Re: [Crash-utility] arm64: "bt -f" output

Hi Takahiro, To address my concerns about your patch, I added a few additional changes and attached it to this email. The changes are: (1) Prevent the stack dump "below" the #0 level. Yes, the stack data region is contained within the incoming frame parameters, but it's ugly and we really don't care to see what's before the #0 crash_kexec and crash_save_cpu #0 frames. (2) Fill in the missing stack dump at the top of the process stack, up to, but not including the user-space exception frame. (3) Instead of showing the fp of 0 in the top-most frame's stack address, fill it in with the address of the user-space exception frame. Note that there is no dump of the stack containing the user-space exception frame, but the register dump itself should suffice.

If you can live with the display, I'll clean up the patch, and maybe add the stack-layout diagram from your last post into a comment. It was quite helpful, especially in comparison to the x86_64 model, which is what I was mistakenly using as a guide. Thanks, Dave

diff --git a/arm64.c b/arm64.c index 86ec348..3b29ef4 100644 --- a/arm64.c +++ b/arm64.c @@ -1407,13 +1407,14 @@ arm64_print_stackframe_entry(struct bt_info *bt, int level, struct arm64_stackfr value_to_symstr(frame->pc, buf, bt->radix); } - if (bt->flags & BT_FULL) { - arm64_display_full_frame(bt, frame->sp); - bt->frameptr = frame->sp; + if ((bt->flags & BT_FULL) && level) { + arm64_display_full_frame(bt, frame->fp); + bt->frameptr = frame->fp; } fprintf(ofp, "%s#%d [%8lx] %s at %lx", level < 10 ? " " : "", level, - frame->sp, name_plus_offset ? name_plus_offset : name, frame->pc); +// frame->fp, name_plus_offset ? name_plus_offset : name, frame->pc); + frame->fp ? frame->fp : bt->stacktop - USER_EFRAME_OFFSET, name_plus_offset ? name_plus_offset : name, frame->pc); if (BT_REFERENCE_CHECK(bt)) arm64_do_bt_reference_check(bt, frame->pc, name); @@ -1447,8 +1448,12 @@ arm64_display_full_frame(struct bt_info *bt, ulong sp) if (bt->frameptr == sp) return; - if (!INSTACK(sp, bt) || !INSTACK(bt->frameptr, bt)) - return; + if (!INSTACK(sp, bt) || !INSTACK(bt->frameptr, bt)) { + if (sp == 0) + sp = bt->stacktop - USER_EFRAME_OFFSET; + else + return; + } words = (sp - bt->frameptr) / sizeof(ulong); @@ -1471,12 +1476,10 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame) { unsigned long high, low, fp; unsigned long stack_mask; - unsigned long irq_stack_ptr, orig_sp, sp_in; + unsigned long irq_stack_ptr, orig_sp; struct arm64_pt_regs *ptregs; struct machine_specific *ms; - sp_in = frame->sp; - stack_mask = (unsigned long)(ARM64_STACK_SIZE) - 1; fp = frame->fp; @@ -1513,7 +1516,7 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame) ptregs = (struct arm64_pt_regs *)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(orig_sp))]; frame->sp = orig_sp; frame->pc = ptregs->pc; - bt->bptr = sp_in; + bt->bptr = fp; if (CRASHDEBUG(1)) error(INFO, "arm64_unwind_frame: switch stacks: fp: %lx sp: %lx pc: %lx\n", @@ -1904,8 +1907,10 @@ arm64_print_exception_frame(struct bt_info *bt, ulong pt_regs, int mode, FILE *o ulong LR, SP, offset; char buf[BUFSIZE]; +#if 0 /* FIXME? */ if (bt->flags & BT_FULL) arm64_display_full_frame(bt, pt_regs); +#endif if (CRASHDEBUG(1)) fprintf(ofp, "pt_regs: %lx\n", pt_regs);

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