ntdll: Share RtlCaptureStackBackTrace implementation across platforms.

dlls/ntdll/exception.c

@@ -510,6 +510,27 @@ __ASM_GLOBAL_IMPORT(IsBadStringPtrA)
 __ASM_GLOBAL_IMPORT(IsBadStringPtrW)
 #endif
 
+
+/*************************************************************************
+ *		RtlCaptureStackBackTrace (NTDLL.@)
+ */
+USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, void **buffer, ULONG *hash_ret )
+{
+    ULONG i, ret, hash;
+
+    TRACE( "(%lu, %lu, %p, %p)\n", skip, count, buffer, hash_ret );
+
+    skip++;  /* skip our own frame */
+    ret = RtlWalkFrameChain( buffer, count + skip, skip << 8 );
+    if (hash_ret)
+    {
+        for (i = hash = 0; i < ret; i++) hash += (ULONG_PTR)buffer[i];
+        *hash_ret = hash;
+    }
+    return ret;
+}
+
+
 /**********************************************************************
  *              RtlGetEnabledExtendedFeatures   (NTDLL.@)
  */

dlls/ntdll/signal_arm.c

@@ -737,15 +737,6 @@ __ASM_GLOBAL_FUNC( RtlRaiseException,
                     "bl " __ASM_NAME("NtRaiseException") "\n\t"
                     "bl " __ASM_NAME("RtlRaiseStatus") )
 
-/*************************************************************************
- *             RtlCaptureStackBackTrace (NTDLL.@)
- */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
-{
-    FIXME( "(%ld, %ld, %p, %p) stub!\n", skip, count, buffer, hash );
-    return 0;
-}
-
 
 /***********************************************************************
  *           _setjmp (NTDLL.@)

dlls/ntdll/signal_arm64.c

@@ -849,15 +849,6 @@ __ASM_GLOBAL_FUNC( RtlRaiseException,
                    "bl " __ASM_NAME("NtRaiseException") "\n\t"
                    "bl " __ASM_NAME("RtlRaiseStatus") /* does not return */ );
 
-/*************************************************************************
- *             RtlCaptureStackBackTrace (NTDLL.@)
- */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
-{
-    FIXME( "(%ld, %ld, %p, %p) stub!\n", skip, count, buffer, hash );
-    return 0;
-}
-
 
 /***********************************************************************
  *           _setjmpex (NTDLL.@)

dlls/ntdll/signal_arm64ec.c

@@ -2040,16 +2040,6 @@ EXCEPTION_DISPOSITION WINAPI __C_specific_handler( EXCEPTION_RECORD *rec,
 }
 
 
-/*************************************************************************
- *		RtlCaptureStackBackTrace (NTDLL.@)
- */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
-{
-    FIXME( "not implemented\n" );
-    return 0;
-}
-
-
 static int code_match( BYTE *code, const BYTE *seq, size_t len )
 {
     for ( ; len; len--, code++, seq++) if (*seq && *code != *seq) return 0;

dlls/ntdll/signal_i386.c

@@ -474,36 +474,6 @@ ULONG WINAPI RtlWalkFrameChain( void **buffer, ULONG count, ULONG flags )
 }
 
 
-/*************************************************************************
- *		RtlCaptureStackBackTrace (NTDLL.@)
- */
-USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
-{
-    CONTEXT context;
-    ULONG i;
-    ULONG *frame;
-
-    RtlCaptureContext( &context );
-    if (hash) *hash = 0;
-    frame = (ULONG *)context.Ebp;
-
-    while (skip--)
-    {
-        if (!is_valid_frame( (ULONG_PTR)frame )) return 0;
-        frame = (ULONG *)*frame;
-    }
-
-    for (i = 0; i < count; i++)
-    {
-        if (!is_valid_frame( (ULONG_PTR)frame )) break;
-        buffer[i] = (void *)frame[1];
-        if (hash) *hash += frame[1];
-        frame = (ULONG *)*frame;
-    }
-    return i;
-}
-
-
 /***********************************************************************
  *           RtlUserThreadStart (NTDLL.@)
  */

dlls/ntdll/signal_x86_64.c

@@ -988,70 +988,6 @@ ULONG WINAPI RtlWalkFrameChain( void **buffer, ULONG count, ULONG flags )
 }
 
 
-static inline ULONG hash_pointers( void **ptrs, ULONG count )
-{
-    /* Based on MurmurHash2, which is in the public domain */
-    static const ULONG m = 0x5bd1e995;
-    static const ULONG r = 24;
-    ULONG hash = count * sizeof(void*);
-    for (; count > 0; ptrs++, count--)
-    {
-        ULONG_PTR data = (ULONG_PTR)*ptrs;
-        ULONG k1 = (ULONG)(data & 0xffffffff), k2 = (ULONG)(data >> 32);
-        k1 *= m;
-        k1 = (k1 ^ (k1 >> r)) * m;
-        k2 *= m;
-        k2 = (k2 ^ (k2 >> r)) * m;
-        hash = (((hash * m) ^ k1) * m) ^ k2;
-    }
-    hash = (hash ^ (hash >> 13)) * m;
-    return hash ^ (hash >> 15);
-}
-
-
-/*************************************************************************
- *		RtlCaptureStackBackTrace (NTDLL.@)
- */
-USHORT WINAPI RtlCaptureStackBackTrace( 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;
-
-    TRACE( "(%lu, %lu, %p, %p)\n", skip, count, buffer, hash );
-
-    RtlCaptureContext( &context );
-    dispatch.TargetIp      = 0;
-    dispatch.ContextRecord = &context;
-    dispatch.HistoryTable  = &table;
-    if (hash) *hash = 0;
-    for (i = 0; i < skip + count; i++)
-    {
-        status = virtual_unwind( UNW_FLAG_NHANDLER, &dispatch, &context );
-        if (status != STATUS_SUCCESS) return i;
-
-        if (!dispatch.EstablisherFrame) break;
-
-        if (!is_valid_frame( dispatch.EstablisherFrame ))
-        {
-            ERR( "invalid frame %p (%p-%p)\n", (void *)dispatch.EstablisherFrame,
-                 NtCurrentTeb()->Tib.StackLimit, NtCurrentTeb()->Tib.StackBase );
-            break;
-        }
-
-        if (context.Rsp == (ULONG64)NtCurrentTeb()->Tib.StackBase) break;
-
-        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 );
-    return num_entries;
-}
-
-
 /***********************************************************************
  *           _setjmp (NTDLL.@)
  *           _setjmpex (NTDLL.@)

dlls/ntdll/tests/exception.c

@@ -10287,6 +10287,30 @@ static void test_set_live_context(void)
 }
 #endif
 
+static void test_backtrace(void)
+{
+    void *buffer[1024];
+    WCHAR *p, name[MAX_PATH];
+    void *module;
+    ULONG hash, hash_expect;
+    int i, count = RtlCaptureStackBackTrace( 0, 1024, buffer, &hash );
+
+    ok( count > 1, "got %u entries\n", count );
+    for (i = hash_expect = 0; i < count; i++) hash_expect += (ULONG_PTR)buffer[i];
+    ok( hash == hash_expect, "hash mismatch %lx / %lx\n", hash, hash_expect );
+    RtlPcToFileHeader( buffer[0], &module );
+    ok( module == GetModuleHandleA(0), "wrong module %p/%p for %p\n",
+        module, GetModuleHandleA(0), buffer[0]);
+
+    if (count && !buffer[count - 1]) count--;  /* win11 32-bit */
+    RtlPcToFileHeader( buffer[count - 1], &module );
+    GetModuleFileNameW( module, name, sizeof(name) );
+    if ((p = wcsrchr( name, '\\' ))) p++;
+    else p = name;
+    ok( !wcsicmp( p, L"ntdll.dll" ), "wrong module %p %s for frame %u %p\n",
+        module, debugstr_w(name), count - 1, buffer[count - 1] );
+}
+
 START_TEST(exception)
 {
     HMODULE hkernel32 = GetModuleHandleA("kernel32.dll");
@@ -10562,5 +10586,6 @@ START_TEST(exception)
     test_suspend_thread();
     test_suspend_process();
     test_unload_trace();
+    test_backtrace();
     VirtualFree(code_mem, 0, MEM_RELEASE);
 }