xaudio2_7: Also preserve %ebx in call_on_voice_processing_pass_start().

It is tested that EBX register is not preserved by IXAudio2VoiceCallback_OnVoiceProcessingPassStart callback in League of Legends. It doesn't lead to crash in the present xaudio, while it might still be a potential issue. Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=46870Signed-off-by: Paul Gofman <gofmanp@gmail.com> Signed-off-by: Andrew Eikum <aeikum@codeweavers.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

xaudio2_7: Also preserve %ebx in call_on_voice_processing_pass_start().
a5b22c86 · Paul Gofman · Alexandre Julliard · 7ca60b90 · a5b22c86
Commit a5b22c86 authored Apr 11, 2019 by Paul Gofman Committed by Alexandre Julliard Apr 12, 2019
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xaudio_dll.c dlls/xaudio2_7/xaudio_dll.c +8 -3

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--- a/dlls/xaudio2_7/xaudio_dll.c
+++ b/dlls/xaudio2_7/xaudio_dll.c
@@ -41,7 +41,8 @@
 WINE_DEFAULT_DEBUG_CHANNEL(xaudio2);

 #if XAUDIO2_VER != 0 && defined(__i386__)
-/* EVE Online uses an OnVoiceProcessingPassStart callback which corrupts %esi. */
+/* EVE Online uses an OnVoiceProcessingPassStart callback which corrupts %esi;
+ * League of Legends uses a callback which corrupts %ebx. */
 #define IXAudio2VoiceCallback_OnVoiceProcessingPassStart(a, b) call_on_voice_processing_pass_start(a, b)
 extern void call_on_voice_processing_pass_start(IXAudio2VoiceCallback *This, UINT32 BytesRequired);
 __ASM_GLOBAL_FUNC( call_on_voice_processing_pass_start,
@@ -54,13 +55,17 @@ __ASM_GLOBAL_FUNC( call_on_voice_processing_pass_start,
                  __ASM_CFI(".cfi_rel_offset %esi,-4\n\t")
                   "pushl %edi\n\t"
                  __ASM_CFI(".cfi_rel_offset %edi,-8\n\t")
-                   "subl $8,%esp\n\t"
+                   "pushl %ebx\n\t"
+                  __ASM_CFI(".cfi_rel_offset %ebx,-12\n\t")
+                   "subl $4,%esp\n\t"
                   "pushl 12(%ebp)\n\t"     /* BytesRequired */
                   "pushl 8(%ebp)\n\t"      /* This */
                   "movl 8(%ebp),%eax\n\t"
                   "movl 0(%eax),%eax\n\t"
                   "call *0(%eax)\n\t"      /* This->lpVtbl->OnVoiceProcessingPassStart */
-                   "leal -8(%ebp),%esp\n\t"
+                   "leal -12(%ebp),%esp\n\t"
+                   "popl %ebx\n\t"
+                   __ASM_CFI(".cfi_same_value %ebx\n\t")
                   "popl %edi\n\t"
                   __ASM_CFI(".cfi_same_value %edi\n\t")
                   "popl %esi\n\t"