Re: [PATCH] docs: fault-injection: fix non-working usage of negative values

From: Geert Uytterhoeven
Date: Thu Jun 03 2021 - 09:27:33 EST


Hi Wolfram,

On Thu, Jun 3, 2021 at 2:59 PM Wolfram Sang
<wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> Fault injection uses debugfs in a way that the provided values via sysfs
> are interpreted as u64. Providing negative numbers results in an error:
>
> /sys/kernel/debug/fail_function# echo -1 > times
> sh: write error: Invalid argument

Interesting...

> Update the docs and examples to use "printf %#x <val>" in these cases.
> For "retval", reword the paragraph a little and fix a typo.

Presumably this is something that used to work, but was broken (not
so) recently. Perhaps the code should be fixed instead?

The code uses debugfs_create_atomic_t(), and atomic_t is signed, so
I'd expect negative numbers to work.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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