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, 49 insertions, 0 deletions

diff --git a/drivers/gpib/include/amcc5920.h b/drivers/gpib/include/amcc5920.h
new file mode 100644
index 000000000..7a88bd282
--- /dev/null
+++ b/drivers/gpib/include/amcc5920.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/***************************************************************************
+ *  Header for amcc5920 pci chip
+ *
+ *   copyright		  : (C) 2002 by Frank Mori Hess
+ ***************************************************************************/
+
+// plx pci chip registers and bits
+enum amcc_registers {
+	AMCC_INTCS_REG = 0x38,
+	AMCC_PASS_THRU_REG	= 0x60,
+};
+
+enum amcc_incsr_bits {
+	AMCC_ADDON_INTR_ENABLE_BIT = 0x2000,
+	AMCC_ADDON_INTR_ACTIVE_BIT = 0x400000,
+	AMCC_INTR_ACTIVE_BIT = 0x800000,
+};
+
+static const int bits_per_region = 8;
+
+static inline uint32_t amcc_wait_state_bits(unsigned int region, unsigned int num_wait_states)
+{
+	return (num_wait_states & 0x7) << (--region * bits_per_region);
+};
+
+enum amcc_prefetch_bits {
+	PREFETCH_DISABLED = 0x0,
+	PREFETCH_SMALL = 0x8,
+	PREFETCH_MEDIUM = 0x10,
+	PREFETCH_LARGE = 0x18,
+};
+
+static inline uint32_t amcc_prefetch_bits(unsigned int region, enum amcc_prefetch_bits prefetch)
+{
+	return prefetch << (--region * bits_per_region);
+};
+
+static inline uint32_t amcc_PTADR_mode_bit(unsigned int region)
+{
+	return 0x80 << (--region * bits_per_region);
+};
+
+static inline uint32_t amcc_disable_write_fifo_bit(unsigned int region)
+{
+	return 0x20 << (--region * bits_per_region);
+};
+