3 files changed, 10 insertions, 68 deletions

diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index dd8bc2167e36..6f86d53e3d69 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -3,16 +3,14 @@
 # Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 #
 
-obj-y := clone.o stub.o mmu.o process.o syscall.o uaccess.o
+obj-y := stub.o mmu.o process.o syscall.o uaccess.o
 
-# clone.o and stub.o are in the stub, so it can't be built with profiling
+# stub.o is in the stub, so it can't be built with profiling
 # GCC hardened also auto-enables -fpic, but we need %ebx so it can't work ->
 # disable it
 
-CFLAGS_clone.o := $(CFLAGS_NO_HARDENING)
 CFLAGS_stub.o := $(CFLAGS_NO_HARDENING)
-UNPROFILE_OBJS := clone.o stub.o
-
+UNPROFILE_OBJS := stub.o
 KCOV_INSTRUMENT := n
 
 include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
deleted file mode 100644
index b59fa43d68ce..000000000000
--- a/arch/um/kernel/skas/clone.c
+++ /dev/null
@@ -1,50 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
- * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- */
-
-#include <signal.h>
-#include <sched.h>
-#include <asm/unistd.h>
-#include <sys/time.h>
-#include <as-layout.h>
-#include <ptrace_user.h>
-#include <stub-data.h>
-#include <sysdep/stub.h>
-
-/*
- * This is in a separate file because it needs to be compiled with any
- * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
- *
- * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
- * on some systems.
- */
-
-void __attribute__ ((__section__ (".__syscall_stub")))
-stub_clone_handler(void)
-{
-	struct stub_data *data = get_stub_data();
-	long err;
-
-	/* syscall data as a temporary stack area (bottom half). */
-	err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
-			    (unsigned long) data->syscall_data +
-					    sizeof(data->syscall_data) / 2 -
-					    sizeof(void *));
-	if (err) {
-		data->err = err;
-		goto done;
-	}
-
-	err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
-	if (err) {
-		data->child_err = err;
-		goto done;
-	}
-
-	remap_stack_and_trap();
-
- done:
-	trap_myself();
-}
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 968e254cf709..697dad49c36b 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -21,8 +21,7 @@ static_assert(sizeof(struct stub_data) == STUB_DATA_PAGES * UM_KERN_PAGE_SIZE);
 
 int init_new_context(struct task_struct *task, struct mm_struct *mm)
 {
- 	struct mm_context *from_mm = NULL;
-	struct mm_context *to_mm = &mm->context;
+	struct mm_id *new_id = &mm->context.id;
 	unsigned long stack = 0;
 	int ret = -ENOMEM;
 
@@ -30,27 +29,22 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
 	if (stack == 0)
 		goto out;
 
-	to_mm->id.stack = stack;
-	if (current->mm != NULL && current->mm != &init_mm)
-		from_mm = &current->mm->context;
+	new_id->stack = stack;
 
 	block_signals_trace();
-	if (from_mm)
-		to_mm->id.u.pid = copy_context_skas0(stack,
-						     from_mm->id.u.pid);
-	else to_mm->id.u.pid = start_userspace(stack);
+	new_id->u.pid = start_userspace(stack);
 	unblock_signals_trace();
 
-	if (to_mm->id.u.pid < 0) {
-		ret = to_mm->id.u.pid;
+	if (new_id->u.pid < 0) {
+		ret = new_id->u.pid;
 		goto out_free;
 	}
 
 	return 0;
 
  out_free:
-	if (to_mm->id.stack != 0)
-		free_pages(to_mm->id.stack, ilog2(STUB_DATA_PAGES));
+	if (new_id->stack != 0)
+		free_pages(new_id->stack, ilog2(STUB_DATA_PAGES));
  out:
 	return ret;
 }