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/drivers/parisc/gsc.h b/drivers/parisc/gsc.h
new file mode 100644
index 000000000..73cbd0bb1
--- /dev/null
+++ b/drivers/parisc/gsc.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * drivers/parisc/gsc.h
+ * Declarations for functions in gsc.c
+ * Copyright (c) 2000-2002 Helge Deller, Matthew Wilcox
+ */
+
+#include <linux/interrupt.h>
+#include <asm/hardware.h>
+#include <asm/parisc-device.h>
+
+#define OFFSET_IRR 0x0000   /* Interrupt request register */
+#define OFFSET_IMR 0x0004   /* Interrupt mask register */
+#define OFFSET_IPR 0x0008   /* Interrupt pending register */
+#define OFFSET_ICR 0x000C   /* Interrupt control register */
+#define OFFSET_IAR 0x0010   /* Interrupt address register */
+
+/* PA I/O Architected devices support at least 5 bits in the EIM register. */
+#define GSC_EIM_WIDTH 5
+
+struct gsc_irq {
+	unsigned long txn_addr;	/* IRQ "target" */
+	int txn_data;		/* HW "IRQ" */
+	int irq;		/* virtual IRQ */
+};
+
+struct gsc_asic {
+	struct parisc_device *gsc;
+	unsigned long hpa;
+	char *name;
+	int version;
+	int type;
+	int eim;
+	struct gsc_irq gsc_irq;
+	int global_irq[32];
+};
+
+int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic);
+int gsc_alloc_irq(struct gsc_irq *dev);			/* dev needs an irq */
+int gsc_claim_irq(struct gsc_irq *dev, int irq);	/* dev needs this irq */
+int gsc_assign_irq(struct irq_chip *type, void *data);
+int gsc_find_local_irq(unsigned int irq, int *global_irq, int limit);
+void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
+		void (*choose)(struct parisc_device *child, void *ctrl));
+void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp);
+
+irqreturn_t gsc_asic_intr(int irq, void *dev);