selftests/bpf: Test packet range of pointers sharing an idgrafted

Add tests where two packet pointers share an id and tightening one
pointer's umax from its var_off would put it less than their constant
distance from the other's umax: with an index & 0x38 capped at 50, the
base pointer keeps umax 50, so the pointer 8 bytes further on must keep
umax 58, even though its known bits allow at most 56.

These refused a valid program or accepted an out-of-bounds access before
the fix:

- check the advanced copy, load through the base: valid, was refused;
- check the base, load the byte at base + 1 through a copy advanced by
  8: was accepted;
- check base + 4, load 4 bytes at base + 2 through base + 8: reads two
  bytes past the checked range, was accepted;
- the same as the second with data_meta pointers checked against data:
  was accepted.

These pass with and without the fix and cover nearby paths:

- subtract an unknown scalar from a checked pointer and load below it
  (the range is kept across a new id);
- reach a load through two paths whose checks cover 8 and 7 bytes after
  the loaded pointer; the second path must not be pruned by the first;
- spill a copy of a pointer, check the pointer, fill the copy and load
  one byte past the checked range: the load is refused, and the copy
  has the range of the check.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-sp.h b/drivers/clocksource/timer-sp.h
new file mode 100644
index 000000000..811f840be
--- /dev/null
+++ b/drivers/clocksource/timer-sp.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ARM timer implementation, found in Integrator, Versatile and Realview
+ * platforms.  Not all platforms support all registers and bits in these
+ * registers, so we mark them with A for Integrator AP, C for Integrator
+ * CP, V for Versatile and R for Realview.
+ *
+ * Integrator AP has 16-bit timers, Integrator CP, Versatile and Realview
+ * can have 16-bit or 32-bit selectable via a bit in the control register.
+ *
+ * Every SP804 contains two identical timers.
+ */
+#define NR_TIMERS	2
+#define TIMER_1_BASE	0x00
+#define TIMER_2_BASE	0x20
+
+#define TIMER_LOAD	0x00			/* ACVR rw */
+#define TIMER_VALUE	0x04			/* ACVR ro */
+#define TIMER_CTRL	0x08			/* ACVR rw */
+#define TIMER_CTRL_ONESHOT	(1 << 0)	/*  CVR */
+#define TIMER_CTRL_32BIT	(1 << 1)	/*  CVR */
+#define TIMER_CTRL_DIV1		(0 << 2)	/* ACVR */
+#define TIMER_CTRL_DIV16	(1 << 2)	/* ACVR */
+#define TIMER_CTRL_DIV256	(2 << 2)	/* ACVR */
+#define TIMER_CTRL_IE		(1 << 5)	/*   VR */
+#define TIMER_CTRL_PERIODIC	(1 << 6)	/* ACVR */
+#define TIMER_CTRL_ENABLE	(1 << 7)	/* ACVR */
+
+#define TIMER_INTCLR	0x0c			/* ACVR wo */
+#define TIMER_RIS	0x10			/*  CVR ro */
+#define TIMER_MIS	0x14			/*  CVR ro */
+#define TIMER_BGLOAD	0x18			/*  CVR rw */
+
+struct sp804_timer {
+	int load;
+	int load_h;
+	int value;
+	int value_h;
+	int ctrl;
+	int intclr;
+	int ris;
+	int mis;
+	int bgload;
+	int bgload_h;
+	int timer_base[NR_TIMERS];
+	int width;
+};
+
+struct sp804_clkevt {
+	void __iomem *base;
+	void __iomem *load;
+	void __iomem *load_h;
+	void __iomem *value;
+	void __iomem *value_h;
+	void __iomem *ctrl;
+	void __iomem *intclr;
+	void __iomem *ris;
+	void __iomem *mis;
+	void __iomem *bgload;
+	void __iomem *bgload_h;
+	unsigned long reload;
+	int width;
+};