[PATCH 4/4] ntdll: Handle invalid FP state in usr1_handler() on i386.

[Paul Gofman]

From: Paul Gofman

---
 dlls/ntdll/unix/signal_i386.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/dlls/ntdll/unix/signal_i386.c b/dlls/ntdll/unix/signal_i386.c
index d628d44272d..d1c61d5685c 100644
--- a/dlls/ntdll/unix/signal_i386.c
+++ b/dlls/ntdll/unix/signal_i386.c
@@ -505,6 +505,8 @@ struct syscall_frame

C_ASSERT( sizeof(struct syscall_frame) == 0x280 );

+#define RESTORE_FLAGS_INVALID_FPSTATE 0x00008000
+
 struct x86_thread_data
 {
     UINT               fs;            /* 1d4 TEB selector */
@@ -1859,12 +1861,14 @@ static BOOL handle_syscall_trap( ucontext_t *sigcontext, siginfo_t *siginfo )
         extern void __wine_syscall_dispatcher_prolog_end(void);

EIP_sig( sigcontext ) = (ULONG)__wine_syscall_dispatcher_prolog_end;
+        frame->restore_flags = LOWORD(CONTEXT_CONTROL);
     }
     else if ((void *)EIP_sig( sigcontext ) == __wine_unix_call_dispatcher)
     {
         extern void __wine_unix_call_dispatcher_prolog_end(void);

EIP_sig( sigcontext ) = (ULONG)__wine_unix_call_dispatcher_prolog_end;
+        frame->restore_flags = LOWORD(CONTEXT_CONTROL | RESTORE_FLAGS_INVALID_FPSTATE);
     }
     else if (siginfo->si_code == 4 /* TRAP_HWBKPT */ && is_inside_syscall( ESP_sig(sigcontext) ))
     {
@@ -1877,7 +1881,6 @@ static BOOL handle_syscall_trap( ucontext_t *sigcontext, siginfo_t *siginfo )

frame->eip = *(ULONG *)ESP_sig( sigcontext );
     frame->eflags = EFL_sig(sigcontext);
-    frame->restore_flags = LOWORD(CONTEXT_CONTROL);

ECX_sig( sigcontext ) = (ULONG)frame;
     ESP_sig( sigcontext ) += sizeof(ULONG);
@@ -2135,6 +2138,20 @@ static void usr1_handler( int signal, siginfo_t *siginfo, void *sigcontext )
             return;
         }
         context->c.ContextFlags = CONTEXT_FULL | CONTEXT_EXCEPTION_REQUEST;
+        if (frame->restore_flags & RESTORE_FLAGS_INVALID_FPSTATE)
+        {
+            /* frame FP state is not fully filled, fill in the missing state from the current Unix side context. */
+            frame->restore_flags &= ~RESTORE_FLAGS_INVALID_FPSTATE;
+            memset( &frame->xstate, 0, sizeof(frame->xstate) );
+            if (user_shared_data->XState.CompactionEnabled)
+                frame->xstate.CompactionMask = 0x8000000000000000 | user_shared_data->XState.EnabledFeatures;
+            if (FPUX_sig(ucontext))
+            {
+                frame->u.xsave = *FPUX_sig(ucontext);
+                frame->xstate.Mask = XSTATE_MASK_LEGACY;
+            }
+            else if (FPU_sig(ucontext)) frame->u.fsave = *FPU_sig(ucontext);
+        }
         NtGetContextThread( GetCurrentThread(), &context->c );
         if (xstate_extended_features)
         {
@@ -2697,7 +2714,7 @@ __ASM_GLOBAL_FUNC( __wine_syscall_dispatcher_return,
  */
 __ASM_GLOBAL_FUNC( __wine_unix_call_dispatcher,
                    "movl %fs:0x218,%ecx\n\t"   /* thread_data->syscall_frame */
-                   "movl $0,(%ecx)\n\t"        /* frame->restore_flags */
+                   "movl $0x8000,(%ecx)\n\t"   /* frame->restore_flags <- RESTORE_FLAGS_INVALID_FPSTATE */
                    "popl 0x08(%ecx)\n\t"       /* frame->eip */
                    __ASM_CFI(".cfi_adjust_cfa_offset -4\n\t")
                    "pushfl\n\t"
@@ -2738,7 +2755,7 @@ __ASM_GLOBAL_FUNC( __wine_unix_call_dispatcher,
                    __ASM_CFI(".cfi_offset %edi,-20\n\t")
                    "call *(%eax,%edx,4)\n\t"
                    "leal 16(%esp),%esp\n\t"
-                   "testl $0xffff,(%esp)\n\t"  /* frame->restore_flags */
+                   "testl $0x7fff,(%esp)\n\t"  /* frame->restore_flags */
                    "jnz " __ASM_LOCAL_LABEL("__wine_syscall_dispatcher_return") "\n\t"
                    "movl 0x08(%esp),%ecx\n\t"  /* frame->eip */
                    /* switch to user stack */