arm64: sanitize copy_thread(), switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 4 insertions, 26 deletions

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 8a5f3341861e..5a1335caf6f1 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -235,15 +235,15 @@ asmlinkage void ret_from_fork(void) asm("ret_from_fork");
 
 int copy_thread(unsigned long clone_flags, unsigned long stack_start,
                 unsigned long stk_sz, struct task_struct *p,
-                struct pt_regs *regs)
+                struct pt_regs *unused)
 {
         struct pt_regs *childregs = task_pt_regs(p);
         unsigned long tls = p->thread.tp_value;
 
         memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
 
-        if (likely(regs)) {
-                *childregs = *regs;
+        if (likely(!(p->flags & PF_KTHREAD))) {
+                *childregs = *current_pt_regs();
                 childregs->regs[0] = 0;
                 if (is_compat_thread(task_thread_info(p))) {
                         if (stack_start)
@@ -266,7 +266,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
                  * for the new thread.
                  */
                 if (clone_flags & CLONE_SETTLS)
-                        tls = regs->regs[3];
+                        tls = childregs->regs[3];
         } else {
                 memset(childregs, 0, sizeof(struct pt_regs));
                 childregs->pstate = PSR_MODE_EL1h;
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 4364df85050e..8292a9b090f8 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -26,17 +26,6 @@
 #include <linux/slab.h>
 #include <linux/syscalls.h>
 
-/*
- * Clone a task - this clones the calling program thread.
- */
-asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
-                          int __user *parent_tidptr, unsigned long tls_val,
-                          int __user *child_tidptr)
-{
-        return do_fork(clone_flags, newsp, current_pt_regs(), 0,
-                        parent_tidptr, child_tidptr);
-}
-
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
                          unsigned long prot, unsigned long flags,
                          unsigned long fd, off_t off)
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index 6fabc1912da0..f7b05edf8ce3 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -28,17 +28,6 @@
 #include <asm/cacheflush.h>
 #include <asm/unistd32.h>
 
-asmlinkage int compat_sys_fork(void)
-{
-        return do_fork(SIGCHLD, 0, current_pt_regs(), 0, NULL, NULL);
-}
-
-asmlinkage int compat_sys_vfork(void)
-{
-        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
-                       current_pt_regs(), 0, NULL, NULL);
-}
-
 asmlinkage int compat_sys_sched_rr_get_interval(compat_pid_t pid,
                                                 struct compat_timespec __user *interval)
 {