[PATCH] ntdll: Avoid truncating a nonzero exit code to zero in unix

[Martin Storsjo]

On Windows, the exit codes can use the full 32 bit range, while
on unix, they are truncated to the lowest 8 bits. If the intended
exit code is nonzero, to indicate failure, but the lower 8 bits
are zero (like when winedbg tries to exit with EXCEPTION_WINE_STUB,
80000100), the observed exit code used to be zero, indicating
successful execution.

Signed-off-by: Martin Storsjo <martin at martin.st>
---
This is an alternative to https://source.winehq.org/patches/data/164482
(fixing the same issue in winedbg), by keeping the full range of the
winedbg exit code and just avoiding the issue right before calling
exit/_exit.
---
 dlls/ntdll/loader.c         | 3 +++
 dlls/ntdll/process.c        | 7 ++++++-
 dlls/ntdll/signal_arm.c     | 3 +++
 dlls/ntdll/signal_arm64.c   | 3 +++
 dlls/ntdll/signal_i386.c    | 3 +++
 dlls/ntdll/signal_powerpc.c | 3 +++
 dlls/ntdll/signal_x86_64.c  | 3 +++
 dlls/ntdll/thread.c         | 7 ++++++-
 8 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index 994ff6f215..0279c81aa7 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -3264,6 +3264,9 @@ void WINAPI RtlExitUserProcess( DWORD status )
     NtTerminateProcess( 0, status );
     LdrShutdownProcess();
     NtTerminateProcess( GetCurrentProcess(), status );
+    /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+    if (status != 0 && (status & 0xff) == 0)
+        status = 1;
     exit( status );
 }
 
diff --git a/dlls/ntdll/process.c b/dlls/ntdll/process.c
index 573a7a771d..ea3565cb1c 100644
--- a/dlls/ntdll/process.c
+++ b/dlls/ntdll/process.c
@@ -88,7 +88,12 @@ NTSTATUS WINAPI NtTerminateProcess( HANDLE handle, LONG exit_code )
         self = !ret && reply->self;
     }
     SERVER_END_REQ;
-    if (self && handle) _exit( exit_code );
+    if (self && handle) {
+        /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+        if (exit_code != 0 && (exit_code & 0xff) == 0)
+            exit_code = 1;
+        _exit( exit_code );
+    }
     return ret;
 }
 
diff --git a/dlls/ntdll/signal_arm.c b/dlls/ntdll/signal_arm.c
index e01c8ce219..4f4dcced05 100644
--- a/dlls/ntdll/signal_arm.c
+++ b/dlls/ntdll/signal_arm.c
@@ -1396,6 +1396,9 @@ void signal_exit_thread( int status )
  */
 void signal_exit_process( int status )
 {
+    /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+    if (status != 0 && (status & 0xff) == 0)
+        status = 1;
     call_thread_exit_func( status, exit, NtCurrentTeb() );
 }
 
diff --git a/dlls/ntdll/signal_arm64.c b/dlls/ntdll/signal_arm64.c
index 8114d45fef..e56dd6b1ab 100644
--- a/dlls/ntdll/signal_arm64.c
+++ b/dlls/ntdll/signal_arm64.c
@@ -1171,6 +1171,9 @@ void signal_exit_thread( int status )
  */
 void signal_exit_process( int status )
 {
+    /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+    if (status != 0 && (status & 0xff) == 0)
+        status = 1;
     exit( status );
 }
 
diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
index 053c87da83..a89ff20fd6 100644
--- a/dlls/ntdll/signal_i386.c
+++ b/dlls/ntdll/signal_i386.c
@@ -2817,6 +2817,9 @@ void signal_exit_thread( int status )
  */
 void signal_exit_process( int status )
 {
+    /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+    if (status != 0 && (status & 0xff) == 0)
+        status = 1;
     call_thread_exit_func( status, exit );
 }
 
diff --git a/dlls/ntdll/signal_powerpc.c b/dlls/ntdll/signal_powerpc.c
index 86398d8f54..a5cce9bae3 100644
--- a/dlls/ntdll/signal_powerpc.c
+++ b/dlls/ntdll/signal_powerpc.c
@@ -1240,6 +1240,9 @@ void signal_exit_thread( int status )
  */
 void signal_exit_process( int status )
 {
+    /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+    if (status != 0 && (status & 0xff) == 0)
+        status = 1;
     exit( status );
 }
 
diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
index 21e7098876..140e11b491 100644
--- a/dlls/ntdll/signal_x86_64.c
+++ b/dlls/ntdll/signal_x86_64.c
@@ -4603,6 +4603,9 @@ void signal_exit_thread( int status )
  */
 void signal_exit_process( int status )
 {
+    /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+    if (status != 0 && (status & 0xff) == 0)
+        status = 1;
     call_thread_exit_func( status, exit );
 }
 
diff --git a/dlls/ntdll/thread.c b/dlls/ntdll/thread.c
index be4621819b..66a92eb3fc 100644
--- a/dlls/ntdll/thread.c
+++ b/dlls/ntdll/thread.c
@@ -291,7 +291,12 @@ static void free_thread_data( TEB *teb )
 void abort_thread( int status )
 {
     pthread_sigmask( SIG_BLOCK, &server_block_set, NULL );
-    if (interlocked_xchg_add( &nb_threads, -1 ) <= 1) _exit( status );
+    if (interlocked_xchg_add( &nb_threads, -1 ) <= 1) {
+        /* Prevent a nonzero exit code to end up truncated to zero in unix. */
+        if (status != 0 && (status & 0xff) == 0)
+            status = 1;
+        _exit( status );
+    }
     signal_exit_thread( status );
 }
 
-- 
2.17.1