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>

2 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/PCI/endpoint/function/binding/pci-ntb.rst b/Documentation/PCI/endpoint/function/binding/pci-ntb.rst
new file mode 100644
index 000000000..40253d3d5
--- /dev/null
+++ b/Documentation/PCI/endpoint/function/binding/pci-ntb.rst
@@ -0,0 +1,38 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+PCI NTB Endpoint Function
+==========================
+
+1) Create a subdirectory to pci_epf_ntb directory in configfs.
+
+Standard EPF Configurable Fields:
+
+================   ===========================================================
+vendorid	   should be 0x104c
+deviceid	   should be 0xb00d for TI's J721E SoC
+revid		   don't care
+progif_code	   don't care
+subclass_code	   should be 0x00
+baseclass_code	   should be 0x5
+cache_line_size	   don't care
+subsys_vendor_id   don't care
+subsys_id	   don't care
+interrupt_pin	   don't care
+msi_interrupts	   don't care
+msix_interrupts	   don't care
+================   ===========================================================
+
+2) Create a subdirectory to directory created in 1
+
+NTB EPF specific configurable fields:
+
+================   ===========================================================
+db_count	   Number of doorbells; default = 4
+mw1     	   size of memory window1
+mw2     	   size of memory window2
+mw3     	   size of memory window3
+mw4     	   size of memory window4
+num_mws     	   Number of memory windows; max = 4
+spad_count     	   Number of scratchpad registers; default = 64
+================   ===========================================================
diff --git a/Documentation/PCI/endpoint/function/binding/pci-test.rst b/Documentation/PCI/endpoint/function/binding/pci-test.rst
new file mode 100644
index 000000000..57ee866fb
--- /dev/null
+++ b/Documentation/PCI/endpoint/function/binding/pci-test.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+PCI Test Endpoint Function
+==========================
+
+name: Should be "pci_epf_test" to bind to the pci_epf_test driver.
+
+Configurable Fields:
+
+================   ===========================================================
+vendorid	   should be 0x104c
+deviceid	   should be 0xb500 for DRA74x and 0xb501 for DRA72x
+revid		   don't care
+progif_code	   don't care
+subclass_code	   don't care
+baseclass_code	   should be 0xff
+cache_line_size	   don't care
+subsys_vendor_id   don't care
+subsys_id	   don't care
+interrupt_pin	   Should be 1 - INTA, 2 - INTB, 3 - INTC, 4 -INTD
+msi_interrupts	   Should be 1 to 32 depending on the number of MSI interrupts
+		   to test
+msix_interrupts	   Should be 1 to 2048 depending on the number of MSI-X
+		   interrupts to test
+================   ===========================================================