mm: mlock: add new mlock system call

With the refactored mlock code, introduce a new system call for mlock. The new call will allow the user to specify what lock states are being added. mlock2 is trivial at the moment, but a follow on patch will add a new mlock state making it useful. Signed-off-by: Eric B Munson <emunson@akamai.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
quadcores · Nov 6, 2015 · a8ca5d0 · a8ca5d0
1 parent 1aab92e
commit a8ca5d0
Show file tree

Hide file tree

Showing 6 changed files with 16 additions and 1 deletion.
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -382,3 +382,4 @@
 373	i386	shutdown		sys_shutdown
 374	i386	userfaultfd		sys_userfaultfd
 375	i386	membarrier		sys_membarrier
+376	i386	mlock2			sys_mlock2
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -331,6 +331,7 @@
 322	64	execveat		stub_execveat
 323	common	userfaultfd		sys_userfaultfd
 324	common	membarrier		sys_membarrier
+325	common	mlock2			sys_mlock2
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
@@ -887,4 +887,6 @@ asmlinkage long sys_execveat(int dfd, const char __user *filename,
 
 asmlinkage long sys_membarrier(int cmd, int flags);
 
+asmlinkage long sys_mlock2(unsigned long start, size_t len, int flags);
+
 #endif
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
@@ -713,9 +713,11 @@ __SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat)
 __SYSCALL(__NR_userfaultfd, sys_userfaultfd)
 #define __NR_membarrier 283
 __SYSCALL(__NR_membarrier, sys_membarrier)
+#define __NR_mlock2 284
+__SYSCALL(__NR_mlock2, sys_mlock2)
 
 #undef __NR_syscalls
-#define __NR_syscalls 284
+#define __NR_syscalls 285
 
 /*
  * All syscalls below here should go away really,

diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
@@ -194,6 +194,7 @@ cond_syscall(sys_mlock);
 cond_syscall(sys_munlock);
 cond_syscall(sys_mlockall);
 cond_syscall(sys_munlockall);
+cond_syscall(sys_mlock2);
 cond_syscall(sys_mincore);
 cond_syscall(sys_madvise);
 cond_syscall(sys_mremap);

diff --git a/mm/mlock.c b/mm/mlock.c
@@ -644,6 +644,14 @@ SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
 	return do_mlock(start, len, VM_LOCKED);
 }
 
+SYSCALL_DEFINE3(mlock2, unsigned long, start, size_t, len, int, flags)
+{
+	if (flags)
+		return -EINVAL;
+
+	return do_mlock(start, len, VM_LOCKED);
+}
+
 SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
 {
 	int ret;
Original file line number	Diff line number	Diff line change
Expand Up		@@ -887,4 +887,6 @@ asmlinkage long sys_execveat(int dfd, const char __user *filename,

		asmlinkage long sys_membarrier(int cmd, int flags);

		asmlinkage long sys_mlock2(unsigned long start, size_t len, int flags);

		#endif