Fix stack alignment when resuming from a signal handler in the soft d…

…ebugger. Fixes #647464.
mono · Nov 25, 2010 · 99f99ef · 99f99ef
1 parent 4905ef1
commit 99f99ef
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Showing 4 changed files with 22 additions and 3 deletions.
diff --git a/mono/mini/debugger-agent.c b/mono/mini/debugger-agent.c
@@ -3529,8 +3529,11 @@ resume_from_signal_handler (void *sigctx, void *func)
 
 	mono_arch_sigctx_to_monoctx (sigctx, &ctx);
 	memcpy (&tls->handler_ctx, &ctx, sizeof (MonoContext));
+#ifdef MONO_ARCH_HAVE_SETUP_RESUME_FROM_SIGNAL_HANDLER_CTX
+	mono_arch_setup_resume_sighandler_ctx (&ctx, func);
+#else
 	MONO_CONTEXT_SET_IP (&ctx, func);
-
+#endif
 	mono_arch_monoctx_to_sigctx (&ctx, sigctx);
 }
 

diff --git a/mono/mini/exceptions-amd64.c b/mono/mini/exceptions-amd64.c
@@ -1458,3 +1458,19 @@ mono_tasklets_arch_restore (void)
 }
 #endif
 
+/*
+ * mono_arch_setup_resume_sighandler_ctx:
+ *
+ *   Setup CTX so execution continues at FUNC.
+ */
+void
+mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
+{
+	/* 
+	 * When resuming from a signal handler, the stack should be misaligned, just like right after
+	 * a call.
+	 */
+	if ((((guint64)MONO_CONTEXT_GET_SP (ctx)) % 16) == 0)
+		MONO_CONTEXT_SET_SP (ctx, (guint64)MONO_CONTEXT_GET_SP (ctx) - 8);
+	MONO_CONTEXT_SET_IP (ctx, func);
+}
diff --git a/mono/mini/mini-amd64.h b/mono/mini/mini-amd64.h
@@ -376,8 +376,7 @@ typedef struct {
 #define MONO_ARCH_DYN_CALL_PARAM_AREA 0
 
 #define MONO_ARCH_HAVE_LLVM_IMT_TRAMPOLINE 1
-
-#define MONO_ARCH_USE_OP_TAIL_CALL(caller_sig, callee_sig) mono_metadata_signature_equal ((caller_sig), (callee_sig))
+#define MONO_ARCH_HAVE_SETUP_RESUME_FROM_SIGNAL_HANDLER_CTX 1
 
 /* Used for optimization, not complete */
 #define MONO_ARCH_IS_OP_MEMBASE(opcode) ((opcode) == OP_X86_PUSH_MEMBASE)

diff --git a/mono/mini/mini.h b/mono/mini/mini.h
@@ -1709,6 +1709,7 @@ guint8*   mono_arch_get_ip_for_breakpoint       (MonoJitInfo *ji, MonoContext *c
 void     mono_arch_skip_breakpoint              (MonoContext *ctx) MONO_INTERNAL;
 void     mono_arch_skip_single_step             (MonoContext *ctx) MONO_INTERNAL;
 gpointer mono_arch_get_seq_point_info           (MonoDomain *domain, guint8 *code) MONO_INTERNAL;
+void     mono_arch_setup_resume_sighandler_ctx  (MonoContext *ctx, gpointer func) MONO_INTERNAL;
 #endif
 
 MonoJitInfo *mono_arch_find_jit_info            (MonoDomain *domain,