Hi! On Thu, Nov 11, 2021 at 11:40:10AM -0300, Raphael Moreira Zinsly wrote: > Changes since v1: > - Removed -Wmissing-prototypes fix. > - Fixed formatting of Changelog and patch. > > --->8--- > > At the end of the backtrace stream _Unwind_Find_FDE() may not be able > to find the frame unwind info and will later call the backtrace fallback > instead of finishing. This occurs when using an old libc on ppc64 due to > dl_iterate_phdr() not being able to set the fde in the last trace. > When this occurs the cfa of the trace will be behind of context's cfa. > Also, libgo’s probestackmaps() calls the backtrace with a null pointer > and can get to the backchain fallback with the same problem, in this case > we are only interested in find a stack map, we don't need nor can do a > backchain. > _Unwind_ForcedUnwind_Phase2() can hit the same issue as it uses > uw_frame_state_for(), so we need to treat _URC_NORMAL_STOP. > > libgcc/ChangeLog: > > * config/rs6000/linux-unwind.h (ppc_backchain_fallback): Check if > it's > called with a null argument or at the end of the backtrace and return. > * unwind.inc (_Unwind_ForcedUnwind_Phase2): Treat _URC_NORMAL_STOP.
Committed, thanks! Please note the changelog formatting fixes I had to do, for later patches :-) Segher
