bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/tools/perf/ui/progress.c b/tools/perf/ui/progress.c
new file mode 100644
index 000000000..99d60223c
--- /dev/null
+++ b/tools/perf/ui/progress.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include "progress.h"
+
+static void null_progress__update(struct ui_progress *p __maybe_unused)
+{
+}
+
+static struct ui_progress_ops null_progress__ops =
+{
+	.update = null_progress__update,
+};
+
+struct ui_progress_ops *ui_progress__ops = &null_progress__ops;
+
+void ui_progress__update(struct ui_progress *p, u64 adv)
+{
+	u64 last = p->curr;
+
+	p->curr += adv;
+
+	if (p->curr >= p->next) {
+		u64 nr = DIV_ROUND_UP(p->curr - last, p->step);
+
+		p->next += nr * p->step;
+		ui_progress__ops->update(p);
+	}
+}
+
+void __ui_progress__init(struct ui_progress *p, u64 total,
+			 const char *title, bool size)
+{
+	p->curr = 0;
+	p->next = p->step = total / 16 ?: 1;
+	p->total = total;
+	p->title = title;
+	p->size  = size;
+
+	if (ui_progress__ops->init)
+		ui_progress__ops->init(p);
+}
+
+void ui_progress__finish(void)
+{
+	if (ui_progress__ops->finish)
+		ui_progress__ops->finish();
+}