On Tue, Oct 3, 2017 at 5:37 PM, Nicolas Pitre [off-list ref] wrote:

On Tue, 3 Oct 2017, Geert Uytterhoeven wrote:

quoted

If CONFIG_DEBUG_LOCK_ALLOC=y, the kernel log is spammed with a few
hundred identical messages:

    unwind: Unknown symbol address c0800300
    unwind: Index not found c0800300

c0800300 is the return address from the last subroutine call (to
__memzero()) in __mmap_switched().  Apparently having this address in
the link register confuses the unwinder.

To fix this, reset the link register to zero before jumping to
start_kernel().

Fixes: 9520b1a1b5f7a348 ("ARM: head-common.S: speed up startup code")
Suggested-by: Ard Biesheuvel <redacted>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Good! This fixes another similar case I had but I didn't come around to
look at closely yet.

Acked-by: Nicolas Pitre <redacted>

Thanks!

Please send it to RMK's patch system.

Done (I hope so ;-)

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds