* Re: [PATCH] mmap.2: fix EINVAL conditions
[not found] <ba87bced44ac346f45887c6e91d0d29b0632a7f9.camel@redhat.com>
@ 2019-09-13 14:26 ` Michael Kerrisk (man-pages)
0 siblings, 0 replies; only message in thread
From: Michael Kerrisk (man-pages) @ 2019-09-13 14:26 UTC (permalink / raw)
To: nforro; +Cc: mtk.manpages, linux-man
Hello Nikola,
On 6/24/19 1:20 PM, Nikola Forró wrote:
> Since introduction of MAP_SHARED_VALIDATE, in case flags contain
> both MAP_PRIVATE and MAP_SHARED, mmap() doesn't fail with EINVAL,
> it succeeds.
>
> The reason for that is that MAP_SHARED_VALIDATE is in fact equal
> to MAP_PRIVATE | MAP_SHARED.
>
> This is intended behavior, see:
> https://lwn.net/Articles/758594/
> https://lwn.net/Articles/758598/
Patch applied. Thanks for the excellent detail in covering
message.
Cheers,
Michael
>
> Signed-off-by: Nikola Forró <nforro@redhat.com>
> ---
> man2/mmap.2 | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/man2/mmap.2 b/man2/mmap.2
> index cea0bd372..b41e8b9ca 100644
> --- a/man2/mmap.2
> +++ b/man2/mmap.2
> @@ -565,11 +565,11 @@ was 0.
> .TP
> .B EINVAL
> .I flags
> -contained neither
> -.B MAP_PRIVATE
> +contained none of
> +.BR MAP_PRIVATE ,
> +.B MAP_SHARED
> or
> -.BR MAP_SHARED ,
> -or contained both of these values.
> +.BR MAP_SHARED_VALIDATE .
> .TP
> .B ENFILE
> .\" This is for shared anonymous segments
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
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