From 7fcc801d0183f89934ec230c2782591bdd5b285c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Janiszewski?= <janisozaur@gmail.com>
Date: Wed, 28 Oct 2015 22:41:17 +0100
Subject: [PATCH] Cleanup allocated segments on disposal

---
 src/openrct2.c | 70 ++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 59 insertions(+), 11 deletions(-)

diff --git a/src/openrct2.c b/src/openrct2.c
index 02243a2530..8271397a2f 100644
--- a/src/openrct2.c
+++ b/src/openrct2.c
@@ -58,6 +58,12 @@ bool gOpenRCT2Headless = false;
 
 bool gOpenRCT2ShowChangelog;
 
+#if defined(__linux__)
+void *gDataSegment;
+void *gTextSegment;
+int gExeFd;
+#endif // defined(__linux__)
+
 /** If set, will end the OpenRCT2 game loop. Intentially private to this module so that the flag can not be set back to 0. */
 int _finished;
 
@@ -66,6 +72,7 @@ static struct { sint16 x, y, z; } _spritelocations1[MAX_SPRITES], _spritelocatio
 
 static void openrct2_loop();
 static bool openrct2_setup_rct2_segment();
+static bool openrct2_release_rct2_segment();
 static void openrct2_setup_rct2_hooks();
 
 static void openrct2_copy_files_over(const utf8 *originalDirectory, const utf8 *newDirectory, const utf8 *extension)
@@ -308,6 +315,7 @@ void openrct2_dispose()
 	network_close();
 	http_dispose();
 	language_close_all();
+	openrct2_release_rct2_segment();
 	platform_free();
 }
 
@@ -465,8 +473,8 @@ static bool openrct2_setup_rct2_segment()
 	#define DATA_OFFSET 0x004A4000
 
 	const char *exepath = "openrct2.exe";
-	int fd = open(exepath, O_RDONLY);
-	if (fd < 0) {
+	gExeFd = open(exepath, O_RDONLY);
+	if (gExeFd < 0) {
 		log_fatal("failed to open %s, errno = %d", exepath, errno);
 		exit(1);
 	}
@@ -503,23 +511,22 @@ static bool openrct2_setup_rct2_segment()
 
 	int len = 0x01429000 - 0x8a4000; // 0xB85000, 12079104 bytes or around 11.5MB
 	// section: rw data
-	void *base = mmap((void *)0x8a4000, len, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_ANONYMOUS | MAP_SHARED, 0, 0);
-	log_warning("base = %x, 0x01423b40 >= base == %i, 0x01423b40 < base + len == %i", base, (void *)0x01423b40 >= base, (void *)0x01423b40 < base + len);
-	if (base == MAP_FAILED) {
-		log_warning("errno = %i", errno);
+	gDataSegment = mmap((void *)0x8a4000, len, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_ANONYMOUS | MAP_SHARED, 0, 0);
+	if (gDataSegment != (void *)0x8a4000) {
+		log_fatal("mmap failed to get required offset for data segment! got %p, expected %p, errno = %d", gDataSegment, (void *)(0x8a4000), errno);
 		exit(1);
 	}
 
 	len = 0x004A3000;
 	// section: text
-	void *base2 = mmap((void *)(0x401000), len, PROT_EXEC | PROT_WRITE | PROT_READ, MAP_FIXED | MAP_PRIVATE, fd, 0x1000);
-	if (base2 != (void *)(0x401000))
+	gTextSegment = mmap((void *)(0x401000), len, PROT_EXEC | PROT_WRITE | PROT_READ, MAP_FIXED | MAP_PRIVATE, gExeFd, 0x1000);
+	if (gTextSegment != (void *)(0x401000))
 	{
-		log_fatal("mmap failed to get required offset! got %p, expected %p, errno = %d", base2, (void *)(0x401000), errno);
+		log_fatal("mmap failed to get required offset for text segment! got %p, expected %p, errno = %d", gTextSegment, (void *)(0x401000), errno);
 		exit(1);
 	}
 
-	void *fbase = mmap(NULL, file_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	void *fbase = mmap(NULL, file_size, PROT_READ, MAP_PRIVATE, gExeFd, 0);
 	int err = errno;
 	log_warning("mmapped file to %p", fbase);
 	if (fbase == MAP_FAILED)
@@ -529,7 +536,13 @@ static bool openrct2_setup_rct2_segment()
 	}
 	// .rdata and real part of .data
 	// 0x9e2000 - 0x8a4000 = 0x13e000
-	memcpy(base, fbase + DATA_OFFSET, 0x13e000);
+	memcpy(gDataSegment, fbase + DATA_OFFSET, 0x13e000);
+	err = munmap(fbase, file_size);
+	if (err != 0)
+	{
+		err = errno;
+		log_error("Failed to unmap file! errno = %d", err);
+	}
 #endif // __linux__
 
 	// Check that the expected data is at various addresses.
@@ -546,6 +559,41 @@ static bool openrct2_setup_rct2_segment()
 	return true;
 }
 
+/**
+ * Releases segments created with @ref openrct2_setup_rct2_segment, if any.
+ */
+static bool openrct2_release_rct2_segment()
+{
+	bool result = true;
+#if defined(__linux__)
+	int len = 0x01429000 - 0x8a4000; // 0xB85000, 12079104 bytes or around 11.5MB
+	int err;
+	err = munmap(gDataSegment, len);
+	if (err != 0)
+	{
+		err = errno;
+		log_error("Failed to unmap data segment! errno = %d", err);
+		result = false;
+	}
+	len = 0x004A3000;
+	err = munmap(gTextSegment, len);
+	if (err != 0)
+	{
+		err = errno;
+		log_error("Failed to unmap text segment! errno = %d", err);
+		result = false;
+	}
+	err = close(gExeFd);
+	if (err != 0)
+	{
+		err = errno;
+		log_error("Failed to close file! errno = %d", err);
+		result = false;
+	}
+#endif // defined(__linux__)
+	return result;
+}
+
 /**
  * Setup hooks to allow RCT2 to call OpenRCT2 functions instead.
  */