lkml.org 
[lkml]   [2018]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 047/109] mm: add kernel_[sg]et_mempolicy() helpers; remove in-kernel calls to syscalls
    Date
    Using the mm-internal kernel_[sg]et_mempolicy() helper allows us to get
    rid of the mm-internal calls to the sys_[sg]et_mempolicy() syscalls.

    This patch is part of a series which removes in-kernel calls to syscalls.
    On this basis, the syscall entry path can be streamlined. For details, see
    http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: linux-mm@kvack.org
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
    ---
    mm/mempolicy.c | 29 ++++++++++++++++++++++-------
    1 file changed, 22 insertions(+), 7 deletions(-)

    diff --git a/mm/mempolicy.c b/mm/mempolicy.c
    index e4d7d4c0b253..ca817e768d0e 100644
    --- a/mm/mempolicy.c
    +++ b/mm/mempolicy.c
    @@ -1365,8 +1365,8 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
    }

    /* Set the process memory policy */
    -SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
    - unsigned long, maxnode)
    +static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
    + unsigned long maxnode)
    {
    int err;
    nodemask_t nodes;
    @@ -1384,6 +1384,12 @@ SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
    return do_set_mempolicy(mode, flags, &nodes);
    }

    +SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
    + unsigned long, maxnode)
    +{
    + return kernel_set_mempolicy(mode, nmask, maxnode);
    +}
    +
    static int kernel_migrate_pages(pid_t pid, unsigned long maxnode,
    const unsigned long __user *old_nodes,
    const unsigned long __user *new_nodes)
    @@ -1485,9 +1491,11 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,


    /* Retrieve NUMA policy */
    -SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
    - unsigned long __user *, nmask, unsigned long, maxnode,
    - unsigned long, addr, unsigned long, flags)
    +static int kernel_get_mempolicy(int __user *policy,
    + unsigned long __user *nmask,
    + unsigned long maxnode,
    + unsigned long addr,
    + unsigned long flags)
    {
    int err;
    int uninitialized_var(pval);
    @@ -1510,6 +1518,13 @@ SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
    return err;
    }

    +SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
    + unsigned long __user *, nmask, unsigned long, maxnode,
    + unsigned long, addr, unsigned long, flags)
    +{
    + return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags);
    +}
    +
    #ifdef CONFIG_COMPAT

    COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
    @@ -1528,7 +1543,7 @@ COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
    if (nmask)
    nm = compat_alloc_user_space(alloc_size);

    - err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
    + err = kernel_get_mempolicy(policy, nm, nr_bits+1, addr, flags);

    if (!err && nmask) {
    unsigned long copy_size;
    @@ -1560,7 +1575,7 @@ COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
    return -EFAULT;
    }

    - return sys_set_mempolicy(mode, nm, nr_bits+1);
    + return kernel_set_mempolicy(mode, nm, nr_bits+1);
    }

    COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
    --
    2.16.3
    \
     
     \ /
      Last update: 2018-03-29 13:51    [W:4.051 / U:0.840 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site