tools/sched_ext: Sync with scx repo

Synchronize with https://github.com/sched-ext/scx at d384453984a0 ("kernel:
Sync at ad3b301aa0 ("sched_ext: Provides a sysfs 'events' to expose core
event counters")").

Signed-off-by: Tejun Heo <tj@kernel.org>

tools/sched_ext/include/scx/common.bpf.h

@@ -7,6 +7,13 @@
 #ifndef __SCX_COMMON_BPF_H
 #define __SCX_COMMON_BPF_H
 
+/*
+ * The generated kfunc prototypes in vmlinux.h are missing address space
+ * attributes which cause build failures. For now, suppress the generated
+ * prototypes. See https://github.com/sched-ext/scx/issues/1111.
+ */
+#define BPF_NO_KFUNC_PROTOTYPES
+
 #ifdef LSP
 #define __bpf__
 #include "../vmlinux.h"
@@ -78,10 +85,7 @@ s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym;
 struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym;
 struct cgroup *scx_bpf_task_cgroup(struct task_struct *p) __ksym __weak;
 u64 scx_bpf_now(void) __ksym __weak;
-
 void scx_bpf_events(struct scx_event_stats *events, size_t events__sz) __ksym __weak;
-#define scx_read_event(e, name)							\
-	(bpf_core_field_exists((e)->name) ? (e)->name : 0)
 
 /*
  * Use the following as @it__iter when calling scx_bpf_dsq_move[_vtime]() from
@@ -89,6 +93,9 @@ void scx_bpf_events(struct scx_event_stats *events, size_t events__sz) __ksym __
  */
 #define BPF_FOR_EACH_ITER	(&___it)
 
+#define scx_read_event(e, name)							\
+	(bpf_core_field_exists((e)->name) ? (e)->name : 0)
+
 static inline __attribute__((format(printf, 1, 2)))
 void ___scx_bpf_bstr_format_checker(const char *fmt, ...) {}
 
@@ -581,6 +588,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 	__u.__val;					\
 })
 
+#define READ_ONCE_ARENA(type, x)				\
+({								\
+	union { type __val; char __c[1]; } __u =		\
+		{ .__c = { 0 } };				\
+	__read_once_size((void *)&(x), __u.__c, sizeof(x));	\
+	__u.__val;						\
+})
+
+#define WRITE_ONCE_ARENA(type, x, val)				\
+({								\
+	union { type __val; char __c[1]; } __u =		\
+		{ .__val = (val) }; 				\
+	__write_once_size((void *)&(x), __u.__c, sizeof(x));	\
+	__u.__val;						\
+})
+
 /*
  * log2_u32 - Compute the base 2 logarithm of a 32-bit exponential value.
  * @v: The value for which we're computing the base 2 logarithm.

tools/sched_ext/scx_central.bpf.c

@@ -256,7 +256,6 @@ static int central_timerfn(void *map, int *key, struct bpf_timer *timer)
 	u64 now = scx_bpf_now();
 	u64 nr_to_kick = nr_queued;
 	s32 i, curr_cpu;
-	struct scx_event_stats events;
 
 	curr_cpu = bpf_get_smp_processor_id();
 	if (timer_pinned && (curr_cpu != central_cpu)) {
@@ -292,7 +291,6 @@ static int central_timerfn(void *map, int *key, struct bpf_timer *timer)
 
 	bpf_timer_start(timer, TIMER_INTERVAL_NS, BPF_F_TIMER_CPU_PIN);
 	__sync_fetch_and_add(&nr_timers, 1);
-
 	return 0;
 }
 

tools/sched_ext/scx_central.c

@@ -10,6 +10,7 @@
 #include <unistd.h>
 #include <inttypes.h>
 #include <signal.h>
+#include <assert.h>
 #include <libgen.h>
 #include <bpf/bpf.h>
 #include <scx/common.h>
@@ -60,14 +61,22 @@ restart:
 	skel->rodata->nr_cpu_ids = libbpf_num_possible_cpus();
 	skel->rodata->slice_ns = __COMPAT_ENUM_OR_ZERO("scx_public_consts", "SCX_SLICE_DFL");
 
+	assert(skel->rodata->nr_cpu_ids <= INT32_MAX);
+
 	while ((opt = getopt(argc, argv, "s:c:pvh")) != -1) {
 		switch (opt) {
 		case 's':
 			skel->rodata->slice_ns = strtoull(optarg, NULL, 0) * 1000;
 			break;
-		case 'c':
-			skel->rodata->central_cpu = strtoul(optarg, NULL, 0);
+		case 'c': {
+			u32 central_cpu = strtoul(optarg, NULL, 0);
+			if (central_cpu >= skel->rodata->nr_cpu_ids) {
+				fprintf(stderr, "invalid central CPU id value, %u given (%u max)\n", central_cpu, skel->rodata->nr_cpu_ids);
+				return -1;
+			}
+			skel->rodata->central_cpu = (s32)central_cpu;
 			break;
+		}
 		case 'v':
 			verbose = true;
 			break;
@@ -96,7 +105,7 @@ restart:
 	 */
 	cpuset = CPU_ALLOC(skel->rodata->nr_cpu_ids);
 	SCX_BUG_ON(!cpuset, "Failed to allocate cpuset");
-	CPU_ZERO(cpuset);
+	CPU_ZERO_S(CPU_ALLOC_SIZE(skel->rodata->nr_cpu_ids), cpuset);
 	CPU_SET(skel->rodata->central_cpu, cpuset);
 	SCX_BUG_ON(sched_setaffinity(0, sizeof(*cpuset), cpuset),
 		   "Failed to affinitize to central CPU %d (max %d)",