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, 21 insertions, 0 deletions

diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile
new file mode 100644
index 000000000..2caa90fa4
--- /dev/null
+++ b/drivers/cxl/Makefile
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Order is important here for the built-in case:
+# - 'core' first for fundamental init
+# - 'port' before platform root drivers like 'acpi' so that CXL-root ports
+#   are immediately enabled
+# - 'mem' and 'pmem' before endpoint drivers so that memdevs are
+#   immediately enabled
+# - 'pci' last, also mirrors the hardware enumeration hierarchy
+obj-y += core/
+obj-$(CONFIG_CXL_PORT) += cxl_port.o
+obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o
+obj-$(CONFIG_CXL_PMEM) += cxl_pmem.o
+obj-$(CONFIG_CXL_MEM) += cxl_mem.o
+obj-$(CONFIG_CXL_PCI) += cxl_pci.o
+
+cxl_port-y := port.o
+cxl_acpi-y := acpi.o
+cxl_pmem-y := pmem.o security.o
+cxl_mem-y := mem.o
+cxl_pci-y := pci.o