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, 103 insertions, 0 deletions

diff --git a/include/soc/tegra/ivc.h b/include/soc/tegra/ivc.h
new file mode 100644
index 000000000..be45d5f5a
--- /dev/null
+++ b/include/soc/tegra/ivc.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#ifndef __TEGRA_IVC_H
+#define __TEGRA_IVC_H
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/iosys-map.h>
+#include <linux/types.h>
+
+struct tegra_ivc_header;
+
+struct tegra_ivc {
+	struct device *peer;
+
+	struct {
+		struct iosys_map map;
+		unsigned int position;
+		dma_addr_t phys;
+	} rx, tx;
+
+	void (*notify)(struct tegra_ivc *ivc, void *data);
+	void *notify_data;
+
+	unsigned int num_frames;
+	size_t frame_size;
+};
+
+/**
+ * tegra_ivc_read_get_next_frame - Peek at the next frame to receive
+ * @ivc		pointer of the IVC channel
+ *
+ * Peek at the next frame to be received, without removing it from
+ * the queue.
+ *
+ * Returns a pointer to the frame, or an error encoded pointer.
+ */
+int tegra_ivc_read_get_next_frame(struct tegra_ivc *ivc, struct iosys_map *map);
+
+/**
+ * tegra_ivc_read_advance - Advance the read queue
+ * @ivc		pointer of the IVC channel
+ *
+ * Advance the read queue
+ *
+ * Returns 0, or a negative error value if failed.
+ */
+int tegra_ivc_read_advance(struct tegra_ivc *ivc);
+
+/**
+ * tegra_ivc_write_get_next_frame - Poke at the next frame to transmit
+ * @ivc		pointer of the IVC channel
+ *
+ * Get access to the next frame.
+ *
+ * Returns a pointer to the frame, or an error encoded pointer.
+ */
+int tegra_ivc_write_get_next_frame(struct tegra_ivc *ivc, struct iosys_map *map);
+
+/**
+ * tegra_ivc_write_advance - Advance the write queue
+ * @ivc		pointer of the IVC channel
+ *
+ * Advance the write queue
+ *
+ * Returns 0, or a negative error value if failed.
+ */
+int tegra_ivc_write_advance(struct tegra_ivc *ivc);
+
+/**
+ * tegra_ivc_notified - handle internal messages
+ * @ivc		pointer of the IVC channel
+ *
+ * This function must be called following every notification.
+ *
+ * Returns 0 if the channel is ready for communication, or -EAGAIN if a channel
+ * reset is in progress.
+ */
+int tegra_ivc_notified(struct tegra_ivc *ivc);
+
+/**
+ * tegra_ivc_reset - initiates a reset of the shared memory state
+ * @ivc		pointer of the IVC channel
+ *
+ * This function must be called after a channel is reserved before it is used
+ * for communication. The channel will be ready for use when a subsequent call
+ * to notify the remote of the channel reset.
+ */
+void tegra_ivc_reset(struct tegra_ivc *ivc);
+
+size_t tegra_ivc_align(size_t size);
+unsigned tegra_ivc_total_queue_size(unsigned queue_size);
+int tegra_ivc_init(struct tegra_ivc *ivc, struct device *peer, const struct iosys_map *rx,
+		   dma_addr_t rx_phys, const struct iosys_map *tx, dma_addr_t tx_phys,
+		   unsigned int num_frames, size_t frame_size,
+		   void (*notify)(struct tegra_ivc *ivc, void *data),
+		   void *data);
+void tegra_ivc_cleanup(struct tegra_ivc *ivc);
+
+#endif /* __TEGRA_IVC_H */