[PATCH 0/1] MR8577: wow64cpu: In Unix calls, always return the status from the non-Wow dispatcher.

[Tim Clem (＠tclem)]

Even if WOW64_CPURESERVED_FLAG_RESET_STATE ends up being set.

---

Unix call equivalent of 419e4d69d6c3a4ea8b355f8b3fc211950eed0cdd. After 7ef95229913cf004d002459fe9e53307344479f2, a SIGUSR1 in the middle of a Unix call can set WOW64_CPURESERVED_FLAG_RESET_STATE. If that happens, the original eax from before the Unix call will be restored in syscall_32to64_return, stomping on the actual return from the Unix function.

Thanks to @gofman for help spotting this!

[PATCH 1/1] wow64cpu: In Unix calls, always return the status from the non-Wow dispatcher.

[Tim Clem]

From: Tim Clem

Even if WOW64_CPURESERVED_FLAG_RESET_STATE ends up being set.
---
 dlls/wow64cpu/cpu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dlls/wow64cpu/cpu.c b/dlls/wow64cpu/cpu.c
index f5900aa36ed..453c5dfb4d8 100644
--- a/dlls/wow64cpu/cpu.c
+++ b/dlls/wow64cpu/cpu.c
@@ -255,6 +255,7 @@ __ASM_GLOBAL_FUNC( unix_call_32to64,
                    "movl 12(%r14),%edx\n\t"     /* code */
                    "movl 16(%r14),%r8d\n\t"     /* args */
                    "callq *__wine_unix_call_dispatcher(%rip)\n\t"
+                   "movl %eax,0xb0(%r13)\n\t"   /* context->Eax */
                    "btrl $0,-4(%r13)\n\t"       /* cpu->Flags & WOW64_CPURESERVED_FLAG_RESET_STATE */
                    "jc .Lsyscall_32to64_return\n\t"
                    "movl 0xb8(%r13),%edx\n\t"   /* context->Eip */