From b11288ea44f003c96bbcdbf09cb24d40131f27f0 Mon Sep 17 00:00:00 2001
From: yellows8 <yellows8@users.noreply.github.com>
Date: Mon, 21 May 2018 16:57:11 -0400
Subject: [PATCH] In jitTransitionToWritable() and jitTransitionToExecutable(),
 only run the JitType_CodeMemory handling code when it's actually needed.
 Actually free j->rx_addr in jitClose() for JitType_JitMemory.

---
 nx/include/switch/kernel/jit.h |  1 +
 nx/source/kernel/jit.c         | 21 ++++++++++++++-------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/nx/include/switch/kernel/jit.h b/nx/include/switch/kernel/jit.h
index 978e3f14..f6261663 100644
--- a/nx/include/switch/kernel/jit.h
+++ b/nx/include/switch/kernel/jit.h
@@ -20,6 +20,7 @@ typedef struct {
     void*   src_addr;
     void*   rx_addr;
     void*   rw_addr;
+    bool    is_executable;
     Handle  handle;
 } Jit;
 
diff --git a/nx/source/kernel/jit.c b/nx/source/kernel/jit.c
index f9f2cc59..5715048c 100644
--- a/nx/source/kernel/jit.c
+++ b/nx/source/kernel/jit.c
@@ -40,6 +40,7 @@ Result jitCreate(Jit* j, size_t size)
     j->src_addr = src_addr;
     j->rx_addr = virtmemReserve(j->size);
     j->handle = INVALID_HANDLE;
+    j->is_executable = 0;
 
     Result rc = 0;
 
@@ -94,7 +95,7 @@ Result jitTransitionToWritable(Jit* j)
 
     switch (j->type) {
     case JitType_CodeMemory:
-        rc = svcUnmapProcessCodeMemory(envGetOwnProcessHandle(), (u64) j->rx_addr, (u64) j->src_addr, j->size);
+        if (j->is_executable) rc = svcUnmapProcessCodeMemory(envGetOwnProcessHandle(), (u64) j->rx_addr, (u64) j->src_addr, j->size);
         break;
 
     case JitType_JitMemory:
@@ -102,6 +103,8 @@ Result jitTransitionToWritable(Jit* j)
         break;
     }
 
+    if (R_SUCCEEDED(rc)) j->is_executable = 0;
+
     return rc;
 }
 
@@ -111,13 +114,15 @@ Result jitTransitionToExecutable(Jit* j)
 
     switch (j->type) {
     case JitType_CodeMemory:
-        rc = svcMapProcessCodeMemory(envGetOwnProcessHandle(), (u64) j->rx_addr, (u64) j->src_addr, j->size);
+        if (!j->is_executable) {
+            rc = svcMapProcessCodeMemory(envGetOwnProcessHandle(), (u64) j->rx_addr, (u64) j->src_addr, j->size);
 
-        if (R_SUCCEEDED(rc)) {
-            rc = svcSetProcessMemoryPermission(envGetOwnProcessHandle(), (u64) j->rx_addr, j->size, Perm_Rx);
+            if (R_SUCCEEDED(rc)) {
+                rc = svcSetProcessMemoryPermission(envGetOwnProcessHandle(), (u64) j->rx_addr, j->size, Perm_Rx);
 
-            if (R_FAILED(rc)) {
-                jitTransitionToWritable(j);
+                if (R_FAILED(rc)) {
+                    jitTransitionToWritable(j);
+                }
             }
         }
         break;
@@ -128,6 +133,8 @@ Result jitTransitionToExecutable(Jit* j)
         break;
     }
 
+    if (R_SUCCEEDED(rc)) j->is_executable = 1;
+
     return rc;
 }
 
@@ -154,7 +161,7 @@ Result jitClose(Jit* j)
             rc = svcControlCodeMemory(j->handle, CodeMapOperation_UnmapSlave, j->rx_addr, j->size, 0);
 
             if (R_SUCCEEDED(rc)) {
-                virtmemFree(j->rw_addr, j->size);
+                virtmemFree(j->rx_addr, j->size);
                 svcCloseHandle(j->handle);
             }
         }