Commit 95837924 authored by Feng Tang's avatar Feng Tang Committed by Linus Torvalds

mm/mempolicy: unify the parameter sanity check for mbind and set_mempolicy

Currently the kernel_mbind() and kernel_set_mempolicy() do almost the same
operation for parameter sanity check.

Add a helper function to unify the code to reduce the redundancy, and make
it easier for changing the sanity check code in future.

[thanks to David Rientjes for suggesting using helper function instead of
macro].

[feng.tang@intel.com: add comment]
  Link: https://lkml.kernel.org/r/1622560492-1294-4-git-send-email-feng.tang@intel.com

Link: https://lkml.kernel.org/r/1622469956-82897-4-git-send-email-feng.tang@intel.comSigned-off-by: default avatarFeng Tang <feng.tang@intel.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7858d7bc
......@@ -1441,26 +1441,38 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
}
/* Basic parameter sanity check used by both mbind() and set_mempolicy() */
static inline int sanitize_mpol_flags(int *mode, unsigned short *flags)
{
*flags = *mode & MPOL_MODE_FLAGS;
*mode &= ~MPOL_MODE_FLAGS;
if ((unsigned int)(*mode) >= MPOL_MAX)
return -EINVAL;
if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES))
return -EINVAL;
return 0;
}
static long kernel_mbind(unsigned long start, unsigned long len,
unsigned long mode, const unsigned long __user *nmask,
unsigned long maxnode, unsigned int flags)
{
unsigned short mode_flags;
nodemask_t nodes;
int lmode = mode;
int err;
unsigned short mode_flags;
start = untagged_addr(start);
mode_flags = mode & MPOL_MODE_FLAGS;
mode &= ~MPOL_MODE_FLAGS;
if (mode >= MPOL_MAX)
return -EINVAL;
if ((mode_flags & MPOL_F_STATIC_NODES) &&
(mode_flags & MPOL_F_RELATIVE_NODES))
return -EINVAL;
err = sanitize_mpol_flags(&lmode, &mode_flags);
if (err)
return err;
err = get_nodes(&nodes, nmask, maxnode);
if (err)
return err;
return do_mbind(start, len, mode, mode_flags, &nodes, flags);
return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
}
SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
......@@ -1474,20 +1486,20 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
unsigned long maxnode)
{
int err;
unsigned short mode_flags;
nodemask_t nodes;
unsigned short flags;
int lmode = mode;
int err;
err = sanitize_mpol_flags(&lmode, &mode_flags);
if (err)
return err;
flags = mode & MPOL_MODE_FLAGS;
mode &= ~MPOL_MODE_FLAGS;
if ((unsigned int)mode >= MPOL_MAX)
return -EINVAL;
if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
return -EINVAL;
err = get_nodes(&nodes, nmask, maxnode);
if (err)
return err;
return do_set_mempolicy(mode, flags, &nodes);
return do_set_mempolicy(lmode, mode_flags, &nodes);
}
SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
......
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