[PATCH v2 8/8] scripts/gdb/vmalloc: add vmallocinfo support

[Kuan-Ying Lee]

This GDB script shows the vmallocinfo for user to
analyze the vmalloc memory usage.

Example output:
0xffff800008000000-0xffff800008009000      36864 <start_kernel+372> pages=8 vmalloc
0xffff800008009000-0xffff80000800b000       8192 <gicv2m_init_one+400> phys=0x8020000 ioremap
0xffff80000800b000-0xffff80000800d000       8192 <bpf_prog_alloc_no_stats+72> pages=1 vmalloc
0xffff80000800d000-0xffff80000800f000       8192 <bpf_jit_alloc_exec+16> pages=1 vmalloc
0xffff800008010000-0xffff80000ad30000   47316992 <paging_init+452> phys=0x40210000 vmap
0xffff80000ad30000-0xffff80000c1c0000   21561344 <paging_init+556> phys=0x42f30000 vmap
0xffff80000c1c0000-0xffff80000c370000    1769472 <paging_init+592> phys=0x443c0000 vmap
0xffff80000c370000-0xffff80000de90000   28442624 <paging_init+692> phys=0x44570000 vmap
0xffff80000de90000-0xffff80000f4c1000   23269376 <paging_init+788> phys=0x46090000 vmap
0xffff80000f4c1000-0xffff80000f4c3000       8192 <gen_pool_add_owner+112> pages=1 vmalloc
0xffff80000f4c3000-0xffff80000f4c5000       8192 <gen_pool_add_owner+112> pages=1 vmalloc
0xffff80000f4c5000-0xffff80000f4c7000       8192 <gen_pool_add_owner+112> pages=1 vmalloc

Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee at mediatek.com>
---
 scripts/gdb/linux/constants.py.in |  8 +++++
 scripts/gdb/linux/vmalloc.py      | 56 +++++++++++++++++++++++++++++++
 scripts/gdb/vmlinux-gdb.py        |  1 +
 3 files changed, 65 insertions(+)
 create mode 100644 scripts/gdb/linux/vmalloc.py

diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in
index 03fa6d2cfe01..e3517d4ab8ec 100644
--- a/scripts/gdb/linux/constants.py.in
+++ b/scripts/gdb/linux/constants.py.in
@@ -22,6 +22,7 @@
 #include <linux/radix-tree.h>
 #include <linux/slab.h>
 #include <linux/threads.h>
+#include <linux/vmalloc.h>
 
 /* We need to stringify expanded macros so that they can be parsed */
 
@@ -91,6 +92,13 @@ LX_GDBPARSED(RADIX_TREE_MAP_SIZE)
 LX_GDBPARSED(RADIX_TREE_MAP_SHIFT)
 LX_GDBPARSED(RADIX_TREE_MAP_MASK)
 
+/* linux/vmalloc.h */
+LX_VALUE(VM_IOREMAP)
+LX_VALUE(VM_ALLOC)
+LX_VALUE(VM_MAP)
+LX_VALUE(VM_USERMAP)
+LX_VALUE(VM_DMA_COHERENT)
+
 /* linux/page_ext.h */
 if IS_BUILTIN(CONFIG_PAGE_OWNER):
     LX_GDBPARSED(PAGE_EXT_OWNER)
diff --git a/scripts/gdb/linux/vmalloc.py b/scripts/gdb/linux/vmalloc.py
new file mode 100644
index 000000000000..48e4a4fae7bb
--- /dev/null
+++ b/scripts/gdb/linux/vmalloc.py
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2023 MediaTek Inc.
+#
+# Authors:
+#  Kuan-Ying Lee <Kuan-Ying.Lee at mediatek.com>
+#
+
+import gdb
+import re
+from linux import lists, utils, stackdepot, constants, mm
+
+vmap_area_type = utils.CachedType('struct vmap_area')
+vmap_area_ptr_type = vmap_area_type.get_type().pointer()
+
+def is_vmalloc_addr(x):
+    pg_ops = mm.page_ops().ops
+    addr = pg_ops.kasan_reset_tag(x)
+    return addr >= pg_ops.VMALLOC_START and addr < pg_ops.VMALLOC_END
+
+class LxVmallocInfo(gdb.Command):
+    """Show vmallocinfo"""
+
+    def __init__(self):
+        super(LxVmallocInfo, self).__init__("lx-vmallocinfo", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        vmap_area_list = gdb.parse_and_eval('vmap_area_list')
+        for vmap_area in lists.list_for_each_entry(vmap_area_list, vmap_area_ptr_type, "list"):
+            if not vmap_area['vm']:
+                gdb.write("0x%x-0x%x %10d vm_map_ram\n" % (vmap_area['va_start'], vmap_area['va_end'],
+                    vmap_area['va_end'] - vmap_area['va_start']))
+                continue
+            v = vmap_area['vm']
+            gdb.write("0x%x-0x%x %10d" % (v['addr'], v['addr'] + v['size'], v['size']))
+            if v['caller']:
+                gdb.write(" %s" % str(v['caller']).split(' ')[-1])
+            if v['nr_pages']:
+                gdb.write(" pages=%d" % v['nr_pages'])
+            if v['phys_addr']:
+                gdb.write(" phys=0x%x" % v['phys_addr'])
+            if v['flags'] & constants.LX_VM_IOREMAP:
+                gdb.write(" ioremap")
+            if v['flags'] & constants.LX_VM_ALLOC:
+                gdb.write(" vmalloc")
+            if v['flags'] & constants.LX_VM_MAP:
+                gdb.write(" vmap")
+            if v['flags'] & constants.LX_VM_USERMAP:
+                gdb.write(" user")
+            if v['flags'] & constants.LX_VM_DMA_COHERENT:
+                gdb.write(" dma-coherent")
+            if is_vmalloc_addr(v['pages']):
+                gdb.write(" vpages")
+            gdb.write("\n")
+
+LxVmallocInfo()
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 2526364f31fd..fc53cdf286f1 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -48,3 +48,4 @@ else:
     import linux.stackdepot
     import linux.page_owner
     import linux.slab
+    import linux.vmalloc
-- 
2.18.0