From: Zoltan Varga <vargaz@gmail.com>
Date: Mon, 28 Aug 2017 08:37:53 +0000 (-0400)
Subject: [amd64] Make code patching smp safe for the case where we emit a mov + call_reg.... 
X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=commitdiff_plain;ds=sidebyside;h=9a634c1810aad46d30a674f3a97ab263dcd4272e;p=mono.git

[amd64] Make code patching smp safe for the case where we emit a mov + call_reg. Hopefully fixes #57959. (#5452)
---

diff --git a/mono/mini/cpu-amd64.md b/mono/mini/cpu-amd64.md
index d35a867778f..b2354f17628 100755
--- a/mono/mini/cpu-amd64.md
+++ b/mono/mini/cpu-amd64.md
@@ -99,8 +99,8 @@ long_min_un: dest:i src1:i src2:i len:16 clob:1
 long_max: dest:i src1:i src2:i len:16 clob:1
 long_max_un: dest:i src1:i src2:i len:16 clob:1
 
-throw: src1:i len:18
-rethrow: src1:i len:18
+throw: src1:i len:24
+rethrow: src1:i len:24
 start_handler: len:16
 endfinally: len:9
 endfilter: src1:a len:9
diff --git a/mono/mini/mini-amd64.c b/mono/mini/mini-amd64.c
index 02f056f694d..949e5a362a6 100644
--- a/mono/mini/mini-amd64.c
+++ b/mono/mini/mini-amd64.c
@@ -2870,6 +2870,11 @@ emit_call_body (MonoCompile *cfg, guint8 *code, MonoJumpInfoType patch_type, gco
 			amd64_call_code (code, 0);
 		}
 		else {
+			if (!no_patch && ((guint32)(code + 2 - cfg->native_code) % 8) != 0) {
+				guint32 pad_size = 8 - ((guint32)(code + 2 - cfg->native_code) % 8);
+				amd64_padding (code, pad_size);
+				g_assert ((guint64)(code + 2 - cfg->native_code) % 8 == 0);
+			}
 			mono_add_patch_info (cfg, code - cfg->native_code, patch_type, data);
 			amd64_set_reg_template (code, GP_SCRATCH_REG);
 			amd64_call_reg (code, GP_SCRATCH_REG);
diff --git a/mono/mini/tramp-amd64.c b/mono/mini/tramp-amd64.c
index ea912ba6ce9..365b0ae8163 100644
--- a/mono/mini/tramp-amd64.c
+++ b/mono/mini/tramp-amd64.c
@@ -144,6 +144,7 @@ mono_arch_patch_callsite (guint8 *method_start, guint8 *orig_code, guint8 *addr)
 	if (((code [-13] == 0x49) && (code [-12] == 0xbb)) || (code [-5] == 0xe8)) {
 		if (code [-5] != 0xe8) {
 			if (can_write) {
+				g_assert ((guint64)(orig_code - 11) % 8 == 0);
 				InterlockedExchangePointer ((gpointer*)(orig_code - 11), addr);
 				VALGRIND_DISCARD_TRANSLATIONS (orig_code - 11, sizeof (gpointer));
 			}