On Tue, 17 Sep 2019 at 14:08, Christophe Lyon <christophe.l...@st.com> wrote: > > On 17/09/2019 13:38, Wilco Dijkstra wrote: > > Hi Christophe, > > > > Can you explain this in more detail - it doesn't make sense to me to force > > the > > Thumb bit during unwinding since it should already be correct, even on a > > Thumb-only CPU. Perhaps the kernel code that pushes an incorrect address on > > the stack could be fixed instead? > > > >> Without this, when we are unwinding across a signal frame we can jump > >> to an even address which leads to an exception. > >> > >> This is needed in __gnu_persnality_sigframe_fdpic() when restoring the > >> PC from the signal frame since the PC saved by the kernel has the LSB > >> bit set to zero. > > > > Wilco > > . > > > > Indeed, I've noticed the problem mentioned by Matthew since I committed that > patch. > > I was about to propose a fix, replacing #if (__thumb__) with #if > (!__ARM_ARCH_ISA_ARM), but you are right: maybe the kernel code should be > fixed instead. > > So far I haven't managed to reproduce a failure in FDPIC mode without this > patch though... > > Thanks and sorry for the breakage. >
I'm having problems with the board I use for testing, so I propose to revert that patch until I have a better description of the problem it fixed. OK? Christophe > Christophe >
