[PATCH v4 3/4] ntdll: Handle invalid FP state in usr1_handler() on x64.

[Paul Gofman]

From: Paul Gofman

---
 dlls/ntdll/unix/signal_x86_64.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/unix/signal_x86_64.c b/dlls/ntdll/unix/signal_x86_64.c
index 6564074893a..2cd1c8a3444 100644
--- a/dlls/ntdll/unix/signal_x86_64.c
+++ b/dlls/ntdll/unix/signal_x86_64.c
@@ -439,6 +439,7 @@ C_ASSERT( offsetof(struct callback_stack_layout, machine_frame) == 0x30 );
 C_ASSERT( sizeof(struct callback_stack_layout) == 0x58 );

#define RESTORE_FLAGS_INSTRUMENTATION CONTEXT_i386
+#define RESTORE_FLAGS_INVALID_FPSTATE CONTEXT_ARM

struct syscall_frame
 {
@@ -2069,6 +2070,7 @@ static BOOL handle_syscall_trap( ucontext_t *sigcontext, siginfo_t *siginfo )
         extern const void *__wine_syscall_dispatcher_prolog_end_ptr;

RIP_sig( sigcontext ) = (ULONG64)__wine_syscall_dispatcher_prolog_end_ptr;
+        frame->restore_flags = CONTEXT_CONTROL;
     }
     else if ((void *)RIP_sig( sigcontext ) == __wine_unix_call_dispatcher)
     {
@@ -2076,6 +2078,7 @@ static BOOL handle_syscall_trap( ucontext_t *sigcontext, siginfo_t *siginfo )

RIP_sig( sigcontext ) = (ULONG64)__wine_unix_call_dispatcher_prolog_end_ptr;
         R10_sig( sigcontext ) = RCX_sig( sigcontext );
+        frame->restore_flags = CONTEXT_CONTROL | RESTORE_FLAGS_INVALID_FPSTATE;
     }
     else if (siginfo->si_code == 4 /* TRAP_HWBKPT */ && is_inside_syscall( RSP_sig(sigcontext) ))
     {
@@ -2089,7 +2092,6 @@ static BOOL handle_syscall_trap( ucontext_t *sigcontext, siginfo_t *siginfo )

frame->rip = *(ULONG64 *)RSP_sig( sigcontext );
     frame->eflags = EFL_sig(sigcontext);
-    frame->restore_flags = CONTEXT_CONTROL;
     if (instrumentation_callback) frame->restore_flags |= RESTORE_FLAGS_INSTRUMENTATION;

RCX_sig( sigcontext ) = (ULONG64)frame;
@@ -2430,6 +2432,24 @@ static void usr1_handler( int signal, siginfo_t *siginfo, void *sigcontext )
             return;
         }
         context->c.ContextFlags = CONTEXT_FULL | CONTEXT_SEGMENTS | 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 (FPU_sig(ucontext))
+            {
+                XSAVE_FORMAT xsave;
+
+                xsave = *FPU_sig(ucontext);
+                memcpy( &xsave.XmmRegisters[6], &frame->xsave.XmmRegisters[6], 10 * sizeof(*xsave.XmmRegisters) );
+                xsave.MxCsr = frame->xsave.MxCsr;
+                frame->xsave = xsave;
+                frame->xstate.Mask = XSTATE_MASK_LEGACY;
+            }
+        }
         NtGetContextThread( GetCurrentThread(), &context->c );
         if (xstate_extended_features)
         {
@@ -3145,7 +3165,7 @@ __ASM_GLOBAL_FUNC( __wine_unix_call_dispatcher,
                    "popq 0x80(%rcx)\n\t"           /* frame->eflags */
                    __ASM_CFI(".cfi_adjust_cfa_offset -8\n\t")
                    __ASM_CFI_REG_IS_AT2(rip, rcx, 0xf0,0x00)
-                   "movl $0,0xb4(%rcx)\n\t"        /* frame->restore_flags */
+                   "movl $0x200000,0xb4(%rcx)\n\t" /* frame->restore_flags <- RESTORE_FLAGS_INVALID_FPSTATE */
                    __ASM_LOCAL_LABEL("__wine_unix_call_dispatcher_prolog_end") ":\n\t"
                    "movq %rbx,0x08(%rcx)\n\t"
                    __ASM_CFI_REG_IS_AT1(rbx, rcx, 0x08)