Re: [PATCH] ntdll: Implement RtlCaptureStackBackTrace() for x86_64.

[Zebediah Figura]

For what it's worth:

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=40868
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=47101

On 7/31/19 4:57 PM, Chip Davis wrote:
> Signed-off-by: Chip Davis
>
> dlls/ntdll/signal_x86_64.c | 111 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 109 insertions(+), 2 deletions(-)
>
> diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
> index b024de76421..94412302152 100644
> --- a/dlls/ntdll/signal_x86_64.c
> +++ b/dlls/ntdll/signal_x86_64.c
> @@ -4436,13 +4436,120 @@ __ASM_GLOBAL_FUNC( RtlRaiseException,
>                      "call " __ASM_NAME("RtlRaiseStatus") /* does not return */ );
>
> +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 )
> {
> - FIXME( "(%d, %d, %p, %p) stub!\n", skip, count, buffer, hash );
> - return 0;
> - UNWIND_HISTORY_TABLE table;
> - DISPATCHER_CONTEXT dispatch;
> - CONTEXT context;
> - LDR_MODULE *module;
> - NTSTATUS status;
> - ULONG i;
> - USHORT num_entries = 0;
> -
> - TRACE( "(%u, %u, %p, %p)", 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++)
> - {
> -
>    /* FIXME: should use the history table to make things faster */
> -
> -
>    dispatch.ImageBase = 0;
> -
>    dispatch.ControlPc = context.Rip;
> -
>    dispatch.ScopeIndex = 0;
> -
> -
>    /* first look for PE exception information */
> -
> -
>    if ((dispatch.FunctionEntry = lookup_function_info( dispatch.ControlPc, &dispatch.ImageBase, &module )))
> -
>    {
> -
>        RtlVirtualUnwind( UNW_FLAG_NHANDLER, dispatch.ImageBase, dispatch.ControlPc,
> -
>                          dispatch.FunctionEntry, &context, &dispatch.HandlerData,
> -
>                          &dispatch.EstablisherFrame, NULL );
> -
>        goto unwind_done;
> -
>    }
> -
> -
>    /* then look for host system exception information */
> -
> -
>    if (!module || (module->Flags & LDR_WINE_INTERNAL))
> -
>    {
> -
>        BOOL got_info = FALSE;
> -
>        struct dwarf_eh_bases bases;
> -
>        const struct dwarf_fde *fde = _Unwind_Find_FDE( (void *)(dispatch.ControlPc - 1), &bases );
> -
> -
>        if (fde)
> -
>        {
> -
>            status = dwarf_virtual_unwind( dispatch.ControlPc, &dispatch.EstablisherFrame, &context,
> -
>                                           fde, &bases, &dispatch.LanguageHandler, &dispatch.HandlerData );
> -
>            if (status != STATUS_SUCCESS) return status;
> -
>            got_info = TRUE;
> -
>        }
>
> +#ifdef HAVE_LIBUNWIND_H
> -
>        else
> -
>        {
> -
>            status = libunwind_virtual_unwind( dispatch.ControlPc, &got_info, &dispatch.EstablisherFrame, &context,
> -
>                                               &dispatch.LanguageHandler, &dispatch.HandlerData );
> -
>            if (status != STATUS_SUCCESS) return i;
> -
>        }
>
> +#endif
> -
> -
>        if (got_info)
> -
>        {
> -
>            dispatch.FunctionEntry = NULL;
> -
>            goto unwind_done;
> -
>        }
> -
>    }
> -
>    else WARN( "exception data not found in %s\n", debugstr_w(module->BaseDllName.Buffer) );
> -
> -
>    context.Rip = *(ULONG64 *)context.Rsp;
> -
>    context.Rsp = context.Rsp + sizeof(ULONG64);
> -
>    dispatch.EstablisherFrame = context.Rsp;
> -
> - unwind_done:
> -
>    if (!dispatch.EstablisherFrame) break;
> -
> -
>    if ((dispatch.EstablisherFrame & 7) ||
> -
>        dispatch.EstablisherFrame < (ULONG64)NtCurrentTeb()->Tib.StackLimit ||
> -
>        dispatch.EstablisherFrame > (ULONG64)NtCurrentTeb()->Tib.StackBase)
> -
>    {
> -
>        ERR( "invalid frame %lx (%p-%p)\n", 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;
> }