From 71401b0731594c6a54b73bfa17a6cb38ae15919e Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Tue, 28 Jan 2020 01:13:21 +0000
Subject: [PATCH] thermosphere: add structural changes needed for range step

---
 thermosphere/src/core_ctx.h      |  2 ++
 thermosphere/src/debug_manager.c | 16 ++++++++++++++--
 thermosphere/src/debug_manager.h |  2 ++
 thermosphere/src/single_step.c   | 13 +++++++++++--
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/thermosphere/src/core_ctx.h b/thermosphere/src/core_ctx.h
index 974688d1c..fbd4392b1 100644
--- a/thermosphere/src/core_ctx.h
+++ b/thermosphere/src/core_ctx.h
@@ -35,6 +35,8 @@ typedef struct ALIGN(64) CoreCtx {
 
     // Debug features
     bool wasPaused;                                         // @0x1F
+    uintptr_t steppingRangeStartAddr;                       // @0x20
+    uintptr_t steppingRangeEndAddr;                         // @0x28
 
     // Most likely written to:
 
diff --git a/thermosphere/src/debug_manager.c b/thermosphere/src/debug_manager.c
index 66074762c..dc4a091fb 100644
--- a/thermosphere/src/debug_manager.c
+++ b/thermosphere/src/debug_manager.c
@@ -29,6 +29,8 @@ GDBContext g_gdbContext = { 0 };
 
 typedef struct DebugManager {
     DebugEventInfo              debugEventInfos[MAX_CORE];
+    uintptr_t                   steppingRangeStartAddrs[MAX_CORE];
+    uintptr_t                   steppingRangeEndAddrs[MAX_CORE];
 
     ALIGN(64) atomic_uint       pausedCoreList;
     atomic_uint                 singleStepCoreList;
@@ -94,8 +96,12 @@ bool debugManagerHandlePause(void)
     // Single-step: if inactive and requested, start single step; cancel if active and not requested
     u32 ssReqd = (atomic_load(&g_debugManager.singleStepCoreList) & BIT(currentCoreCtx->coreId)) != 0;
     SingleStepState singleStepState = singleStepGetNextState(currentCoreCtx->guestFrame);
-    if (ssReqd && singleStepState == SingleStepState_Inactive) {
-        singleStepSetNextState(currentCoreCtx->guestFrame, SingleStepState_ActiveNotPending);
+    if (ssReqd) {
+        currentCoreCtx->steppingRangeStartAddr = g_debugManager.steppingRangeStartAddrs[coreId];
+        currentCoreCtx->steppingRangeEndAddr = g_debugManager.steppingRangeEndAddrs[coreId];
+        if(singleStepState == SingleStepState_Inactive) {
+            singleStepSetNextState(currentCoreCtx->guestFrame, SingleStepState_ActiveNotPending);
+        }
     } else if (!ssReqd && singleStepState != SingleStepState_Inactive) {
         singleStepSetNextState(currentCoreCtx->guestFrame, SingleStepState_Inactive);
     }
@@ -128,6 +134,12 @@ void debugManagerUnpauseCores(u32 coreList, u32 singleStepList)
     __sev();
 }
 
+void debugManagerSetSteppingRange(u32 coreId, uintptr_t startAddr, uintptr_t endAddr)
+{
+    g_debugManager.steppingRangeStartAddrs[coreId] = startAddr;
+    g_debugManager.steppingRangeEndAddrs[coreId] = endAddr;
+}
+
 u32 debugManagerGetPausedCoreList(void)
 {
     return atomic_load(&g_debugManager.pausedCoreList);
diff --git a/thermosphere/src/debug_manager.h b/thermosphere/src/debug_manager.h
index 07df9640e..dab24e9de 100644
--- a/thermosphere/src/debug_manager.h
+++ b/thermosphere/src/debug_manager.h
@@ -57,6 +57,8 @@ bool debugManagerHandlePause(void);
 void debugManagerPauseCores(u32 coreList);
 void debugManagerUnpauseCores(u32 coreList, u32 singleStepList);
 
+void debugManagerSetSteppingRange(u32 coreId, uintptr_t startAddr, uintptr_t endAddr);
+
 u32 debugManagerGetPausedCoreList(void);
 
 const DebugEventInfo *debugManagerMarkAndGetCoreDebugEvent(u32 coreId);
diff --git a/thermosphere/src/single_step.c b/thermosphere/src/single_step.c
index cbeb84202..582cf24fe 100644
--- a/thermosphere/src/single_step.c
+++ b/thermosphere/src/single_step.c
@@ -62,8 +62,17 @@ void singleStepSetNextState(ExceptionStackFrame *frame, SingleStepState state)
 
 void handleSingleStep(ExceptionStackFrame *frame, ExceptionSyndromeRegister esr)
 {
-    // Disable single-step ASAP
-    singleStepSetNextState(NULL, SingleStepState_Inactive);
+    uintptr_t addr = frame->elr_el2;
+
+    // Stepping range support;
+    if (addr >= currentCoreCtx->steppingRangeStartAddr && addr < currentCoreCtx->steppingRangeEndAddr) {
+        // Reactivate single-step
+        singleStepSetNextState(frame, SingleStepState_ActiveNotPending);
+    } else {
+        // Disable single-step
+        singleStepSetNextState(frame, SingleStepState_Inactive);
+        // TODO report exception to gdb
+    }
 
     DEBUG("Single-step exeception ELR = 0x%016llx, ISV = %u, EX = %u\n", frame->elr_el2, (esr.iss >> 24) & 1, (esr.iss >> 6) & 1);
 }