Commit af03c4ac authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

mm: add kernel_[sg]et_mempolicy() helpers; remove in-kernel calls to syscalls 

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent e7dc9ad6

mm/mempolicy.c

+22 −7
Original line number Diff line number Diff line
@@ -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,