Merge tag 'sched_ext-for-7.0-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - Fix starvation of scx_enable() under fair-class saturation by
   offloading the enable path to an RT kthread

 - Fix out-of-bounds access in idle mask initialization on systems with
   non-contiguous NUMA node IDs

 - Fix a preemption window during scheduler exit and a refcount
   underflow in cgroup init error path

 - Fix SCX_EFLAG_INITIALIZED being a no-op flag

 - Add READ_ONCE() annotations for KCSAN-clean lockless accesses and
   replace naked scx_root dereferences with container_of() in kobject
   callbacks

 - Tooling and selftest fixes: compilation issues with clang 17,
   strtoul() misuse, unused options cleanup, and Kconfig sync

* tag 'sched_ext-for-7.0-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Fix starvation of scx_enable() under fair-class saturation
  sched_ext: Remove redundant css_put() in scx_cgroup_init()
  selftests/sched_ext: Fix peek_dsq.bpf.c compile error for clang 17
  selftests/sched_ext: Add -fms-extensions to bpf build flags
  tools/sched_ext: Add -fms-extensions to bpf build flags
  sched_ext: Use READ_ONCE() for plain reads of scx_watchdog_timeout
  sched_ext: Replace naked scx_root dereferences in kobject callbacks
  sched_ext: Use READ_ONCE() for the read side of dsq->nr update
  tools/sched_ext: fix strtoul() misuse in scx_hotplug_seq()
  sched_ext: Fix SCX_EFLAG_INITIALIZED being a no-op flag
  sched_ext: Fix out-of-bounds access in scx_idle_init_masks()
  sched_ext: Disable preemption between scx_claim_exit() and kicking helper work
  tools/sched_ext: Add Kconfig to sync with upstream
  tools/sched_ext: Sync README.md Kconfig with upstream scx
  selftests/sched_ext: Remove duplicated unistd.h include in rt_stall.c
  tools/sched_ext: scx_sdt: Remove unused '-f' option
  tools/sched_ext: scx_central: Remove unused '-p' option
  selftests/sched_ext: Fix unused-result warning for read()
  selftests/sched_ext: Abort test loop on signal

5 files changed, 9 insertions, 4 deletions

diff --git a/tools/testing/selftests/sched_ext/Makefile b/tools/testing/selftests/sched_ext/Makefile
index 2c601a7eaff5..006300ac6dff 100644
--- a/tools/testing/selftests/sched_ext/Makefile
+++ b/tools/testing/selftests/sched_ext/Makefile
@@ -93,6 +93,8 @@ BPF_CFLAGS = -g -D__TARGET_ARCH_$(SRCARCH)					\
 	     $(CLANG_SYS_INCLUDES) 						\
 	     -Wall -Wno-compare-distinct-pointer-types				\
 	     -Wno-incompatible-function-pointer-types				\
+	     -Wno-microsoft-anon-tag						\
+	     -fms-extensions							\
 	     -O2 -mcpu=v3
 
 # sort removes libbpf duplicates when not cross-building
diff --git a/tools/testing/selftests/sched_ext/init_enable_count.c b/tools/testing/selftests/sched_ext/init_enable_count.c
index 82c71653977b..44577e30e764 100644
--- a/tools/testing/selftests/sched_ext/init_enable_count.c
+++ b/tools/testing/selftests/sched_ext/init_enable_count.c
@@ -57,7 +57,8 @@ static enum scx_test_status run_test(bool global)
 			char buf;
 
 			close(pipe_fds[1]);
-			read(pipe_fds[0], &buf, 1);
+			if (read(pipe_fds[0], &buf, 1) < 0)
+				exit(1);
 			close(pipe_fds[0]);
 			exit(0);
 		}
diff --git a/tools/testing/selftests/sched_ext/peek_dsq.bpf.c b/tools/testing/selftests/sched_ext/peek_dsq.bpf.c
index a3faf5bb49d6..784f2f6c1af9 100644
--- a/tools/testing/selftests/sched_ext/peek_dsq.bpf.c
+++ b/tools/testing/selftests/sched_ext/peek_dsq.bpf.c
@@ -58,14 +58,14 @@ static void record_peek_result(long pid)
 {
 	u32 slot_key;
 	long *slot_pid_ptr;
-	int ix;
+	u32 ix;
 
 	if (pid <= 0)
 		return;
 
 	/* Find an empty slot or one with the same PID */
 	bpf_for(ix, 0, 10) {
-		slot_key = (pid + ix) % MAX_SAMPLES;
+		slot_key = ((u64)pid + ix) % MAX_SAMPLES;
 		slot_pid_ptr = bpf_map_lookup_elem(&peek_results, &slot_key);
 		if (!slot_pid_ptr)
 			continue;
diff --git a/tools/testing/selftests/sched_ext/rt_stall.c b/tools/testing/selftests/sched_ext/rt_stall.c
index ab772e336f86..81ea9b4883e5 100644
--- a/tools/testing/selftests/sched_ext/rt_stall.c
+++ b/tools/testing/selftests/sched_ext/rt_stall.c
@@ -15,7 +15,6 @@
 #include <signal.h>
 #include <bpf/bpf.h>
 #include <scx/common.h>
-#include <unistd.h>
 #include "rt_stall.bpf.skel.h"
 #include "scx_test.h"
 #include "../kselftest.h"
diff --git a/tools/testing/selftests/sched_ext/runner.c b/tools/testing/selftests/sched_ext/runner.c
index 5748d2c69903..761c21f96404 100644
--- a/tools/testing/selftests/sched_ext/runner.c
+++ b/tools/testing/selftests/sched_ext/runner.c
@@ -166,6 +166,9 @@ int main(int argc, char **argv)
 		enum scx_test_status status;
 		struct scx_test *test = &__scx_tests[i];
 
+		if (exit_req)
+			break;
+
 		if (list) {
 			printf("%s\n", test->name);
 			if (i == (__scx_num_tests - 1))