3 files changed, 50 insertions, 9 deletions

diff --git a/arch/um/include/shared/skas/mm_id.h b/arch/um/include/shared/skas/mm_id.h
index e82e203f5f41..140388c282f6 100644
--- a/arch/um/include/shared/skas/mm_id.h
+++ b/arch/um/include/shared/skas/mm_id.h
@@ -7,12 +7,11 @@
 #define __MM_ID_H
 
 struct mm_id {
-	union {
-		int mm_fd;
-		int pid;
-	} u;
+	int pid;
 	unsigned long stack;
-	int kill;
+	int syscall_data_len;
 };
 
+void __switch_mm(struct mm_id *mm_idp);
+
 #endif
diff --git a/arch/um/include/shared/skas/skas.h b/arch/um/include/shared/skas/skas.h
index c93d2cbc8f32..85c50122ab98 100644
--- a/arch/um/include/shared/skas/skas.h
+++ b/arch/um/include/shared/skas/skas.h
@@ -10,10 +10,10 @@
 
 extern int userspace_pid[];
 
-extern int user_thread(unsigned long stack, int flags);
 extern void new_thread_handler(void);
 extern void handle_syscall(struct uml_pt_regs *regs);
-extern long execute_syscall_skas(void *r);
 extern unsigned long current_stub_stack(void);
+extern struct mm_id *current_mm_id(void);
+extern void current_mm_sync(void);
 
 #endif
diff --git a/arch/um/include/shared/skas/stub-data.h b/arch/um/include/shared/skas/stub-data.h
index 5e3ade3fb38b..81a4cace032c 100644
--- a/arch/um/include/shared/skas/stub-data.h
+++ b/arch/um/include/shared/skas/stub-data.h
@@ -8,10 +8,52 @@
 #ifndef __STUB_DATA_H
 #define __STUB_DATA_H
 
+#include <linux/compiler_types.h>
+#include <as-layout.h>
+#include <sysdep/tls.h>
+
+struct stub_init_data {
+	unsigned long stub_start;
+
+	int stub_code_fd;
+	unsigned long stub_code_offset;
+	int stub_data_fd;
+	unsigned long stub_data_offset;
+
+	unsigned long segv_handler;
+};
+
+#define STUB_NEXT_SYSCALL(s) \
+	((struct stub_syscall *) (((unsigned long) s) + (s)->cmd_len))
+
+enum stub_syscall_type {
+	STUB_SYSCALL_UNSET = 0,
+	STUB_SYSCALL_MMAP,
+	STUB_SYSCALL_MUNMAP,
+};
+
+struct stub_syscall {
+	struct {
+		unsigned long addr;
+		unsigned long length;
+		unsigned long offset;
+		int fd;
+		int prot;
+	} mem;
+
+	enum stub_syscall_type syscall;
+};
+
 struct stub_data {
 	unsigned long offset;
-	int fd;
-	long parent_err, child_err;
+	long err, child_err;
+
+	int syscall_data_len;
+	/* 128 leaves enough room for additional fields in the struct */
+	struct stub_syscall syscall_data[(UM_KERN_PAGE_SIZE - 128) / sizeof(struct stub_syscall)] __aligned(16);
+
+	/* Stack for our signal handlers and for calling into . */
+	unsigned char sigstack[UM_KERN_PAGE_SIZE] __aligned(UM_KERN_PAGE_SIZE);
 };
 
 #endif