1 files changed, 64 insertions, 0 deletions

diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
new file mode 100644
index 000000000000..99522f78b162
--- /dev/null
+++ b/arch/x86/um/sys_call_table_64.c
@@ -0,0 +1,64 @@
+/*
+ * System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
+ * with some changes for UML.
+ */
+
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <linux/cache.h>
+
+#define __NO_STUBS
+
+/*
+ * Below you can see, in terms of #define's, the differences between the x86-64
+ * and the UML syscall table.
+ */
+
+/* Not going to be implemented by UML, since we have no hardware. */
+#define stub_iopl sys_ni_syscall
+#define sys_ioperm sys_ni_syscall
+
+/*
+ * The UML TLS problem. Note that x86_64 does not implement this, so the below
+ * is needed only for the ia32 compatibility.
+ */
+
+/* On UML we call it this way ("old" means it's not mmap2) */
+#define sys_mmap old_mmap
+
+#define stub_clone sys_clone
+#define stub_fork sys_fork
+#define stub_vfork sys_vfork
+#define stub_execve sys_execve
+#define stub_rt_sigsuspend sys_rt_sigsuspend
+#define stub_sigaltstack sys_sigaltstack
+#define stub_rt_sigreturn sys_rt_sigreturn
+
+#define __SYSCALL(nr, sym) extern asmlinkage void sym(void) ;
+#undef _ASM_X86_UNISTD_64_H
+#include "../../x86/include/asm/unistd_64.h"
+
+#undef __SYSCALL
+#define __SYSCALL(nr, sym) [ nr ] = sym,
+#undef _ASM_X86_UNISTD_64_H
+
+typedef void (*sys_call_ptr_t)(void);
+
+extern void sys_ni_syscall(void);
+
+/*
+ * We used to have a trick here which made sure that holes in the
+ * x86_64 table were filled in with sys_ni_syscall, but a comment in
+ * unistd_64.h says that holes aren't allowed, so the trick was
+ * removed.
+ * The trick looked like this
+ *      [0 ... UM_NR_syscall_max] = &sys_ni_syscall
+ * before including unistd_64.h - the later initializations overwrote
+ * the sys_ni_syscall filler.
+ */
+
+sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
+#include <asm/unistd_64.h>
+};
+
+int syscall_table_size = sizeof(sys_call_table);