Ian Lance Taylor wrote: > Andrew Pinski <pins...@gmail.com> writes: > > On Tue, Mar 22, 2011 at 9:42 AM, Ian Lance Taylor <i...@google.com> wrote: > >> > >> Any target on which _Unwind_Word is larger than void * is broken today, > >> so I don't think we need to care about that case. > > > > So a MIPS N32 is broken? Lots of people use that target already and > > nothing like this has showed up yet. > > That is a fair question. It does seem to me that it must be broken in > some cases. _Unwind_GetGRPtr will return &context->reg[index], which is > a void** cast to void*. We will then pass that to _Unwind_SetGRPtr. If > we later call _Unwind_SetGR on that register, it will write a value of > size _Unwind_Word through that pointer. Similarly if we call > _Unwind_GetGR, it will read a value of size _Unwind_Word. In both > cases, we will be accessing a 4-byte field as an 8-byte value. > > If MIPS N32 works today, then something must be ensuring that that > sequence can never occur, or that for some reason it never matters.
Well, the whole problem only occurs when using the "by value" mechanism, which is only triggered by DW_CFA_val_... CFI statements, which are new in Dwarf-3 and seem to be very rarely used: they are apparently never generated by GCC, and the only files I could find in current glibc that create such CFI by hand are Intel-specific. Bye, Ulrich -- Dr. Ulrich Weigand GNU Toolchain for Linux on System z and Cell BE ulrich.weig...@de.ibm.com
