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Add vectorinfo module
Prints x86_64 per-cpu and system vector information. Orabug: 38383772 Authored-by: Partha Satapathy [email protected] Co-authored-by: Srivathsa Dara [email protected]
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‎drgn_tools/vectorinfo.py‎

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# Copyright (c) 2025, Oracle and/or its affiliates.
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# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
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"""
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Helper to print x86_64 CPU vector information
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"""
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import argparse
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from drgn import Object
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from drgn import Program
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from drgn.helpers.linux.percpu import for_each_online_cpu
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from drgn.helpers.linux.percpu import per_cpu
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from drgn.helpers.linux.percpu import per_cpu_ptr
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from drgn_tools.corelens import CorelensModule
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from drgn_tools.table import Table
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from drgn_tools.util import has_member
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"""
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Linux IRQ vector layout (x86).
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* Vectors 0 ... 31 : system traps and exceptions - hardcoded events (RESERVED)
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* Vectors 32 ... 127 : device interrupts
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* Vector 128 : legacy int80 syscall interface (RESERVED)
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* Vectors 129 ... LOCAL_TIMER_VECTOR-1
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* Vectors LOCAL_TIMER_VECTOR ... 255 : special interrupts (RESERVED)
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Reserved vectors = 32 (system traps and exceptions) + 1 (sycall interface)
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+ 20 (special interrupts)
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"""
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NR_VECTORS = 256
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IA32_SYSCALL_VECTOR = 0x80
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FIRST_EXTERNAL_VECTOR = 0x20
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LOCAL_TIMER_VECTOR = 0xEC
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RESERVED_VECTORS = 53
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def dump_vectors(vectors: str) -> None:
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"""
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Print the given string with a space after every 8 characters,
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and a newline after every 64 characters.
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"""
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for i in range(0, len(vectors), 8):
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if i and i % 64 == 0:
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print()
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print(vectors[i : i + 8], end=" ")
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print()
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def print_vector_matrix(prog: Program) -> None:
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"""
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Print vector matrix information
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"""
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try:
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vector_matrix = prog["vector_matrix"]
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except KeyError:
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print("\n'vector_matrix' not found — requires UEK6 or newer.\n")
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return
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per_cpu_vector_map = vector_matrix.maps
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print("System vector matrix:")
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print(f"\t{'Vector bits':25}: {vector_matrix.matrix_bits.value_()}")
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print(
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f"\t{'Vector allocation start':25}: {vector_matrix.alloc_start.value_()}"
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)
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print(
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f"\t{'Vector allocation end':25}: {vector_matrix.alloc_end.value_()}"
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)
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print(
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f"\t{'Vector allocation size':25}: {vector_matrix.alloc_size.value_()}"
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)
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print(
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f"\t{'Global available':25}: {vector_matrix.global_available.value_()}"
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)
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print(
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f"\t{'Global reserved':25}: {vector_matrix.global_reserved.value_()}"
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)
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print(
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f"\t{'Total allocated':25}: {vector_matrix.total_allocated.value_()}"
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)
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print(f"\t{'Online maps':25}: {vector_matrix.online_maps.value_()}")
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print()
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for cpu in for_each_online_cpu(prog):
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per_cpu_vector_matrix = per_cpu_ptr(per_cpu_vector_map, cpu)
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print(f"Per-CPU IRQ vector map (CPU {cpu}):")
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print(
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f"\t{'Available':25}: {per_cpu_vector_matrix.available.value_()}"
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)
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print(
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f"\t{'Allocated':25}: {per_cpu_vector_matrix.allocated.value_()}"
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)
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print(f"\t{'Managed':25}: {per_cpu_vector_matrix.managed.value_()}")
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print(
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f"\t{'Managed Allocated':25}: {per_cpu_vector_matrix.managed_allocated.value_()}"
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)
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print()
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def print_vectors(prog: Program, verbose: bool) -> None:
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"""
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Print vector information
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If -v flag specified, print per vector information
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"""
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VECTOR_SHUTDOWN = Object(prog, "void *", -1)
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VECTOR_RETRIGGERED = Object(prog, "void *", -2)
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vector_irq = prog["vector_irq"]
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total_vectors_used = 0
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total_cpus = 0
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total_avl_vectors = 0
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system_vectors = []
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system_table = Table(
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[
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"CPU",
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"Total Vectors",
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"Used Vectors",
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"Reserved Vectors",
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"Available Vectors",
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]
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)
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for cpu in for_each_online_cpu(prog):
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total_cpus += 1
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cpu_vector_list = ["0"] * NR_VECTORS
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cpu_vectors = per_cpu(vector_irq, cpu)
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per_cpu_vectors_used = 0
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per_cpu_avl_vectors = 0
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if verbose:
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print(f"\nCPU : {cpu}")
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per_cpu_table = Table(
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["Vector", "IRQ", "Address", "Function", "Device", "Module"]
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)
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for vec in range(NR_VECTORS):
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if not cpu_vectors[vec]:
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if (
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vec >= FIRST_EXTERNAL_VECTOR
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and vec < LOCAL_TIMER_VECTOR
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and vec != IA32_SYSCALL_VECTOR
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):
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per_cpu_avl_vectors += 1
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continue
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irqdesc = cpu_vectors[vec]
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per_cpu_vectors_used += 1
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cpu_vector_list[vec] = "1"
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if not verbose:
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continue
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irqdesc_irq = irqdesc_fn = irqdesc_dev = irqdesc_mod = ""
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if irqdesc == VECTOR_SHUTDOWN:
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irqdesc_addr = "SHUTDOWN"
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elif irqdesc == VECTOR_RETRIGGERED:
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irqdesc_addr = "RETRIGGERED"
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else:
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irqdesc_addr = hex(irqdesc)
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irqdesc_irq = irqdesc_fn = irqdesc_dev = irqdesc_mod = "NA"
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if irqdesc.action:
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irqdesc_irq = irqdesc.action.irq.value_()
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if irqdesc.action.name:
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irqdesc_fn = irqdesc.action.name.string_().decode(
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"utf-8"
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)
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if has_member(irqdesc, "dev_name") and irqdesc.dev_name:
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irqdesc_dev = irqdesc.dev_name.string_().decode("utf-8")
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if irqdesc.owner and irqdesc.owner.name:
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irqdesc_mod = irqdesc.owner.name.string_().decode("utf-8")
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per_cpu_table.row(
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vec,
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irqdesc_irq,
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irqdesc_addr,
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irqdesc_fn,
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irqdesc_dev,
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irqdesc_mod,
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)
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if verbose:
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per_cpu_table.write()
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print(
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f"Total: {NR_VECTORS}\tUsed: {per_cpu_vectors_used}\tReserved: {RESERVED_VECTORS}\tAvailable: {per_cpu_avl_vectors}"
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)
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system_vectors.append("".join(cpu_vector_list))
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total_vectors_used += per_cpu_vectors_used
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total_avl_vectors += per_cpu_avl_vectors
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system_table.row(
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cpu,
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NR_VECTORS,
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per_cpu_vectors_used,
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RESERVED_VECTORS,
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per_cpu_avl_vectors,
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)
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total_system_vectors = NR_VECTORS * total_cpus
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total_res_vectors = RESERVED_VECTORS * total_cpus
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for i in range(total_cpus):
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print(f"\nCPU : {i}")
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dump_vectors(system_vectors[i])
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print()
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system_table.row(
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"Total",
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total_system_vectors,
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total_vectors_used,
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total_res_vectors,
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total_avl_vectors,
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)
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system_table.write()
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def print_vector_info(prog: Program, verbose: bool = False) -> None:
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"""
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Helper to print CPU vector information
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"""
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if prog.platform.arch.name != "X86_64":
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print("Non-x86_64 architectures are not supported at this time")
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return
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print_vector_matrix(prog)
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print_vectors(prog, verbose)
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class VectorInfo(CorelensModule):
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"""
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Prints x86_64 interrupt vector information
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"""
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name = "vectorinfo"
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def add_args(self, parser: argparse.ArgumentParser) -> None:
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parser.add_argument(
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"-v",
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"--verbose",
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action="store_true",
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help="Print per vector information",
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)
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def run(self, prog: Program, args: argparse.Namespace) -> None:
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print_vector_info(prog, verbose=args.verbose)

‎tests/test_vectorinfo.py‎

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# Copyright (c) 2025, Oracle and/or its affiliates.
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# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
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from drgn_tools import vectorinfo
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def test_vectorinfo(prog):
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vectorinfo.print_vector_matrix(prog)
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vectorinfo.print_vectors(prog, True)

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