From: Paul Cercueil <paul@crapouillou.net>
Date: Thu, 27 Jul 2023 09:32:58 +0000 (+0200)
Subject: lightrec: use mmap() for code buffer if possible
X-Git-Tag: r24l~276^2
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;ds=sidebyside;h=c4f51fd8528e1dec6713cd32e982e11e865d28bc;p=pcsx_rearmed.git

lightrec: use mmap() for code buffer if possible

When not using the custom memory map, the code buffer was simply
malloc'd. This only works if the memory returned has no protection,
which is not the case e.g. on Linux.

If mmap() is available, use it to allocate the code buffer, so that the
proper memory protection flags can be used.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---

diff --git a/libpcsxcore/lightrec/plugin.c b/libpcsxcore/lightrec/plugin.c
index 8d96c0a3..72201c16 100644
--- a/libpcsxcore/lightrec/plugin.c
+++ b/libpcsxcore/lightrec/plugin.c
@@ -6,6 +6,10 @@
 #include <signal.h>
 #include <assert.h>
 
+#if P_HAVE_MMAP
+#include <sys/mman.h>
+#endif
+
 #include "../cdrom.h"
 #include "../gpu.h"
 #include "../gte.h"
@@ -436,9 +440,17 @@ static int lightrec_plugin_init(void)
 	lightrec_map[PSX_MAP_PARALLEL_PORT].address = psxP;
 
 	if (!LIGHTREC_CUSTOM_MAP) {
+#if P_HAVE_MMAP
+		code_buffer = mmap(0, CODE_BUFFER_SIZE,
+				   PROT_EXEC | PROT_READ | PROT_WRITE,
+				   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+		if (code_buffer == MAP_FAILED)
+			return -ENOMEM;
+#else
 		code_buffer = malloc(CODE_BUFFER_SIZE);
 		if (!code_buffer)
 			return -ENOMEM;
+#endif
 	}
 
 	if (LIGHTREC_CUSTOM_MAP) {
@@ -571,8 +583,13 @@ static void lightrec_plugin_shutdown(void)
 {
 	lightrec_destroy(lightrec_state);
 
-	if (!LIGHTREC_CUSTOM_MAP)
+	if (!LIGHTREC_CUSTOM_MAP) {
+#if P_HAVE_MMAP
+		munmap(code_buffer, CODE_BUFFER_SIZE);
+#else
 		free(code_buffer);
+#endif
+	}
 }
 
 static void lightrec_plugin_reset(void)