Re: [PATCH 03/24] x86: Do not free zero sized per cpu areas

From: Johannes Weiner
Date: Fri Mar 26 2010 - 19:42:46 EST


On Fri, Mar 26, 2010 at 03:21:33PM -0700, Yinghai Lu wrote:
> From: Ian Campbell <ian.campbell@xxxxxxxxxx>
>
> This avoids an infinite loop in free_early_partial().
>
> Add a warning to free_early_partial to catch future problems.
>
> -v5: put back start > end back into WARN_ONCE()
> -v6: use one line for warning according to linus
> -v7: more test by
>
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Tested-by: Joel Becker <joel.becker@xxxxxxxxxx>
> Tested-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> ---
> kernel/early_res.c | 6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/early_res.c b/kernel/early_res.c
> index 3cb2c66..69bed5b 100644
> --- a/kernel/early_res.c
> +++ b/kernel/early_res.c
> @@ -333,6 +333,12 @@ void __init free_early_partial(u64 start, u64 end)
> struct early_res *r;
> int i;
>
> + if (start == end)
> + return;
> +
> + if (WARN_ONCE(start > end, "free_early_partial: wrong range [%#llx, %#llx]\n", start, end))
> + return;

I think you can drop the function name, it will be in the stack dump
anyway. And that would get the line back into bounds :)

Other than that,
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
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