[PATCH] migrate_pages.2: add EFAULT/EINVAL errors

[PATCH] migrate_pages.2: add EFAULT/EINVAL errors

[Jan Stancek]

migrate_pages(2) can return also EFAULT and EINVAL errors.

I encountered these errors while writing testcase for migrate_pages
syscall for LTP (Linux test project).

I checked stable kernel tree 3.5 to see which paths return these.
Both can be returned from get_nodes(), which is called from:
SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
                const unsigned long __user *, old_nodes,
                const unsigned long __user *, new_nodes)

The testcase does following:
EFAULT
a) old_nodes/new_nodes is area mmaped with PROT_NONE
b) old_nodes/new_nodes is area not mmapped in process address space,
   -1 or area that has been just munmmaped

EINVAL
a) maxnodes overflows kernel limit
b) new_nodes contain node, which has no memory or does not exist or is
   not returned for get_mempolicy(MPOL_F_MEMS_ALLOWED).

Signed-off-by: Jan Stancek <jstancek-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 man2/migrate_pages.2 |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/man2/migrate_pages.2 b/man2/migrate_pages.2
index 416a569..0493459 100644
--- a/man2/migrate_pages.2
+++ b/man2/migrate_pages.2
@@ -106,6 +106,32 @@ to access the specified target nodes.
 No process matching
 .I pid
 could be found.
+.TP
+.B EFAULT
+Part or all of the memory range specified by
+.I old_nodes
+/
+.I new_nodes
+and
+.I maxnode
+points outside your accessible address space.
+.TP
+.B EINVAL
+The value specified by
+.I maxnode
+exceeds a kernel-imposed limit.
+.\" As at 3.5, this limit is "a page worth of bits", e.g.,
+.\" 8 * 4096 bits, assuming a 4kB page size.
+Or,
+.I old_nodes
+/
+.I new_nodes
+specifies one or more node IDs that are
+greater than the maximum supported node ID.
+Or, none of the node IDs specified by
+.I new_nodes
+are on-line and allowed by the process's current cpuset context,
+or none of the specified nodes contain memory.
 .\" FIXME There are other errors
 .SH VERSIONS
 The
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] migrate_pages.2: add EFAULT/EINVAL errors

[Michael Kerrisk (man-pages)]

On 07/26/2012 12:51 PM, Jan Stancek wrote:
> migrate_pages(2) can return also EFAULT and EINVAL errors.

Applied. Thanks, Jan.

Cheers,

Michael


> I encountered these errors while writing testcase for migrate_pages
> syscall for LTP (Linux test project).
> 
> I checked stable kernel tree 3.5 to see which paths return these.
> Both can be returned from get_nodes(), which is called from:
> SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
>                 const unsigned long __user *, old_nodes,
>                 const unsigned long __user *, new_nodes)
> 
> The testcase does following:
> EFAULT
> a) old_nodes/new_nodes is area mmaped with PROT_NONE
> b) old_nodes/new_nodes is area not mmapped in process address space,
>    -1 or area that has been just munmmaped
> 
> EINVAL
> a) maxnodes overflows kernel limit
> b) new_nodes contain node, which has no memory or does not exist or is
>    not returned for get_mempolicy(MPOL_F_MEMS_ALLOWED).
> 
> Signed-off-by: Jan Stancek <jstancek-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  man2/migrate_pages.2 |   26 ++++++++++++++++++++++++++
>  1 files changed, 26 insertions(+), 0 deletions(-)
> 
> diff --git a/man2/migrate_pages.2 b/man2/migrate_pages.2
> index 416a569..0493459 100644
> --- a/man2/migrate_pages.2
> +++ b/man2/migrate_pages.2
> @@ -106,6 +106,32 @@ to access the specified target nodes.
>  No process matching
>  .I pid
>  could be found.
> +.TP
> +.B EFAULT
> +Part or all of the memory range specified by
> +.I old_nodes
> +/
> +.I new_nodes
> +and
> +.I maxnode
> +points outside your accessible address space.
> +.TP
> +.B EINVAL
> +The value specified by
> +.I maxnode
> +exceeds a kernel-imposed limit.
> +.\" As at 3.5, this limit is "a page worth of bits", e.g.,
> +.\" 8 * 4096 bits, assuming a 4kB page size.
> +Or,
> +.I old_nodes
> +/
> +.I new_nodes
> +specifies one or more node IDs that are
> +greater than the maximum supported node ID.
> +Or, none of the node IDs specified by
> +.I new_nodes
> +are on-line and allowed by the process's current cpuset context,
> +or none of the specified nodes contain memory.
>  .\" FIXME There are other errors
>  .SH VERSIONS
>  The
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html