[PATCH] uml: skas0 stubs now check system call return values

Change syscall-stub's data to include a "expected retval".

Stub now checks syscalls retval and aborts execution of syscall list, if
retval != expected retval.

run_syscall_stub prints the data of the failed syscall, using the data pointer
and retval written by the stub to the beginning of the stack.

one_syscall_stub is removed, to simplify code, because only some instructions
are saved by one_syscall_stub, no host-syscall.

Using the stub with additional data (modify_ldt via stub)
is prepared also.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

8 files changed, 348 insertions, 238 deletions

diff --git a/arch/um/include/tlb.h b/arch/um/include/tlb.h
index 2deefb99c63c..45d7da6c3b2c 100644
--- a/arch/um/include/tlb.h
+++ b/arch/um/include/tlb.h
@@ -38,9 +38,9 @@ extern void mprotect_kernel_vm(int w);
 extern void force_flush_all(void);
 extern void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                              unsigned long end_addr, int force,
-			     void *(*do_ops)(union mm_context *,
-					     struct host_vm_op *, int, int,
-					     void *));
+			     int (*do_ops)(union mm_context *,
+					   struct host_vm_op *, int, int,
+					   void **));
 extern int flush_tlb_kernel_range_common(unsigned long start,
 					 unsigned long end);
 
diff --git a/arch/um/kernel/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h