[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>

1 files changed, 16 insertions, 15 deletions

diff --git a/arch/um/kernel/skas/tlb.c b/arch/um/kernel/skas/tlb.c
index 4b5fd2049547..6e84963dfc29 100644
--- a/arch/um/kernel/skas/tlb.c
+++ b/arch/um/kernel/skas/tlb.c
@@ -18,30 +18,31 @@
 #include "os.h"
 #include "tlb.h"
 
-static void *do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
-                    int finished, void *flush)
+static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
+                  int finished, void **flush)
 {
         struct host_vm_op *op;
-        int i;
+        int i, ret = 0;
 
-        for(i = 0; i <= last; i++){
+        for(i = 0; i <= last && !ret; i++){
                 op = &ops[i];
                 switch(op->type){
                 case MMAP:
-                        flush = map(&mmu->skas.id, op->u.mmap.addr,
-                                    op->u.mmap.len, op->u.mmap.r, op->u.mmap.w,
-                                    op->u.mmap.x, op->u.mmap.fd,
-                                    op->u.mmap.offset, finished, flush);
+                        ret = map(&mmu->skas.id, op->u.mmap.addr,
+                                  op->u.mmap.len, op->u.mmap.r, op->u.mmap.w,
+                                  op->u.mmap.x, op->u.mmap.fd,
+                                  op->u.mmap.offset, finished, flush);
                         break;
                 case MUNMAP:
-                        flush = unmap(&mmu->skas.id, (void *) op->u.munmap.addr,
-                                      op->u.munmap.len, finished, flush);
+                        ret = unmap(&mmu->skas.id,
+                                    (void *) op->u.munmap.addr,
+                                    op->u.munmap.len, finished, flush);
                         break;
                 case MPROTECT:
-                        flush = protect(&mmu->skas.id, op->u.mprotect.addr,
-                                        op->u.mprotect.len, op->u.mprotect.r,
-                                        op->u.mprotect.w, op->u.mprotect.x,
-                                        finished, flush);
+                        ret = protect(&mmu->skas.id, op->u.mprotect.addr,
+                                      op->u.mprotect.len, op->u.mprotect.r,
+                                      op->u.mprotect.w, op->u.mprotect.x,
+                                      finished, flush);
                         break;
                 default:
                         printk("Unknown op type %d in do_ops\n", op->type);
@@ -49,7 +50,7 @@ static void *do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
                 }
         }
 
-        return flush;
+        return ret;
 }
 
 extern int proc_mm;