From bd6ecbe48ada79bb14cbb30ef8318495b5237790 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Martin=20Storsj=C3=B6?= Date: Tue, 8 Sep 2020 15:21:51 +0300 Subject: [PATCH] libgcc: Expose the instruction pointer and stack pointer in SEH _Unwind_Backtrace MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Previously, the SEH version of _Unwind_Backtrace did unwind the stack and call the provided callback function as intended, but there was little the caller could do within the callback to actually get any info about that particular level in the unwind. Set the ra and cfa pointers, which are used by _Unwind_GetIP and _Unwind_GetCFA, to allow using these functions from the callacb to inspect the state at each stack frame. 2020-09-08 Martin Storsjö libgcc/ * unwind-seh.c (_Unwind_Backtrace): Set the ra and cfa pointers before calling the callback. --- libgcc/unwind-seh.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libgcc/unwind-seh.c b/libgcc/unwind-seh.c index 1a70180cfaa..275d782903a 100644 --- a/libgcc/unwind-seh.c +++ b/libgcc/unwind-seh.c @@ -466,6 +466,11 @@ _Unwind_Backtrace(_Unwind_Trace_Fn trace, &gcc_context.disp->HandlerData, &gcc_context.disp->EstablisherFrame, NULL); + /* Set values that the callback can inspect via _Unwind_GetIP + * and _Unwind_GetCFA. */ + gcc_context.ra = ms_context.Rip; + gcc_context.cfa = ms_context.Rsp; + /* Call trace function. */ if (trace (&gcc_context, trace_argument) != _URC_NO_REASON) return _URC_FATAL_PHASE1_ERROR; -- 2.30.2