From 756a73471e1ac700c0a7635cffe2166ea2376e36 Mon Sep 17 00:00:00 2001
From: Pankaj Raghav <p.raghav@samsung.com>
Date: Wed, 12 Apr 2023 22:49:07 +0200
Subject: Kernel: Use SpinlockProtected list in SharedIRQHandler

Adding handlers to the SharedIRQHandler without any lock is not thread
safe. Use SpinlockProtected list instead.
---
 Kernel/Interrupts/SharedIRQHandler.cpp | 21 +++++++++++----------
 Kernel/Interrupts/SharedIRQHandler.h   |  8 ++++++--
 2 files changed, 17 insertions(+), 12 deletions(-)

(limited to 'Kernel/Interrupts')

diff --git a/Kernel/Interrupts/SharedIRQHandler.cpp b/Kernel/Interrupts/SharedIRQHandler.cpp
index a232faad27..64212e2971 100644
--- a/Kernel/Interrupts/SharedIRQHandler.cpp
+++ b/Kernel/Interrupts/SharedIRQHandler.cpp
@@ -23,15 +23,17 @@ UNMAP_AFTER_INIT void SharedIRQHandler::initialize(u8 interrupt_number)
 void SharedIRQHandler::register_handler(GenericInterruptHandler& handler)
 {
     dbgln_if(INTERRUPT_DEBUG, "Interrupt Handler registered @ Shared Interrupt Handler {}", interrupt_number());
-    m_handlers.append(handler);
+    m_handlers.with([&handler](auto& list) { list.append(handler); });
     enable_interrupt_vector();
 }
 void SharedIRQHandler::unregister_handler(GenericInterruptHandler& handler)
 {
     dbgln_if(INTERRUPT_DEBUG, "Interrupt Handler unregistered @ Shared Interrupt Handler {}", interrupt_number());
-    m_handlers.remove(handler);
-    if (m_handlers.is_empty())
-        disable_interrupt_vector();
+    m_handlers.with([&handler, this](auto& list) {
+        list.remove(handler);
+        if (list.is_empty())
+            disable_interrupt_vector();
+    });
 }
 
 bool SharedIRQHandler::eoi()
@@ -43,9 +45,7 @@ bool SharedIRQHandler::eoi()
 
 void SharedIRQHandler::enumerate_handlers(Function<void(GenericInterruptHandler&)>& callback)
 {
-    for (auto& handler : m_handlers) {
-        callback(handler);
-    }
+    m_handlers.for_each([&](auto& handler) { callback(handler); });
 }
 
 SharedIRQHandler::SharedIRQHandler(u8 irq)
@@ -67,11 +67,11 @@ bool SharedIRQHandler::handle_interrupt(RegisterState const& regs)
 
     if constexpr (INTERRUPT_DEBUG) {
         dbgln("Interrupt @ {}", interrupt_number());
-        dbgln("Interrupt Handlers registered - {}", m_handlers.size_slow());
+        dbgln("Interrupt Handlers registered - {}", sharing_devices_count());
     }
     int i = 0;
     bool was_handled = false;
-    for (auto& handler : m_handlers) {
+    m_handlers.for_each([&](auto& handler) {
         dbgln_if(INTERRUPT_DEBUG, "Going for Interrupt Handling @ {}, Shared Interrupt {}", i, interrupt_number());
         if (handler.handle_interrupt(regs)) {
             handler.increment_call_count();
@@ -79,7 +79,8 @@ bool SharedIRQHandler::handle_interrupt(RegisterState const& regs)
         }
         dbgln_if(INTERRUPT_DEBUG, "Going for Interrupt Handling @ {}, Shared Interrupt {} - End", i, interrupt_number());
         i++;
-    }
+    });
+
     return was_handled;
 }
 
diff --git a/Kernel/Interrupts/SharedIRQHandler.h b/Kernel/Interrupts/SharedIRQHandler.h
index 6f942fc6ae..85741e77d1 100644
--- a/Kernel/Interrupts/SharedIRQHandler.h
+++ b/Kernel/Interrupts/SharedIRQHandler.h
@@ -11,6 +11,7 @@
 #include <Kernel/Arch/IRQController.h>
 #include <Kernel/Interrupts/GenericInterruptHandler.h>
 #include <Kernel/Library/LockRefPtr.h>
+#include <Kernel/Locking/SpinlockProtected.h>
 
 namespace Kernel {
 class IRQHandler;
@@ -27,7 +28,10 @@ public:
 
     void enumerate_handlers(Function<void(GenericInterruptHandler&)>&);
 
-    virtual size_t sharing_devices_count() const override { return m_handlers.size_slow(); }
+    virtual size_t sharing_devices_count() const override
+    {
+        return m_handlers.with([](auto& list) { return list.size_slow(); });
+    }
     virtual bool is_shared_handler() const override { return true; }
     virtual bool is_sharing_with_others() const override { return false; }
 
@@ -40,7 +44,7 @@ private:
     void disable_interrupt_vector();
     explicit SharedIRQHandler(u8 interrupt_number);
     bool m_enabled { true };
-    GenericInterruptHandler::List m_handlers;
+    SpinlockProtected<GenericInterruptHandler::List, LockRank::None> m_handlers;
     NonnullLockRefPtr<IRQController> m_responsible_irq_controller;
 };
 }
-- 
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