6 +12,7 @@ evergreen_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" > /dev/null 2>&1 && pwd)"
 . "$evergreen_dir/prelude_venv.sh"
 . "$evergreen_dir/prelude_db_contrib_tool.sh"
 . "$evergreen_dir/prelude_mongo_task_generator.sh"
+. "$evergreen_dir/prelude_system_env_variables.sh"
 
 expansions_yaml="$evergreen_dir/../../expansions.yml"
 expansions_default_yaml="$evergreen_dir/../etc/expansions.default.yml"
diff --git a/evergreen/prelude_system_env_variables.sh b/evergreen/prelude_system_env_variables.sh
new file mode 100755
index 00000000000..4ad4ba073a2
--- /dev/null
+++ b/evergreen/prelude_system_env_variables.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+get_glibc_version() {
+  getconf GNU_LIBC_VERSION | cut -d ' ' -f 2
+}
+
+# Systems with glibc 2.34 or newer register custom rseq ABI
+# behavior that is incompatible with the new TCMalloc, and will cause
+# TCMalloc's rseq functionality to break and fall back to the per-thread
+# cache behavior. Systems with an older glibc version will successfully
+# use TCMalloc's per-CPU caches. We must ensure this environment variable is
+# set on problematic systems.
+configure_glibc_pthread_req() {
+  if [[ "$OSTYPE" == "linux-gnu"* ]]; then
+    local ver="$(get_glibc_version)"
+    local major="$(echo $ver | cut -d '.' -f 1)"
+    local minor="$(echo $ver | cut -d '.' -f 2)"
+    if ((major > 2 || ((major == 2 && minor >= 34)))); then
+      export GLIBC_TUNABLES="glibc.pthread.rseq=0"
+      echo "glibc version >= 2.34 detected, setting env variable GLIBC_TUNABLES=glibc.pthread.rseq=0"
+    fi
+  fi
+}
+
+configure_glibc_pthread_req