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-rw-r--r--arch/um/kernel/skas/clone.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
new file mode 100644
index 000000000..bfb70c456
--- /dev/null
+++ b/arch/um/kernel/skas/clone.c
@@ -0,0 +1,52 @@
+// 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 = (struct stub_data *) STUB_DATA;
+ long err;
+
+ err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
+ STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
+ if (err != 0)
+ goto out;
+
+ err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
+ if (err)
+ goto out;
+
+ remap_stack(data->fd, data->offset);
+ goto done;
+
+ out:
+ /*
+ * save current result.
+ * Parent: pid;
+ * child: retcode of mmap already saved and it jumps around this
+ * assignment
+ */
+ data->err = err;
+ done:
+ trap_myself();
+}