On Sun, Oct 6, 2019 at 3:20 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> this patch causes all my sparc64 emulations to stall during boot. It causes
> all alpha emulations to crash with [1a] and [1b] when booting from a virtual
> disk, and one of the xtensa emulations to crash with [2].
Ho humm. I've run variations of that patch over a few years on x86,
but obviously not on alpha/sparc.
At least I should still be able to read alpha assembly, even after all
these years. Would you mind sending me the result of
make fs/readdir.s
on alpha with the broken config? I'd hope that the sparc issue is the same.
Actually, could you also do
make fs/readdir.o
and then send me the "objdump --disassemble" of that? That way I get
the instruction offsets without having to count by hand.
> Unable to handle kernel paging request at virtual address 0000000000000004
> rcS(47): Oops -1
> pc = [<0000000000000004>] ra = [<fffffc00004512e4>] ps = 0000 Not tainted
> pc is at 0x4
That is _funky_. I'm not seeing how it could possibly jump to 0x4, but
it clearly does.
That said, are you sure it's _that_ commit? Because this pattern:
> a0 = fffffc0007dbca56 a1 = 2f2f2f2f2f2f2f2f a2 = 000000000000000a
implicates the memchr('/') call in the next one. That's a word full of
'/' characters.
Of course, it could just be left-over register contents from that
memchr(), but it makes me wonder. Particularly since it seems to
happen early in filldir64():
> ra is at filldir64+0x64/0x320
which is just a fairly small handful of instructions in, and I
wouldn't be shocked if that's the return address for the call to
memchr.
Linus
