thermosphere: hw breakpoint/watchpoint managers

thermosphere/src/cpu/hvisor_cpu_debug_register_pair.hpp

@@ -63,9 +63,10 @@ namespace ams::hvisor::cpu {
 
         // Watchpoints only
         enum LoadStoreControl {
-            Load         = 1,
-            Store        = 2,
-            LoadStore    = 3,
+            NotAWatchpoint  = 0,
+            Load            = 1,
+            Store           = 2,
+            LoadStore       = 3,
         };
 
         // bas only 4 bits for breakpoints, other bits res0.

thermosphere/src/hvisor_hw_breakpoint_manager.cpp

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hvisor_hw_breakpoint_manager.hpp"
+#include "cpu/hvisor_cpu_instructions.hpp"
+
+#define _REENT_ONLY
+#include <cerrno>
+
+namespace ams::hvisor {
+
+    HwBreakpointManager HwBreakpointManager::instance{};
+
+    void HwBreakpointManager::ReloadOnAllCoresSgiHandler()
+    {
+        // TODO
+    }
+
+    void HwBreakpointManager::ReloadOnAllCores() const
+    {
+        cpu::dmb();
+        // TODO
+    }
+
+    bool HwBreakpointManager::FindPredicate(const cpu::DebugRegisterPair &pair, uintptr_t addr, size_t, cpu::DebugRegisterPair::LoadStoreControl) const
+    {
+        return pair.vr == addr;
+    }
+
+    // Note: A32/T32/T16 support intentionnally left out
+    // Note: addresses are supposed to be well-formed regarding the sign extension bits
+    int HwBreakpointManager::Add(uintptr_t addr)
+    {
+        // Reject misaligned addresses
+        if (addr & 3) {
+            return -EINVAL;
+        }
+
+        cpu::DebugRegisterPair bp{};
+        bp.cr.bt = cpu::DebugRegisterPair::AddressMatch;
+        bp.cr.bas = 0xF; // mandated
+        bp.vr = addr;
+
+        return AddImpl(addr, 0, bp);
+    }
+
+    int HwBreakpointManager::Remove(uintptr_t addr)
+    {
+        // Reject misaligned addresses
+        if (addr & 3) {
+            return -EINVAL;
+        }
+
+        return RemoveImpl(addr, 0, cpu::DebugRegisterPair::NotAWatchpoint);
+    }
+}

thermosphere/src/hvisor_hw_breakpoint_manager.hpp

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "hvisor_hw_stop_point_manager.hpp"
+
+namespace ams::hvisor {
+
+    class HwBreakpointManager final : public HwStopPointManager {
+        protected:
+            virtual bool FindPredicate(const cpu::DebugRegisterPair &pair, uintptr_t addr, size_t, cpu::DebugRegisterPair::LoadStoreControl) const;
+
+        private:
+            static HwBreakpointManager instance;
+
+        public:
+            virtual void ReloadOnAllCores() const;
+            static void ReloadOnAllCoresSgiHandler();
+
+            cpu::DebugRegisterPair RetrieveWatchpointConfig(uintptr_t addr, cpu::DebugRegisterPair::LoadStoreControl direction) const;
+            int Add(uintptr_t addr);
+            int Remove(uintptr_t addr);
+
+            HwBreakpointManager &GetInstance() { return instance; }
+
+        public:
+            constexpr HwBreakpointManager() : HwStopPointManager(MAX_BCR) {}
+    };
+}

thermosphere/src/hvisor_hw_stop_point_manager.cpp

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hvisor_hw_stop_point_manager.hpp"
+#include <mutex>
+
+#define _REENT_ONLY
+#include <cerrno>
+
+namespace ams::hvisor {
+
+    cpu::DebugRegisterPair *HwStopPointManager::Allocate()
+    {
+        size_t pos = __builtin_ffs(m_freeBitmap);
+        if (pos == 0) {
+            return nullptr;
+        } else {
+            m_freeBitmap &= ~BIT(pos - 1);
+            m_usedBitmap |= BIT(pos - 1);
+            return &m_stopPoints[pos - 1];
+        }
+    }
+
+    void HwStopPointManager::Free(size_t pos)
+    {
+        m_stopPoints[pos] = {};
+        m_freeBitmap |= BIT(pos);
+        m_usedBitmap &= ~BIT(pos);
+    }
+
+    const cpu::DebugRegisterPair *HwStopPointManager::Find(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl dir) const
+    {
+        for (auto bit: util::BitsOf{m_usedBitmap}) {
+            auto *p = &m_stopPoints[bit];
+            if (FindPredicate(*p, addr, size, dir)) {
+                return p;
+            }
+        }
+
+        return nullptr;
+    }
+
+    int HwStopPointManager::AddImpl(uintptr_t addr, size_t size, cpu::DebugRegisterPair preconfiguredPair)
+    {
+        std::scoped_lock lk{m_lock};
+        auto lsc = preconfiguredPair.cr.lsc;
+
+        if (m_freeBitmap == 0) {
+            // Oops
+            return -EBUSY;
+        }
+
+        if (Find(addr, size, lsc) != nullptr) {
+            // Already exists
+            return -EEXIST;
+        }
+
+        auto *regs = Allocate();
+        regs->SetDefaults();
+
+        // Apply preconfig
+        regs->cr.raw |= preconfiguredPair.cr.raw;
+        regs->vr = preconfiguredPair.vr;
+        regs->cr.enabled = true;
+
+        ReloadOnAllCores();
+        return 0;
+    }
+
+    int HwStopPointManager::RemoveImpl(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl dir)
+    {
+        std::scoped_lock lk{m_lock};
+        const auto *p = Find(addr, size, dir);
+        if (p == nullptr) {
+            return -ENOENT;
+        }
+
+        Free(p - m_stopPoints.data());
+        return 0;
+    }
+
+    void HwStopPointManager::RemoveAll()
+    {
+        std::scoped_lock lk{m_lock};
+        m_freeBitmap |= m_usedBitmap;
+        m_usedBitmap = 0;
+        std::fill(m_stopPoints.begin(), m_stopPoints.end(), cpu::DebugRegisterPair{});
+        ReloadOnAllCores();
+    }
+
+}

thermosphere/src/hvisor_hw_stop_point_manager.hpp

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "defines.hpp"
+#include "hvisor_synchronization.hpp"
+#include "cpu/hvisor_cpu_debug_register_pair.hpp"
+
+namespace ams::hvisor {
+
+    class HwStopPointManager {
+        NON_COPYABLE(HwStopPointManager);
+        NON_MOVEABLE(HwStopPointManager);
+        protected:
+            static constexpr size_t maxStopPoints = std::max(MAX_BCR, MAX_WCR);
+
+            mutable RecursiveSpinlock m_lock{};
+            u16 m_freeBitmap;
+            u16 m_usedBitmap = 0;
+            std::array<cpu::DebugRegisterPair, maxStopPoints> m_stopPoints{};
+
+        protected:
+            cpu::DebugRegisterPair *Allocate();
+            void Free(size_t pos);
+            const cpu::DebugRegisterPair *Find(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl dir) const;
+
+            virtual bool FindPredicate(const cpu::DebugRegisterPair &pair, uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction) const = 0;
+
+            int AddImpl(uintptr_t addr, size_t size, cpu::DebugRegisterPair preconfiguredPair);
+            int RemoveImpl(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction);
+
+        protected:
+            constexpr HwStopPointManager(size_t numStopPoints) : m_freeBitmap(MASK(numStopPoints)) {}
+
+        public:
+            virtual void ReloadOnAllCores() const = 0;
+            void RemoveAll();
+    };
+}

thermosphere/src/hvisor_synchronization.hpp

@@ -27,7 +27,7 @@ namespace ams::hvisor {
         private:
             u32 m_val = 0;
         public:
-            Spinlock() = default;
+            constexpr Spinlock() = default;
             void lock();
             void unlock() noexcept;
     };
@@ -38,7 +38,7 @@ namespace ams::hvisor {
         private:
             u32 m_val = 0;
         public:
-            Barrier() = default;
+            constexpr Barrier() = default;
             void Join();
 
             constexpr void Reset(u32 val)
@@ -55,7 +55,7 @@ namespace ams::hvisor {
             u32 m_tag = 0;
             u32 m_count = 0;
         public:
-            RecursiveSpinlock() = default;
+            constexpr RecursiveSpinlock() = default;
             void lock();
             void unlock() noexcept;
     };

thermosphere/src/hvisor_watchpoint_manager.cpp

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hvisor_watchpoint_manager.hpp"
+#include "cpu/hvisor_cpu_instructions.hpp"
+#include <mutex>
+
+#define _REENT_ONLY
+#include <cerrno>
+
+namespace {
+    constexpr bool IsRangeMaskWatchpoint(uintptr_t addr, size_t size)
+    {
+        // size needs to be a power of 2, at least 8 (we'll only allow 16+ though), addr needs to be aligned.
+        bool ret = (size & (size - 1)) == 0 && size >= 16 && (addr & (size - 1)) == 0;
+        return ret;
+    }
+
+    constexpr bool CheckWatchpointAddressAndSizeParams(uintptr_t addr, size_t size)
+    {
+        if (size == 0) {
+            return false;
+        } else if (size > 8) {
+            return IsRangeMaskWatchpoint(addr, size);
+        } else {
+            return ((addr + size) & ~7ul) == (addr & ~7ul);
+        }
+    }
+}
+
+namespace ams::hvisor {
+
+    WatchpointManager WatchpointManager::instance{};
+
+    void WatchpointManager::ReloadOnAllCoresSgiHandler()
+    {
+        // TODO
+    }
+
+    void WatchpointManager::ReloadOnAllCores() const
+    {
+        cpu::dmb();
+        // TODO
+    }
+
+    bool WatchpointManager::FindPredicate(const cpu::DebugRegisterPair &pair, uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction) const
+    {
+        size_t off;
+        size_t sz;
+        size_t nmask;
+    
+        if (pair.cr.mask != 0) {
+            off = 0;
+            sz = MASK(pair.cr.mask);
+            nmask = ~sz;
+        } else {
+            off = __builtin_ffs(pair.cr.bas) - 1;
+            sz = __builtin_popcount(pair.cr.bas);
+            nmask = ~7ul;
+        }
+
+        if (size != 0) {
+            // Strict watchpoint check
+            if (addr == pair.vr + off && direction == pair.cr.lsc && sz == size) {
+                return true;
+            }
+        } else {
+            // Return first wp that could have triggered the exception
+            if ((addr & nmask) == pair.vr && (direction & pair.cr.lsc) != 0) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    cpu::DebugRegisterPair WatchpointManager::RetrieveWatchpointConfig(uintptr_t addr, cpu::DebugRegisterPair::LoadStoreControl direction) const
+    {
+        std::scoped_lock lk{m_lock};
+        const cpu::DebugRegisterPair *p = Find(addr, 0, direction);
+        return p != nullptr ? *p : cpu::DebugRegisterPair{};
+    }
+
+    int WatchpointManager::Add(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction)
+    {
+        if (!CheckWatchpointAddressAndSizeParams(addr, size)) {
+            return -EINVAL;
+        }
+
+        cpu::DebugRegisterPair wp{};
+        wp.cr.lsc = direction;
+        if (IsRangeMaskWatchpoint(addr, size)) {
+            wp.vr = addr;
+            wp.cr.bas = 0xFF; // TRM-mandated
+            wp.cr.mask = static_cast<u32>(__builtin_ffsl(size) - 1);
+        } else {
+            size_t off = addr & 7ull;
+            wp.vr = addr & ~7ul;
+            wp.cr.bas = MASK2(off + size, off);
+        }
+
+        return AddImpl(addr, size, wp);
+    }
+
+    int WatchpointManager::Remove(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction)
+    {
+        if (!CheckWatchpointAddressAndSizeParams(addr, size)) {
+            return -EINVAL;
+        }
+
+        return RemoveImpl(addr, size, direction);
+    }
+}

thermosphere/src/hvisor_watchpoint_manager.hpp

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "hvisor_hw_stop_point_manager.hpp"
+
+namespace ams::hvisor {
+
+    class WatchpointManager final : public HwStopPointManager {
+        protected:
+            virtual bool FindPredicate(const cpu::DebugRegisterPair &pair, uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction) const;
+
+        private:
+            static WatchpointManager instance;
+
+        public:
+            virtual void ReloadOnAllCores() const;
+            static void ReloadOnAllCoresSgiHandler();
+
+            cpu::DebugRegisterPair RetrieveWatchpointConfig(uintptr_t addr, cpu::DebugRegisterPair::LoadStoreControl direction) const;
+            int Add(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction);
+            int Remove(uintptr_t addr, size_t size, cpu::DebugRegisterPair::LoadStoreControl direction);
+
+            WatchpointManager &GetInstance() { return instance; }
+
+        public:
+            constexpr WatchpointManager() : HwStopPointManager(MAX_WCR) {}
+    };
+}