[PATCH] uml: move LDT creation
s390 doesn't have a LDT. So MM_COPY_SEGMENTS will not be supported on s390.
The only user of MM_COPY_SEGMENTS is new_mm(), but that's no longer useful, as
arch/sys-i386/ldt.c defines init_new_ldt(), which is called immediately after
new_mm(). So we should copy host's LDT in init_new_ldt(), if /proc/mm is
available, to have this subarch specific call in subarch code.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 17746b4..0cdfd44 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -16,6 +16,8 @@
#include "choose-mode.h"
#include "kern.h"
#include "mode_kern.h"
+#include "proc_mm.h"
+#include "os.h"
extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
@@ -456,13 +458,14 @@
int i;
long page, err=0;
void *addr = NULL;
+ struct proc_mm_op copy;
- memset(&desc, 0, sizeof(desc));
if(!ptrace_ldt)
init_MUTEX(&new_mm->ldt.semaphore);
if(!from_mm){
+ memset(&desc, 0, sizeof(desc));
/*
* We have to initialize a clean ldt.
*/
@@ -494,8 +497,26 @@
}
}
new_mm->ldt.entry_count = 0;
+
+ goto out;
}
- else if (!ptrace_ldt) {
+
+ if(proc_mm){
+ /* We have a valid from_mm, so we now have to copy the LDT of
+ * from_mm to new_mm, because using proc_mm an new mm with
+ * an empty/default LDT was created in new_mm()
+ */
+ copy = ((struct proc_mm_op) { .op = MM_COPY_SEGMENTS,
+ .u =
+ { .copy_segments =
+ from_mm->id.u.mm_fd } } );
+ i = os_write_file(new_mm->id.u.mm_fd, ©, sizeof(copy));
+ if(i != sizeof(copy))
+ printk("new_mm : /proc/mm copy_segments failed, "
+ "err = %d\n", -i);
+ }
+
+ if(!ptrace_ldt) {
/* Our local LDT is used to supply the data for
* modify_ldt(READLDT), if PTRACE_LDT isn't available,
* i.e., we have to use the stub for modify_ldt, which
@@ -524,6 +545,7 @@
up(&from_mm->ldt.semaphore);
}
+ out:
return err;
}