scripts/gdb: fix interrupts.py after maple tree conversion

In commit 721255b9826b ("genirq: Use a maple tree for interrupt descriptor
management"), the irq_desc_tree was replaced with a sparse_irqs tree using
a maple tree structure.  Since the script looked for the irq_desc_tree
symbol which is no longer available, no interrupts would be printed and
the script output would not be useful anymore.

In addition to looking up the correct symbol (sparse_irqs), a new module
(mapletree.py) is added whose mtree_load() implementation is largely
copied after the C version and uses the same variable and intermediate
function names wherever possible to ensure that both the C and Python
version be updated in the future.

This restores the scripts' output to match that of /proc/interrupts.

Link: https://lkml.kernel.org/r/20250625021020.1056930-1-florian.fainelli@broadcom.com
Fixes: 721255b9826b ("genirq: Use a maple tree for interrupt descriptor management")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Shanker Donthineni <sdonthineni@nvidia.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/scripts/gdb/linux/interrupts.py b/scripts/gdb/linux/interrupts.py
index 199d9e8193f4..492d1f1e9529 100644
--- a/scripts/gdb/linux/interrupts.py
+++ b/scripts/gdb/linux/interrupts.py
@@ -7,7 +7,7 @@ import gdb
 from linux import constants
 from linux import cpus
 from linux import utils
-from linux import radixtree
+from linux import mapletree
 
 irq_desc_type = utils.CachedType("struct irq_desc")
 
@@ -23,12 +23,12 @@ def irqd_is_level(desc):
 def show_irq_desc(prec, irq):
     text = ""
 
-    desc = radixtree.lookup(gdb.parse_and_eval("&irq_desc_tree"), irq)
+    desc = mapletree.mtree_load(gdb.parse_and_eval("&sparse_irqs"), irq)
     if desc is None:
         return text
 
-    desc = desc.cast(irq_desc_type.get_type())
-    if desc is None:
+    desc = desc.cast(irq_desc_type.get_type().pointer())
+    if desc == 0:
         return text
 
     if irq_settings_is_hidden(desc):
@@ -221,8 +221,8 @@ class LxInterruptList(gdb.Command):
             gdb.write("CPU%-8d" % cpu)
         gdb.write("\n")
 
-        if utils.gdb_eval_or_none("&irq_desc_tree") is None:
-            return
+        if utils.gdb_eval_or_none("&sparse_irqs") is None:
+            raise gdb.GdbError("Unable to find the sparse IRQ tree, is CONFIG_SPARSE_IRQ enabled?")
 
         for irq in range(nr_irqs):
             gdb.write(show_irq_desc(prec, irq))