From 5de05ed8a8641fa73861dd3e792bc4b539096dc6 Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Thu, 23 Jan 2020 02:32:27 +0000
Subject: [PATCH] thermosphere: retrieve wp direction

---
 thermosphere/src/gdb/debug.c   | 13 ++++++++++---
 thermosphere/src/watchpoints.c |  8 ++++++--
 thermosphere/src/watchpoints.h |  2 +-
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/thermosphere/src/gdb/debug.c b/thermosphere/src/gdb/debug.c
index 60b18dc91..8847018dc 100644
--- a/thermosphere/src/gdb/debug.c
+++ b/thermosphere/src/gdb/debug.c
@@ -228,9 +228,16 @@ int GDB_SendStopReply(GDBContext *ctx, const DebugEventInfo *info)
 
                 case Exception_WatchpointLowerEl: {
                     static const char *kinds[] = { "", "r", "", "a" };
-                    n = GDB_ParseExceptionFrame(buffer, ctx, SIGTRAP);
-                    u32 kind = 3; // TODO: retrieve the actual wp direction (if it's a bidirectional wp or not)
-                    sprintf(buffer + n, "%swatch:%016lx;", kinds[kind], info->frame->far_el2);
+                    // Note: exception info doesn't provide us with the access size. Use 1.
+                    bool wnr = (info->frame->esr_el2.iss & BIT(6)) != 0;
+                    WatchpointLoadStoreControl dr = wnr ? WatchpointLoadStoreControl_Store : WatchpointLoadStoreControl_Load;
+                    DebugControlRegister cr = retrieveSplitWatchpointConfig(info->frame->far_el2, 1, dr, false);
+                    if (!cr.enabled) {
+                        DEBUG("GDB: oops, unhandled watchpoint for core id %u, far=%016lx\n", info->coreId, info->frame->far_el2);
+                    } else {
+                        n = GDB_ParseExceptionFrame(buffer, ctx, SIGTRAP);
+                        sprintf(buffer + n, "%swatch:%016lx;", kinds[cr.lsc], info->frame->far_el2);
+                    }
                 }
 
                 // Note: we don't really support 32-bit sw breakpoints, we'll still report them
diff --git a/thermosphere/src/watchpoints.c b/thermosphere/src/watchpoints.c
index 6fb792376..3cd1d06c7 100644
--- a/thermosphere/src/watchpoints.c
+++ b/thermosphere/src/watchpoints.c
@@ -189,10 +189,14 @@ static DebugRegisterPair *doFindSplitWatchpoint(u64 addr, size_t size, Watchpoin
     return NULL;
 }
 
-DebugRegisterPair *findSplitWatchpoint(u64 addr, size_t size, WatchpointLoadStoreControl direction, bool strict)
+DebugControlRegister retrieveSplitWatchpointConfig(u64 addr, size_t size, WatchpointLoadStoreControl direction, bool strict)
 {
     recursiveSpinlockLock(&g_watchpointManager.lock);
-    DebugRegisterPair *ret = doFindSplitWatchpoint(addr, size, direction, strict);
+    DebugRegisterPair *wp = doFindSplitWatchpoint(addr, size, direction, strict);
+    DebugControlRegister ret = { 0 };
+    if (wp != NULL) {
+        ret = wp->cr;
+    }
     recursiveSpinlockUnlock(&g_watchpointManager.lock);
     return ret;
 }
diff --git a/thermosphere/src/watchpoints.h b/thermosphere/src/watchpoints.h
index 1ab79fafa..b277efee4 100644
--- a/thermosphere/src/watchpoints.h
+++ b/thermosphere/src/watchpoints.h
@@ -35,7 +35,7 @@ typedef struct WatchpointManager {
 extern WatchpointManager g_watchpointManager;
 
 void initWatchpoints(void);
-DebugRegisterPair *findSplitWatchpoint(u64 addr, size_t size, WatchpointLoadStoreControl direction, bool strict);
+DebugControlRegister retrieveSplitWatchpointConfig(u64 addr, size_t size, WatchpointLoadStoreControl direction, bool strict);
 int addWatchpoint(u64 addr, size_t size, WatchpointLoadStoreControl direction);
 int removeWatchpoint(u64 addr, size_t size, WatchpointLoadStoreControl direction);
 int removeAllWatchpoints(void);