Huw Davies : kernel32: Save xmm0 - 3 to work around a Delphi bug on x86_64.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 1e945155f906bde15c5d70ec5ed253c1d7ce5148
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=1e945155f906bde15c5d70ec5...

Author: Huw Davies 
Date:   Tue Feb  6 10:26:13 2018 +0000

kernel32: Save xmm0 - 3 to work around a Delphi bug on x86_64.

When delay loading a symbol, Delphi saves rcx, rdx, r8 and r9 to the
stack.  It then calls GetProcAddress(), pops the saved registers and
calls the function.  This works fine if all of the parameters are
ints.  However, since it does not save xmm0 - 3, it relies on
GetProcAddress() preserving these registers if the function takes
floating point parameters.

Signed-off-by: Huw Davies 
Signed-off-by: Alexandre Julliard

---

dlls/kernel32/module.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/dlls/kernel32/module.c b/dlls/kernel32/module.c
index b97c79b..a5346db 100644
--- a/dlls/kernel32/module.c
+++ b/dlls/kernel32/module.c
@@ -1363,7 +1363,7 @@ BOOL WINAPI DECLSPEC_HOTPATCH FreeLibrary(HINSTANCE hLibModule)
  *  Success: A pointer to the symbol in the process address space.
  *  Failure: NULL. Use GetLastError() to determine the cause.
  */
-FARPROC WINAPI GetProcAddress( HMODULE hModule, LPCSTR function )
+FARPROC get_proc_address( HMODULE hModule, LPCSTR function )
 {
     NTSTATUS    nts;
     FARPROC     fp;
@@ -1387,6 +1387,54 @@ FARPROC WINAPI GetProcAddress( HMODULE hModule, LPCSTR function )
     return fp;
 }

+#ifdef __x86_64__
+/*
+ * Work around a Delphi bug on x86_64.  When delay loading a symbol,
+ * Delphi saves rcx, rdx, r8 and r9 to the stack.  It then calls
+ * GetProcAddress(), pops the saved registers and calls the function.
+ * This works fine if all of the parameters are ints.  However, since
+ * it does not save xmm0 - 3, it relies on GetProcAddress() preserving
+ * these registers if the function takes floating point parameters.
+ * This wrapper saves xmm0 - 3 to the stack.
+ */
+extern FARPROC get_proc_address_wrapper( HMODULE module, LPCSTR function );
+
+__ASM_GLOBAL_FUNC( get_proc_address_wrapper,
+                   "pushq %rbp\n\t"
+                   __ASM_CFI(".cfi_adjust_cfa_offset 8\n\t")
+                   __ASM_CFI(".cfi_rel_offset %rbp,0\n\t")
+                   "movq %rsp,%rbp\n\t"
+                   __ASM_CFI(".cfi_def_cfa_register %rbp\n\t")
+                   "subq $0x40,%rsp\n\t"
+                   "movaps %xmm0,-0x10(%rbp)\n\t"
+                   "movaps %xmm1,-0x20(%rbp)\n\t"
+                   "movaps %xmm2,-0x30(%rbp)\n\t"
+                   "movaps %xmm3,-0x40(%rbp)\n\t"
+                   "call " __ASM_NAME("get_proc_address") "\n\t"
+                   "movaps -0x40(%rbp), %xmm3\n\t"
+                   "movaps -0x30(%rbp), %xmm2\n\t"
+                   "movaps -0x20(%rbp), %xmm1\n\t"
+                   "movaps -0x10(%rbp), %xmm0\n\t"
+                   "movq %rbp,%rsp\n\t"
+                   __ASM_CFI(".cfi_def_cfa_register %rsp\n\t")
+                   "popq %rbp\n\t"
+                   __ASM_CFI(".cfi_adjust_cfa_offset -8\n\t")
+                   __ASM_CFI(".cfi_same_value %rbp\n\t")
+                   "ret" )
+#else /* __x86_64__ */
+
+static inline FARPROC get_proc_address_wrapper( HMODULE module, LPCSTR function )
+{
+    return get_proc_address( module, function );
+}
+
+#endif /* __x86_64__ */
+
+FARPROC WINAPI GetProcAddress( HMODULE hModule, LPCSTR function )
+{
+    return get_proc_address_wrapper( hModule, function );
+}
+
 /***********************************************************************
  *           DelayLoadFailureHook  (KERNEL32.@)
  */