[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/kernel/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h
index 01d489de3986d76b4bea09f3fdd9986112a9a53a..a7f7cd556f1f8752e64350a7e9751e9df5a5fabf 100644 (file)
--- a/arch/um/kernel/skas/include/skas.h
+++ b/arch/um/kernel/skas/include/skas.h
@@ -33,7 +33,7 @@ extern int protect(struct mm_id * mm_idp, unsigned long addr,
                   unsigned long len, int r, int w, int x, int done,
                   void **data);
 extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
-extern int new_mm(int from, unsigned long stack);
+extern int new_mm(unsigned long stack);
 extern int start_userspace(unsigned long stub_stack);
 extern int copy_context_skas0(unsigned long stack, int pid);
 extern void get_skas_faultinfo(int pid, struct faultinfo * fi);

diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 677871f1b37c65d2379cd4b4b3f58e2fc9aec067..c5c9885a82979f70c2a66a1753ef683a0114b932 100644 (file)
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -78,7 +78,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
        struct mmu_context_skas *from_mm = NULL;
        struct mmu_context_skas *to_mm = &mm->context.skas;
        unsigned long stack = 0;
-       int from_fd, ret = -ENOMEM;
+       int ret = -ENOMEM;
 
        if(skas_needs_stub){
                stack = get_zeroed_page(GFP_KERNEL);
@@ -108,11 +108,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
                from_mm = &current->mm->context.skas;
 
        if(proc_mm){
-               if(from_mm)
-                       from_fd = from_mm->id.u.mm_fd;
-               else from_fd = -1;
-
-               ret = new_mm(from_fd, stack);
+               ret = new_mm(stack);
                if(ret < 0){
                        printk("init_new_context_skas - new_mm failed, "
                               "errno = %d\n", ret);

diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c
index dc41c6dc2f343cce1fb28723a76534221be30e3b..fcddee76c7c08f57e0e328294d7b33d29df6f06e 100644 (file)
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -20,7 +20,6 @@
 #include "tlb.h"
 #include "kern.h"
 #include "mode.h"
-#include "proc_mm.h"
 #include "registers.h"
 
 void switch_to_skas(void *prev, void *next)
@@ -125,25 +124,14 @@ int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 
 extern void map_stub_pages(int fd, unsigned long code,
                           unsigned long data, unsigned long stack);
-int new_mm(int from, unsigned long stack)
+int new_mm(unsigned long stack)
 {
-       struct proc_mm_op copy;
-       int n, fd;
+       int fd;
 
        fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
        if(fd < 0)
                return(fd);
 
-       if(from != -1){
-               copy = ((struct proc_mm_op) { .op       = MM_COPY_SEGMENTS,
-                                             .u        =
-                                             { .copy_segments  = from } } );
-               n = os_write_file(fd, &copy, sizeof(copy));
-               if(n != sizeof(copy))
-                       printk("new_mm : /proc/mm copy_segments failed, "
-                              "err = %d\n", -n);
-       }
-
        if(skas_needs_stub)
                map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 

diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 17746b4c08ff00afee1407018b05611e78e69bbe..0cdfd4481d5e4c4214e9dfaaaff8d965c3fbddad 100644 (file)
--- 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 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
        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 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
                        }
                }
                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, &copy, 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 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
                up(&from_mm->ldt.semaphore);
        }
 
+    out:
        return err;
 }