[PATCH v5 1/4] ntdll: Factor out capture_stack_back_trace() helper.

[Paul Gofman]

Signed-off-by: Paul Gofman 
---
v5:
    - fix max USHORT value.

dlls/ntdll/exception.c     | 12 ++++++++++++
 dlls/ntdll/ntdll_misc.h    |  2 ++
 dlls/ntdll/signal_arm.c    |  4 ++--
 dlls/ntdll/signal_arm64.c  |  4 ++--
 dlls/ntdll/signal_i386.c   |  6 ++++--
 dlls/ntdll/signal_x86_64.c | 10 ++++++----
 6 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/dlls/ntdll/exception.c b/dlls/ntdll/exception.c
index c3714e8369b..e956d8a722f 100644
--- a/dlls/ntdll/exception.c
+++ b/dlls/ntdll/exception.c
@@ -1065,3 +1065,15 @@ NTSTATUS WINAPI RtlCopyExtendedContext( CONTEXT_EX *dst, ULONG context_flags, CO
         memcpy( &dst_xs->YmmContext, &src_xs->YmmContext, sizeof(dst_xs->YmmContext) );
     return STATUS_SUCCESS;
 }
+
+
+/*************************************************************************
+ *		RtlCaptureStackBackTrace (NTDLL.@)
+ */
+USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
+{
+    ULONG ret;
+
+    ret = capture_stack_back_trace( skip, count, buffer, hash );
+    return min( ret, (USHORT)~0 );
+}
diff --git a/dlls/ntdll/ntdll_misc.h b/dlls/ntdll/ntdll_misc.h
index 34af6b780cf..31a33b04dbf 100644
--- a/dlls/ntdll/ntdll_misc.h
+++ b/dlls/ntdll/ntdll_misc.h
@@ -57,6 +57,8 @@ extern void WINAPI KiUserCallbackDispatcher(ULONG,void*,ULONG) DECLSPEC_HIDDEN;
 extern RUNTIME_FUNCTION *lookup_function_info( ULONG_PTR pc, ULONG_PTR *base, LDR_DATA_TABLE_ENTRY **module ) DECLSPEC_HIDDEN;
 #endif

+extern ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash ) DECLSPEC_HIDDEN;
+
 /* debug helpers */
 extern LPCSTR debugstr_us( const UNICODE_STRING *str ) DECLSPEC_HIDDEN;
 extern const char *debugstr_exception_code( DWORD code ) DECLSPEC_HIDDEN;
diff --git a/dlls/ntdll/signal_arm.c b/dlls/ntdll/signal_arm.c
index 0ef210a0331..241ddc3ce70 100644
--- a/dlls/ntdll/signal_arm.c
+++ b/dlls/ntdll/signal_arm.c
@@ -300,9 +300,9 @@ __ASM_STDCALL_FUNC( RtlRaiseException, 4,
                     "bl " __ASM_NAME("RtlRaiseStatus") )

/*************************************************************************
- *             RtlCaptureStackBackTrace (NTDLL.@)
+ *             capture_stack_back_trace
  */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
+ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
 {
     FIXME( "(%d, %d, %p, %p) stub!\n", skip, count, buffer, hash );
     return 0;
diff --git a/dlls/ntdll/signal_arm64.c b/dlls/ntdll/signal_arm64.c
index 290639b676b..1bffbe7efe9 100644
--- a/dlls/ntdll/signal_arm64.c
+++ b/dlls/ntdll/signal_arm64.c
@@ -1473,9 +1473,9 @@ __ASM_STDCALL_FUNC( RtlRaiseException, 4,
                    "bl " __ASM_NAME("RtlRaiseStatus") /* does not return */ );

/*************************************************************************
- *             RtlCaptureStackBackTrace (NTDLL.@)
+ *             capture_stack_back_trace
  */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
+ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
 {
     FIXME( "(%d, %d, %p, %p) stub!\n", skip, count, buffer, hash );
     return 0;
diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
index 14971032ce6..26150ce877b 100644
--- a/dlls/ntdll/signal_i386.c
+++ b/dlls/ntdll/signal_i386.c
@@ -481,14 +481,16 @@ __ASM_STDCALL_FUNC( RtlRaiseException, 4,

/*************************************************************************
- *		RtlCaptureStackBackTrace (NTDLL.@)
+ *		capture_stack_back_trace
  */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
+ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
 {
     CONTEXT context;
     ULONG i;
     ULONG *frame;

+    ++skip;
+
     RtlCaptureContext( &context );
     if (hash) *hash = 0;
     frame = (ULONG *)context.Ebp;
diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
index ef32eba68b7..5f3c8f70208 100644
--- a/dlls/ntdll/signal_x86_64.c
+++ b/dlls/ntdll/signal_x86_64.c
@@ -1490,19 +1490,21 @@ static inline ULONG hash_pointers( void **ptrs, ULONG count )

/*************************************************************************
- *		RtlCaptureStackBackTrace (NTDLL.@)
+ *		capture_stack_back_trace
  */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
+ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
 {
     UNWIND_HISTORY_TABLE table;
     DISPATCHER_CONTEXT dispatch;
     CONTEXT context;
     NTSTATUS status;
     ULONG i;
-    USHORT num_entries = 0;
+    ULONG num_entries = 0;

TRACE( "(%u, %u, %p, %p)\n", skip, count, buffer, hash );

+    ++skip;
+
     RtlCaptureContext( &context );
     dispatch.TargetIp      = 0;
     dispatch.ContextRecord = &context;
@@ -1529,7 +1531,7 @@ USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer,
         if (i >= skip) buffer[num_entries++] = (void *)context.Rip;
     }
     if (hash && num_entries > 0) *hash = hash_pointers( buffer, num_entries );
-    TRACE( "captured %hu frames\n", num_entries );
+    TRACE( "captured %u frames\n", num_entries );
     return num_entries;
 }

[PATCH v5 2/4] ntdll: Implement RtlWalkFrameChain() for x86 and x86_64.

[Paul Gofman]

Signed-off-by: Paul Gofman 
---
v5:
    - also test for requested_count == frame_count + 1.

dlls/ntdll/exception.c              | 24 ++++++++-
 dlls/ntdll/ntdll.spec               |  2 +-
 dlls/ntdll/signal_i386.c            | 17 +++---
 dlls/ntdll/signal_x86_64.c          |  7 +--
 dlls/ntdll/tests/exception.c        | 83 +++++++++++++++++++++++++++++
 dlls/ntoskrnl.exe/ntoskrnl.exe.spec |  2 +-
 include/ddk/ntddk.h                 |  3 ++
 include/winnt.h                     |  2 +
 8 files changed, 124 insertions(+), 16 deletions(-)

diff --git a/dlls/ntdll/exception.c b/dlls/ntdll/exception.c
index e956d8a722f..b020b829ae7 100644
--- a/dlls/ntdll/exception.c
+++ b/dlls/ntdll/exception.c
@@ -30,6 +30,7 @@
 #define WIN32_NO_STATUS
 #include "windef.h"
 #include "winternl.h"
+#include "ddk/ntddk.h"
 #include "ddk/wdm.h"
 #include "wine/exception.h"
 #include "wine/list.h"
@@ -1074,6 +1075,25 @@ USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer,
 {
     ULONG ret;

-    ret = capture_stack_back_trace( skip, count, buffer, hash );
-    return min( ret, (USHORT)~0 );
+    ret = capture_stack_back_trace( skip, skip + count, buffer, hash );
+    if (ret < skip) return 0;
+    return min( ret - skip, (USHORT)~0 );
+}
+
+
+/**********************************************************************
+ *              RtlWalkFrameChain      (NTDLL.@)
+ */
+ULONG WINAPI RtlWalkFrameChain( void **callers, ULONG count, ULONG skip )
+{
+    TRACE( "callers %p, count %u, skip %#x.\n", callers, count, skip );
+
+    if (skip & ~(0xff << RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT))
+    {
+        WARN( "Invalid flags %#x.\n", skip );
+        return 0;
+    }
+    skip >>= RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT;
+
+    return capture_stack_back_trace( skip, count, callers, NULL );
 }
diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index 13e65f65139..c54b2e205aa 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -1073,7 +1073,7 @@
 @ stdcall RtlWakeAddressSingle(ptr)
 @ stdcall RtlWakeAllConditionVariable(ptr)
 @ stdcall RtlWakeConditionVariable(ptr)
-@ stub RtlWalkFrameChain
+@ stdcall RtlWalkFrameChain(ptr long long)
 @ stdcall RtlWalkHeap(long ptr)
 @ stdcall RtlWow64EnableFsRedirection(long)
 @ stdcall RtlWow64EnableFsRedirectionEx(long ptr)
diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
index 26150ce877b..ff3e837c784 100644
--- a/dlls/ntdll/signal_i386.c
+++ b/dlls/ntdll/signal_i386.c
@@ -488,27 +488,26 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
     CONTEXT context;
     ULONG i;
     ULONG *frame;
+    ULONG num_entries = 0;

++skip;
+    ++count;

RtlCaptureContext( &context );
     if (hash) *hash = 0;
     frame = (ULONG *)context.Ebp;

-    while (skip--)
-    {
-        if (!is_valid_frame( frame )) return 0;
-        frame = (ULONG *)*frame;
-    }
-
     for (i = 0; i < count; i++)
     {
         if (!is_valid_frame( frame )) break;
-        buffer[i] = (void *)frame[1];
-        if (hash) *hash += frame[1];
+        if (i >= skip)
+        {
+            buffer[num_entries++] = (void *)frame[1];
+            if (hash) *hash += frame[1];
+        }
         frame = (ULONG *)*frame;
     }
-    return i;
+    return i ? i - 1 : 0;
 }

diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
index 5f3c8f70208..4a9c7d4b9ff 100644
--- a/dlls/ntdll/signal_x86_64.c
+++ b/dlls/ntdll/signal_x86_64.c
@@ -1504,16 +1504,17 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
     TRACE( "(%u, %u, %p, %p)\n", skip, count, buffer, hash );

++skip;
+    ++count;

RtlCaptureContext( &context );
     dispatch.TargetIp      = 0;
     dispatch.ContextRecord = &context;
     dispatch.HistoryTable  = &table;
     if (hash) *hash = 0;
-    for (i = 0; i < skip + count; i++)
+    for (i = 0; i < count; i++)
     {
         status = virtual_unwind( UNW_FLAG_NHANDLER, &dispatch, &context );
-        if (status != STATUS_SUCCESS) return i;
+        if (status != STATUS_SUCCESS) break;

if (!dispatch.EstablisherFrame) break;

@@ -1532,7 +1533,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
     }
     if (hash && num_entries > 0) *hash = hash_pointers( buffer, num_entries );
     TRACE( "captured %u frames\n", num_entries );
-    return num_entries;
+    return i ? i - 1 : 0;
 }

diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
index 6af68317732..6f3b08b5ea6 100644
--- a/dlls/ntdll/tests/exception.c
+++ b/dlls/ntdll/tests/exception.c
@@ -28,6 +28,7 @@
 #include "winnt.h"
 #include "winreg.h"
 #include "winternl.h"
+#include "ddk/ntddk.h"
 #include "ddk/wdm.h"
 #include "excpt.h"
 #include "wine/test.h"
@@ -9113,6 +9114,87 @@ static void test_copy_context(void)
 }
 #endif

+static void test_walk_stack(void)
+{
+    ULONG count, expected, frame_count, requested_count, skip_count;
+    void *addrs[256], *addrs2[256];
+    void *start, *end;
+    unsigned int i, j;
+
+    memset(addrs, 0xcc, sizeof(addrs));
+    memset(addrs2, 0xcc, sizeof(addrs2));
+
+    frame_count = RtlCaptureStackBackTrace(0, ARRAY_SIZE(addrs), addrs, NULL);
+    count = RtlWalkFrameChain(addrs2, ARRAY_SIZE(addrs2), 0);
+
+    trace("frame_count %u.\n", frame_count);
+
+    ok(frame_count > 1, "Got zero frame_count.\n");
+    ok(count == frame_count, "Got unexpected frame_count %u, count %u.\n", frame_count, count);
+
+    start = test_walk_stack;
+    end = (BYTE *)start + 0x1000;
+    todo_wine_if(sizeof(void *) == 4)
+    ok(addrs[0] >= start && addrs[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
+            start, end, addrs[0]);
+    todo_wine_if(sizeof(void *) == 4)
+    ok(addrs2[0] >= start && addrs2[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
+            start, end, addrs2[0]);
+
+    for (i = 1; i < frame_count; ++i)
+    {
+        ok(addrs[i] == addrs2[i], "i %u, addresses do not match, %p vs %p.\n", i, addrs[i], addrs2[i]);
+    }
+    todo_wine ok(!!addrs[frame_count - 1], "Expected non-NULL last address.\n");
+
+    for (requested_count = frame_count - 1; requested_count <= frame_count + 1; ++requested_count)
+    {
+        for (i = 0; i < 32; ++i)
+        {
+            winetest_push_context("requested_count %u, i %u", requested_count, i);
+            skip_count = (1 << i) >> 8;
+
+            if (i < RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT
+                    || i >= RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT + 8)
+                expected = 0;
+            else
+                expected = min(frame_count, requested_count);
+
+            memset(addrs2, 0xcc, sizeof(addrs2));
+            count = RtlWalkFrameChain(addrs2, requested_count, 1 << i);
+            ok(count == expected, "Got unexpected frame_count %u, expected %u.\n", count, expected);
+
+            if (skip_count < count)
+                count -= skip_count;
+            else
+                count = 0;
+
+            for (j = 0; j < count; ++j)
+                ok( addrs2[j] != (void *)(ULONG_PTR)0xcccccccccccccccc, "Address is not set, j %u.\n", j );
+            for (; j < ARRAY_SIZE(addrs2); ++j)
+                ok( addrs2[j] == (void *)(ULONG_PTR)0xcccccccccccccccc, "Address is set, j %u.\n", j );
+
+            if (!count)
+            {
+                winetest_pop_context();
+                continue;
+            }
+
+            memset(addrs, 0xcc, sizeof(addrs));
+            expected = skip_count > frame_count ? 0 : min(frame_count - skip_count, requested_count);
+            count = RtlCaptureStackBackTrace(skip_count, requested_count, addrs, NULL);
+            ok(count == expected, "Got unexpected frame_count %u, expected %u. i %u.\n", count, expected, i);
+
+            count = min(frame_count, requested_count) - skip_count;
+            for (j = 0; j < count; ++j)
+            {
+                ok(addrs[j] == addrs2[j], "Addresses do not match, j %u, %p, %p.\n", j, addrs[j], addrs2[j]);
+            }
+            winetest_pop_context();
+        }
+    }
+}
+
 START_TEST(exception)
 {
     HMODULE hntdll = GetModuleHandleA("ntdll.dll");
@@ -9339,5 +9421,6 @@ START_TEST(exception)
     test_suspend_thread();
     test_suspend_process();
     test_unload_trace();
+    test_walk_stack();
     VirtualFree(code_mem, 0, MEM_RELEASE);
 }
diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 0208e2f633f..b94e58ccb26 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -1300,7 +1300,7 @@
 @ stdcall RtlVerifyVersionInfo(ptr long int64)
 @ stdcall -arch=arm64,x86_64 RtlVirtualUnwind(long long long ptr ptr ptr ptr ptr)
 @ stub RtlVolumeDeviceToDosName
-@ stub RtlWalkFrameChain
+@ stdcall RtlWalkFrameChain(ptr long long)
 @ stdcall RtlWriteRegistryValue(long ptr ptr long ptr long)
 @ stub RtlZeroHeap
 @ stdcall RtlZeroMemory(ptr long)
diff --git a/include/ddk/ntddk.h b/include/ddk/ntddk.h
index 41ad3d721bd..ce558139aa6 100644
--- a/include/ddk/ntddk.h
+++ b/include/ddk/ntddk.h
@@ -245,6 +245,8 @@ typedef EXPAND_STACK_CALLOUT *PEXPAND_STACK_CALLOUT;
 typedef GUID UUID;
 #endif

+#define RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT 8
+
 NTSTATUS  WINAPI ExUuidCreate(UUID*);
 NTSTATUS  WINAPI IoQueryDeviceDescription(PINTERFACE_TYPE,PULONG,PCONFIGURATION_TYPE,PULONG,
                                   PCONFIGURATION_TYPE,PULONG,PIO_QUERY_DEVICE_ROUTINE,PVOID);
@@ -267,5 +269,6 @@ NTSTATUS  WINAPI PsSetCreateThreadNotifyRoutine(PCREATE_THREAD_NOTIFY_ROUTINE);
 NTSTATUS  WINAPI PsSetLoadImageNotifyRoutine(PLOAD_IMAGE_NOTIFY_ROUTINE);
 void      WINAPI RtlInitializeGenericTableAvl(PRTL_AVL_TABLE,PRTL_AVL_COMPARE_ROUTINE,PRTL_AVL_ALLOCATE_ROUTINE, PRTL_AVL_FREE_ROUTINE,void *);
 void      WINAPI RtlInsertElementGenericTableAvl(PRTL_AVL_TABLE,void *,ULONG,BOOL*);
+ULONG     WINAPI RtlWalkFrameChain(void **,ULONG,ULONG);

#endif
diff --git a/include/winnt.h b/include/winnt.h
index ef731e29c52..eb1bd165720 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -1840,6 +1840,8 @@ NTSYSAPI PVOID   WINAPI RtlVirtualUnwind(DWORD,ULONG_PTR,ULONG_PTR,RUNTIME_FUNCT

#endif

+NTSYSAPI USHORT  WINAPI RtlCaptureStackBackTrace(ULONG,ULONG,void **,ULONG *);
+
 /*
  * Product types
  */

[PATCH v5 2/4] ntdll: Implement RtlWalkFrameChain() for x86 and x86_64.

[Marvin]

Hi,

While running your changed tests, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?

Full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=101233

Your paranoid android.

=== w10pro64 (64 bit report) ===

ntdll:
exception.c:4406: Test failed: cs32: got eip 77a52a2c / 77a52a2c

=== debiant2 (32 bit Chinese:China report) ===

ntdll:
virtual: Timeout

[PATCH v5 2/4] ntdll: Implement RtlWalkFrameChain() for x86 and x86_64.

[Giovanni Mascellani]

Signed-off-by: Giovanni Mascellani

On 03/11/21 11:41, Paul Gofman wrote:
> Signed-off-by: Paul Gofman
>
> v5:
>      - also test for requested_count == frame_count + 1.
>
> dlls/ntdll/exception.c              | 24 ++++++++-
>   dlls/ntdll/ntdll.spec               |  2 +-
>   dlls/ntdll/signal_i386.c            | 17 +++---
>   dlls/ntdll/signal_x86_64.c          |  7 +--
>   dlls/ntdll/tests/exception.c        | 83 +++++++++++++++++++++++++++++
>   dlls/ntoskrnl.exe/ntoskrnl.exe.spec |  2 +-
>   include/ddk/ntddk.h                 |  3 ++
>   include/winnt.h                     |  2 +
>   8 files changed, 124 insertions(+), 16 deletions(-)
>
> diff --git a/dlls/ntdll/exception.c b/dlls/ntdll/exception.c
> index e956d8a722f..b020b829ae7 100644
> --- a/dlls/ntdll/exception.c
> +++ b/dlls/ntdll/exception.c
> @@ -30,6 +30,7 @@
>   #define WIN32_NO_STATUS
>   #include "windef.h"
>   #include "winternl.h"
> +#include "ddk/ntddk.h"
>   #include "ddk/wdm.h"
>   #include "wine/exception.h"
>   #include "wine/list.h"
> @@ -1074,6 +1075,25 @@ USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer,
>   {
>       ULONG ret;
> - ret = capture_stack_back_trace( skip, count, buffer, hash );
> - return min( ret, (USHORT)~0 );
> - ret = capture_stack_back_trace( skip, skip + count, buffer, hash );
> - if (ret < skip) return 0;
> - return min( ret - skip, (USHORT)~0 );
>
> +}
> -
> -
>
> +/**********************************************************************
> -
> -
>          RtlWalkFrameChain      (NTDLL.@)
> - */
>
> +ULONG WINAPI RtlWalkFrameChain( void **callers, ULONG count, ULONG skip )
> +{
> - TRACE( "callers %p, count %u, skip %#x.\n", callers, count, skip );
> -
> - if (skip & ~(0xff << RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT))
> - {
> -
>    WARN( "Invalid flags %#x.\n", skip );
> -
>    return 0;
> - }
> - skip >>= RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT;
> -
> - return capture_stack_back_trace( skip, count, callers, NULL );
> }
>
> diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
> index 13e65f65139..c54b2e205aa 100644
> --- a/dlls/ntdll/ntdll.spec
> +++ b/dlls/ntdll/ntdll.spec
> @@ -1073,7 +1073,7 @@
>   @ stdcall RtlWakeAddressSingle(ptr)
>   @ stdcall RtlWakeAllConditionVariable(ptr)
>   @ stdcall RtlWakeConditionVariable(ptr)
> -@ stub RtlWalkFrameChain
> +@ stdcall RtlWalkFrameChain(ptr long long)
>   @ stdcall RtlWalkHeap(long ptr)
>   @ stdcall RtlWow64EnableFsRedirection(long)
>   @ stdcall RtlWow64EnableFsRedirectionEx(long ptr)
> diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
> index 26150ce877b..ff3e837c784 100644
> --- a/dlls/ntdll/signal_i386.c
> +++ b/dlls/ntdll/signal_i386.c
> @@ -488,27 +488,26 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>       CONTEXT context;
>       ULONG i;
>       ULONG *frame;
> -
>
> ULONG num_entries = 0;
>
> ++skip;
> -
>
> ++count;
>
> RtlCaptureContext( &context );
>  if (hash) *hash = 0;
>  frame = (ULONG *)context.Ebp;
> - while (skip--)
> - {
> -
>    if (!is_valid_frame( frame )) return 0;
> -
>    frame = (ULONG *)*frame;
> - }
> -
> for (i = 0; i < count; i++)
> {
>     if (!is_valid_frame( frame )) break;
> -
>    buffer[i] = (void *)frame[1];
> -
>    if (hash) *hash += frame[1];
> -
>    if (i >= skip)
> -
>    {
> -
>        buffer[num_entries++] = (void *)frame[1];
> -
>        if (hash) *hash += frame[1];
> -
>    }
>     frame = (ULONG *)*frame;
> }
> - return i;
> - return i ? i - 1 : 0;
> }
>
> diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
> index 5f3c8f70208..4a9c7d4b9ff 100644
> --- a/dlls/ntdll/signal_x86_64.c
> +++ b/dlls/ntdll/signal_x86_64.c
> @@ -1504,16 +1504,17 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>       TRACE( "(%u, %u, %p, %p)\n", skip, count, buffer, hash );
>   ++skip;
> -
>
> ++count;
>
> RtlCaptureContext( &context );
>  dispatch.TargetIp      = 0;
>  dispatch.ContextRecord = &context;
>  dispatch.HistoryTable  = &table;
>  if (hash) *hash = 0;
> - for (i = 0; i < skip + count; i++)
> - for (i = 0; i < count; i++)
>  {
>      status = virtual_unwind( UNW_FLAG_NHANDLER, &dispatch, &context );
> -
>    if (status != STATUS_SUCCESS) return i;
> -
>    if (status != STATUS_SUCCESS) break;
>
>     if (!dispatch.EstablisherFrame) break;
>
> @@ -1532,7 +1533,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>       }
>       if (hash && num_entries > 0) *hash = hash_pointers( buffer, num_entries );
>       TRACE( "captured %u frames\n", num_entries );
> - return num_entries;
> - return i ? i - 1 : 0;
> }
>
> diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
> index 6af68317732..6f3b08b5ea6 100644
> --- a/dlls/ntdll/tests/exception.c
> +++ b/dlls/ntdll/tests/exception.c
> @@ -28,6 +28,7 @@
>   #include "winnt.h"
>   #include "winreg.h"
>   #include "winternl.h"
> +#include "ddk/ntddk.h"
>   #include "ddk/wdm.h"
>   #include "excpt.h"
>   #include "wine/test.h"
> @@ -9113,6 +9114,87 @@ static void test_copy_context(void)
>   }
>   #endif
>
> +static void test_walk_stack(void)
> +{
> - ULONG count, expected, frame_count, requested_count, skip_count;
> - void *addrs[256], *addrs2[256];
> - void *start, *end;
> - unsigned int i, j;
> -
> - memset(addrs, 0xcc, sizeof(addrs));
> - memset(addrs2, 0xcc, sizeof(addrs2));
> -
> - frame_count = RtlCaptureStackBackTrace(0, ARRAY_SIZE(addrs), addrs, NULL);
> - count = RtlWalkFrameChain(addrs2, ARRAY_SIZE(addrs2), 0);
> -
> - trace("frame_count %u.\n", frame_count);
> -
> - ok(frame_count > 1, "Got zero frame_count.\n");
> - ok(count == frame_count, "Got unexpected frame_count %u, count %u.\n", frame_count, count);
> -
> - start = test_walk_stack;
> - end = (BYTE *)start + 0x1000;
> - todo_wine_if(sizeof(void *) == 4)
> - ok(addrs[0] >= start && addrs[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
> -
>        start, end, addrs[0]);
> - todo_wine_if(sizeof(void *) == 4)
> - ok(addrs2[0] >= start && addrs2[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
> -
>        start, end, addrs2[0]);
> -
> - for (i = 1; i < frame_count; ++i)
> - {
> -
>    ok(addrs[i] == addrs2[i], "i %u, addresses do not match, %p vs %p.\n", i, addrs[i], addrs2[i]);
> - }
> - todo_wine ok(!!addrs[frame_count - 1], "Expected non-NULL last address.\n");
> -
> - for (requested_count = frame_count - 1; requested_count <= frame_count + 1; ++requested_count)
> - {
> -
>    for (i = 0; i < 32; ++i)
> -
>    {
> -
>        winetest_push_context("requested_count %u, i %u", requested_count, i);
> -
>        skip_count = (1 << i) >> 8;
> -
> -
>        if (i < RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT
> -
>                || i >= RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT + 8)
> -
>            expected = 0;
> -
>        else
> -
>            expected = min(frame_count, requested_count);
> -
> -
>        memset(addrs2, 0xcc, sizeof(addrs2));
> -
>        count = RtlWalkFrameChain(addrs2, requested_count, 1 << i);
> -
>        ok(count == expected, "Got unexpected frame_count %u, expected %u.\n", count, expected);
> -
> -
>        if (skip_count < count)
> -
>            count -= skip_count;
> -
>        else
> -
>            count = 0;
> -
> -
>        for (j = 0; j < count; ++j)
> -
>            ok( addrs2[j] != (void *)(ULONG_PTR)0xcccccccccccccccc, "Address is not set, j %u.\n", j );
> -
>        for (; j < ARRAY_SIZE(addrs2); ++j)
> -
>            ok( addrs2[j] == (void *)(ULONG_PTR)0xcccccccccccccccc, "Address is set, j %u.\n", j );
> -
> -
>        if (!count)
> -
>        {
> -
>            winetest_pop_context();
> -
>            continue;
> -
>        }
> -
> -
>        memset(addrs, 0xcc, sizeof(addrs));
> -
>        expected = skip_count > frame_count ? 0 : min(frame_count - skip_count, requested_count);
> -
>        count = RtlCaptureStackBackTrace(skip_count, requested_count, addrs, NULL);
> -
>        ok(count == expected, "Got unexpected frame_count %u, expected %u. i %u.\n", count, expected, i);
> -
> -
>        count = min(frame_count, requested_count) - skip_count;
> -
>        for (j = 0; j < count; ++j)
> -
>        {
> -
>            ok(addrs[j] == addrs2[j], "Addresses do not match, j %u, %p, %p.\n", j, addrs[j], addrs2[j]);
> -
>        }
> -
>        winetest_pop_context();
> -
>    }
> - }
>
> +}
> - START_TEST(exception)
> {
>     HMODULE hntdll = GetModuleHandleA("ntdll.dll");
>
> @@ -9339,5 +9421,6 @@ START_TEST(exception)
>       test_suspend_thread();
>       test_suspend_process();
>       test_unload_trace();
> - test_walk_stack();
>  VirtualFree(code_mem, 0, MEM_RELEASE);
> }
>
> diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
> index 0208e2f633f..b94e58ccb26 100644
> --- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
> +++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
> @@ -1300,7 +1300,7 @@
>   @ stdcall RtlVerifyVersionInfo(ptr long int64)
>   @ stdcall -arch=arm64,x86_64 RtlVirtualUnwind(long long long ptr ptr ptr ptr ptr)
>   @ stub RtlVolumeDeviceToDosName
> -@ stub RtlWalkFrameChain
> +@ stdcall RtlWalkFrameChain(ptr long long)
>   @ stdcall RtlWriteRegistryValue(long ptr ptr long ptr long)
>   @ stub RtlZeroHeap
>   @ stdcall RtlZeroMemory(ptr long)
> diff --git a/include/ddk/ntddk.h b/include/ddk/ntddk.h
> index 41ad3d721bd..ce558139aa6 100644
> --- a/include/ddk/ntddk.h
> +++ b/include/ddk/ntddk.h
> @@ -245,6 +245,8 @@ typedef EXPAND_STACK_CALLOUT *PEXPAND_STACK_CALLOUT;
>   typedef GUID UUID;
>   #endif
>
> +#define RTL_STACK_WALKING_MODE_FRAMES_TO_SKIP_SHIFT 8
> - NTSTATUS  WINAPI ExUuidCreate(UUID*);
> NTSTATUS  WINAPI IoQueryDeviceDescription(PINTERFACE_TYPE,PULONG,PCONFIGURATION_TYPE,PULONG,
>                                   PCONFIGURATION_TYPE,PULONG,PIO_QUERY_DEVICE_ROUTINE,PVOID);
>
> @@ -267,5 +269,6 @@ NTSTATUS  WINAPI PsSetCreateThreadNotifyRoutine(PCREATE_THREAD_NOTIFY_ROUTINE);
>   NTSTATUS  WINAPI PsSetLoadImageNotifyRoutine(PLOAD_IMAGE_NOTIFY_ROUTINE);
>   void      WINAPI RtlInitializeGenericTableAvl(PRTL_AVL_TABLE,PRTL_AVL_COMPARE_ROUTINE,PRTL_AVL_ALLOCATE_ROUTINE, PRTL_AVL_FREE_ROUTINE,void *);
>   void      WINAPI RtlInsertElementGenericTableAvl(PRTL_AVL_TABLE,void *,ULONG,BOOL*);
> +ULONG     WINAPI RtlWalkFrameChain(void **,ULONG,ULONG);
>
> #endif
> diff --git a/include/winnt.h b/include/winnt.h
> index ef731e29c52..eb1bd165720 100644
> --- a/include/winnt.h
> +++ b/include/winnt.h
> @@ -1840,6 +1840,8 @@ NTSYSAPI PVOID   WINAPI RtlVirtualUnwind(DWORD,ULONG_PTR,ULONG_PTR,RUNTIME_FUNCT
>
> #endif
>
> +NTSYSAPI USHORT  WINAPI RtlCaptureStackBackTrace(ULONG,ULONG,void **,ULONG *);
> - /*
> - Product types
> */

[PATCH v5 3/4] ntdll: Also capture first frame in back trace on x86.

[Paul Gofman]

Signed-off-by: Paul Gofman 
---
 dlls/ntdll/signal_i386.c     | 5 +----
 dlls/ntdll/tests/exception.c | 2 --
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
index ff3e837c784..b28684839b7 100644
--- a/dlls/ntdll/signal_i386.c
+++ b/dlls/ntdll/signal_i386.c
@@ -490,9 +490,6 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
     ULONG *frame;
     ULONG num_entries = 0;

-    ++skip;
-    ++count;
-
     RtlCaptureContext( &context );
     if (hash) *hash = 0;
     frame = (ULONG *)context.Ebp;
@@ -507,7 +504,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
         }
         frame = (ULONG *)*frame;
     }
-    return i ? i - 1 : 0;
+    return i;
 }

diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
index 6f3b08b5ea6..6e57c94703c 100644
--- a/dlls/ntdll/tests/exception.c
+++ b/dlls/ntdll/tests/exception.c
@@ -9134,10 +9134,8 @@ static void test_walk_stack(void)

start = test_walk_stack;
     end = (BYTE *)start + 0x1000;
-    todo_wine_if(sizeof(void *) == 4)
     ok(addrs[0] >= start && addrs[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
             start, end, addrs[0]);
-    todo_wine_if(sizeof(void *) == 4)
     ok(addrs2[0] >= start && addrs2[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
             start, end, addrs2[0]);

[PATCH v5 3/4] ntdll: Also capture first frame in back trace on x86.

[Marvin]

Hi,

While running your changed tests, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?

Full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=101234

Your paranoid android.

=== debiant2 (32 bit Chinese:China report) ===

ntdll:
virtual: Timeout

[PATCH v5 3/4] ntdll: Also capture first frame in back trace on x86.

[Giovanni Mascellani]

Signed-off-by: Giovanni Mascellani

On 03/11/21 11:41, Paul Gofman wrote:
> Signed-off-by: Paul Gofman
>
> dlls/ntdll/signal_i386.c     | 5 +----
>   dlls/ntdll/tests/exception.c | 2 --
>   2 files changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
> index ff3e837c784..b28684839b7 100644
> --- a/dlls/ntdll/signal_i386.c
> +++ b/dlls/ntdll/signal_i386.c
> @@ -490,9 +490,6 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>       ULONG *frame;
>       ULONG num_entries = 0;
> - ++skip;
> - ++count;
> -
> RtlCaptureContext( &context );
> if (hash) *hash = 0;
> frame = (ULONG *)context.Ebp;
>
> @@ -507,7 +504,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>           }
>           frame = (ULONG *)*frame;
>       }
> - return i ? i - 1 : 0;
> - return i;
> }
>
> diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
> index 6f3b08b5ea6..6e57c94703c 100644
> --- a/dlls/ntdll/tests/exception.c
> +++ b/dlls/ntdll/tests/exception.c
> @@ -9134,10 +9134,8 @@ static void test_walk_stack(void)
>   start = test_walk_stack;
>   end = (BYTE *)start + 0x1000;
> - todo_wine_if(sizeof(void *) == 4)
>  ok(addrs[0] >= start && addrs[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
>          start, end, addrs[0]);
> - todo_wine_if(sizeof(void *) == 4)
>  ok(addrs2[0] >= start && addrs2[0] < end, "Address is not inside test function, start %p, end %p, addr %p.\n",
>          start, end, addrs2[0]);

[PATCH v5 4/4] ntdll: Don't return the last NULL address when capturing frames.

[Paul Gofman]

Signed-off-by: Paul Gofman 
---
 dlls/ntdll/signal_i386.c     | 2 +-
 dlls/ntdll/signal_x86_64.c   | 2 +-
 dlls/ntdll/tests/exception.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
index b28684839b7..5613af4bce0 100644
--- a/dlls/ntdll/signal_i386.c
+++ b/dlls/ntdll/signal_i386.c
@@ -496,7 +496,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U

for (i = 0; i < count; i++)
     {
-        if (!is_valid_frame( frame )) break;
+        if (!is_valid_frame( frame ) || !frame[1]) break;
         if (i >= skip)
         {
             buffer[num_entries++] = (void *)frame[1];
diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
index 4a9c7d4b9ff..0b6bbc09ed0 100644
--- a/dlls/ntdll/signal_x86_64.c
+++ b/dlls/ntdll/signal_x86_64.c
@@ -1516,7 +1516,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
         status = virtual_unwind( UNW_FLAG_NHANDLER, &dispatch, &context );
         if (status != STATUS_SUCCESS) break;

-        if (!dispatch.EstablisherFrame) break;
+        if (!dispatch.EstablisherFrame || !context.Rip) break;

if ((dispatch.EstablisherFrame & 7) ||
             dispatch.EstablisherFrame < (ULONG64)NtCurrentTeb()->Tib.StackLimit ||
diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
index 6e57c94703c..60f5472793f 100644
--- a/dlls/ntdll/tests/exception.c
+++ b/dlls/ntdll/tests/exception.c
@@ -9143,7 +9143,7 @@ static void test_walk_stack(void)
     {
         ok(addrs[i] == addrs2[i], "i %u, addresses do not match, %p vs %p.\n", i, addrs[i], addrs2[i]);
     }
-    todo_wine ok(!!addrs[frame_count - 1], "Expected non-NULL last address.\n");
+    ok(!!addrs[frame_count - 1], "Expected non-NULL last address.\n");

for (requested_count = frame_count - 1; requested_count <= frame_count + 1; ++requested_count)
     {

[PATCH v5 4/4] ntdll: Don't return the last NULL address when capturing frames.

[Giovanni Mascellani]

Signed-off-by: Giovanni Mascellani

On 03/11/21 11:41, Paul Gofman wrote:
> Signed-off-by: Paul Gofman
>
> dlls/ntdll/signal_i386.c     | 2 +-
>   dlls/ntdll/signal_x86_64.c   | 2 +-
>   dlls/ntdll/tests/exception.c | 2 +-
>   3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
> index b28684839b7..5613af4bce0 100644
> --- a/dlls/ntdll/signal_i386.c
> +++ b/dlls/ntdll/signal_i386.c
> @@ -496,7 +496,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>   for (i = 0; i < count; i++)
>   {
> -
>    if (!is_valid_frame( frame )) break;
> -
>    if (!is_valid_frame( frame ) || !frame[1]) break;
>     if (i >= skip)
>     {
>         buffer[num_entries++] = (void *)frame[1];
>
> diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
> index 4a9c7d4b9ff..0b6bbc09ed0 100644
> --- a/dlls/ntdll/signal_x86_64.c
> +++ b/dlls/ntdll/signal_x86_64.c
> @@ -1516,7 +1516,7 @@ ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, U
>           status = virtual_unwind( UNW_FLAG_NHANDLER, &dispatch, &context );
>           if (status != STATUS_SUCCESS) break;
> -
>    if (!dispatch.EstablisherFrame) break;
> -
>    if (!dispatch.EstablisherFrame || !context.Rip) break;
>
>     if ((dispatch.EstablisherFrame & 7) ||
>         dispatch.EstablisherFrame < (ULONG64)NtCurrentTeb()->Tib.StackLimit ||
>
> diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
> index 6e57c94703c..60f5472793f 100644
> --- a/dlls/ntdll/tests/exception.c
> +++ b/dlls/ntdll/tests/exception.c
> @@ -9143,7 +9143,7 @@ static void test_walk_stack(void)
>       {
>           ok(addrs[i] == addrs2[i], "i %u, addresses do not match, %p vs %p.\n", i, addrs[i], addrs2[i]);
>       }
> - todo_wine ok(!!addrs[frame_count - 1], "Expected non-NULL last address.\n");
> -
>
> ok(!!addrs[frame_count - 1], "Expected non-NULL last address.\n");
>
> for (requested_count = frame_count - 1; requested_count <= frame_count + 1; ++requested_count)
>  {

[Giovanni Mascellani]

Signed-off-by: Giovanni Mascellani

On 03/11/21 11:41, Paul Gofman wrote:
> Signed-off-by: Paul Gofman
>
> v5:
>      - fix max USHORT value.
>
> dlls/ntdll/exception.c     | 12 ++++++++++++
>   dlls/ntdll/ntdll_misc.h    |  2 ++
>   dlls/ntdll/signal_arm.c    |  4 ++--
>   dlls/ntdll/signal_arm64.c  |  4 ++--
>   dlls/ntdll/signal_i386.c   |  6 ++++--
>   dlls/ntdll/signal_x86_64.c | 10 ++++++----
>   6 files changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/dlls/ntdll/exception.c b/dlls/ntdll/exception.c
> index c3714e8369b..e956d8a722f 100644
> --- a/dlls/ntdll/exception.c
> +++ b/dlls/ntdll/exception.c
> @@ -1065,3 +1065,15 @@ NTSTATUS WINAPI RtlCopyExtendedContext( CONTEXT_EX *dst, ULONG context_flags, CO
>           memcpy( &dst_xs->YmmContext, &src_xs->YmmContext, sizeof(dst_xs->YmmContext) );
>       return STATUS_SUCCESS;
>   }
> -
> -
>
> +/*************************************************************************
> -
> -
> RtlCaptureStackBackTrace (NTDLL.@)
> - */
>
> +USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
> +{
> - ULONG ret;
> -
> - ret = capture_stack_back_trace( skip, count, buffer, hash );
> - return min( ret, (USHORT)~0 );
>
> +}
> diff --git a/dlls/ntdll/ntdll_misc.h b/dlls/ntdll/ntdll_misc.h
> index 34af6b780cf..31a33b04dbf 100644
> --- a/dlls/ntdll/ntdll_misc.h
> +++ b/dlls/ntdll/ntdll_misc.h
> @@ -57,6 +57,8 @@ extern void WINAPI KiUserCallbackDispatcher(ULONG,void*,ULONG) DECLSPEC_HIDDEN;
>   extern RUNTIME_FUNCTION *lookup_function_info( ULONG_PTR pc, ULONG_PTR *base, LDR_DATA_TABLE_ENTRY **module ) DECLSPEC_HIDDEN;
>   #endif
>
> +extern ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash ) DECLSPEC_HIDDEN;
> - /* debug helpers */
> extern LPCSTR debugstr_us( const UNICODE_STRING *str ) DECLSPEC_HIDDEN;
> extern const char *debugstr_exception_code( DWORD code ) DECLSPEC_HIDDEN;
>
> diff --git a/dlls/ntdll/signal_arm.c b/dlls/ntdll/signal_arm.c
> index 0ef210a0331..241ddc3ce70 100644
> --- a/dlls/ntdll/signal_arm.c
> +++ b/dlls/ntdll/signal_arm.c
> @@ -300,9 +300,9 @@ __ASM_STDCALL_FUNC( RtlRaiseException, 4,
>                       "bl " __ASM_NAME("RtlRaiseStatus") )
>
> /*************************************************************************
> -
> -
>         RtlCaptureStackBackTrace (NTDLL.@)
> -
> -
>         capture_stack_back_trace
> */
>
> -USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
> +ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
>   {
>       FIXME( "(%d, %d, %p, %p) stub!\n", skip, count, buffer, hash );
>       return 0;
> diff --git a/dlls/ntdll/signal_arm64.c b/dlls/ntdll/signal_arm64.c
> index 290639b676b..1bffbe7efe9 100644
> --- a/dlls/ntdll/signal_arm64.c
> +++ b/dlls/ntdll/signal_arm64.c
> @@ -1473,9 +1473,9 @@ __ASM_STDCALL_FUNC( RtlRaiseException, 4,
>                      "bl " __ASM_NAME("RtlRaiseStatus") /* does not return */ );
>
> /*************************************************************************
> -
> -
>         RtlCaptureStackBackTrace (NTDLL.@)
> -
> -
>         capture_stack_back_trace
> */
>
> -USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
> +ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
>   {
>       FIXME( "(%d, %d, %p, %p) stub!\n", skip, count, buffer, hash );
>       return 0;
> diff --git a/dlls/ntdll/signal_i386.c b/dlls/ntdll/signal_i386.c
> index 14971032ce6..26150ce877b 100644
> --- a/dlls/ntdll/signal_i386.c
> +++ b/dlls/ntdll/signal_i386.c
> @@ -481,14 +481,16 @@ __ASM_STDCALL_FUNC( RtlRaiseException, 4,
>
> /*************************************************************************
> -
> -
> RtlCaptureStackBackTrace (NTDLL.@)
> -
> -
> capture_stack_back_trace
> */
>
> -USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
> +ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
>   {
>       CONTEXT context;
>       ULONG i;
>       ULONG *frame;
> - ++skip;
> -
> RtlCaptureContext( &context );
> if (hash) *hash = 0;
> frame = (ULONG *)context.Ebp;
>
> diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
> index ef32eba68b7..5f3c8f70208 100644
> --- a/dlls/ntdll/signal_x86_64.c
> +++ b/dlls/ntdll/signal_x86_64.c
> @@ -1490,19 +1490,21 @@ static inline ULONG hash_pointers( void **ptrs, ULONG count )
>
> /*************************************************************************
> -
> -
> RtlCaptureStackBackTrace (NTDLL.@)
> -
> -
> capture_stack_back_trace
> */
>
> -USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
> +ULONG WINAPI capture_stack_back_trace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
>   {
>       UNWIND_HISTORY_TABLE table;
>       DISPATCHER_CONTEXT dispatch;
>       CONTEXT context;
>       NTSTATUS status;
>       ULONG i;
> - USHORT num_entries = 0;
> -
>
> ULONG num_entries = 0;
>
> TRACE( "(%u, %u, %p, %p)\n", skip, count, buffer, hash );
> -
>
> ++skip;
> -
> RtlCaptureContext( &context );
> dispatch.TargetIp      = 0;
> dispatch.ContextRecord = &context;
>
> @@ -1529,7 +1531,7 @@ USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer,
>           if (i >= skip) buffer[num_entries++] = (void *)context.Rip;
>       }
>       if (hash && num_entries > 0) *hash = hash_pointers( buffer, num_entries );
> - TRACE( "captured %hu frames\n", num_entries );
> - TRACE( "captured %u frames\n", num_entries );
>  return num_entries;
> }