On Thu, Apr 11, 2013 at 1:33 PM, Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx> wrote: > > On Apr 5, 2013, at 2:53 AM, Bhushan Bharat-R65777 wrote: > >> Hi Kumar/Benh, >> >> After further looking into the code I think that if we correct the vector range below in DebugDebug handler then we do not need the change I provided in this patch. >> >> Here is the snapshot for 32 bit (head_booke.h, same will be true for 64 bit): >> >> #define DEBUG_DEBUG_EXCEPTION \ >> START_EXCEPTION(DebugDebug); \ >> DEBUG_EXCEPTION_PROLOG; \ >> \ >> /* \ >> * If there is a single step or branch-taken exception in an \ >> * exception entry sequence, it was probably meant to apply to \ >> * the code where the exception occurred (since exception entry \ >> * doesn't turn off DE automatically). We simulate the effect \ >> * of turning off DE on entry to an exception handler by turning \ >> * off DE in the DSRR1 value and clearing the debug status. \ >> */ \ >> mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \ >> andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \ >> beq+ 2f; \ >> \ >> lis r10,KERNELBASE@h; /* check if exception in vectors */ \ >> ori r10,r10,KERNELBASE@l; \ >> cmplw r12,r10; \ >> blt+ 2f; /* addr below exception vectors */ \ >> \ >> lis r10,DebugDebug@h; \ >> ori r10,r10,DebugDebug@l; \ >> >> ^^^^ >> Here we assume all exception vector ends at DebugDebug, which is not correct. >> We probably should get proper end by using some start_vector and end_vector lebels >> or at least use end at Ehvpriv (which is last defined in head_fsl_booke.S for PowerPC. Is that correct? >> >> >> cmplw r12,r10; \ >> bgt+ 2f; /* addr above exception vectors */ \ >> >> Thanks >> -Bharat > > I talked to Stuart and this general approach is good. Just make sure to update both head_44x.S and head_fsl_booke.S. Plus do this for both DEBUG_CRIT_EXCEPTION & DEBUG_DEBUG_EXCEPTION Also, it looks like 64-bit already handles this properly with symbols identifying the start/end of the vectors (exceptions-64e.S). Stuart -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
