From c48e84016b7e37b6635642ffca817bc2030c5052 Mon Sep 17 00:00:00 2001
From: jxuanli <junxua01@student.ubc.ca>
Date: Fri, 30 May 2025 07:37:04 -0700
Subject: [PATCH] actually adding the remamed file

---
 pwndbg/commands/paging.py | 118 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 pwndbg/commands/paging.py

diff --git a/pwndbg/commands/paging.py b/pwndbg/commands/paging.py
new file mode 100644
index 000000000..b09bbd91c
--- /dev/null
+++ b/pwndbg/commands/paging.py
@@ -0,0 +1,118 @@
+from __future__ import annotations
+
+import argparse
+
+import pwndbg.aglib.kernel
+import pwndbg.aglib.regs
+import pwndbg.color as C
+import pwndbg.color.message as M
+from pwndbg.commands import CommandCategory
+from pwndbg.lib.regs import BitFlags
+
+parser = argparse.ArgumentParser(description="Performs pagewalk.")
+parser.add_argument("vaddr", type=str, help="virtual address to walk")
+parser.add_argument("--pgd", dest="entry", type=str, default=None, help="")
+
+
+pageflags = BitFlags([("NX", 63), ("PS", 7), ("A", 5), ("W", 1), ("P", 0)])
+
+
+def print_pagetable_entry(name: str, paddr: int | None, vaddr: int):
+    flags = ""
+    arrow_right = pwndbg.chain.c.arrow(f"{pwndbg.chain.config_arrow_right}")
+    if paddr is not None:
+        flags = f"{arrow_right} {name + 'e'}: {C.context.format_flags(paddr, pageflags, paddr)}"
+    print(f"{C.blue(name)} @ {C.yellow(hex(vaddr))} {flags}")
+
+
+def pg_indices(vaddr, nr_level):
+    result = [vaddr & (0x1000 - 1)]
+    vaddr >>= 12
+    for _ in range(nr_level):
+        result.append(vaddr & (0x1FF))
+        vaddr >>= 9
+    return result
+
+
+@pwndbg.commands.Command(parser, category=CommandCategory.KERNEL)
+@pwndbg.commands.OnlyWhenQemuKernel
+@pwndbg.commands.OnlyWhenPagingEnabled
+def pagewalk(vaddr, entry=None):
+    vaddr = int(pwndbg.dbg.selected_frame().evaluate_expression(vaddr))
+    # https://blog.zolutal.io/understanding-paging/
+    base = pwndbg.aglib.kernel.physmap_base()
+    level = 4
+    names = (
+        "Page",
+        "PT",
+        "PMD",
+        "PUD",
+        "PGD",
+    )
+    if pwndbg.aglib.kernel.uses_5lvl_paging():
+        level = 5
+        names = (
+            "Page",
+            "PT",
+            "PMD",
+            "P4D",
+            "PUD",
+            "PGD",
+        )
+    if entry is None:
+        entry = pwndbg.aglib.regs["cr3"]
+    else:
+        entry = int(pwndbg.dbg.selected_frame().evaluate_expression(entry))
+    if entry > base:
+        # user inputted a physmap address as pointer to pgd
+        entry -= base
+    offset = 0
+    entry_mask = ~((1 << 12) - 1) & ((1 << 51) - 1)
+    for i in range(level, 0, -1):
+        cur = (entry & entry_mask) + base
+        if entry & (1 << 7) > 0:
+            break
+        shift = (i - 1) * 9 + 12
+        offset = vaddr & ((1 << shift) - 1)
+        idx = (vaddr & (0x1FF << shift)) >> shift
+        entry = 0
+        try:
+            table = pwndbg.aglib.memory.get_typed_pointer("unsigned long", cur)
+            entry = int(table[idx])
+            print_pagetable_entry(names[i], entry, cur)
+        except Exception as e:
+            print(M.warn(f"Exception while page walking: {e}"))
+            entry = 0
+        if entry == 0:
+            print(M.warn("address is not mapped"))
+            return
+    virtual = base + (entry & entry_mask) + offset
+    print(f"pagewalk result: {C.green(hex(virtual))} [phys: {C.yellow(hex(virtual - base))}]")
+
+
+p2v_parser = argparse.ArgumentParser(
+    description="Translate physical address to its corresponding virtual address."
+)
+p2v_parser.add_argument("paddr", type=str, help="")
+
+
+@pwndbg.commands.Command(p2v_parser, category=CommandCategory.KERNEL)
+@pwndbg.commands.OnlyWhenQemuKernel
+@pwndbg.commands.OnlyWhenPagingEnabled
+def p2v(paddr):
+    paddr = pwndbg.dbg.selected_frame().evaluate_expression(paddr)
+    return pwndbg.aglib.kernel.phys_to_virt(int(paddr))
+
+
+v2p_parser = argparse.ArgumentParser(
+    description="Translate virtual address to its corresponding physical address."
+)
+v2p_parser.add_argument("vaddr", type=str, help="")
+
+
+@pwndbg.commands.Command(v2p_parser, category=CommandCategory.KERNEL)
+@pwndbg.commands.OnlyWhenQemuKernel
+@pwndbg.commands.OnlyWhenPagingEnabled
+def v2p(vaddr):
+    vaddr = pwndbg.dbg.selected_frame().evaluate_expression(vaddr)
+    return pwndbg.aglib.kernel.virt_to_phys(int(vaddr))