2020-05-21 22:28:05

by Ian Rogers

[permalink] [raw]
Subject: [PATCH] proc.5: add "wf" to VmFlags in /proc/[pid]/smaps

This patch documents a flag added in the following kernel commit:

commit d2cd9ede6e193dd7d88b6d27399e96229a551b19
Author: Rik van Riel <[email protected]>
Date: Wed Sep 6 16:25:15 2017 -0700

mm,fork: introduce MADV_WIPEONFORK

This was already documented in man2/madvise.2 in the commit:

commit c0c4f6c29c494c466f3a2a6273c5b55b76a72927
Author: Rik van Riel <[email protected]>
Date: Tue Sep 19 20:32:00 2017 +0200

madvise.2: Document MADV_WIPEONFORK and MADV_KEEPONFORK

Signed-off-by: Ian Rogers <[email protected]>
---
man5/proc.5 | 1 +
1 file changed, 1 insertion(+)

diff --git a/man5/proc.5 b/man5/proc.5
index 46d603f28..3e5b91af0 100644
--- a/man5/proc.5
+++ b/man5/proc.5
@@ -2020,6 +2020,7 @@ encoded using the following two-letter codes:
ht - area uses huge tlb pages
nl - non-linear mapping
ar - architecture specific flag
+ wf - wipe on fork
dd - do not include area into core dump
sd - soft-dirty flag
mm - mixed map area
--
2.27.0.rc0.183.gde8f92d652-goog


2020-05-21 23:16:04

by Ian Rogers

[permalink] [raw]
Subject: Re: [PATCH] proc.5: add "wf" to VmFlags in /proc/[pid]/smaps

On Thu, May 21, 2020 at 3:25 PM Ian Rogers <[email protected]> wrote:
>
> This patch documents a flag added in the following kernel commit:
>
> commit d2cd9ede6e193dd7d88b6d27399e96229a551b19
> Author: Rik van Riel <[email protected]>
> Date: Wed Sep 6 16:25:15 2017 -0700
>
> mm,fork: introduce MADV_WIPEONFORK
>
> This was already documented in man2/madvise.2 in the commit:
>
> commit c0c4f6c29c494c466f3a2a6273c5b55b76a72927
> Author: Rik van Riel <[email protected]>
> Date: Tue Sep 19 20:32:00 2017 +0200
>
> madvise.2: Document MADV_WIPEONFORK and MADV_KEEPONFORK
>
> Signed-off-by: Ian Rogers <[email protected]>

Doing a quick audit of fs/proc/task_mmu.c having noticed this flag was
missing I note:
- "mp" isn't documented, only possible with INTEL_MPX
- "nl" is documented but not present in show_smap_vma_flags
- "um" and "uw" aren't documented

Thanks,
Ian

> ---
> man5/proc.5 | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/man5/proc.5 b/man5/proc.5
> index 46d603f28..3e5b91af0 100644
> --- a/man5/proc.5
> +++ b/man5/proc.5
> @@ -2020,6 +2020,7 @@ encoded using the following two-letter codes:
> ht - area uses huge tlb pages
> nl - non-linear mapping
> ar - architecture specific flag
> + wf - wipe on fork
> dd - do not include area into core dump
> sd - soft-dirty flag
> mm - mixed map area
> --
> 2.27.0.rc0.183.gde8f92d652-goog
>

Subject: Re: [PATCH] proc.5: add "wf" to VmFlags in /proc/[pid]/smaps

On 5/22/20 1:13 AM, Ian Rogers wrote:
> On Thu, May 21, 2020 at 3:25 PM Ian Rogers <[email protected]> wrote:
>>
>> This patch documents a flag added in the following kernel commit:
>>
>> commit d2cd9ede6e193dd7d88b6d27399e96229a551b19
>> Author: Rik van Riel <[email protected]>
>> Date: Wed Sep 6 16:25:15 2017 -0700
>>
>> mm,fork: introduce MADV_WIPEONFORK
>>
>> This was already documented in man2/madvise.2 in the commit:
>>
>> commit c0c4f6c29c494c466f3a2a6273c5b55b76a72927
>> Author: Rik van Riel <[email protected]>
>> Date: Tue Sep 19 20:32:00 2017 +0200
>>
>> madvise.2: Document MADV_WIPEONFORK and MADV_KEEPONFORK
>>
>> Signed-off-by: Ian Rogers <[email protected]>
>
> Doing a quick audit of fs/proc/task_mmu.c having noticed this flag was
> missing I note:
> - "mp" isn't documented, only possible with INTEL_MPX
> - "nl" is documented but not present in show_smap_vma_flags
> - "um" and "uw" aren't documented

I took a shot at fixing these:


mp - MPX-specific VMA (x86, since Linux 3.19)
nl - non-linear mapping (removed in Linux 4.0)
um - userfaultfd missing pages tracking (since Linux 4.3)
uw - userfaultfd wprotect pages tracking (since Linux 4.3)
sf - perform synchronous page faults (since Linux 4.15)

Thanks,

Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/

2020-05-25 20:05:06

by Kirill A. Shutemov

[permalink] [raw]
Subject: Re: [PATCH] proc.5: add "wf" to VmFlags in /proc/[pid]/smaps

On Mon, May 25, 2020 at 03:50:38PM +0200, Michael Kerrisk (man-pages) wrote:
> On 5/22/20 1:13 AM, Ian Rogers wrote:
> > On Thu, May 21, 2020 at 3:25 PM Ian Rogers <[email protected]> wrote:
> >>
> >> This patch documents a flag added in the following kernel commit:
> >>
> >> commit d2cd9ede6e193dd7d88b6d27399e96229a551b19
> >> Author: Rik van Riel <[email protected]>
> >> Date: Wed Sep 6 16:25:15 2017 -0700
> >>
> >> mm,fork: introduce MADV_WIPEONFORK
> >>
> >> This was already documented in man2/madvise.2 in the commit:
> >>
> >> commit c0c4f6c29c494c466f3a2a6273c5b55b76a72927
> >> Author: Rik van Riel <[email protected]>
> >> Date: Tue Sep 19 20:32:00 2017 +0200
> >>
> >> madvise.2: Document MADV_WIPEONFORK and MADV_KEEPONFORK
> >>
> >> Signed-off-by: Ian Rogers <[email protected]>
> >
> > Doing a quick audit of fs/proc/task_mmu.c having noticed this flag was
> > missing I note:
> > - "mp" isn't documented, only possible with INTEL_MPX
> > - "nl" is documented but not present in show_smap_vma_flags
> > - "um" and "uw" aren't documented
>
> I took a shot at fixing these:
>
>
> mp - MPX-specific VMA (x86, since Linux 3.19)

This one is gone. The patch to remove leftovers of MPX is linux-next.

--
Kirill A. Shutemov

Subject: Re: [PATCH] proc.5: add "wf" to VmFlags in /proc/[pid]/smaps

Hello Ian,

On 5/22/20 12:25 AM, Ian Rogers wrote:
> This patch documents a flag added in the following kernel commit:
>
> commit d2cd9ede6e193dd7d88b6d27399e96229a551b19
> Author: Rik van Riel <[email protected]>
> Date: Wed Sep 6 16:25:15 2017 -0700
>
> mm,fork: introduce MADV_WIPEONFORK
>
> This was already documented in man2/madvise.2 in the commit:
>
> commit c0c4f6c29c494c466f3a2a6273c5b55b76a72927
> Author: Rik van Riel <[email protected]>
> Date: Tue Sep 19 20:32:00 2017 +0200
>
> madvise.2: Document MADV_WIPEONFORK and MADV_KEEPONFORK

Thanks. Patch applied.

Cheers,

Michael

> Signed-off-by: Ian Rogers <[email protected]>
> ---
> man5/proc.5 | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/man5/proc.5 b/man5/proc.5
> index 46d603f28..3e5b91af0 100644
> --- a/man5/proc.5
> +++ b/man5/proc.5
> @@ -2020,6 +2020,7 @@ encoded using the following two-letter codes:
> ht - area uses huge tlb pages
> nl - non-linear mapping
> ar - architecture specific flag
> + wf - wipe on fork
> dd - do not include area into core dump
> sd - soft-dirty flag
> mm - mixed map area
>


--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/

Subject: Re: [PATCH] proc.5: add "wf" to VmFlags in /proc/[pid]/smaps

On Mon, 25 May 2020 at 16:59, Kirill A. Shutemov <[email protected]> wrote:
>
> On Mon, May 25, 2020 at 03:50:38PM +0200, Michael Kerrisk (man-pages) wrote:
> > On 5/22/20 1:13 AM, Ian Rogers wrote:
> > > On Thu, May 21, 2020 at 3:25 PM Ian Rogers <[email protected]> wrote:
> > >>
> > >> This patch documents a flag added in the following kernel commit:
> > >>
> > >> commit d2cd9ede6e193dd7d88b6d27399e96229a551b19
> > >> Author: Rik van Riel <[email protected]>
> > >> Date: Wed Sep 6 16:25:15 2017 -0700
> > >>
> > >> mm,fork: introduce MADV_WIPEONFORK
> > >>
> > >> This was already documented in man2/madvise.2 in the commit:
> > >>
> > >> commit c0c4f6c29c494c466f3a2a6273c5b55b76a72927
> > >> Author: Rik van Riel <[email protected]>
> > >> Date: Tue Sep 19 20:32:00 2017 +0200
> > >>
> > >> madvise.2: Document MADV_WIPEONFORK and MADV_KEEPONFORK
> > >>
> > >> Signed-off-by: Ian Rogers <[email protected]>
> > >
> > > Doing a quick audit of fs/proc/task_mmu.c having noticed this flag was
> > > missing I note:
> > > - "mp" isn't documented, only possible with INTEL_MPX
> > > - "nl" is documented but not present in show_smap_vma_flags
> > > - "um" and "uw" aren't documented
> >
> > I took a shot at fixing these:
> >
> >
> > mp - MPX-specific VMA (x86, since Linux 3.19)
>
> This one is gone. The patch to remove leftovers of MPX is linux-next.

Thanks, Kirill. I'll simply remove that entry.

Cheers,

Michael

--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/