----- Original Message ----- > On Fri, Dec 18, 2015 at 11:55:07PM +0100, Andrew Jones wrote: > > compat user mode prstatus already just works, almost. This missing > > pieces are that pt_regs->sp and pt_regs->fp are not in their usual > > locations. We need to pull them out of their architecturally mapped > > general purpose registers. > > --- > > arm64.c | 42 ++++++++++++++++++++++++++++++++++-------- > > 1 file changed, 34 insertions(+), 8 deletions(-) > > > > diff --git a/arm64.c b/arm64.c > > index 183e768498fe8..3a82d20cdd465 100644 > > --- a/arm64.c > > +++ b/arm64.c > > @@ -993,6 +993,25 @@ arm64_stackframe_init(void) > > #define PSR_MODE_EL3h 0x0000000d > > #define PSR_MODE_MASK 0x0000000f > > > > +/* Architecturally defined mapping between AArch32 and AArch64 registers > > */ > > +#define compat_usr(x) regs[(x)] > > +#define compat_fp regs[11] > > +#define compat_sp regs[13] > > +#define compat_lr regs[14] > > + > > +#define user_mode(ptregs) \ > > + (((ptregs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t) > > + > > +#define compat_user_mode(ptregs) \ > > + (((ptregs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \ > > + (PSR_MODE32_BIT | PSR_MODE_EL0t)) > > + > > +#define user_stack_pointer(ptregs) \ > > + (!compat_user_mode(ptregs) ? (ptregs)->sp : (ptregs)->compat_sp) > > + > > +#define user_frame_pointer(ptregs) \ > > + (!compat_user_mode(ptregs) ? (ptregs)->regs[29] : (ptregs)->compat_fp) > > + > > static int > > arm64_is_kernel_exception_frame(struct bt_info *bt, ulong stkptr) > > { > > @@ -1340,21 +1359,28 @@ arm64_get_dumpfile_stackframe(struct bt_info *bt, > > struct arm64_stackframe *frame > > struct machine_specific *ms = machdep->machspec; > > struct arm64_pt_regs *ptregs; > > > > - if (!ms->panic_task_regs || > > - (!ms->panic_task_regs[bt->tc->processor].sp && > > - !ms->panic_task_regs[bt->tc->processor].pc)) { > > + if (!ms->panic_task_regs || !ms->panic_task_regs[bt->tc->processor].pc) { > > Hi Dave, > > I'm having second thoughts about keeping the > !ms->panic_task_regs[bt->tc->processor].pc test. pc being zero sounds > like a good reason to crash, or a potential status of a pc after a crash. > I don't think we should be too hasty to reject the rest of the registers. > Is there anyway we can relax the sanity checking, but still keep the crash > utility happy? > > Thanks, > drew Hi Drew, OK, refresh my mind -- I'm not sure what the reasoning behind the patch snippet above? Originally the code checked whether *both* the sp and pc are NULL, and if so, returns BT_REGS_NOT_FOUD (which seems fair to me). Your patch stops checking for a NULL sp, but still checks for a NULL pc. In this QEMU dump, the patch doesn't really accomplish anything, since both incoming registers are non-NULL (albeit with a sp pointing to 16-bytes below the top of the stack). It seems like we could leave it as-is. Dave > > bt->flags |= BT_REGS_NOT_FOUND; > > return FALSE; > > } > > > > ptregs = &ms->panic_task_regs[bt->tc->processor]; > > - frame->sp = ptregs->sp; > > frame->pc = ptregs->pc; > > - frame->fp = ptregs->regs[29]; > > - > > - if (!is_kernel_text(frame->pc) && > > - in_user_stack(bt->tc->task, frame->sp)) > > + if (user_mode(ptregs)) { > > + frame->sp = user_stack_pointer(ptregs); > > + frame->fp = user_frame_pointer(ptregs); > > + if (is_kernel_text(frame->pc) || > > + !in_user_stack(bt->tc->task, frame->sp)) { > > + error(WARNING, "Corrupt prstatus? pstate=0x%lx, but no user frame > > found\n", > > + ptregs->pstate); > > + bt->flags |= BT_REGS_NOT_FOUND; > > + return FALSE; > > + } > > bt->flags |= BT_USER_SPACE; > > + } else { > > + frame->sp = ptregs->sp; > > + frame->fp = ptregs->regs[29]; > > + } > > > > if (arm64_in_kdump_text(bt, frame)) > > bt->flags |= BT_KDUMP_ADJUST; > > -- > > 1.8.3.1 > > > > -- > > Crash-utility mailing list > > Crash-utility@xxxxxxxxxx > > https://www.redhat.com/mailman/listinfo/crash-utility > > -- > Crash-utility mailing list > Crash-utility@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/crash-utility > -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility