MIPS: Wire up clone3 syscall

Wire up the new clone3 syscall for MIPS, using save_static_function() to
generate a wrapper that saves registers $s0-$s7 prior to invoking the
generic sys_clone3 function just like we do for plain old clone.

Tested atop 64r6el_defconfig using o32, n32 & n64 builds of the simple
test program from:

  https://lore.kernel.org/lkml/20190716130631.tohj4ub54md25dys@brauner.io/

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Christian Brauner <christian@brauner.io>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: linux-mips@vger.kernel.org

5 files changed, 5 insertions, 3 deletions

diff --git a/arch/mips/include/asm/unistd.h b/arch/mips/include/asm/unistd.h
index 071053ece677..5d70babfc9ee 100644
--- a/arch/mips/include/asm/unistd.h
+++ b/arch/mips/include/asm/unistd.h
@@ -52,6 +52,7 @@
 # endif
 #define __ARCH_WANT_SYS_FORK
 #define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_CLONE3
 
 /* whitelists for checksyscalls */
 #define __IGNORE_fadvise64_64
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index b0e25e913bdb..3f16f3823031 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -80,6 +80,7 @@ SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
 
 save_static_function(sys_fork);
 save_static_function(sys_clone);
+save_static_function(sys_clone3);
 
 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
 {
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index c9c879ec9b6d..e7c5ab38e403 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -373,4 +373,4 @@
 432     n32     fsmount                         sys_fsmount
 433     n32     fspick                          sys_fspick
 434     n32     pidfd_open                      sys_pidfd_open
-# 435 reserved for clone3
+435     n32     clone3                          __sys_clone3
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index bbce9159caa1..13cd66581f3b 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -349,4 +349,4 @@
 432     n64     fsmount                         sys_fsmount
 433     n64     fspick                          sys_fspick
 434     n64     pidfd_open                      sys_pidfd_open
-# 435 reserved for clone3
+435     n64     clone3                          __sys_clone3
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 9653591428ec..353539ea4140 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -422,4 +422,4 @@
 432     o32     fsmount                         sys_fsmount
 433     o32     fspick                          sys_fspick
 434     o32     pidfd_open                      sys_pidfd_open
-# 435 reserved for clone3
+435     o32     clone3                          __sys_clone3